1
|
Korejwo E, Panasiuk A, Wawrzynek-Borejko J, Jędruch A, Bełdowski J, Paturej A, Bełdowska M. Mercury concentrations in Antarctic zooplankton with a focus on the krill species, Euphausia superba. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 905:167239. [PMID: 37742970 DOI: 10.1016/j.scitotenv.2023.167239] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 09/19/2023] [Accepted: 09/19/2023] [Indexed: 09/26/2023]
Abstract
The Antarctic is the most isolated region in the world; nevertheless, it has not avoided the negative impact of human activity, including the inflow of toxic mercury (Hg). Hg deposited in the Antarctic marine environment can be bioavailable and accumulate in the food web, reaching elevated concentrations in high-trophic-level biota, especially if methylated. Zooplankton, together with phytoplankton, are critical for the transport of pollutants, including Hg to higher trophic levels. For the Southern Ocean ecosystem, one of the key zooplankton components is the Antarctic krill Euphausia superba, the smaller euphausiid Thysanoessa macrura, and the amphipod Themisto gaudichaudii - a crucial food source for most predatory fish, birds, and mammals. The main goal of this study was to determine the Hg burden, as well as the distribution of different Hg forms, in these dominant Antarctic planktonic crustaceans. The results showed that the highest concentrations of Hg were found in T. gaudichaudii, a typically predatory taxon. Most of the Hg in the tested crustaceans was labile and potentially bioavailable for planktivorous organisms, with the most dangerous methylmercury (MeHg) accounting for an average of 16 % of the total mercury. Elevated Hg concentrations were observed close to the land, which is influenced by the proximity to penguin and pinniped colonies. In areas near the shore, volcanic activity might be a possible cause of the increase in mercury sulfide (HgS) content. The total Hg concentration increased with the trophic position and ontogenetic stage of predation, specific to adult organisms. In contrast, the proportion of MeHg decreased with age, indicating more efficient demethylation or elimination. The Hg magnification kinetics in the study area were relatively high, which may be related to climate-change induced alterations of the Antarctic ecosystem: additional food sources and reshaped trophic structure.
Collapse
Affiliation(s)
- Ewa Korejwo
- Polish Academy of Sciences, Institute of Oceanology, Department of Marine Chemistry, and Biochemistry, ul. Powstańców Warszawy 55, 81-712 Sopot, Poland.
| | - Anna Panasiuk
- University of Gdansk, Faculty of Oceanography and Geography Laboratory of Marine Plankton Biology, Division of Marine Biology and Biotechnology, Al. Piłsudskiego 46, 81-378 Gdynia, Poland
| | - Justyna Wawrzynek-Borejko
- University of Gdansk, Faculty of Oceanography and Geography, Division of Marine Ecosystems Functioning, Al. Piłsudskiego 46, 81-378 Gdynia, Poland
| | - Agnieszka Jędruch
- Polish Academy of Sciences, Institute of Oceanology, Department of Marine Chemistry, and Biochemistry, ul. Powstańców Warszawy 55, 81-712 Sopot, Poland
| | - Jacek Bełdowski
- Polish Academy of Sciences, Institute of Oceanology, Department of Marine Chemistry, and Biochemistry, ul. Powstańców Warszawy 55, 81-712 Sopot, Poland
| | - Alicja Paturej
- University of Gdansk, Faculty of Oceanography and Geography, Division of Chemical Oceanography and Marine Geology, Al. Piłsudskiego 46, 81-378 Gdynia, Poland
| | - Magdalena Bełdowska
- University of Gdansk, Faculty of Oceanography and Geography, Division of Chemical Oceanography and Marine Geology, Al. Piłsudskiego 46, 81-378 Gdynia, Poland
| |
Collapse
|
2
|
