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Song J, Farhadi A, Tan K, Lim L, Tan K. Impact of anthropogenic global hypoxia on the physiological response of bivalves. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 926:172056. [PMID: 38552980 DOI: 10.1016/j.scitotenv.2024.172056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2024] [Revised: 03/17/2024] [Accepted: 03/26/2024] [Indexed: 04/06/2024]
Abstract
Dissolved oxygen (DO) is an important parameter that affects the biology, physiology, and immunology of aquatic animals. In recent decades, DO levels in the global oceans have sharply decreased, partly due to an increase in atmospheric carbon dioxide, temperature, and anthropogenic nutrient loads. Although there have been many reports on the effects of hypoxia on the survival, growth, behavior, and immunity of bivalves, this information has not been well organized. Therefore, this article provides a comprehensive review of the effects of hypoxia on bivalves. In general, hypoxia negatively impacts the food consumption rate and assimilation efficiency, as well as increasing respiration rates in many bivalves. As a result, it reduces the energy allocation for bivalve growth, shell formation, and reproduction. In severe cases, prolonged exposure to hypoxia can result in mass mortality in bivalves. Moreover, hypoxia also has adverse effects on the immunity and response of bivalves to predators, including decreased burial depths, sensitivity to predators, impairment of byssus production, and negatively impacts on the integrity, strength, and composition of bivalve shells. The tolerance of bivalves to hypoxia largely depends on size and species, with larger bivalves being more susceptible to hypoxia and intertidal species being relatively more tolerant to hypoxia. The information in this article is very useful for elucidating the current research status of hypoxia on bivalves and determining future research directions.
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Affiliation(s)
- Jingjing Song
- College of Marine Science, Guangxi Key Laboratory of Beibu Gulf Biodiversity Conservation, Beibu Gulf Ocean Development Research Centre, Beibu Gulf University, Qinzhou, Guangxi, China
| | - Ardavan Farhadi
- Key Laboratory of Tropical Hydrobiology and Biotechnology of Hainan Province, Hainan Aquaculture Breeding Engineering Research Center, College of Marine Biology and Aquaculture, Hainan University, Haikou, Hainan 570228, China
| | - Kianann Tan
- College of Marine Science, Guangxi Key Laboratory of Beibu Gulf Biodiversity Conservation, Beibu Gulf Ocean Development Research Centre, Beibu Gulf University, Qinzhou, Guangxi, China
| | - Leongseng Lim
- Borneo Marine Research Institute, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia
| | - Karsoon Tan
- College of Marine Science, Guangxi Key Laboratory of Beibu Gulf Biodiversity Conservation, Beibu Gulf Ocean Development Research Centre, Beibu Gulf University, Qinzhou, Guangxi, China.
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Park S, Kim K, Hibino T, Kim K. Machine learning-based prediction of seasonal hypoxia in eutrophic estuary using capacitive potentiometric sensor. MARINE ENVIRONMENTAL RESEARCH 2024; 196:106445. [PMID: 38489919 DOI: 10.1016/j.marenvres.2024.106445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Revised: 02/26/2024] [Accepted: 03/10/2024] [Indexed: 03/17/2024]
Abstract
A hypoxia occurred in eutrophic estuary was predicted using long short-term memory (LSTM) model with prediction time steps (PTSs) of 0, 1, 12, and 24 h. A capacitive potential (CP), which provides quantitative information on dissolved oxygen (DO) concentration, was used as a predictor along with precipitation, tide level, salinity, and water temperature. First, annual changes in DO concentration were clustered in three phases of annual DO trends (oversaturation, depletion, and stable) using k-means clustering. CP was the most influential variable in clustering the DO phases. The LSTM was implemented to predict the DO phases and hypoxia occurrences. In the simultaneous prediction of the depletion phase and hypoxia occurrence with a 12 h PTS, the accuracy was 92.1% using CP along with other variables; it was 3.3% higher than that achieved using variables other than CP. In the case of predicting the depletion phase and hypoxia non-occurrence using CP along with other variables, the accuracy was 61.1%, which was 5.5% higher than that when CP was not used. When using CP along with other variables, the total accuracy was highest for all PTS. Overall, the utilization of CP and machine learning techniques enables accurate predictions of both short-term and long-term hypoxia occurrences, providing us with the opportunity to proactively respond to disasters in aquaculture and environmental management due to hypoxia.
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Affiliation(s)
- Seongsik Park
- Department of Ocean Engineering, Pukyong National University, Busan, Republic of Korea.
| | - Kyunghoi Kim
- Department of Ocean Engineering, Pukyong National University, Busan, Republic of Korea
| | - Tadashi Hibino
- Graduate School of Advanced Science and Engineering, Hiroshima University, Higashi-Hiroshima, Japan
| | - Kyeongmin Kim
- Faculty of Global Interdisciplinary Science and Innovation, Shizuoka University, Shizuoka, Japan.
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Kessouri F, Sutula MA, Bianchi D, Ho M, Damien P, McWilliams JC, Frieder CA, Renault L, Frenzel H, McLaughlin K, Deutsch C. Cross-shore transport and eddies promote large scale response to urban eutrophication. Sci Rep 2024; 14:7240. [PMID: 38538671 DOI: 10.1038/s41598-024-57626-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 03/20/2024] [Indexed: 05/01/2024] Open
Abstract
A key control on the magnitude of coastal eutrophication is the degree to which currents quickly transport nitrogen derived from human sources away from the coast to the open ocean before eutrophication develops. In the Southern California Bight (SCB), an upwelling-dominated eastern boundary current ecosystem, anthropogenic nitrogen inputs increase algal productivity and cause subsurface acidification and oxygen (O2 ) loss along the coast. However, the extent of anthropogenic influence on eutrophication beyond the coastal band, and the physical transport mechanisms and biogeochemical processes responsible for these effects are still poorly understood. Here, we use a submesoscale-resolving numerical model to document the detailed biogeochemical mass balance of nitrogen, carbon and oxygen, their physical transport, and effects on offshore habitats. Despite management of terrestrial nutrients that has occurred in the region over the last 20 years, coastal eutrophication continues to persist. The input of anthropogenic nutrients promote an increase in productivity, remineralization and respiration offshore, with recurrent O2 loss and pH decline in a region located 30-90 km from the mainland. During 2013 to 2017, the spatially averaged 5-year loss rate across the Bight was 1.3 mmol m- 3 O2 , with some locations losing on average up to 14.2 mmol m- 3 O2 . The magnitude of loss is greater than model uncertainty assessed from data-model comparisons and from quantification of intrinsic variability. This phenomenon persists for 4 to 6 months of the year over an area of 278,40 km2 ( ∼ 30% of SCB area). These recurrent features of acidification and oxygen loss are associated with cross-shore transport of nutrients by eddies and plankton biomass and their accumulation and retention within persistent eddies offshore within the SCB.
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Affiliation(s)
- Fayçal Kessouri
- Department of Biogeochemistry, Southern California Coastal Water Research Project, 3535 Harbor Blvd, Suite 110, Costa Mesa, CA, 92626, USA.
- Department of Atmospheric and Oceanic Sciences, University of California Los Angeles, Los Angeles, CA, 90095, USA.
| | - Martha A Sutula
- Department of Biogeochemistry, Southern California Coastal Water Research Project, 3535 Harbor Blvd, Suite 110, Costa Mesa, CA, 92626, USA
| | - Daniele Bianchi
- Department of Atmospheric and Oceanic Sciences, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Minna Ho
- Department of Biogeochemistry, Southern California Coastal Water Research Project, 3535 Harbor Blvd, Suite 110, Costa Mesa, CA, 92626, USA
- Department of Atmospheric and Oceanic Sciences, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Pierre Damien
- Department of Atmospheric and Oceanic Sciences, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - James C McWilliams
- Department of Atmospheric and Oceanic Sciences, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Christina A Frieder
- Department of Biogeochemistry, Southern California Coastal Water Research Project, 3535 Harbor Blvd, Suite 110, Costa Mesa, CA, 92626, USA
| | - Lionel Renault
- Laboratoire d'Études en Géophysique et Océanographie Spatiale, IRD, CNRS, CNES, UPS, Toulouse, 31400, France
| | - Hartmut Frenzel
- School of Oceanography, Seattle, WA, 98195, USA
- CICOES, University of Washington and NOAA PMEL, Seattle, WA, 98105, USA
| | - Karen McLaughlin
- Department of Biogeochemistry, Southern California Coastal Water Research Project, 3535 Harbor Blvd, Suite 110, Costa Mesa, CA, 92626, USA
| | - Curtis Deutsch
- Department of Geosciences, High Meadows Environmental Institute, Princeton University, Princeton, NJ, 08544, USA
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Barth JA, Pierce SD, Carter BR, Chan F, Erofeev AY, Fisher JL, Feely RA, Jacobson KC, Keller AA, Morgan CA, Pohl JE, Rasmuson LK, Simon V. Widespread and increasing near-bottom hypoxia in the coastal ocean off the United States Pacific Northwest. Sci Rep 2024; 14:3798. [PMID: 38361014 PMCID: PMC10869825 DOI: 10.1038/s41598-024-54476-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 02/11/2024] [Indexed: 02/17/2024] Open
Abstract
The 2021 summer upwelling season off the United States Pacific Northwest coast was unusually strong leading to widespread near-bottom, low-oxygen waters. During summer 2021, an unprecedented number of ship- and underwater glider-based measurements of dissolved oxygen were made in this region. Near-bottom hypoxia, that is dissolved oxygen less than 61 µmol kg-1 and harmful to marine animals, was observed over nearly half of the continental shelf inshore of the 200-m isobath, covering 15,500 square kilometers. A mid-shelf ribbon with near-bottom, dissolved oxygen less than 50 µmol kg-1 extended for 450 km off north-central Oregon and Washington. Spatial patterns in near-bottom oxygen are related to the continental shelf width and other features of the region. Maps of near-bottom oxygen since 1950 show a consistent trend toward lower oxygen levels over time. The fraction of near-bottom water inshore of the 200-m isobath that is hypoxic on average during the summer upwelling season increases over time from nearly absent (2%) in 1950-1980, to 24% in 2009-2018, compared with 56% during the anomalously strong upwelling conditions in 2021. Widespread and increasing near-bottom hypoxia is consistent with increased upwelling-favorable wind forcing under climate change.
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Affiliation(s)
- John A Barth
- College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR, 97331, USA.
| | - Stephen D Pierce
- College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR, 97331, USA
| | - Brendan R Carter
- Pacific Marine Environmental Laboratory, National Oceanic and Atmospheric Administration, Seattle, WA, 98115, USA
- Cooperative Institute for Climate, Ocean, and Ecosystem Studies, Seattle, WA, 98105, USA
| | - Francis Chan
- Department of Integrative Biology, Oregon State University, Corvallis, OR, 97331, USA
- Cooperative Institute for Marine Ecosystem and Resources Studies, Oregon State University, Newport, OR, 97365, USA
| | - Anatoli Y Erofeev
- College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR, 97331, USA
| | - Jennifer L Fisher
- Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, WA, 98112, USA
| | - Richard A Feely
- Pacific Marine Environmental Laboratory, National Oceanic and Atmospheric Administration, Seattle, WA, 98115, USA
| | - Kym C Jacobson
- Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, WA, 98112, USA
| | - Aimee A Keller
- Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, WA, 98112, USA
| | - Cheryl A Morgan
- Cooperative Institute for Marine Ecosystem and Resources Studies, Oregon State University, Newport, OR, 97365, USA
| | - John E Pohl
- Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, WA, 98112, USA
| | - Leif K Rasmuson
- Oregon Department of Fish and Wildlife, Newport, OR, 97365, USA
| | - Victor Simon
- Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, WA, 98112, USA
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Gomes DGE, Ruzicka JJ, Crozier LG, Huff DD, Phillips EM, Hernvann PY, Morgan CA, Brodeur RD, Zamon JE, Daly EA, Bizzarro JJ, Fisher JL, Auth TD. An updated end-to-end ecosystem model of the Northern California Current reflecting ecosystem changes due to recent marine heatwaves. PLoS One 2024; 19:e0280366. [PMID: 38241310 PMCID: PMC10798527 DOI: 10.1371/journal.pone.0280366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Accepted: 12/19/2023] [Indexed: 01/21/2024] Open
Abstract
The Northern California Current is a highly productive marine upwelling ecosystem that is economically and ecologically important. It is home to both commercially harvested species and those that are federally listed under the U.S. Endangered Species Act. Recently, there has been a global shift from single-species fisheries management to ecosystem-based fisheries management, which acknowledges that more complex dynamics can reverberate through a food web. Here, we have integrated new research into an end-to-end ecosystem model (i.e., physics to fisheries) using data from long-term ocean surveys, phytoplankton satellite imagery paired with a vertically generalized production model, a recently assembled diet database, fishery catch information, species distribution models, and existing literature. This spatially-explicit model includes 90 living and detrital functional groups ranging from phytoplankton, krill, and forage fish to salmon, seabirds, and marine mammals, and nine fisheries that occur off the coast of Washington, Oregon, and Northern California. This model was updated from previous regional models to account for more recent changes in the Northern California Current (e.g., increases in market squid and some gelatinous zooplankton such as pyrosomes and salps), to expand the previous domain to increase the spatial resolution, to include data from previously unincorporated surveys, and to add improved characterization of endangered species, such as Chinook salmon (Oncorhynchus tshawytscha) and southern resident killer whales (Orcinus orca). Our model is mass-balanced, ecologically plausible, without extinctions, and stable over 150-year simulations. Ammonium and nitrate availability, total primary production rates, and model-derived phytoplankton time series are within realistic ranges. As we move towards holistic ecosystem-based fisheries management, we must continue to openly and collaboratively integrate our disparate datasets and collective knowledge to solve the intricate problems we face. As a tool for future research, we provide the data and code to use our ecosystem model.
