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Aeman H, Shu H, Aisha H, Nadeem I, Aslam RW. Quantifying the scale of erosion along major coastal aquifers of Pakistan using geospatial and machine learning approaches. Environ Sci Pollut Res Int 2024:10.1007/s11356-024-33296-9. [PMID: 38662291 DOI: 10.1007/s11356-024-33296-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2023] [Accepted: 04/08/2024] [Indexed: 04/26/2024]
Abstract
Insufficient freshwater recharge and climate change resulted in seawater intrusion in most of the coastal aquifers in Pakistan. Coastal aquifers represent diverse landcover types with varying spectral properties, making it challenging to extract information about their state hence, such investigation requires a combination of geospatial tools. This study aims to monitor erosion along the major coastal aquifers of Pakistan and propose an approach that combines data fusion into the machine and deep learning image segmentation architectures for the erosion and accretion assessment in seascapes. The analysis demonstrated the image segmentation U-Net with EfficientNet backbone achieved the highest F1 score of 0.93, while ResNet101 achieved the lowest F1 score of 0.77. Resultant erosion maps indicated that Sandspit experiencing erosion at 3.14 km2 area. Indus delta is showing erosion, approximately 143 km2 of land over the past 30 years. Sonmiani has undergone substantial erosion with 52.2 km2 land. Miani Hor has experienced erosion up to 298 km2, Bhuri creek has eroded over 4.11 km2, east Phitii creek over 3.30 km2, and Waddi creek over 3.082 km2 land. Tummi creek demonstrates erosion, at 7.12 km2 of land, and East Khalri creek near Keti Bandar has undergone a measured loss of 5.2 km2 land linked with quantified reduction in the vertical sediment flow from 50 (billion cubic meters) to 10 BCM. Our analysis suggests that intense erosions are primarily a result of reduced sediment flow and climate change. Addressing this issue needs to be prioritized coastal management and climate change mitigation framework in Pakistan to safeguard communities. Leveraging emerging solutions, such as loss and damage financing and the integration of nature-based solutions (NbS), should be prioritized for the revival of the coastal aquifers.
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Affiliation(s)
- Hafsa Aeman
- State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University, Wuhan, China.
| | - Hong Shu
- State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University, Wuhan, China
| | - Hamera Aisha
- World Wildlife Fund for Nature (WWF), Lahore, Pakistan
| | - Imran Nadeem
- Institute of Meteorology and Climatology, Department of Water, Atmosphere and Environment, University of Natural Resources and Life Sciences (BOKU), Vienna, Austria
| | - Rana Waqar Aslam
- State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University, Wuhan, China
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2
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Jezycki KE, Rodriguez E, Craft CB, Neubauer SC, Morris JT, Goldsmith ST, Kremer P, Weston NB. Metal accumulation in salt marsh soils along the East Coast of the United States. Sci Total Environ 2024; 922:171025. [PMID: 38387593 DOI: 10.1016/j.scitotenv.2024.171025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2023] [Revised: 02/13/2024] [Accepted: 02/14/2024] [Indexed: 02/24/2024]
Abstract
Coastal salt marshes are depositional environments that can accumulate pollutants introduced to the environment from human activities. Metals are a contaminant of concern in coastal environments due to their longevity and toxicity. We assessed metal concentrations and accumulation rates in nine salt marsh sites along the U.S. East Coast from Maine to Georgia. Following a metal mobility assay in organic-rich and mineral dominated salt marsh soils under aerobic/anaerobic and freshwater/saltwater conditions, we focused on profiles of chromium, nickel, copper, zinc, cadmium, lead, and uranium in two soil cores from each of the nine marshes that had previously been dated using lead-210 radioisotope techniques. We examined how land cover and the spatial distribution of land cover, marsh vertical accretion, and other watershed characteristics correlated with metal concentrations and depth/time-integrated accumulation of metals. We found statistically significant differences in metal concentrations and/or inventories between sites, with accumulation of metals positively correlated with both developed land cover in the watershed and rates of vertical accretion in the tidal marsh. The accumulation of chromium, cadmium, and lead were significantly correlated with developed land cover while the accumulation of chromium, nickel, copper, zinc, and lead were correlated with factors that determine sediment delivery from the landscape (e.g., riverine suspended sediment, soil erodibility in the watershed, and agricultural land cover skewed towards the coast) and measured wetland accretion rates. We observed declines in the concentration of many metals since 1925 at sites along the U.S. East Coast, indicating pollution mitigation strategies have succeeded in reducing metal pollution and delivery to the coastal zone. However, increasing rates of salt marsh vertical accretion over recent decades largely offset reductions in metal concentrations, resulting in rates of metal accumulation in coastal salt marsh soils that have not changed or, in some instances, increased over time.