Kim J, La HS, Kim JH, Jo N, Lee J, Kim BK, Son W, Kim K, Jang HK, Park S, Yoo H, Kim J, Park J, Ahn SH, Lee SH. Spatio-temporal variations in organic carbon composition driven by two different major phytoplankton communities in the Ross Sea, Antarctica. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 891:164666. [PMID: 37286011 DOI: 10.1016/j.scitotenv.2023.164666] [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: 02/06/2023] [Revised: 05/30/2023] [Accepted: 06/02/2023] [Indexed: 06/09/2023]
Abstract
The compositions of organic carbon could be important in determining biological carbon pump efficiency. However, little information on them in relation to each algal assemblage is currently available in the Ross Sea. Here, we investigated the seasonal variations in organic carbon composition and the relative abundance of each organic carbon, including particulate organic carbon (POC), dissolved organic carbon (DOC), and transparent exopolymer particles (TEPs), characterized by different algal groups in the Ross Sea. The average POC and DOC contributions to the total organic carbon (TOC = POC + DOC) were 13.8 ± 3.7 % and 86.2 ± 3.7 % in mid-January 2019 and 20.9 ± 4.1 % and 79.1 ± 4.1 % in February-March 2018, respectively. The carbon content of TEP (TEP-C) contributed 19.6 ± 11.7 % and 4.6 ± 7.0 % of POC and TOC in mid-January and 36.2 ± 14.8 % and 9.0 ± 6.7 % in February-March, respectively. We found that the organic carbon compositions were affected by seasonal variations in the phytoplankton bloom phase, physical characteristics, and phytoplankton community structure. DOC concentrations and contributions to the TOC increased as phytoplankton cells became senescent in mid-January and decreased in February-March when phytoplankton were relatively active. From February-March, the deepened mixed layer depth encouraged TEP formation, subsequently increasing the TEP contributions. Regardless of the sampling season, all organic carbon concentrations per unit Chl-a were significantly higher in P. antarctica-abundant groups. The DOC contributions to the TOC were correspondingly higher at the P. antarctica-abundant stations in mid-January, which indicates that P. antarctica could be also important in the DOC contributions in the Ross Sea. The rapid alteration in environmental characteristics and phytoplankton community structures in the Ross Sea due to climate change could affect the organic carbon pool at the euphotic layer which consequently could determine the efficiency of the biological pump.
Collapse
Affiliation(s)
- Jaehong Kim
- Department of Oceanography, Pusan National University, Busan, South Korea
| | - Hyoung Sul La
- Division of Ocean Sciences, Korea Polar Research Institute, Incheon, South Korea
| | - Jeong-Hoon Kim
- Division of Life Sciences, Korea Polar Research Institute, Incheon, South Korea
| | - Naeun Jo
- Department of Oceanography, Pusan National University, Busan, South Korea
| | - Junbeom Lee
- Department of Oceanography, Pusan National University, Busan, South Korea
| | - Bo Kyung Kim
- Division of Ocean Sciences, Korea Polar Research Institute, Incheon, South Korea
| | - Wuju Son
- Division of Ocean Sciences, Korea Polar Research Institute, Incheon, South Korea; Department of Polar Science, University of Science and Technology, Daejeon, South Korea
| | - Kwanwoo Kim
- Department of Oceanography, Pusan National University, Busan, South Korea
| | - Hyo-Keun Jang
- Department of Oceanography, Pusan National University, Busan, South Korea
| | - Sanghoon Park
- Department of Oceanography, Pusan National University, Busan, South Korea
| | - Hyeju Yoo
- Division of Ocean Sciences, Korea Polar Research Institute, Incheon, South Korea
| | - Jaesoon Kim
- Department of Oceanography, Pusan National University, Busan, South Korea
| | - Jisoo Park
- Division of Ocean Sciences, Korea Polar Research Institute, Incheon, South Korea
| | - So Hyun Ahn
- Horn Point Laboratory, University of Maryland Center for Environmental Science, Cambridge, USA
| | - Sang Heon Lee
- Department of Oceanography, Pusan National University, Busan, South Korea.