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Affiliation(s)
- Dylan G. E. Gomes
- National Academy of Sciences NRC Research Associateship Program, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, WA, United States of America
- Cooperative Institute for Marine Ecosystem and Resources Studies, Hatfield Marine Science Center, Oregon State University, Newport, OR, United States of America
| | - James J. Ruzicka
- Ecosystem Sciences Division, Pacific Islands Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Honolulu, HI, United States of America
| | - Lisa G. Crozier
- Fish Ecology Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, WA, United States of America
| | - David D. Huff
- Fish Ecology Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Newport, OR, United States of America
| | - Elizabeth M. Phillips
- Fishery Resource Analysis and Monitoring Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, WA, United States of America
| | - Pierre-Yves Hernvann
- Conservation Biology Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Newport, OR, United States of America
- Institute of Marine Sciences, University of California, Santa Cruz, Santa Cruz, CA, United States of America
| | - Cheryl A. Morgan
- Cooperative Institute for Marine Ecosystem and Resources Studies, Hatfield Marine Science Center, Oregon State University, Newport, OR, United States of America
| | - Richard D. Brodeur
- Fish Ecology Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Newport, OR, United States of America
| | - Jen E. Zamon
- Fish Ecology Division, Point Adams Research Station, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Hammond, OR, United States of America
| | - Elizabeth A. Daly
- Cooperative Institute for Marine Ecosystem and Resources Studies, Hatfield Marine Science Center, Oregon State University, Newport, OR, United States of America
| | - Joseph J. Bizzarro
- Fisheries Ecology Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Santa Cruz, CA, United States of America
- Fisheries Collaborative Program, University of Santa Cruz, Santa Cruz, CA, United States of America
| | - Jennifer L. Fisher
- Fish Ecology Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Newport, OR, United States of America
| | - Toby D. Auth
- Pacific States Marine Fisheries Commission, Newport, OR, United States of America
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Liu R, Wang T, Li J, Liu X, Zhu Q. Simulation of seasonal transport of microplastics and influencing factors in the China Seas based on the ROMS model. WATER RESEARCH 2023; 244:120493. [PMID: 37683497 DOI: 10.1016/j.watres.2023.120493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Revised: 08/12/2023] [Accepted: 08/14/2023] [Indexed: 09/10/2023]
Abstract
Elucidating the mechanisms governing microplastic transport and spatial distribution in offshore waters is essential to microplastic control. However, current research on microplastic transport in the China Seas is largely restricted to small-scale investigations, which do not provide a comprehensive result. Therefore, in this study, we used the Regional Ocean Modeling System (ROMS) combined with the Lagrangian Transport (LTRANS v.2) model to investigate how microplastics are transported around the China Seas during different seasons and under climatological river discharge. Our findings showed that the microplastic pathways and spatial distributions exhibit marked seasonal variations controlled by circulation patterns in the China Seas, river discharge values, and the characteristics of the microplastic materials. Floating microplastics exhibited the longest transport distance in summer, when microplastics from the Pearl River could be transported up to 1375.8 km through the Tokara and Tsushima straits. The heavy pollution areas in summer were located in the South Yellow Sea and East China Sea, mainly resulting from the contribution of the Yangtze River (>66%). In autumn and winter, more than three-quarters of the microplastics beached off the south-central Chinese coast. In addition, simulating the vertical velocity of the water prolonged the time required for microplastics to reach the open ocean, thereby reducing the amount of microplastics entering the Pacific Ocean by 6% compared to the simulation without the vertical velocity of the water in summer. Microplastics with higher densities were generally transported shorter distances. The transmission distances of PET and PS were two orders of magnitude smaller than that of PE. This study enhances knowledge of the sources and fates of offshore microplastics and provides scientific support for offshore microplastic control.
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Affiliation(s)
- Rongze Liu
- College of Oceanography, Hohai University, Nanjing 210098, China
| | - Teng Wang
- College of Oceanography, Hohai University, Nanjing 210098, China.
| | - Junde Li
- College of Oceanography, Hohai University, Nanjing 210098, China
| | - Xiaohui Liu
- State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou 310012, China
| | - Qing Zhu
- Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
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Swain S, Pattanaik S, Akhand A, Chanda A, Sahu RN, Majhi A, Panda CR, Satapathy DR, Sahoo RK, Roy R, Vedabrata A. Interannual and seasonal variability and future forecasting of pCO 2(water) using the ARIMA model and CO 2 fluxes in a tropical estuary. ENVIRONMENTAL MONITORING AND ASSESSMENT 2023; 195:1225. [PMID: 37725220 DOI: 10.1007/s10661-023-11816-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 08/30/2023] [Indexed: 09/21/2023]
Abstract
The seasonal and interannual variation in the partial pressure of carbon dioxide in water [pCO2(water)] and air-water CO2 exchange in the Mahanadi estuary situated on the east coast of India was studied between March 2013 and March 2021. The principal aim of the study was to analyze the spatiotemporal variability and future trend of pCO2 and air-water CO2 fluxes along with the related carbonate chemistry parameters like water temperature, pH, salinity, nutrients, and total alkalinity, over 9 years. The seasonal CO2 flux over nine years was also calculated using five worldwide accepted equations. The seasonal map of pCO2(water) followed a general trend of being high in monsoon (2628 ± 3484 μatm) associated with high river inflow and low during pre-monsoon (445.6 ± 270.0 μatm). High pCO2 in water compared to the atmosphere (average 407.6-409.4 μatm) was observed in the estuary throughout the sampling period. The CO2 efflux computed using different gas transfer velocity formulas was also consistent with pCO2 water acquiring the peak during monsoon in the Mahanadi estuary (6033 ± 9478 μmol m-2 h-1) and trough during pre-monsoon (21.66± 187.2 μmol m-2 h-1). The estuary acted as a net source of CO2 throughout the study period, with significant seasonality in the flux magnitudes. However, CO2 sequestration via photosynthesis by phytoplankton resulted in lower emission rates toward the atmosphere in summer. This study uses the autoregressive integrated moving average (ARIMA) model to forecast pCO2(water) for the future. Using measured and predicted values, our work demonstrated that pCO2(water) has an upward trend in the Mahanadi estuary. Our results demonstrate that long-term observations from estuaries should be prioritized to upscale the global carbon budget.
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Affiliation(s)
- Sanhita Swain
- CSIR-Institute of Minerals and Materials Technology, Bhubaneswar, 751013, India
- Maharaja Sriram Chandra Bhanja Deo University, Sriram Chandra Vihar, Baripada, Odisha, 757003, India
| | - Suchismita Pattanaik
- CSIR-Institute of Minerals and Materials Technology, Bhubaneswar, 751013, India.
| | - Anirban Akhand
- Department of Ocean Science, Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
| | - Abhra Chanda
- School of Oceanographic Studies, Jadavpur University, Kolkata, 700032, India
| | - Rabi Narayan Sahu
- CSIR-Institute of Minerals and Materials Technology, Bhubaneswar, 751013, India
| | - Arakshita Majhi
- CSIR-Institute of Minerals and Materials Technology, Bhubaneswar, 751013, India
| | - Chitta Ranjan Panda
- CSIR-Institute of Minerals and Materials Technology, Bhubaneswar, 751013, India
| | | | - Ranajit Kumar Sahoo
- CSIR-Institute of Minerals and Materials Technology, Bhubaneswar, 751013, India
| | - Rajdeep Roy
- National Remote Sensing Centre-Indian Space Research Organization, Hyderabad, 500037, India
| | - Arya Vedabrata
- ByteIQ Analytics Private Limited, Bhubaneswar, 751013, India
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Zhao L, Fu G, Pang W, Li X, Pan C, Hu Z. A novel autotrophic denitrification and nitrification integrated constructed wetland process for marine aquaculture wastewater treatment. CHEMOSPHERE 2023; 321:138157. [PMID: 36796520 DOI: 10.1016/j.chemosphere.2023.138157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 01/29/2023] [Accepted: 02/13/2023] [Indexed: 06/18/2023]
Abstract
We undertook a lab-scale evaluation of a novel autotrophic denitrification and nitrification integrated constructed wetland (ADNI-CW) for improved carbon (C), nitrogen (N), and sulfur (S) cycling to treat mariculture wastewater. The process involved an up-flow autotrophic denitrification constructed wetland unit (AD-CW) for sulfate reduction and autotrophic denitrification, and an autotrophic nitrification constructed wetland unit (AN-CW) for nitrification. The 400-day experiment investigated the performance of the AD-CW, AN-CW, and entire ADNI-CW processes under various hydraulic retention times (HRTs), nitrate concentrations, dissolved oxygen levels, and recirculation ratios. Under various HRTs, the AN-CW achieved a nitrification performance exceeding 92%. Correlation analysis of the chemical oxygen demand (COD) revealed that, on average, approximately 96% of COD was removed by sulfate reduction. Under different HRTs, increases in influent NO3--N concentrations caused the amount of sulfide to gradually decrease from sufficient to deficient, and the autotrophic denitrification rate also decreased from 62.18 to 40.93%. In addition, when the NO3--N load rate was above 21.53 g N/m2·d, the transformation of organic N by mangrove roots may have increased NO3--N in the top effluent of the AD-CW. The coupling of N and S metabolic processes mediated by various functional microorganisms (Proteobacteria, Chloroflexi, Actinobacteria, Bacteroidetes, and unclassified_d__Bacteria) enhanced N removal. We intensively explored the effects of changing inputs as culture species developed on the physical, chemical, and microbial changes of CW to ensure a consistent and effective management of C, N, and S. This study lays the foundation for green and sustainable mariculture development.
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Affiliation(s)
- Lin Zhao
- Guangdong Technology Research Center for Marine Algal Bioengineering, Shenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060, China; Shenzhen Engineering Laboratory for Marine Algal Biotechnology, Longhua Innovation Institute for Biotechnology, Shenzhen University, Shenzhen, 518055, China
| | - Guiping Fu
- Guangdong Technology Research Center for Marine Algal Bioengineering, Shenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060, China.
| | - Weicheng Pang
- Guangdong Technology Research Center for Marine Algal Bioengineering, Shenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060, China
| | - Xiaxin Li
- Guangdong Technology Research Center for Marine Algal Bioengineering, Shenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060, China
| | - Chao Pan
- Guangdong Technology Research Center for Marine Algal Bioengineering, Shenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060, China
| | - Zhangli Hu
- Guangdong Technology Research Center for Marine Algal Bioengineering, Shenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060, China; Shenzhen Engineering Laboratory for Marine Algal Biotechnology, Longhua Innovation Institute for Biotechnology, Shenzhen University, Shenzhen, 518055, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China.
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Bograd SJ, Jacox MG, Hazen EL, Lovecchio E, Montes I, Pozo Buil M, Shannon LJ, Sydeman WJ, Rykaczewski RR. Climate Change Impacts on Eastern Boundary Upwelling Systems. ANNUAL REVIEW OF MARINE SCIENCE 2023; 15:303-328. [PMID: 35850490 DOI: 10.1146/annurev-marine-032122-021945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The world's eastern boundary upwelling systems (EBUSs) contribute disproportionately to global ocean productivity and provide critical ecosystem services to human society. The impact of climate change on EBUSs and the ecosystems they support is thus a subject of considerable interest. Here, we review hypotheses of climate-driven change in the physics, biogeochemistry, and ecology of EBUSs; describe observed changes over recent decades; and present projected changes over the twenty-first century. Similarities in historical and projected change among EBUSs include a trend toward upwelling intensification in poleward regions, mitigatedwarming in near-coastal regions where upwelling intensifies, and enhanced water-column stratification and a shoaling mixed layer. However, there remains significant uncertainty in how EBUSs will evolve with climate change, particularly in how the sometimes competing changes in upwelling intensity, source-water chemistry, and stratification will affect productivity and ecosystem structure. We summarize the commonalities and differences in historical and projected change in EBUSs and conclude with an assessment of key remaining uncertainties and questions. Future studies will need to address these questions to better understand, project, and adapt to climate-driven changes in EBUSs.
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Affiliation(s)
- Steven J Bograd
- Environmental Research Division, Southwest Fisheries Science Center, National Oceanic and Atmospheric Administration, Monterey, California, USA; , ,
- Institute of Marine Sciences, University of California, Santa Cruz, California, USA;
| | - Michael G Jacox
- Environmental Research Division, Southwest Fisheries Science Center, National Oceanic and Atmospheric Administration, Monterey, California, USA; , ,
- Institute of Marine Sciences, University of California, Santa Cruz, California, USA;
- Physical Sciences Laboratory, National Oceanic and Atmospheric Administration, Boulder, Colorado, USA
| | - Elliott L Hazen
- Environmental Research Division, Southwest Fisheries Science Center, National Oceanic and Atmospheric Administration, Monterey, California, USA; , ,
- Institute of Marine Sciences, University of California, Santa Cruz, California, USA;
| | | | | | - Mercedes Pozo Buil
- Environmental Research Division, Southwest Fisheries Science Center, National Oceanic and Atmospheric Administration, Monterey, California, USA; , ,
- Institute of Marine Sciences, University of California, Santa Cruz, California, USA;
| | - Lynne J Shannon
- Department of Biological Sciences, University of Cape Town, Cape Town, South Africa;
| | | | - Ryan R Rykaczewski
- Pacific Islands Fisheries Science Center, National Oceanic and Atmospheric Administration, Honolulu, Hawaii, USA;
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10
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Davis CV, Sibert EC, Jacobs PH, Burls N, Hull PM. Intermediate water circulation drives distribution of Pliocene Oxygen Minimum Zones. Nat Commun 2023; 14:40. [PMID: 36599835 DOI: 10.1038/s41467-022-35083-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 11/17/2022] [Indexed: 01/06/2023] Open
Abstract
Oxygen minimum zones (OMZs) play a critical role in global biogeochemical cycling and act as barriers to dispersal for marine organisms. OMZs are currently expanding and intensifying with climate change, however past distributions of OMZs are relatively unknown. Here we present evidence for widespread pelagic OMZs during the Pliocene (5.3-2.6 Ma), the most recent epoch with atmospheric CO2 analogous to modern (~400-450 ppm). The global distribution of OMZ-affiliated planktic foraminifer, Globorotaloides hexagonus, and Earth System and Species Distribution Models show that the Indian Ocean, Eastern Equatorial Pacific, eastern South Pacific, and eastern North Atlantic all supported OMZs in the Pliocene, as today. By contrast, low-oxygen waters were reduced in the North Pacific and expanded in the North Atlantic in the Pliocene. This spatially explicit perspective reveals that a warmer world can support both regionally expanded and contracted OMZs, with intermediate water circulation as a key driver.