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Affiliation(s)
- Kristen E Jezycki
- Department of Geography and the Environment, Villanova University, Villanova, PA, USA
| | - Elise Rodriguez
- Department of Geography and the Environment, Villanova University, Villanova, PA, USA
| | - Christopher B Craft
- O'Neill School of Public and Environmental Affairs, Indiana University, Bloomington, IN, USA
| | - Scott C Neubauer
- Department of Biology, Virginia Commonwealth University, Richmond, VA, USA
| | - James T Morris
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
| | - Steven T Goldsmith
- Department of Geography and the Environment, Villanova University, Villanova, PA, USA
| | - Peleg Kremer
- Department of Geography and the Environment, Villanova University, Villanova, PA, USA
| | - Nathaniel B Weston
- Department of Geography and the Environment, Villanova University, Villanova, PA, USA.
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3
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Bansal S, Creed IF, Tangen BA, Bridgham SD, Desai AR, Krauss KW, Neubauer SC, Noe GB, Rosenberry DO, Trettin C, Wickland KP, Allen ST, Arias-Ortiz A, Armitage AR, Baldocchi D, Banerjee K, Bastviken D, Berg P, Bogard MJ, Chow AT, Conner WH, Craft C, Creamer C, DelSontro T, Duberstein JA, Eagle M, Fennessy MS, Finkelstein SA, Göckede M, Grunwald S, Halabisky M, Herbert E, Jahangir MMR, Johnson OF, Jones MC, Kelleway JJ, Knox S, Kroeger KD, Kuehn KA, Lobb D, Loder AL, Ma S, Maher DT, McNicol G, Meier J, Middleton BA, Mills C, Mistry P, Mitra A, Mobilian C, Nahlik AM, Newman S, O’Connell JL, Oikawa P, van der Burg MP, Schutte CA, Song C, Stagg CL, Turner J, Vargas R, Waldrop MP, Wallin MB, Wang ZA, Ward EJ, Willard DA, Yarwood S, Zhu X. Practical Guide to Measuring Wetland Carbon Pools and Fluxes. Wetlands (Wilmington) 2023; 43:105. [PMID: 38037553 PMCID: PMC10684704 DOI: 10.1007/s13157-023-01722-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 07/24/2023] [Indexed: 12/02/2023]
Abstract
Wetlands cover a small portion of the world, but have disproportionate influence on global carbon (C) sequestration, carbon dioxide and methane emissions, and aquatic C fluxes. However, the underlying biogeochemical processes that affect wetland C pools and fluxes are complex and dynamic, making measurements of wetland C challenging. Over decades of research, many observational, experimental, and analytical approaches have been developed to understand and quantify pools and fluxes of wetland C. Sampling approaches range in their representation of wetland C from short to long timeframes and local to landscape spatial scales. This review summarizes common and cutting-edge methodological approaches for quantifying wetland C pools and fluxes. We first define each of the major C pools and fluxes and provide rationale for their importance to wetland C dynamics. For each approach, we clarify what component of wetland C is measured and its spatial and temporal representativeness and constraints. We describe practical considerations for each approach, such as where and when an approach is typically used, who can conduct the measurements (expertise, training requirements), and how approaches are conducted, including considerations on equipment complexity and costs. Finally, we review key covariates and ancillary measurements that enhance the interpretation of findings and facilitate model development. The protocols that we describe to measure soil, water, vegetation, and gases are also relevant for related disciplines such as ecology. Improved quality and consistency of data collection and reporting across studies will help reduce global uncertainties and develop management strategies to use wetlands as nature-based climate solutions. Supplementary Information The online version contains supplementary material available at 10.1007/s13157-023-01722-2.