| |
Collapse
|
3
|
Bi R, Cao Z, Ismar-Rebitz SMH, Sommer U, Zhang H, Ding Y, Zhao M. Responses of Marine Diatom-Dinoflagellate Competition to Multiple Environmental Drivers: Abundance, Elemental, and Biochemical Aspects. Front Microbiol 2021; 12:731786. [PMID: 34526982 PMCID: PMC8435848 DOI: 10.3389/fmicb.2021.731786] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 08/09/2021] [Indexed: 11/13/2022] Open
Abstract
Ocean-related global change has strongly affected the competition between key marine phytoplankton groups, such as diatoms and dinoflagellates, especially with the deleterious consequency of the increasing occurrence of harmful algal blooms. The dominance of diatoms generally shifts toward that of dinoflagellates in response to increasing temperature and reduced nutrient availability; however, contradictory findings have also been observed in certain sea areas. A key challenge in ecology and biogeochemistry is to quantitatively determine the effects of multiple environmental factors on the diatom-dinoflagellate community and the related changes in elemental and biochemical composition. Here, we test the interplay between temperature, nutrient concentrations and their ratios on marine diatom-dinoflagellate competition and chemical composition using bi-algal competition experiments. The ubiquitous diatom Phaeodactylum tricornutum and dinoflagellate Prorocentrum minimum were cultivated semi-continuously, provided with different N and P concentrations (three different levels) and ratios (10:1, 24:1, and 63:1 molar ratios) under three temperatures (12, 18, and 24°C). The responses of diatom-dinoflagellate competition were analyzed by a Lotka-Volterra model and quantified by generalized linear mixed models (GLMMs) and generalized additive models (GAMs). The changes in nutrient concentrations significantly affected diatom-dinoflagellate competition, causing a competitive superiority of the diatoms at high nutrient concentrations, independent of temperature and N:P supply ratios. Interestingly, the effect amplitude of nutrient concentrations varied with different temperatures, showing a switch back toward a competitive superiority of the dinoflagellates at the highest temperature and at very high nutrient concentrations. The ratios of particulate organic nitrogen to phosphorus showed significant negative correlations with increasing diatoms/dinoflagellates ratios, while lipid biomarkers (fatty acids and sterols) correlated positively with increasing diatoms/dinoflagellates ratios over the entire ranges of temperature, N and P concentrations and N:P ratios. Our results indicate that the integration of phytoplankton community structure and chemical composition provides an important step forward to quantitatively understand and predict how phytoplankton community changes affect ecosystem functions and biogeochemical cycles in the ocean.
Collapse
Affiliation(s)
- Rong Bi
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, and Key Laboratory of Marine Chemistry Theory and Technology, Ocean University of China, Ministry of Education, Qingdao, China
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Zhong Cao
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, and Key Laboratory of Marine Chemistry Theory and Technology, Ocean University of China, Ministry of Education, Qingdao, China
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | | | - Ulrich Sommer
- Marine Ecology, GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
| | - Hailong Zhang
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, and Key Laboratory of Marine Chemistry Theory and Technology, Ocean University of China, Ministry of Education, Qingdao, China
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Yang Ding
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, and Key Laboratory of Marine Chemistry Theory and Technology, Ocean University of China, Ministry of Education, Qingdao, China
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Meixun Zhao
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, and Key Laboratory of Marine Chemistry Theory and Technology, Ocean University of China, Ministry of Education, Qingdao, China
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| |
Collapse
|
4
|
Seasonal Variations in the Biochemical Compositions of Phytoplankton and Transparent Exopolymer Particles (TEPs) at Jang Bogo Station (Terra Nova Bay, Ross Sea), 2017–2018. WATER 2021. [DOI: 10.3390/w13162173] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The biochemical composition of particulate organic matter (POM) mainly originates from phytoplankton. Transparent exopolymer particles (TEPs) depend on environmental conditions and play a role in the food web and biogeochemical cycle in marine ecosystems. However, little information on their characteristics in the Southern Ocean is available, particularly in winter. To investigate the seasonal characteristics of POM and TEPSs, seawater samples were collected once every two weeks from November 2017 to October 2018 at Jang Bogo Station (JBS) located on the coast of Terra Nova Bay in the Ross Sea. The total chlorophyll-a (Chl-a) concentrations increased from spring (0.08 ± 0.06 μg L−1) to summer (0.97 ± 0.95 μg L−1) with a highest Chl-a value of 2.15 μg L−1. After sea ice formation, Chl-a rapidly decreased in autumn (0.12 ± 0.10 μg L−1) and winter (0.01 ± 0.01 μg L−1). The low phytoplankton Chl-a measured in this study was related to a short ice-free period in summer. Strong seasonal variations were detected in the concentrations of proteins and lipids (one-way ANOVA test, p < 0.05), whereas no significant difference in carbohydrate concentrations was observed among different seasons (one-way ANOVA test, p > 0.05). The phytoplankton community was mostly composed of diatoms (88.8% ± 11.6%) with a large accumulation of lipids. During the summer, the POM primarily consisted of proteins. The composition being high in lipids and proteins and the high caloric content in summer indicated that the phytoplankton would make a good food source. In winter, the concentrations of proteins decreased sharply. In contrast, relatively stable concentrations of carbohydrates and lipids have been utilized for respiration and long-term energy storage in the survival of phytoplankton. The TEPS values were significantly correlated with variations in the biomass and species of the phytoplankton. Our study site was characterized by dominant diatoms and low Chl-a concentrations, which could have resulted in relatively low TEP concentrations compared to other areas. The average contributions of TEP-C to the total POC were relatively high in autumn (26.9% ± 6.1%), followed by those in summer (21.9% ± 7.1%), winter (13.0% ± 4.2%), and spring (9.8% ± 3.1%).
Collapse
|