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Affiliation(s)
- Catherine V Davis
- Department of Marine, Earth, and Atmospheric Sciences, North Carolina State University, Raleigh, NC, USA.
| | - Elizabeth C Sibert
- Department of Earth and Planetary Sciences, Yale University, New Haven, CT, USA.,Yale Institute for Biospheric Studies, Yale University, New Haven, CT, USA
| | - Peter H Jacobs
- Department of Environmental Science and Policy, George Mason University, Fairfax, VA, USA.,Earth Science Division, NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - Natalie Burls
- Department of Atmospheric, Ocean & Earth Sciences, George Mason University, Fairfax, VA, USA
| | - Pincelli M Hull
- Department of Earth and Planetary Sciences, Yale University, New Haven, CT, USA.,Yale Institute for Biospheric Studies, Yale University, New Haven, CT, USA.,Yale Peabody Museum of Natural History, Yale University, New Haven, CT, USA
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11
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Kekuewa SAH, Courtney TA, Cyronak T, Andersson AJ. Seasonal nearshore ocean acidification and deoxygenation in the Southern California Bight. Sci Rep 2022; 12:17969. [PMID: 36289268 PMCID: PMC9606271 DOI: 10.1038/s41598-022-21831-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 10/04/2022] [Indexed: 01/24/2023] Open
Abstract
The California Current System experiences seasonal ocean acidification and hypoxia (OAH) owing to wind-driven upwelling, but little is known about the intensity, frequency, and depth distribution of OAH in the shallow nearshore environment. Here we present observations of OAH and dissolved inorganic carbon and nutrient parameters based on monthly transects from March 2017 to September 2018 extending from the surf zone to the ~ 40 m depth contour in La Jolla, California. Biologically concerning OAH conditions were observed at depths as shallow as 10 m and as close as 700 m to the shoreline. Below 20 m depth, 8% of observations were undersaturated with respect to aragonite, 28% of observations had a pHT less than 7.85, and 19% of observations were below the sublethal oxygen threshold of 157 µmol kg-1. These observations raise important questions about the impacts of OAH on coastal organisms and ecosystems and how future intensified upwelling may exacerbate these conditions.
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Affiliation(s)
- Samuel A. H. Kekuewa
- grid.266100.30000 0001 2107 4242Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA USA
| | - Travis A. Courtney
- grid.267044.30000 0004 0398 9176Department of Marine Sciences, University of Puerto Rico Mayagüez, Mayagüez, PR USA
| | - Tyler Cyronak
- grid.261241.20000 0001 2168 8324Department of Marine and Environmental Sciences, Halmos College of Natural Sciences and Oceanography, Nova Southeastern University, Dania Beach, FL USA
| | - Andreas J. Andersson
- grid.266100.30000 0001 2107 4242Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA USA
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12
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Sunday JM, Howard E, Siedlecki S, Pilcher DJ, Deutsch C, MacCready P, Newton J, Klinger T. Biological sensitivities to high-resolution climate change projections in the California current marine ecosystem. GLOBAL CHANGE BIOLOGY 2022; 28:5726-5740. [PMID: 35899628 PMCID: PMC9542873 DOI: 10.1111/gcb.16317] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 05/03/2022] [Accepted: 05/21/2022] [Indexed: 06/01/2023]
Abstract
The California Current Marine Ecosystem is a highly productive system that exhibits strong natural variability and vulnerability to anthropogenic climate trends. Relating projections of ocean change to biological sensitivities requires detailed synthesis of experimental results. Here, we combine measured biological sensitivities with high-resolution climate projections of key variables (temperature, oxygen, and pCO2 ) to identify the direction, magnitude, and spatial distribution of organism-scale vulnerabilities to multiple axes of projected ocean change. Among 12 selected species of cultural and economic importance, we find that all are sensitive to projected changes in ocean conditions through responses that affect individual performance or population processes. Response indices were largest in the northern region and inner shelf. While performance traits generally increased with projected changes, fitness traits generally decreased, indicating that concurrent stresses can lead to fitness loss. For two species, combining sensitivities to temperature and oxygen changes through the Metabolic Index shows how aerobic habitat availability could be compressed under future conditions. Our results suggest substantial and specific ecological susceptibility in the next 80 years, including potential regional loss of canopy-forming kelp, changes in nearshore food webs caused by declining rates of survival among red urchins, Dungeness crab, and razor clams, and loss of aerobic habitat for anchovy and pink shrimp. We also highlight fillable gaps in knowledge, including specific physiological responses to stressors, variation in responses across life stages, and responses to multistressor combinations. These findings strengthen the case for filling information gaps with experiments focused on fitness-related responses and those that can be used to parameterize integrative physiological models, and suggest that the CCME is susceptible to substantial changes to ecosystem structure and function within this century.
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Affiliation(s)
| | - Evan Howard
- Department of GeosciencesPrinceton UniversityPrincetonNew JerseyUSA
| | - Samantha Siedlecki
- Department of Marine SciencesUniversity of ConnecticutGrotonConnecticutUSA
| | - Darren J. Pilcher
- Cooperative Institute for Climate, Ocean, and Ecosystem StudiesUniversity of WashingtonSeattleWashingtonUSA
| | - Curtis Deutsch
- Department of GeosciencesPrinceton UniversityPrincetonNew JerseyUSA
- High Meadows Environmental InstitutePrinceton UniversityPrincetonNew JerseyUSA
| | - Parker MacCready
- School of OceanographyUniversity of WashingtonSeattleWashingtonUSA
| | - Jan Newton
- Applied Physics Laboratory, University of WashingtonSeattleWashingtonUSA
| | - Terrie Klinger
- School of Marine and Environmental AffairsUniversity of WashingtonSeattleWashingtonUSA
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13
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Environmental hypoxia: A threat to the gonadal development and reproduction in bony fishes. AQUACULTURE AND FISHERIES 2022. [DOI: 10.1016/j.aaf.2022.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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14
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Calculating dissolved marine oxygen values based on an enhanced Benthic Foraminifera Oxygen Index. Sci Rep 2022; 12:1376. [PMID: 35082337 PMCID: PMC8791969 DOI: 10.1038/s41598-022-05295-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 01/10/2022] [Indexed: 11/29/2022] Open
Abstract
Marine oxygen minimum zones (OMZs) trap greenhouse gases, reduce livable habitats, a critical factor for these changes is the amount of dissolved oxygen (DO). The frequently used tool to reconstruct DO values, the Benthic Foraminifera Oxygen Index (BFOI), showed major shortcomings and lacks effectiveness. Therefore, we enhanced the BFOI and introduce enhanced BFOI (EBFOI) formulas by using all available data benthic foraminifers provide, calculating the whole livable habitat of benthic foraminifers, including bottom water oxygenation (BWO) and pore water oxygenation (PWO). Further, we introduce for the first time a transfer function to convert EBFOI vales directly into DO values, increasing efficiency by up to 38%. All formulas are calibrated on modern samples and applied to fossil datasets. Our new approach provides a major improvement in defining and reconstructing marine oxygen levels and eutrophication, by, providing a new toolset for understanding past changes and tracking actual and predicted future expanding OMZs.
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15
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Meyer‐Gutbrod E, Kui L, Miller R, Nishimoto M, Snook L, Love M. Moving on up: Vertical distribution shifts in rocky reef fish species during climate-driven decline in dissolved oxygen from 1995 to 2009. GLOBAL CHANGE BIOLOGY 2021; 27:6280-6293. [PMID: 34529330 PMCID: PMC9290838 DOI: 10.1111/gcb.15821] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Revised: 07/05/2021] [Accepted: 07/20/2021] [Indexed: 06/13/2023]
Abstract
Anthropogenic climate change has resulted in warming temperatures and reduced oxygen concentrations in the global oceans. Much remains unknown on the impacts of reduced oxygen concentrations on the biology and distribution of marine fishes. In the Southern California Channel Islands, visual fish surveys were conducted frequently in a manned submersible at three rocky reefs between 1995 and 2009. This area is characterized by a steep bathymetric gradient, with the surveyed sites Anacapa Passage, Footprint and Piggy Bank corresponding to depths near 50, 150 and 300 m. Poisson models were developed for each fish species observed consistently in this network of rocky reefs to determine the impact of depth and year on fish peak distribution. The interaction of depth and year was significant in 23 fish types, with 19 of the modelled peak distributions shifting to a shallower depth over the surveyed time period. Across the 23 fish types, the peak distribution shoaled at an average rate of 8.7 m of vertical depth per decade. Many of the species included in the study, including California sheephead, copper rockfish and blue rockfish, are targeted by commercial and recreational fisheries. CalCOFI hydrographic samples are used to demonstrate significant declines in dissolved oxygen at stations near the survey sites which are forced by a combination of natural multidecadal oscillations and anthropogenic climate change. This study demonstrates in situ fish depth distribution shifts over a 15-year period concurrent with oxygen decline. Climate-driven distribution shifts in response to deoxygenation have important implications for fisheries management, including habitat reduction, habitat compression, novel trophic dynamics and reduced body condition. Continued efforts to predict the formation and severity of hypoxic zones and their impact on fisheries dynamics will be essential to guiding effective placement of protected areas and fisheries regulations.
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Affiliation(s)
- Erin Meyer‐Gutbrod
- School of the Earth, Ocean and EnvironmentUniversity of South CarolinaColumbiaSCUSA
| | - Li Kui
- Marine Science InstituteUniversity of CaliforniaSanta BarbaraCAUSA
| | - Robert Miller
- Marine Science InstituteUniversity of CaliforniaSanta BarbaraCAUSA
| | - Mary Nishimoto
- Marine Science InstituteUniversity of CaliforniaSanta BarbaraCAUSA
| | - Linda Snook
- Marine Science InstituteUniversity of CaliforniaSanta BarbaraCAUSA
| | - Milton Love
- Marine Science InstituteUniversity of CaliforniaSanta BarbaraCAUSA
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16
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Retnamma J, Kalathil BK, Loganathan J, Chinnadurai K, Gupta GVM, Chakraborty K, Sahu KC. Why the Gulf of Mannar is a marine biological paradise? ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:64892-64907. [PMID: 34319522 DOI: 10.1007/s11356-021-15530-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 07/16/2021] [Indexed: 06/13/2023]
Abstract
The Gulf of Mannar (GoM), located between India and Sri Lanka, has astonishing faunal richness and diversity. Two oceanographic data sets supplemented with satellite remote sensing observations are discussed here to show the unique ecological setting in the GoM sustaining a rich and diverse fauna. We tested the hypothesis that a specific stretch of a large marine environment behaves differently from the rest of the region due to its peculiar geographical position. Primarily, unlike the adjacent Indian southwestern shelf in the Southeastern Arabian Sea, oxygen deficiency associated with coastal upwelling imparting physiological stress to marine fauna does not occur in the GoM. Secondly, the GoM along the Indian coastline receives an adequate amount of primary (plankton) food from the Arabian Sea and the Bay of Bengal through the advected water associated with the seasonally reversing surface currents. Thirdly, the GoM water has high transparency, aerated sandy seafloor conducive for the growth of diverse corals and much sensitive fauna. All these indicate that an astonishingly rich and diverse aquatic fauna in the GoM is a biological manifestation of a conducive geographical setting and propose that similar other environments worldwide, protected from oxygen deficiency, might also be functioning as a refuge for marine life.
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Affiliation(s)
| | | | | | | | | | - Kunal Chakraborty
- Indian National Centre for Ocean Information Services (MoES), Hyderabad, India
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17
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Hamilton SL, Saccomanno VR, Heady WN, Gehman AL, Lonhart SI, Beas-Luna R, Francis FT, Lee L, Rogers-Bennett L, Salomon AK, Gravem SA. Disease-driven mass mortality event leads to widespread extirpation and variable recovery potential of a marine predator across the eastern Pacific. Proc Biol Sci 2021; 288:20211195. [PMID: 34428964 PMCID: PMC8385337 DOI: 10.1098/rspb.2021.1195] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 08/04/2021] [Indexed: 12/19/2022] Open
Abstract
The prevalence of disease-driven mass mortality events is increasing, but our understanding of spatial variation in their magnitude, timing and triggers are often poorly resolved. Here, we use a novel range-wide dataset comprised 48 810 surveys to quantify how sea star wasting disease affected Pycnopodia helianthoides, the sunflower sea star, across its range from Baja California, Mexico to the Aleutian Islands, USA. We found that the outbreak occurred more rapidly, killed a greater percentage of the population and left fewer survivors in the southern half of the species's range. Pycnopodia now appears to be functionally extinct (greater than 99.2% declines) from Baja California, Mexico to Cape Flattery, Washington, USA and exhibited severe declines (greater than 87.8%) from the Salish Sea to the Gulf of Alaska. The importance of temperature in predicting Pycnopodia distribution rose more than fourfold after the outbreak, suggesting latitudinal variation in outbreak severity may stem from an interaction between disease severity and warmer waters. We found no evidence of population recovery in the years since the outbreak. Natural recovery in the southern half of the range is unlikely over the short term. Thus, assisted recovery will probably be required to restore the functional role of this predator on ecologically relevant time scales.