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Affiliation(s)
- Sheel Bansal
- U.S. Geological Survey, Northern Prairie Wildlife Research Center, Jamestown, ND USA
| | - Irena F. Creed
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, ON Canada
| | - Brian A. Tangen
- U.S. Geological Survey, Northern Prairie Wildlife Research Center, Jamestown, ND USA
| | - Scott D. Bridgham
- Institute of Ecology and Evolution, University of Oregon, Eugene, OR USA
| | - Ankur R. Desai
- Department of Atmospheric and Oceanic Sciences, University of Wisconsin-Madison, Madison, WI USA
| | - Ken W. Krauss
- U.S. Geological Survey, Wetland and Aquatic Research Center, Lafayette, LA USA
| | - Scott C. Neubauer
- Department of Biology, Virginia Commonwealth University, Richmond, VA USA
| | - Gregory B. Noe
- U.S. Geological Survey, Florence Bascom Geoscience Center, Reston, VA USA
| | | | - Carl Trettin
- U.S. Forest Service, Pacific Southwest Research Station, Davis, CA USA
| | - Kimberly P. Wickland
- U.S. Geological Survey, Geosciences and Environmental Change Science Center, Denver, CO USA
| | - Scott T. Allen
- Department of Natural Resources and Environmental Science, University of Nevada, Reno, Reno, NV USA
| | - Ariane Arias-Ortiz
- Ecosystem Science Division, Department of Environmental Science, Policy and Management, University of California, Berkeley, CA USA
| | - Anna R. Armitage
- Department of Marine Biology, Texas A&M University at Galveston, Galveston, TX USA
| | - Dennis Baldocchi
- Department of Environmental Science, Policy and Management, University of California, Berkeley, CA USA
| | - Kakoli Banerjee
- Department of Biodiversity and Conservation of Natural Resources, Central University of Odisha, Koraput, Odisha India
| | - David Bastviken
- Department of Thematic Studies – Environmental Change, Linköping University, Linköping, Sweden
| | - Peter Berg
- Department of Environmental Sciences, University of Virginia, Charlottesville, VA USA
| | - Matthew J. Bogard
- Department of Biological Sciences, University of Lethbridge, Lethbridge, AB Canada
| | - Alex T. Chow
- Earth and Environmental Sciences Programme, The Chinese University of Hong Kong, Shatin, Hong Kong SAR China
| | - William H. Conner
- Baruch Institute of Coastal Ecology and Forest Science, Clemson University, Georgetown, SC USA
| | - Christopher Craft
- O’Neill School of Public and Environmental Affairs, Indiana University, Bloomington, IN USA
| | - Courtney Creamer
- U.S. Geological Survey, Geology, Minerals, Energy and Geophysics Science Center, Menlo Park, CA USA
| | - Tonya DelSontro
- Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, ON Canada
| | - Jamie A. Duberstein
- Baruch Institute of Coastal Ecology and Forest Science, Clemson University, Georgetown, SC USA
| | - Meagan Eagle
- U.S. Geological Survey, Woods Hole Coastal & Marine Science Center, Woods Hole, MA USA
| | | | | | - Mathias Göckede
- Department for Biogeochemical Signals, Max Planck Institute for Biogeochemistry, Jena, Germany
| | - Sabine Grunwald
- Soil, Water and Ecosystem Sciences Department, University of Florida, Gainesville, FL USA
| | - Meghan Halabisky
- School of Environmental and Forest Sciences, University of Washington, Seattle, WA USA
| | | | | | - Olivia F. Johnson
- U.S. Geological Survey, Northern Prairie Wildlife Research Center, Jamestown, ND USA
- Departments of Biology and Environmental Studies, Kent State University, Kent, OH USA
| | - Miriam C. Jones
- U.S. Geological Survey, Florence Bascom Geoscience Center, Reston, VA USA
| | - Jeffrey J. Kelleway
- School of Earth, Atmospheric and Life Sciences and Environmental Futures Research Centre, University of Wollongong, Wollongong, NSW Australia
| | - Sara Knox
- Department of Geography, McGill University, Montreal, Canada
| | - Kevin D. Kroeger
- U.S. Geological Survey, Woods Hole Coastal & Marine Science Center, Woods Hole, MA USA
| | - Kevin A. Kuehn
- School of Biological, Environmental, and Earth Sciences, University of Southern Mississippi, Hattiesburg, MS USA
| | - David Lobb
- Department of Soil Science, University of Manitoba, Winnipeg, MB Canada
| | - Amanda L. Loder
- Department of Geography, University of Toronto, Toronto, ON Canada
| | - Shizhou Ma