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Affiliation(s)
- S. L. Hamilton
- Department of Integrative Biology, Oregon State University, Corvallis, OR 97331-4501, USA
| | | | - W. N. Heady
- The Nature Conservancy, San Francisco, CA, USA
| | - A. L. Gehman
- University of British Columbia, Vancouver, BC V6T 1Z4, Canada
- The Hakai Institute, Campbell River, British Columbia, Canada
| | - S. I. Lonhart
- NOAA's Monterey Bay National Marine Sanctuary, Monterey, CA, USA
| | - R. Beas-Luna
- Universidad Autónoma de Baja California, Mexicali, Baja CA, Mexico
| | - F. T. Francis
- Fisheries and Oceans Canada, Ottawa, Ontario, Canada
| | - L. Lee
- Gwaii Haanas National Park Reserve, National Marine Conservation Area Reserve, and Haida Heritage Site, Parks Canada, British Columbia, Canada
- University of Victoria, Victoria, British Columbia, Canada
| | - L. Rogers-Bennett
- Bodega Marine Laboratory, University of California Davis, Davis, CA, USA
- California Department of Fish and Wildlife, CA, USA
| | | | - S. A. Gravem
- Department of Integrative Biology, Oregon State University, Corvallis, OR 97331-4501, USA
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18
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Abstract
The kinetics of microbial respiration suggests that, if excess organic matter is present, oxygen should fall to nanomolar levels in the range of the Michaelis-Menten constants (Km). Yet even in many biologically productive coastal regions, lowest observed O2 concentrations often remain several orders of magnitude higher than respiratory Km values. We propose the hypoxic barrier hypothesis (HBH) to explain this apparent discrepancy. The HBH postulates that oxidative enzymes involved in organic matter catabolism are kinetically limited by O2 at concentrations far higher than the thresholds for respiration. We found support for the HBH in a meta-analysis of 1,137 O2 Km values reported in the literature: the median value for terminal respiratory oxidases was 350 nM, but for other oxidase types, the median value was 67 μM. The HBH directs our attention to the kinetic properties of an important class of oxygen-dependent reactions that could help explain the trajectories of ocean ecosystems experiencing O2 stress. IMPORTANCE Declining ocean oxygen associated with global warming and climate change is impacting marine ecosystems across scales from microscopic planktonic communities to global fisheries. We report a fundamental dichotomy in the affinities of enzymes for oxygen-the terminal proteins catalyzing respiration are active at much lower oxygen concentrations than oxygenase enzymes involved in organic matter catabolism. We hypothesize that this dichotomy in oxygen affinities will cause some types of organic matter to accumulate in hypoxic ecosystems and will slow rates of oxygen decline. This proposed biochemical barrier may explain why many ocean ecosystems rarely reach anoxia. Competition between intracellular enzymes for oxygen may also have impacted microbial strategies of adaptation to low oxygen, requiring cells to regulate oxygen respiration so that it does not compete with other cellular processes that also require oxygen.
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19
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Gold Z, Curd EE, Goodwin KD, Choi ES, Frable BW, Thompson AR, Walker HJ, Burton RS, Kacev D, Martz LD, Barber PH. Improving metabarcoding taxonomic assignment: A case study of fishes in a large marine ecosystem. Mol Ecol Resour 2021; 21:2546-2564. [PMID: 34235858 DOI: 10.1111/1755-0998.13450] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 05/25/2021] [Accepted: 06/03/2021] [Indexed: 01/08/2023]
Abstract
DNA metabarcoding is an important tool for molecular ecology. However, its effectiveness hinges on the quality of reference sequence databases and classification parameters employed. Here we evaluate the performance of MiFish 12S taxonomic assignments using a case study of California Current Large Marine Ecosystem fishes to determine best practices for metabarcoding. Specifically, we use a taxonomy cross-validation by identity framework to compare classification performance between a global database comprised of all available sequences and a curated database that only includes sequences of fishes from the California Current Large Marine Ecosystem. We demonstrate that the regional database provides higher assignment accuracy than the comprehensive global database. We also document a tradeoff between accuracy and misclassification across a range of taxonomic cutoff scores, highlighting the importance of parameter selection for taxonomic classification. Furthermore, we compared assignment accuracy with and without the inclusion of additionally generated reference sequences. To this end, we sequenced tissue from 597 species using the MiFish 12S primers, adding 252 species to GenBank's existing 550 California Current Large Marine Ecosystem fish sequences. We then compared species and reads identified from seawater environmental DNA samples using global databases with and without our generated references, and the regional database. The addition of new references allowed for the identification of 16 additional native taxa representing 17.0% of total reads from eDNA samples, including species with vast ecological and economic value. Together these results demonstrate the importance of comprehensive and curated reference databases for effective metabarcoding and the need for locus-specific validation efforts.
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Affiliation(s)
- Zachary Gold
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, Los Angeles, California, USA
| | - Emily E Curd
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, Los Angeles, California, USA
| | - Kelly D Goodwin
- Ocean Chemistry and Ecosystems Division, Atlantic Oceanographic and Meteorological Laboratory, National Oceanic and Atmospheric Administration, Stationed at Southwest Fisheries Science Center, La Jolla, California, USA
| | - Emma S Choi
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, USA
| | - Benjamin W Frable
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, USA
| | - Andrew R Thompson
- Southwest Fisheries Science Center, National Oceanic and Atmospheric Administration, La Jolla, California, USA
| | - Harold J Walker
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, USA
| | - Ronald S Burton
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, USA
| | - Dovi Kacev
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, USA
| | - Lucas D Martz
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, USA
| | - Paul H Barber
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, Los Angeles, California, USA
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20
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Sun X, Tu K, Li L, Wu B, Wu L, Liu Z, Zhou L, Tian J, Yang A. Integrated transcriptome and metabolome analysis reveals molecular responses of the clams to acute hypoxia. MARINE ENVIRONMENTAL RESEARCH 2021; 168:105317. [PMID: 33819872 DOI: 10.1016/j.marenvres.2021.105317] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 03/13/2021] [Accepted: 03/18/2021] [Indexed: 06/12/2023]
Abstract
Mudflat shellfish have evolved well-adapted strategies for coping with dynamic environmental fluxes and stressful conditions, including oxygen availability. The Manila clams Ruditapes philippinarum are worldwide cultured shellfish in marine intertidal zone, which usually encounter great risk of acute hypoxia exposure in coastal habitats. To reveal the effects of acute hypoxia on metabolic changes of the clams, we performed the integrated analysis of transcriptomics and metabolomics to investigate the global changes of genes and metabolites during acute hypoxia stress at the whole-organism level. The comparative transcriptome analysis reveals that the clams show the remarkable depression in a variety of biological performance, such as metabolic rates, neuronal activity, biomineralization activity, and cell proliferation and differentiation at the hypoxic condition. The metabolomic analysis reveals that amino acid metabolism plays a critical role in the metabolic changes of the clams in response to acute hypoxia. A variety of free amino acids may not only be served as the potential osmolytes for osmotic regulation, but also may contribute to energy production during the acute hypoxia exposure. The metabolite analysis also reveals several important biomarkers for metabolic changes, and provides new insights into how clams deal with acute hypoxia. These findings suggest that clams may get through acute hypoxia stress by the adaptive metabolic strategy to survive short-period of acute hypoxia which is likely to occur in their typical habitat. The present findings will not only shed lights on the molecular and metabolic mechanisms of adaptive strategies under stressful conditions, but also provide the signaling metabolites to assess the physiological states of clams in aquaculture.
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Affiliation(s)
- Xiujun Sun
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture and Rural Affairs, Laboratory for Marine Fisheries Science and Food Production Processes, Pilot National Laboratory for Marine Science and Technology, Qingdao, 266071, China
| | - Kang Tu
- Putian Institute of Aquaculture Science of Fujian Province, Putian, 351100, China
| | - Li Li
- Marine Biology Institute of Shandong Province, Qingdao, 266104, China
| | - Biao Wu
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture and Rural Affairs, Laboratory for Marine Fisheries Science and Food Production Processes, Pilot National Laboratory for Marine Science and Technology, Qingdao, 266071, China
| | - Lei Wu
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture and Rural Affairs, Laboratory for Marine Fisheries Science and Food Production Processes, Pilot National Laboratory for Marine Science and Technology, Qingdao, 266071, China; Jiangsu Ocean University, Lianyungang, 222005, China
| | - Zhihong Liu
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture and Rural Affairs, Laboratory for Marine Fisheries Science and Food Production Processes, Pilot National Laboratory for Marine Science and Technology, Qingdao, 266071, China
| | - Liqing Zhou
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture and Rural Affairs, Laboratory for Marine Fisheries Science and Food Production Processes, Pilot National Laboratory for Marine Science and Technology, Qingdao, 266071, China
| | - Jiteng Tian
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture and Rural Affairs, Laboratory for Marine Fisheries Science and Food Production Processes, Pilot National Laboratory for Marine Science and Technology, Qingdao, 266071, China
| | - Aiguo Yang
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture and Rural Affairs, Laboratory for Marine Fisheries Science and Food Production Processes, Pilot National Laboratory for Marine Science and Technology, Qingdao, 266071, China.
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21
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Kessouri F, McWilliams JC, Bianchi D, Sutula M, Renault L, Deutsch C, Feely RA, McLaughlin K, Ho M, Howard EM, Bednaršek N, Damien P, Molemaker J, Weisberg SB. Coastal eutrophication drives acidification, oxygen loss, and ecosystem change in a major oceanic upwelling system. Proc Natl Acad Sci U S A 2021; 118:e2018856118. [PMID: 34001604 PMCID: PMC8166049 DOI: 10.1073/pnas.2018856118] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Global change is leading to warming, acidification, and oxygen loss in the ocean. In the Southern California Bight, an eastern boundary upwelling system, these stressors are exacerbated by the localized discharge of anthropogenically enhanced nutrients from a coastal population of 23 million people. Here, we use simulations with a high-resolution, physical-biogeochemical model to quantify the link between terrestrial and atmospheric nutrients, organic matter, and carbon inputs and biogeochemical change in the coastal waters of the Southern California Bight. The model is forced by large-scale climatic drivers and a reconstruction of local inputs via rivers, wastewater outfalls, and atmospheric deposition; it captures the fine scales of ocean circulation along the shelf; and it is validated against a large collection of physical and biogeochemical observations. Local land-based and atmospheric inputs, enhanced by anthropogenic sources, drive a 79% increase in phytoplankton biomass, a 23% increase in primary production, and a nearly 44% increase in subsurface respiration rates along the coast in summer, reshaping the biogeochemistry of the Southern California Bight. Seasonal reductions in subsurface oxygen, pH, and aragonite saturation state, by up to 50 mmol m-3, 0.09, and 0.47, respectively, rival or exceed the global open-ocean oxygen loss and acidification since the preindustrial period. The biological effects of these changes on local fisheries, proliferation of harmful algal blooms, water clarity, and submerged aquatic vegetation have yet to be fully explored.
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Affiliation(s)
- Faycal Kessouri
- Department of Biogeochemistry, Southern California Coastal Water Research Project, Costa Mesa, CA 92626;
- Department of Atmospheric and Oceanic Sciences, University of California Los Angeles, Los Angeles, CA 90095
| | - James C McWilliams
- Department of Atmospheric and Oceanic Sciences, University of California Los Angeles, Los Angeles, CA 90095;
| | - Daniele Bianchi
- Department of Atmospheric and Oceanic Sciences, University of California Los Angeles, Los Angeles, CA 90095
| | - Martha Sutula
- Department of Biogeochemistry, Southern California Coastal Water Research Project, Costa Mesa, CA 92626
| | - Lionel Renault
- Department of Atmospheric and Oceanic Sciences, University of California Los Angeles, Los Angeles, CA 90095
- Laboratoire d'Études en Géophysique et Océanographie Spatiale, Institut de Recherche et de Developpement, CNRS, Université Paul Sabatier, Toulouse 31400, France
| | - Curtis Deutsch
- School of Oceanography, University of Washington, Seattle, WA 98195
| | - Richard A Feely
- Pacific Marine Environmental Laboratory, National Oceanic and Atmospheric Administration, Seattle, WA 98115
| | - Karen McLaughlin
- Department of Biogeochemistry, Southern California Coastal Water Research Project, Costa Mesa, CA 92626
| | - Minna Ho
- Department of Biogeochemistry, Southern California Coastal Water Research Project, Costa Mesa, CA 92626
| | - Evan M Howard
- School of Oceanography, University of Washington, Seattle, WA 98195
| | - Nina Bednaršek
- Department of Biogeochemistry, Southern California Coastal Water Research Project, Costa Mesa, CA 92626
- National Institute of Biology, Marine Biological Station Piran, 6330 Piran, Slovenia
| | - Pierre Damien
- Department of Atmospheric and Oceanic Sciences, University of California Los Angeles, Los Angeles, CA 90095
| | - Jeroen Molemaker
- Department of Atmospheric and Oceanic Sciences, University of California Los Angeles, Los Angeles, CA 90095
| | - Stephen B Weisberg
- Department of Biogeochemistry, Southern California Coastal Water Research Project, Costa Mesa, CA 92626
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22
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Wei Q, Wang B, Zhang X, Ran X, Fu M, Sun X, Yu Z. Contribution of the offshore detached Changjiang (Yangtze River) Diluted Water to the formation of hypoxia in summer. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 764:142838. [PMID: 33757237 DOI: 10.1016/j.scitotenv.2020.142838] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 09/27/2020] [Accepted: 10/04/2020] [Indexed: 06/12/2023]
Abstract
The Changjiang (Yangtze River) Diluted Water (CDW) plume substantially impacts the biogeochemical processes off the estuary and its adjacent area, resulting in considerable environmental and ecological effects. Based on survey data in the northeastern area off the Changjiang Estuary (CE) obtained in the summers of 2008 and 2013, the hypoxia induced by the offshore detached CDW plume and the associated controlling mechanisms were investigated. The results show that the offshore transport of the CDW plume caused a dispersed low-salinity area in the northeastern area off the CE during summer, in sharp contrast with the surrounding high-salinity and high-density waters. There was a hypoxic area with low-pH (i.e., acidification) near the 40-m isobath in bottom waters in the northeastern area off the CE, and its position generally corresponded to the surface offshore CDW plume. In the area affected by the offshore low-salinity water, the surface patch-like phytoplankton bloom and the organic debris produced in situ were the material drivers of the bottom oxygen consumption and led to the corresponding relationship between the bottom hypoxic zone and the high chlorophyll-a (Chl-a) area at the surface. We consider that the local stratification caused by the offshore low-salinity water and the stable environment within the detached CDW plume constituted the external dynamic conditions for maintaining the bottom hypoxia. Our results demonstrate that the offshore detached CDW plume in the northeastern area off the CE may contribute to the formation of a local hypoxic center with low pH. This study would provide basis for understanding of the physical-biogeochemical processes and environmental responses in the offshore areas of the CDW plume.
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Affiliation(s)
- Qinsheng Wei
- First Institute of Oceanography, Ministry of Natural Resources, 6 Xianxialing Road, Qingdao 266061, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, 1 Wenhai Road, Qingdao 266237, China.
| | - Baodong Wang
- First Institute of Oceanography, Ministry of Natural Resources, 6 Xianxialing Road, Qingdao 266061, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, 1 Wenhai Road, Qingdao 266237, China.
| | - Xuelei Zhang
- First Institute of Oceanography, Ministry of Natural Resources, 6 Xianxialing Road, Qingdao 266061, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, 1 Wenhai Road, Qingdao 266237, China
| | - Xiangbin Ran
- First Institute of Oceanography, Ministry of Natural Resources, 6 Xianxialing Road, Qingdao 266061, China
| | - Mingzhu Fu
- First Institute of Oceanography, Ministry of Natural Resources, 6 Xianxialing Road, Qingdao 266061, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, 1 Wenhai Road, Qingdao 266237, China
| | - Xia Sun
- First Institute of Oceanography, Ministry of Natural Resources, 6 Xianxialing Road, Qingdao 266061, China
| | - Zhigang Yu
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, 1 Wenhai Road, Qingdao 266237, China; Frontiers Science Center for Deep Ocean Multispheres and Earth System, and Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, 238 Songling Road, Qingdao 266100, China
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23
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Heinze C, Blenckner T, Martins H, Rusiecka D, Döscher R, Gehlen M, Gruber N, Holland E, Hov Ø, Joos F, Matthews JBR, Rødven R, Wilson S. The quiet crossing of ocean tipping points. Proc Natl Acad Sci U S A 2021; 118:e2008478118. [PMID: 33619085 PMCID: PMC7936299 DOI: 10.1073/pnas.2008478118] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Anthropogenic climate change profoundly alters the ocean's environmental conditions, which, in turn, impact marine ecosystems. Some of these changes are happening fast and may be difficult to reverse. The identification and monitoring of such changes, which also includes tipping points, is an ongoing and emerging research effort. Prevention of negative impacts requires mitigation efforts based on feasible research-based pathways. Climate-induced tipping points are traditionally associated with singular catastrophic events (relative to natural variations) of dramatic negative impact. High-probability high-impact ocean tipping points due to warming, ocean acidification, and deoxygenation may be more fragmented both regionally and in time but add up to global dimensions. These tipping points in combination with gradual changes need to be addressed as seriously as singular catastrophic events in order to prevent the cumulative and often compounding negative societal and Earth system impacts.
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Affiliation(s)
- Christoph Heinze
- Geophysical Institute, University of Bergen, 5020 Bergen, Norway;
- Bjerknes Centre for Climate Research, University of Bergen, 5020 Bergen, Norway
| | - Thorsten Blenckner
- Stockholm Resilience Centre, Stockholm University, 10691 Stockholm, Sweden
| | - Helena Martins
- Rossby Centre, Swedish Meteorological and Hydrological Institute, 60176 Norrköping, Sweden
| | - Dagmara Rusiecka
- Geophysical Institute, University of Bergen, 5020 Bergen, Norway
- Bjerknes Centre for Climate Research, University of Bergen, 5020 Bergen, Norway
| | - Ralf Döscher
- Rossby Centre, Swedish Meteorological and Hydrological Institute, 60176 Norrköping, Sweden
| | - Marion Gehlen
- Laboratoire des Sciences du Climat et de l'Environnement, Institut Pierre Simon Laplace, 91191 Gif-sur-Yvette cedex, France
| | - Nicolas Gruber
- Institute of Biogeochemistry and Pollutant Dynamics, Eidgenössische Technische Hochschule (ETH) Zürich, 8092 Zürich, Switzerland
| | - Elisabeth Holland
- Pacific Centre for the Environment and Sustainable Development, The University of the South Pacific, Suva, Fiji
| | - Øystein Hov
- Norwegian Meteorological Institute, 0371 Oslo, Norway
- The Norwegian Academy of Science and Letters, 0271 Oslo, Norway
| | - Fortunat Joos
- Climate and Environmental Physics, Physics Institute, University of Bern, 3012 Bern, Switzerland
- Oeschger Centre for Climate Change Research, University of Bern, 3012 Bern, Switzerland
| | - John Brian Robin Matthews
- School of Architecture, Computing and Engineering, University of East London, E16 2RD, London, United Kingdom
| | - Rolf Rødven
- Arctic Monitoring and Assessment Programme Secretariat, 9296 Tromsø, Norway
| | - Simon Wilson
- Arctic Monitoring and Assessment Programme Secretariat, 9296 Tromsø, Norway
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24
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Impacts of hypoxic events surpass those of future ocean warming and acidification. Nat Ecol Evol 2021; 5:311-321. [PMID: 33432134 DOI: 10.1038/s41559-020-01370-3] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 12/01/2020] [Indexed: 01/28/2023]
Abstract
Over the past decades, three major challenges to marine life have emerged as a consequence of anthropogenic emissions: ocean warming, acidification and oxygen loss. While most experimental research has targeted the first two stressors, the last remains comparatively neglected. Here, we implemented sequential hierarchical mixed-model meta-analyses (721 control-treatment comparisons) to compare the impacts of oxygen conditions associated with the current and continuously intensifying hypoxic events (1-3.5 O2 mg l-1) with those experimentally yielded by ocean warming (+4 °C) and acidification (-0.4 units) conditions on the basis of IPCC projections (RCP 8.5) for 2100. In contrast to warming and acidification, hypoxic events elicited consistent negative effects relative to control biological performance-survival (-33%), abundance (-65%), development (-51%), metabolism (-33%), growth (-24%) and reproduction (-39%)-across the taxonomic groups (mollusks, crustaceans and fish), ontogenetic stages and climate regions studied. Our findings call for a refocus of global change experimental studies, integrating oxygen concentration drivers as a key factor of ocean change. Given potential combined effects, multistressor designs including gradual and extreme changes are further warranted to fully disclose the future impacts of ocean oxygen loss, warming and acidification.
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25
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Machine Learning Based Predictions of Dissolved Oxygen in a Small Coastal Embayment. JOURNAL OF MARINE SCIENCE AND ENGINEERING 2020. [DOI: 10.3390/jmse8121007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Coastal dissolved oxygen (DO) concentrations have a profound impact on nearshore ecosystems and, in recent years, there has been an increased prevalance of low DO hypoxic events that negatively impact nearshore organisms. Even with advanced numerical models, accurate prediction of coastal DO variability is challenging and computationally expensive. Here, we apply machine learning techniques in order to reconstruct and predict nearshore DO concentrations in a small coastal embayment while using a comprehensive set of nearshore and offshore measurements and easily measured input (training) parameters. We show that both random forest regression (RFR) and support vector regression (SVR) models accurately reproduce both the offshore DO and nearshore DO with extremely high accuracy. In general, RFR consistently peformed slightly better than SVR, the latter of which was more difficult to tune and took longer to train. Although each of the nearshore datasets were able to accurately predict DO values using training data from the same site, the model only had moderate success when using training data from one site to predict DO at another site, which was likely due to the the complexities in the underlying dynamics across the sites. We also show that high accuracy can be achieved with relatively little training data, highlighting a potential application for correcting time series with missing DO data due to quality control or sensor issues. This work establishes the ability of machine learning models to accurately reproduce DO concentrations in both offshore and nearshore coastal waters, with important implications for the ability to detect and indirectly measure coastal hypoxic events in near real-time. Future work should explore the ability of machine learning models in order to accurately forecast hypoxic events.
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26
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Riquelme-Bugueño R, Pérez-Santos I, Alegría N, Vargas CA, Urbina MA, Escribano R. Diel vertical migration into anoxic and high-pCO 2 waters: acoustic and net-based krill observations in the Humboldt Current. Sci Rep 2020; 10:17181. [PMID: 33057075 PMCID: PMC7560619 DOI: 10.1038/s41598-020-73702-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 09/21/2020] [Indexed: 11/29/2022] Open
Abstract
A select group of marine organisms can enter the Oxygen Minimum Zones (OMZs) and even anoxic waters, while performing diel vertical migration (DVM). DVM of the euphausiid Euphausia eximia off northern Chile in the spring of 2015 was documented based on acoustic measurements using an echo sounder along with net samplings. Dissolved oxygen (DO) concentrations were obtained using a vertical profiler, and water samples were collected to obtain in situ nitrite (NO2−) concentrations as well as pHT, total alkalinity (AT), and therefore carbon dioxide partial pressure (pCO2) was estimated. Krill were found to migrate up to the surface (0–50 m) during the night and returned to ca. 200–300 m depth during the day, spending between 11 and 14 h at these layers. At the surface, DO and NO2− concentrations were 208 and 0.14 μM respectively, while pHT was 8.04 and 405 μatm pCO2. In contrast, at the deeper layers (200–300 m), DO and NO2− were < 3 and 6.3 μM respectively, with pHT 7.53 and 1490 μatm pCO2. The pHT and high pCO2 values at depths represent the conditions predicted for open ocean waters in a worst-case global warming scenario by 2150. The acoustic scatter suggested that > 60% of the krill swarms enter the OMZ and anoxic waters during the daytime. These frequent migrations suggest that krill can tolerate such extreme conditions associated with anoxic and high-pCO2 waters. The inferences drawn from the observation of these migrations might have strong implications for the current oceanic carbon pump models, highlighting the need for understanding the molecular and physiological adaptations allowing these migrations.
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Affiliation(s)
- Ramiro Riquelme-Bugueño
- Departamento de Zoología, Facultad de Ciencias Naturales Y Oceanográficas, Universidad de Concepción, Concepción, Chile. .,Instituto Milenio de Oceanografía (IMO), Universidad de Concepción, Concepción, Chile.
| | - Iván Pérez-Santos
- Centro i~mar, Universidad de Los Lagos, Puerto Montt, Chile.,COPAS Sur-Austral, Universidad de Concepción, Concepción, Chile
| | | | - Cristian A Vargas
- Instituto Milenio de Oceanografía (IMO), Universidad de Concepción, Concepción, Chile.,Coastal Ecosystems and Global Environmental Change Lab (ECCA Lab), Department of Aquatic Systems, Faculty of Environmental Sciences and Center for the Study of Multiple-Drivers On Marine Socio-Ecological Systems (MUSELS), Universidad de Concepción, Concepción, Chile
| | - Mauricio A Urbina
- Departamento de Zoología, Facultad de Ciencias Naturales Y Oceanográficas, Universidad de Concepción, Concepción, Chile.,Instituto Milenio de Oceanografía (IMO), Universidad de Concepción, Concepción, Chile
| | - Rubén Escribano
- Instituto Milenio de Oceanografía (IMO), Universidad de Concepción, Concepción, Chile.,Departamento de Oceanografía, Facultad de Ciencias Naturales Y Oceanográficas, Universidad de Concepción, Concepción, Chile
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27
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Abstract
Hypoxia is becoming a serious problem in coastal waters in many parts of the world. Artificial downwelling, which is one of the geoengineering-based adaptation options, was suggested as an effective means of mitigating hypoxia in coastal waters. Artificial downwelling powered by green energy, such as solar, wind, wave, or tidal energy, can develop a compensatory downward flow on a kilometer scale, which favors below-pycnocline ventilation and thus mitigates hypoxia in bottom water. In this paper, we review and assess the technical, numerical, and experimental aspects of artificial downwelling all over the world, as well as its potential environmental effects. Some basic principles are presented, and assessment and advice are provided for each category. Some suggestions for further field-based research on artificial downwelling, especially for long-term field research, are also given.
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28
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Deutsch C, Penn JL, Seibel B. Metabolic trait diversity shapes marine biogeography. Nature 2020; 585:557-562. [PMID: 32939093 DOI: 10.1038/s41586-020-2721-y] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 06/18/2020] [Indexed: 11/09/2022]
Abstract
Climate and physiology shape biogeography, yet the range limits of species can rarely be ascribed to the quantitative traits of organisms1-3. Here we evaluate whether the geographical range boundaries of species coincide with ecophysiological limits to acquisition of aerobic energy4 for a global cross-section of the biodiversity of marine animals. We observe a tight correlation between the metabolic rate and the efficacy of oxygen supply, and between the temperature sensitivities of these traits, which suggests that marine animals are under strong selection for the tolerance of low O2 (hypoxia)5. The breadth of the resulting physiological tolerances of marine animals predicts a variety of geographical niches-from the tropics to high latitudes and from shallow to deep water-which better align with species distributions than do models based on either temperature or oxygen alone. For all studied species, thermal and hypoxic limits are substantially reduced by the energetic demands of ecological activity, a trait that varies similarly among marine and terrestrial taxa. Active temperature-dependent hypoxia thus links the biogeography of diverse marine species to fundamental energetic requirements that are shared across the animal kingdom.
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Affiliation(s)
- Curtis Deutsch
- School of Oceanography, University of Washington, Seattle, WA, USA. .,Department of Biology, University of Washington, Seattle, WA, USA.
| | - Justin L Penn
- School of Oceanography, University of Washington, Seattle, WA, USA
| | - Brad Seibel
- College of Marine Science, University of South Florida, St Petersburg, FL, USA
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29
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Lewis NS, Young DR, Folger CL, DeWitt TH. Assessing the Relative Importance of Estuarine Nursery Habitats - a Dungeness Crab ( Cancer magister) Case Study. ESTUARIES AND COASTS : JOURNAL OF THE ESTUARINE RESEARCH FEDERATION 2020; 44:1062-1073. [PMID: 34017229 PMCID: PMC8128707 DOI: 10.1007/s12237-020-00821-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 08/19/2020] [Accepted: 08/21/2020] [Indexed: 06/12/2023]
Abstract
Estuaries serve as important nurseries for many recreationally and commercially harvested fisheries species. Recent conceptual approaches (i.e., seascape) for assessing the value of estuaries to fisheries have advocated for complex habitat-scale assessments that integrate multiple life-history responses (e.g., abundance, growth, reproduction) and ecological processes across heterogeneous landscapes. Although ecologically compelling, implementing seascape approaches may not be feasible for resource-limited management agencies. In such cases, we propose that resource managers can enhance the identification of fishery-important estuarine habitats by integrating attainable aspects of the seascape approach into a more traditional single response (e.g., abundance) model. Using Dungeness crab (Cancer magister) as a case study, we applied a spatially-explicit hybrid approach to assess the relative contribution of different estuarine habitats to that important fishery species within three Oregon estuaries (Tillamook, Yaquina, and Alsea bays). We measured the abundance of juvenile C. magister from low-tide trawls in estuarine channels and the mosaic of habitat characteristics within defined home-range distances for the crabs. After identifying and reducing strong intercorrelations among habitat variable data, we developed a best-fit model that associated crab abundance with the most influential habitat variables. We found that lower-estuary side channels supported the highest abundance of juvenile crabs; furthermore, crab abundance was positively associated with high salinity and burrowing shrimp (Upogebia pugettensis) density on adjacent unvegetated tidal flats. This hybrid method produced a habitat-specific model that better predicted juvenile C. magister abundance than did a model based on generalized habitat categories.
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Affiliation(s)
- Nathaniel S. Lewis
- ORISE Research Fellow, Pacific Coastal Ecology Branch, Pacific Ecological Systems Division, U.S. Environmental Protection Agency, Newport, OR 97365, USA
| | - David R. Young
- Pacific Coastal Ecology Branch, Pacific Ecological Systems Division, U.S. Environmental Protection Agency, Newport, OR 97365, USA
| | - Christina L. Folger
- Pacific Coastal Ecology Branch, Pacific Ecological Systems Division, U.S. Environmental Protection Agency, Newport, OR 97365, USA
| | - Theodore H. DeWitt
- Pacific Coastal Ecology Branch, Pacific Ecological Systems Division, U.S. Environmental Protection Agency, Newport, OR 97365, USA
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30
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Tolimieri N, Wallace J, Haltuch M. Spatio-temporal patterns in juvenile habitat for 13 groundfishes in the California Current Ecosystem. PLoS One 2020; 15:e0237996. [PMID: 32822408 PMCID: PMC7442253 DOI: 10.1371/journal.pone.0237996] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 08/07/2020] [Indexed: 11/19/2022] Open
Abstract
Identifying juvenile habitats is critical for understanding a species' ecology and for focusing spatial fishery management by defining references like essential fish habitat (EFH). Here, we used vector autoregressive spatio-temporal models (VAST) to delineate spatial and temporal patterns in juvenile density for 13 commercially important species of groundfishes off the US west coast. In particular, we identified hotspots with high juvenile density. Three qualitative patterns of distribution and abundance emerged. First, Dover sole Microstomus pacificus, Pacific grenadier Coryphaenoides acrolepis, shortspine thornyhead Sebastolobus alascanus, and splitnose rockfish Sebastes diploproa had distinct, spatially-limited hotspots that were spatially consistent through time. Next, Pacific hake Merluccius productus and darkblotched rockfish Sebastes crameri had distinct, spatially limited hotspots, but the location of these hotspots varied through time. Finally, arrowtooth flounder Atheresthes stomias, English sole Parophrys vetulus, sablefish Anoplopoma fimbria, Pacific grenadier Coryphaenoides acrolepis, lingcod Ophiodon elongatus, longspine thornyhead Sebastolobus altivelis, petrale sole Eopsetta jordani, and Pacific sanddab Citharichthys sordidus had large hotspots that spanned a broad latitudinal range. These habitats represent potential, if not likely, nursery areas, the location of which will inform spatial management.
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Affiliation(s)
- Nick Tolimieri
- Conservation Biology Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, WA, United States of America
| | - John Wallace
- Fisheries Research, Analysis and Monitoring Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, WA, United States of America
| | - Melissa Haltuch
- Fisheries Research, Analysis and Monitoring Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, WA, United States of America
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31
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Mattiasen EG, Kashef NS, Stafford DM, Logan CA, Sogard SM, Bjorkstedt EP, Hamilton SL. Effects of hypoxia on the behavior and physiology of kelp forest fishes. GLOBAL CHANGE BIOLOGY 2020; 26:3498-3511. [PMID: 32153086 DOI: 10.1111/gcb.15076] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 02/23/2020] [Indexed: 05/14/2023]
Abstract
Forecasts from climate models and oceanographic observations indicate increasing deoxygenation in the global oceans and an elevated frequency and intensity of hypoxic events in the coastal zone, which have the potential to affect marine biodiversity and fisheries. Exposure to low dissolved oxygen (DO) conditions may have deleterious effects on early life stages in fishes. This study aims to identify thresholds to hypoxia while testing behavioral and physiological responses of two congeneric species of kelp forest fish to four DO levels, ranging from normoxic to hypoxic (8.7, 6.0, 4.1, and 2.2 mg O2 /L). Behavioral tests identified changes in exploratory behavior and turning bias (lateralization), whereas physiological tests focused on determining changes in hypoxia tolerance (pCrit), ventilation rates, and metabolic rates, with impacts on the resulting capacity for aerobic activity. Our findings indicated that copper rockfish (Sebastes caurinus) and blue rockfish (Sebastes mystinus) express sensitivity to hypoxia; however, the strength of the response differed between species. Copper rockfish exhibited reduced absolute lateralization and increased escape time at the lowest DO levels, whereas behavioral metrics for blue rockfish did not vary with oxygen level. Both species exhibited decreases in aerobic scope (as a function of reduced maximum metabolic rate) and increases in ventilation rates to compensate for decreasing oxygen levels. Blue rockfish had a lower pCrit and stronger acclimation response compared to copper rockfish. The differences expressed by each species suggest that acclimatization to changing ocean conditions may vary, even among related species that recruit to the same kelp forest habitat, leading to winners and losers under future ocean conditions. Exposure to hypoxia can decrease individual physiological fitness through metabolic and aerobic depression and changes to anti-predator behavior, with implications for the outcome of ecological interactions and the management of fish stocks in the face of climate change.
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Affiliation(s)
| | - Neosha S Kashef
- Fisheries Ecology Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Santa Cruz, CA, USA
- Marine Science Institute, University of California, Santa Cruz, Santa Cruz, CA, USA
| | - David M Stafford
- Fisheries Ecology Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Santa Cruz, CA, USA
- Marine Science Institute, University of California, Santa Cruz, Santa Cruz, CA, USA
| | - Cheryl A Logan
- California State University Monterey Bay, Seaside, CA, USA
| | - Susan M Sogard
- Fisheries Ecology Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Santa Cruz, CA, USA
| | - Eric P Bjorkstedt
- Fisheries Ecology Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Santa Cruz, CA, USA
- Department of Fisheries Biology, Humboldt State University, Trinidad, CA, USA
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32
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Hainey MAH, Emlet RB. Gorgonocephalus eucnemis (Echinodermata: Ophiuroidea) and Bursal Ventilation. THE BIOLOGICAL BULLETIN 2020; 238:193-205. [PMID: 32597717 DOI: 10.1086/709575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The basket star Gorgonocephalus eucnemis is an aerobic organism highly dependent on dissolved oxygen in surrounding waters. Previous observations on the anatomy of Gorgonocephalus state that five pairs of ossicles (the radial shields and genital plates) regulate the position of the roof of the body disc and are responsible for flushing seawater into and out of the bursae, though this seems never to have been empirically tested. In the current study, rates of bursal ventilation were investigated in response to an increase in the availability of food and, separately, exposure to hypoxic levels of dissolved oxygen. When fed with suspended krill particles, basket stars increased rates of bursal ventilation, ranging from 13% to 155%, resulting in a similar increase in volume of water moved in and out of bursae. This rate remained elevated for an average of 25 minutes after active feeding ended. Bursal ventilation rates also increased significantly (~60% average increase) when basket stars were exposed to hypoxic conditions (dissolved oxygen ≤ 3.5 mg O2 L-1 = 2.45 mL O2 L-1). Some specimens exhibited a loss of coordination in hypoxic conditions. All specimens recovered and resumed a normal rate of bursal ventilation when returned to normoxic conditions. Measurements show that dissolved oxygen levels decreased from outside to inside bursae and suggest that dissolved oxygen is absorbed in bursae during bursal ventilations. Increasing rates of bursal ventilation may help meet the increased oxygen demands when feeding and may help animals endure some exposures to hypoxia.
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33
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Low NHN, Micheli F. Short- and long-term impacts of variable hypoxia exposures on kelp forest sea urchins. Sci Rep 2020; 10:2632. [PMID: 32060309 PMCID: PMC7021826 DOI: 10.1038/s41598-020-59483-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 01/30/2020] [Indexed: 11/08/2022] Open
Abstract
Climate change is altering the intensity and variability of environmental stress that organisms and ecosystems experience, but effects of changing stress regimes are not well understood. We examined impacts of constant and variable sublethal hypoxia exposures on multiple biological processes in the sea urchin Strongylocentrotus purpuratus, a key grazer in California Current kelp forests, which experience high variability in physical conditions. We quantified metabolic rates, grazing, growth, calcification, spine regeneration, and gonad production under constant, 3-hour variable, and 6-hour variable exposures to sublethal hypoxia, and compared responses for each hypoxia regime to normoxic conditions. Sea urchins in constant hypoxia maintained baseline metabolic rates, but had lower grazing, gonad development, and calcification rates than those in ambient conditions. The sublethal impacts of variable hypoxia differed among biological processes. Spine regrowth was reduced under all hypoxia treatments, calcification rates under variable hypoxia were intermediate between normoxia and constant hypoxia, and gonad production correlated negatively with continuous time under hypoxia. Therefore, exposure variability can differentially modulate the impacts of sublethal hypoxia, and may impact sea urchin populations and ecosystems via reduced feeding and reproduction. Addressing realistic, multifaceted stressor exposures and multiple biological responses is crucial for understanding climate change impacts on species and ecosystems.
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Affiliation(s)
- Natalie H N Low
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, 93950, USA.
| | - Fiorenza Micheli
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, 93950, USA
- Stanford Center for Ocean Solutions, Pacific Grove, CA, 93950, USA
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Biogeography of Macrophyte Elemental Composition: Spatiotemporal Modification of Species-Level Traits. Ecosystems 2020. [DOI: 10.1007/s10021-020-00484-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Klein SG, Steckbauer A, Duarte CM. Defining CO 2 and O 2 syndromes of marine biomes in the Anthropocene. GLOBAL CHANGE BIOLOGY 2020; 26:355-363. [PMID: 31637801 DOI: 10.1111/gcb.14879] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 09/22/2019] [Accepted: 10/17/2019] [Indexed: 06/10/2023]
Abstract
Research efforts have intensified to foresee the prospects for marine biomes under climate change and anthropogenic drivers over varying temporal and spatial scales. Parallel with these efforts is the utilization of terminology, such as 'ocean acidification' (OA) and 'ocean deoxygenation' (OD), that can foster rapid comprehension of complex processes driving carbon dioxide (CO2 ) and oxygen (O2 ) concentrations in the global ocean and thus, are now widely used in discussions within and beyond academia. However, common usage of the terms 'acidification' and 'deoxygenation' alone are subjective and, without adequate contextualization, have the potential to mislead inferences over drivers that may ultimately shape the future state of marine ecosystems. Here we clarify the usage of the terms OA and OD as global, climate change-driven processes and discuss the various attributes of elevated CO2 and reduced O2 syndromes common to coastal ecosystems. We support the use of the existing terms 'coastal acidification' and 'coastal deoxygenation' because they help differentiate the sometimes rapid and extreme nature of CO2 and O2 syndromes in coastal ecosystems from the global, climate change-driven processes of OA and OD. Given the complexity and breadth of the processes involved in altering CO2 and O2 concentrations across marine ecosystems, we provide a workflow to enable contextualization and clarification of the usage of existing terms and highlight the close link between these two gases across spatial and temporal scales in the ocean. These distinctions are crucial to guide effective communication of research within the scientific community and guide policymakers responsible for intervening on the drivers to secure desirable future ocean states.
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Affiliation(s)
- Shannon G Klein
- Red Sea Research Center and Computational Bioscience Research Center, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Alexandra Steckbauer
- Red Sea Research Center, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Carlos M Duarte
- Red Sea Research Center and Computational Bioscience Research Center, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
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Bashevkin SM, Dibble CD, Dunn RP, Hollarsmith JA, Ng G, Satterthwaite EV, Morgan SG. Larval dispersal in a changing ocean with an emphasis on upwelling regions. Ecosphere 2020. [DOI: 10.1002/ecs2.3015] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Affiliation(s)
- Samuel M. Bashevkin
- Department of Environmental Science and Policy University of California, Davis One Shields Avenue Davis California 95616 USA
- Coastal and Marine Sciences Institute and Bodega Marine Laboratory University of California, Davis 2099 Westshore Road, P.O. Box 247 Bodega Bay California 94923 USA
- Delta Science Program Delta Stewardship Council 980 9th Street, Suite 1500 Sacramento California 95814 USA
| | - Connor D. Dibble
- Department of Environmental Science and Policy University of California, Davis One Shields Avenue Davis California 95616 USA
- Coastal and Marine Sciences Institute and Bodega Marine Laboratory University of California, Davis 2099 Westshore Road, P.O. Box 247 Bodega Bay California 94923 USA
| | - Robert P. Dunn
- Department of Environmental Science and Policy University of California, Davis One Shields Avenue Davis California 95616 USA
- Coastal and Marine Institute & Department of Biology San Diego State University 4165 Spruance Road San Diego California 92182 USA
| | - Jordan A. Hollarsmith
- Department of Environmental Science and Policy University of California, Davis One Shields Avenue Davis California 95616 USA
- Coastal and Marine Sciences Institute and Bodega Marine Laboratory University of California, Davis 2099 Westshore Road, P.O. Box 247 Bodega Bay California 94923 USA
- Department of Biological Sciences Simon Fraser University 8888 University Drive Burnaby British Columbia V5A 1S6 Canada
| | - Gabriel Ng
- Coastal and Marine Sciences Institute and Bodega Marine Laboratory University of California, Davis 2099 Westshore Road, P.O. Box 247 Bodega Bay California 94923 USA
- Department of Evolution and Ecology University of California, Davis One Shields Avenue Davis California 95616 USA
| | - Erin V. Satterthwaite
- Department of Environmental Science and Policy University of California, Davis One Shields Avenue Davis California 95616 USA
- Coastal and Marine Sciences Institute and Bodega Marine Laboratory University of California, Davis 2099 Westshore Road, P.O. Box 247 Bodega Bay California 94923 USA
- National Center for Ecological Analysis and Synthesis University of California Santa Barbara 735 State Street, Suite 300 Santa Barbara California USA
- Future Earth School of Global Environmental Sustainability Colorado State University 108 Johnson Drive Fort Collins Colorado 80523 USA
| | - Steven G. Morgan
- Department of Environmental Science and Policy University of California, Davis One Shields Avenue Davis California 95616 USA
- Coastal and Marine Sciences Institute and Bodega Marine Laboratory University of California, Davis 2099 Westshore Road, P.O. Box 247 Bodega Bay California 94923 USA
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Cline AJ, Hamilton SL, Logan CA. Effects of multiple climate change stressors on gene expression in blue rockfish (Sebastes mystinus). Comp Biochem Physiol A Mol Integr Physiol 2020; 239:110580. [DOI: 10.1016/j.cbpa.2019.110580] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 09/06/2019] [Accepted: 09/11/2019] [Indexed: 12/20/2022]
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Larina E, Bottjer DJ, Corsetti FA, Zonneveld JP, Celestian AJ, Bailey JV. Uppermost Triassic phosphorites from Williston Lake, Canada: link to fluctuating euxinic-anoxic conditions in northeastern Panthalassa before the end-Triassic mass extinction. Sci Rep 2019; 9:18790. [PMID: 31827166 PMCID: PMC6906467 DOI: 10.1038/s41598-019-55162-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 11/19/2019] [Indexed: 12/02/2022] Open
Abstract
The end-Triassic mass extinction (ETE) is associated with a rise in CO2 due to eruptions of the Central Atlantic Magmatic Province (CAMP), and had a particularly dramatic effect on the Modern Fauna, so an understanding of the conditions that led to the ETE has relevance to current rising CO2 levels. Here, we report multiple phosphorite deposits in strata that immediately precede the ETE at Williston Lake, Canada, which allow the paleoenvironmental conditions leading up to the mass extinction to be investigated. The predominance of phosphatic coated grains within phoshorites indicates reworking in shallow water environments. Raman spectroscopy reveals that the phosphorites contain organic carbon, and petrographic and scanning electron microscopic analyses reveal that the phosphorites contain putative microfossils, potentially suggesting microbial involvement in a direct or indirect way. Thus, we favor a mechanism of phosphogenesis that involves microbial polyphosphate metabolism in which phosphatic deposits typically form at the interface of euxinic/anoxic and oxic conditions. When combined with data from deeper water deposits (Kennecott Point) far to the southwest, it would appear a very broad area of northeastern Panthalassa experienced anoxic to euxinic bottom water conditions in the direct lead up to the end-Triassic mass extinction. Such a scenario implies expansion and shallowing of the oxygen minimum zone across a very broad area of northeastern Panthalassa, which potentially created a stressful environment for benthic metazoan communities. Studies of the pre-extinction interval from different sites across the globe are required to resolve the chronology and spatial distribution of processes that governed before the major environmental collapse that caused the ETE. Results from this study demonstrate that fluctuating anoxic and euxinic conditions could have been potentially responsible for reduced ecosystem stability before the onset of CAMP volcanism, at least at the regional scale.
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Affiliation(s)
- Ekaterina Larina
- Earth Sciences, University of Southern California, Los Angeles, USA.
| | - David J Bottjer
- Earth Sciences, University of Southern California, Los Angeles, USA
| | - Frank A Corsetti
- Earth Sciences, University of Southern California, Los Angeles, USA
| | | | | | - Jake V Bailey
- Earth Sciences, University of Minnesota, Minneapolis, USA
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Steingass S, Horning M, Bishop AM. Space use of Pacific harbor seals (Phoca vitulina richardii) from two haulout locations along the Oregon coast. PLoS One 2019; 14:e0219484. [PMID: 31365532 PMCID: PMC6668786 DOI: 10.1371/journal.pone.0219484] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 06/25/2019] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND There are approximately 10,000-12,000 Pacific harbor seals (Phoca vitulina richardii) inhabiting the Oregon coast, and unlike other species of pinnipeds in this region, are reliably present year-round. Despite this, and drastic rebounds in population since the enactment of the Marine Mammal Protection Act, limited data is available for the present period regarding their space use at sea, and within estuarine, riverine, or bay areas within the state. OBJECTIVE To examine site-based differences in space use for 24 adult Pacific harbor seals captured and outfitted with satellite transmitters at two predominant haulout sites on the Oregon Coast, USA. DESIGN We captured 24 adult harbor seals from two haulout sites on the Central Oregon coast between September 2014-16 and fitted them with external Wildlife Computers SPOT5 satellite transmitters to track movement. Using state-space modeled locations derived from satellite telemetry data, we evaluated spatial behavior of these animals using a correlated random walk model via R package crawl. Kernel density estimation was subsequently used to calculate home range and core area for each animal. Percent use of open ocean habitat versus use of estuaries, rivers and bays was quantified, as was an initial examination of presence within five newly-established marine reserves in Oregon. Examination of haulout site-related differences in spatial behavior were examined for seals captured in Netarts and Alsea Bays, Oregon and haul out behavior related to time of day, season, and tidal level was also investigated. RESULTS The average individual home range for seals was 364.47 ± 382.87 km2 with seals captured in Alsea bay demonstrating a significantly higher home range area than those captured in Netarts Bay. Alsea bay seals also tended to range farther from shore than Netarts Bay animals. The average calculated core area for seals encompassed on average 29.41 ± 29.23 km2 per animal, however the home range of one animal was so small, core area could not be calculated. Use of marine reserves was limited for animals in this study, representing less than 2% of locations with a majority occurring in Cape Perpetua Marine Reserve and North Marine Protected Area. Seals were more likely to haul out during low tides and periods of low light (dusk, night and dawn), and hauling out behavior increased in winter months. SIGNIFICANCE These findings demonstrate the first major documentation of space use of harbor seals in the state for nearly three decades, and lends itself to future comparison and formation of mechanistically-based hypotheses for behavior of a common marine mammal in the highly productive northern California Current System.
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Affiliation(s)
- Sheanna Steingass
- Oregon State University Department of Fisheries and Wildlife, Oregon Department of Fish and Wildlife, Corvallis, Oregon, United States of America
| | - Markus Horning
- Alaska SeaLife Center, Seward, Alaska, United States of America
- Oregon State University Department of Fisheries and Wildlife, Newport, Oregon, United States of America
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Loss of the HIF pathway in a widely distributed intertidal crustacean, the copepod Tigriopus californicus. Proc Natl Acad Sci U S A 2019; 116:12913-12918. [PMID: 31182611 PMCID: PMC6600937 DOI: 10.1073/pnas.1819874116] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Oxygen availability is essential for development, growth, and viability of aerobic organisms. The genes in the hypoxia-inducible factor (HIF) pathway are considered master regulators of oxygen sensitivity and distribution inside cells, and they are hence highly conserved across animal groups. These genes are frequent targets of natural selection in organisms living in low-oxygen environments, such as high-altitude humans and birds. Here, we show that the abundant tidepool copepod Tigriopus californicus can withstand prolonged exposure to extreme oxygen deprivation, despite having secondarily lost key HIF-pathway members. Our results suggest the existence of alternative mechanisms of response to hypoxic stress in animals, and we show that genes involved in cuticle reorganization and ion transport may play a major role. Hypoxia is a major physiological constraint for which multicellular eukaryotes have evolved robust cellular mechanisms capable of addressing dynamic changes in O2 availability. In animals, oxygen sensing and regulation is primarily performed by the hypoxia-inducible factor (HIF) pathway, and the key components of this pathway are thought to be highly conserved across metazoans. Marine intertidal habitats are dynamic environments, and their inhabitants are known to tolerate wide fluctuations in salinity, temperature, pH, and oxygen. In this study, we show that an abundant intertidal crustacean, the copepod Tigriopus californicus, has lost major genetic components of the HIF pathway, but still shows robust survivorship and transcriptional response to hypoxia. Mining of protein domains across the genome, followed by phylogenetic analyses of gene families, did not identify two key regulatory elements of the metazoan hypoxia response, namely the transcription factor HIF-α and its oxygen-sensing prolyl hydroxylase repressor, EGLN. Despite this loss, phenotypic assays revealed that this species is tolerant to extremely low levels of available O2 for at least 24 h at both larval and adult stages. RNA-sequencing (seq) of copepods exposed to nearly anoxic conditions showed differential expression of over 400 genes, with evidence for induction of glycolytic metabolism without a depression of oxidative phosphorylation. Moreover, genes involved in chitin metabolism and cuticle reorganization show categorically a consistent pattern of change during anoxia, highlighting this pathway as a potential solution to low oxygen availability in this small animal with no respiratory structures or pigment.
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Li DH, Gilly WF. Hypoxia tolerance of giant axon-mediated escape jetting in California market squid ( Doryteuthis opalescens). ACTA ACUST UNITED AC 2019; 222:jeb.198812. [PMID: 30936266 DOI: 10.1242/jeb.198812] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Accepted: 03/26/2019] [Indexed: 11/20/2022]
Abstract
Squids display a wide range of swimming behaviors, including powerful escape jets mediated by the giant axon system. For California market squid (Doryteuthis opalescens), maintaining essential behaviors like the escape response during environmental variations poses a major challenge as this species often encounters intrusions of cold, hypoxic offshore waters in its coastal spawning habitats. To explore the effects of hypoxia on locomotion and the underlying neural mechanisms, we made in vivo recordings of giant axon activity and simultaneous pressure inside the mantle cavity during escape jets in squid exposed to acute progressive hypoxia followed by return to normal dissolved oxygen (DO) concentration (normoxia). Compared with those in normoxia (>8 mg l-1 DO), escape jets were unchanged in moderate hypoxia (4 and 2 mg l-1 DO), but giant axon activity and associated mantle contractions significantly decreased while neuromuscular latency increased under severe hypoxia (0.5 mg l-1 DO). Animals that survived exposure to severe hypoxia reliably produced escape jets under such conditions and fully recovered as more oxygen became available. The reduction in neuromuscular output under hypoxia suggests that market squid may suppress metabolic activity to maintain sufficient behavioral output, a common strategy in many hypoxia-tolerant species. The ability to recover from the deleterious effects of hypoxia suggests that this species is well adapted to cope with coastal hypoxic events that commonly occur in Monterey Bay, unless these events become more severe in the future as climate change progresses.
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Affiliation(s)
- Diana H Li
- Department of Biology, Hopkins Marine Station of Stanford University, 120 Ocean View Boulevard, Pacific Grove, CA 93950, USA
| | - William F Gilly
- Department of Biology, Hopkins Marine Station of Stanford University, 120 Ocean View Boulevard, Pacific Grove, CA 93950, USA
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42
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Aalto EA, Micheli F, Boch CA, Espinoza Montes JA, Woodson CB, De Leo GA. Catastrophic Mortality, Allee Effects, and Marine Protected Areas. Am Nat 2019; 193:391-408. [DOI: 10.1086/701781] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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43
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Zuercher R, Galloway AWE. Coastal marine ecosystem connectivity: pelagic ocean to kelp forest subsidies. Ecosphere 2019. [DOI: 10.1002/ecs2.2602] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Rachel Zuercher
- University of California Santa Cruz Santa Cruz California 95060 USA
| | - Aaron W. E. Galloway
- Oregon Institute of Marine Biology University of Oregon Charleston Oregon 97420 USA
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Abstract
Aquatic environments experiencing low-oxygen conditions have been described as hypoxic, suboxic, or anoxic zones; oxygen minimum zones; and, in the popular media, the misnomer "dead zones." This review aims to elucidate important aspects underlying oxygen depletion in diverse coastal systems and provides a synthesis of general relationships between hypoxia and its controlling factors. After presenting a generic overview of the first-order processes, we review system-specific characteristics for selected estuaries where adjacent human settlements contribute to high nutrient loads, river-dominated shelves that receive large inputs of fresh water and anthropogenic nutrients, and upwelling regions where a supply of nutrient-rich, low-oxygen waters generates oxygen minimum zones without direct anthropogenic influence. We propose a nondimensional number that relates the hypoxia timescale and water residence time to guide the cross-system comparison. Our analysis reveals the basic principles underlying hypoxia generation in coastal systems and provides a framework for discussing future changes.
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Affiliation(s)
- Katja Fennel
- Department of Oceanography, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada;
| | - Jeremy M Testa
- Chesapeake Biological Laboratory, University of Maryland Center for Environmental Studies, Solomons, Maryland 20688, USA;
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45
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Gómez CE, Wickes L, Deegan D, Etnoyer PJ, Cordes EE. Growth and feeding of deep-sea coral Lophelia pertusa from the California margin under simulated ocean acidification conditions. PeerJ 2018; 6:e5671. [PMID: 30280039 PMCID: PMC6164558 DOI: 10.7717/peerj.5671] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 08/30/2018] [Indexed: 01/28/2023] Open
Abstract
The global decrease in seawater pH known as ocean acidification has important ecological consequences and is an imminent threat for numerous marine organisms. Even though the deep sea is generally considered to be a stable environment, it can be dynamic and vulnerable to anthropogenic disturbances including increasing temperature, deoxygenation, ocean acidification and pollution. Lophelia pertusa is among the better-studied cold-water corals but was only recently documented along the US West Coast, growing in acidified conditions. In the present study, coral fragments were collected at ∼300 m depth along the southern California margin and kept in recirculating tanks simulating conditions normally found in the natural environment for this species. At the collection site, waters exhibited persistently low pH and aragonite saturation states (Ωarag) with average values for pH of 7.66 ± 0.01 and Ωarag of 0.81 ± 0.07. In the laboratory, fragments were grown for three weeks in "favorable" pH/Ωarag of 7.9/1.47 (aragonite saturated) and "unfavorable" pH/Ωarag of 7.6/0.84 (aragonite undersaturated) conditions. There was a highly significant treatment effect (P < 0.001) with an average% net calcification for favorable conditions of 0.023 ± 0.009% d-1 and net dissolution of -0.010 ± 0.014% d-1 for unfavorable conditions. We did not find any treatment effect on feeding rates, which suggests that corals did not depress feeding in low pH/ Ωarag in an attempt to conserve energy. However, these results suggest that the suboptimal conditions for L. pertusa from the California margin could potentially threaten the persistence of this cold-water coral with negative consequences for the future stability of this already fragile ecosystem.
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Affiliation(s)
- Carlos E Gómez
- Department of Biology, Temple University, Philadelphia, PA, United States of America
| | - Leslie Wickes
- JHT, Inc, Orlando, FL, United States of America.,Thrive Blue, LLC, Denver, CO, United States of America
| | - Dan Deegan
- Department of Biology, Temple University, Philadelphia, PA, United States of America
| | - Peter J Etnoyer
- NOAA National Center for Coastal Ocean Science, Charleston, SC, United States of America
| | - Erik E Cordes
- Department of Biology, Temple University, Philadelphia, PA, United States of America
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Fajardo M, Andrade D, Bonicelli J, Bon M, Gómez G, Riascos JM, Pacheco AS. Macrobenthic communities in a shallow normoxia to hypoxia gradient in the Humboldt upwelling ecosystem. PLoS One 2018; 13:e0200349. [PMID: 30016340 PMCID: PMC6049901 DOI: 10.1371/journal.pone.0200349] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 06/25/2018] [Indexed: 11/18/2022] Open
Abstract
Hypoxia is one of the most important stressors affecting the health conditions of coastal ecosystems. In highly productive ecosystems such as the Humboldt Current ecosystem, the oxygen minimum zone is an important abiotic factor modulating the structure of benthic communities over the continental shelf. Herein, we study soft-bottom macrobenthic communities along a depth gradient-at 10, 20, 30 and 50 m-for two years to understand how hypoxia affects the structure of shallow communities at two sites in Mejillones Bay (23°S) in northern Chile. We test the hypothesis that, during months with shallow hypoxic zones, community structure will be much more dissimilar, thereby depicting a clear structural gradient with depth and correlated abiotic variables (e.g. organic matter, temperature and salinity). Likewise, during conditions of deeper hypoxic zones, communities will be similar among habitats as they could develop structure via succession in conditions with less stress. Throughout the sampling period (October 2015 to October 2017), the water column was hypoxic (from 2 to 0.5ml/l O2) most of the time, reaching shallow depths of 20 to 10 m. Only one episode of oxygenation was detected in June 2016, where normoxia (>2ml/l O2) reached down to 50 m. The structure of the communities depicted a clear pattern of increasing dissimilarity from shallow normoxic and deep hypoxic habitat. This pattern was persistent throughout time despite the occurrence of an oxygenation episode. Contrasting species abundance and biomass distribution explained the gradient in structure, arguably reflecting variable levels of hypoxia adaptation, i.e. few polychaetes such as Magelona physilia and Paraprionospio pinnata were only located in low oxygen habitats. The multivariable dispersion of community composition as a proxy of beta diversity decreased significantly with depth, suggesting loss of community structure and variability when transitioning from normoxic to hypoxic conditions. Our results show the presence of semi-permanent shallow hypoxia at Mejillones Bay, constraining diverse and more variable communities at a very shallow depth (10-20 m). These results must be considered in the context of the current decline of dissolved oxygen in most oceans and coastal regions and their impact on seabed biota.
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Affiliation(s)
- Maritza Fajardo
- Magister en Ecología de Sistemas Acuáticos, Universidad de Antofagasta, Antofagasta, Chile
| | - Diego Andrade
- CENSOR Laboratory, Universidad de Antofagasta, Antofagasta, Chile
| | - Jessica Bonicelli
- Estación Costera de Investigaciones Marinas, Pontificia Universidad Católica de Chile, Santiago de Chile, Chile
- Departamento de Oceanografía y Medio Ambiente, Instituto de Fomento Pesquero, Valparaíso, Chile
| | - Melanie Bon
- Programa de Doctorado en Ciencias Aplicadas mención Sistemas Marinos Costeros, Universidad de Antofagasta, Antofagasta, Chile
| | - Gonzalo Gómez
- Magister en Ecología de Sistemas Acuáticos, Universidad de Antofagasta, Antofagasta, Chile
| | - José M. Riascos
- Estuaries & Mangroves Research group, Universidad del Valle, Cali, Colombia
| | - Aldo S. Pacheco
- CENSOR Laboratory, Instituto de Ciencias Naturales Alexander von Humboldt, Universidad de Antofagasta, Antofagasta, Chile
- * E-mail:
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47
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Ren AS, Chai F, Xue H, Anderson DM, Chavez FP. A Sixteen-year Decline in Dissolved Oxygen in the Central California Current. Sci Rep 2018; 8:7290. [PMID: 29740053 PMCID: PMC5940839 DOI: 10.1038/s41598-018-25341-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 04/11/2018] [Indexed: 11/13/2022] Open
Abstract
A potential consequence of climate change is global decrease in dissolved oxygen at depth in the oceans due to changes in the balance of ventilation, mixing, respiration, and photosynthesis. We present hydrographic cruise observations of declining dissolved oxygen collected along CalCOFI Line 66.7 (Line 67) off of Monterey Bay, in the Central California Current region, and investigate likely mechanisms. Between 1998 and 2013, dissolved oxygen decreased at the mean rate of 1.92 µmol kg−1 year−1 on σθ 26.6–26.8 kg m−3 isopycnals (250–400 m), translating to a 40% decline from initial concentrations. Two cores of elevated dissolved oxygen decline at 130 and 240 km from shore, which we suggest are a California Undercurrent and a California Current signal respectively, occurred on σθ ranges of 26.0–26.8 kg m−3 (100–400 m). A box model suggests that small annual changes in dissolved oxygen in source regions are sufficient to be the primary driver of the mid-depth declines. Variation in dissolved oxygen at the bottom of the surface mixed layer suggests that there is also a signal of increased local remineralization.
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Affiliation(s)
- Alice S Ren
- School of Marine Sciences, University of Maine, Orono, Maine, USA. .,Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California, USA.
| | - Fei Chai
- School of Marine Sciences, University of Maine, Orono, Maine, USA
| | - Huijie Xue
- School of Marine Sciences, University of Maine, Orono, Maine, USA
| | - David M Anderson
- Monterey Bay Aquarium Research Institute, Moss Landing, California, USA
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Chu JWF, Curkan C, Tunnicliffe V. Drivers of temporal beta diversity of a benthic community in a seasonally hypoxic fjord. ROYAL SOCIETY OPEN SCIENCE 2018; 5:172284. [PMID: 29765677 PMCID: PMC5936942 DOI: 10.1098/rsos.172284] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 03/13/2018] [Indexed: 05/03/2023]
Abstract
Global expansion of oxygen-deficient (hypoxic) waters will have detrimental effects on marine life in the Northeast Pacific Ocean (NEP) where some of the largest proportional losses in aerobic habitat are predicted to occur. However, few in situ studies have accounted for the high environmental variability in this region while including natural community-assembly dynamics. Here, we present results from a 14-month deployment of a benthic camera platform tethered to the VENUS cabled observatory in the seasonally hypoxic Saanich Inlet. Our time series continuously recorded natural cycles of deoxygenation and reoxygenation that allowed us to test whether a community from the NEP showed hysteresis in its recovery compared to hypoxia-induced decline, and to address the processes driving temporal beta diversity under variable states of hypoxia. Using high-frequency ecological time series, we reveal (i) differences in the response and recovery of the epibenthic community are rate-limited by recovery of the sessile species assemblage; (ii) both environmental and biological processes influence community assembly patterns at multiple timescales; and (iii) interspecific processes can drive temporal beta diversity in seasonal hypoxia. Ultimately, our results illustrate how different timescale-dependent drivers can influence the response and recovery of a marine habitat under increasing stress from environmental change.
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Affiliation(s)
- Jackson W. F. Chu
- Department of Biology, University of Victoria, PO Box 3080, Victoria, BC V8 W 2Y2, Canada
- Fisheries and Oceans Canada, Institute of Ocean Sciences, Sidney, BC V8 L 4B2, Canada
- Author for correspondence: Jackson W. F. Chu e-mail:
| | - Curtis Curkan
- School of Earth & Ocean Sciences, University of Victoria, PO Box 3080, Victoria, BC V8 W 2Y2, Canada
| | - Verena Tunnicliffe
- Department of Biology, University of Victoria, PO Box 3080, Victoria, BC V8 W 2Y2, Canada
- School of Earth & Ocean Sciences, University of Victoria, PO Box 3080, Victoria, BC V8 W 2Y2, Canada
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Future changes in coastal upwelling ecosystems with global warming: The case of the California Current System. Sci Rep 2018; 8:2866. [PMID: 29434297 PMCID: PMC5809506 DOI: 10.1038/s41598-018-21247-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 02/01/2018] [Indexed: 11/08/2022] Open
Abstract
Coastal upwelling ecosystems are among the most productive ecosystems in the world, meaning that their response to climate change is of critical importance. Our understanding of climate change impacts on marine ecosystems is largely limited to the open ocean, mainly because coastal upwelling is poorly reproduced by current earth system models. Here, a high-resolution model is used to examine the response of nutrients and plankton dynamics to future climate change in the California Current System (CCS). The results show increased upwelling intensity associated with stronger alongshore winds in the coastal region, and enhanced upper-ocean stratification in both the CCS and open ocean. Warming of the open ocean forces isotherms downwards, where they make contact with water masses with higher nutrient concentrations, thereby enhancing the nutrient flux to the deep source waters of the CCS. Increased winds and eddy activity further facilitate upward nutrient transport to the euphotic zone. However, the plankton community exhibits a complex and nonlinear response to increased nutrient input, as the food web dynamics tend to interact differently. This analysis highlights the difficulty in understanding how the marine ecosystem responds to a future warming climate, given to range of relevant processes operating at different scales.
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50
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Breitburg D, Levin LA, Oschlies A, Grégoire M, Chavez FP, Conley DJ, Garçon V, Gilbert D, Gutiérrez D, Isensee K, Jacinto GS, Limburg KE, Montes I, Naqvi SWA, Pitcher GC, Rabalais NN, Roman MR, Rose KA, Seibel BA, Telszewski M, Yasuhara M, Zhang J. Declining oxygen in the global ocean and coastal waters. Science 2018; 359:359/6371/eaam7240. [DOI: 10.1126/science.aam7240] [Citation(s) in RCA: 1096] [Impact Index Per Article: 182.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Oxygen is fundamental to life. Not only is it essential for the survival of individual animals, but it regulates global cycles of major nutrients and carbon. The oxygen content of the open ocean and coastal waters has been declining for at least the past half-century, largely because of human activities that have increased global temperatures and nutrients discharged to coastal waters. These changes have accelerated consumption of oxygen by microbial respiration, reduced solubility of oxygen in water, and reduced the rate of oxygen resupply from the atmosphere to the ocean interior, with a wide range of biological and ecological consequences. Further research is needed to understand and predict long-term, global- and regional-scale oxygen changes and their effects on marine and estuarine fisheries and ecosystems.
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