- School of Environment and Sustainability, University of Saskatchewan, Saskatoon, SK Canada
| | - Damien T. Maher
- Faculty of Science and Engineering, Southern Cross University, Lismore, NSW Australia
| | - Gavin McNicol
- Department of Earth and Environmental Sciences, University of Illinois Chicago, Chicago, IL USA
| | - Jacob Meier
- U.S. Geological Survey, Northern Prairie Wildlife Research Center, Jamestown, ND USA
| | - Beth A. Middleton
- U.S. Geological Survey, Wetland and Aquatic Research Center, Lafayette, LA USA
| | - Christopher Mills
- U.S. Geological Survey, Geology, Geophysics, and Geochemistry Science Center, Denver, CO USA
| | - Purbasha Mistry
- School of Environment and Sustainability, University of Saskatchewan, Saskatoon, SK Canada
| | - Abhijit Mitra
- Department of Marine Science, University of Calcutta, Kolkata, West Bengal India
| | - Courtney Mobilian
- O’Neill School of Public and Environmental Affairs, Indiana University, Bloomington, IN USA
| | - Amanda M. Nahlik
- Office of Research and Development, Center for Public Health and Environmental Assessments, Pacific Ecological Systems Division, U.S. Environmental Protection Agency, Corvallis, OR USA
| | - Sue Newman
- South Florida Water Management District, Everglades Systems Assessment Section, West Palm Beach, FL USA
| | - Jessica L. O’Connell
- Department of Ecosystem Science and Sustainability, Colorado State University, Fort Collins, CO USA
| | - Patty Oikawa
- Department of Earth and Environmental Sciences, California State University, East Bay, Hayward, CA USA
| | - Max Post van der Burg
- U.S. Geological Survey, Northern Prairie Wildlife Research Center, Jamestown, ND USA
| | - Charles A. Schutte
- Department of Environmental Science, Rowan University, Glassboro, NJ USA
| | - Changchun Song
- Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, China
| | - Camille L. Stagg
- U.S. Geological Survey, Wetland and Aquatic Research Center, Lafayette, LA USA
| | - Jessica Turner
- Freshwater and Marine Science, University of Wisconsin-Madison, Madison, WI USA
| | - Rodrigo Vargas
- Department of Plant and Soil Sciences, University of Delaware, Newark, DE USA
| | - Mark P. Waldrop
- U.S. Geological Survey, Geology, Minerals, Energy and Geophysics Science Center, Menlo Park, CA USA
| | - Marcus B. Wallin
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Zhaohui Aleck Wang
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA USA
| | - Eric J. Ward
- U.S. Geological Survey, Wetland and Aquatic Research Center, Lafayette, LA USA
| | - Debra A. Willard
- U.S. Geological Survey, Florence Bascom Geoscience Center, Reston, VA USA
| | - Stephanie Yarwood
- Environmental Science and Technology, University of Maryland, College Park, MD USA
| | - Xiaoyan Zhu
- Key Laboratory of Songliao Aquatic Environment, Ministry of Education, Jilin Jianzhu University, Changchun, China
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Aeman H, Shu H, Abbas S, Aisha H, Usman M. Sinking delta: Quantifying the impacts of saltwater intrusion in the Indus Delta of Pakistan. Sci Total Environ 2023; 880:163356. [PMID: 37030381 DOI: 10.1016/j.scitotenv.2023.163356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 04/03/2023] [Accepted: 04/03/2023] [Indexed: 05/27/2023]
Abstract
This study focused on an integrated assessment of coastline change and its impacts on the deltaic sustainability of the Indus Delta, the world's fifth-largest delta. The increase in salinity and degradation of mangrove habitat was examined using multi-temporal Landsat satellite imagery from 1990 to 2020. The tasselled cap transformation indices, multi-statistical End Point Rate and Linear Regression were used to extract the shorelines rates. Mangrove cover area was estimated by applying the Random Forest clasification approach. Impacts of coastal erosion on mangroves and sea-water salinity were determined through the association between electrical conductivity and vegetation soil salinity index (VSSI). The accuracy of the analysis was evaluated using ground truth information obtained from field surveys and Fixed-Point Photography. Major findings of the analysis indicate that the North-West Karachi experienced accretion at an average rate of 7.28 ± 1.15 m/year, with medium salinity (VSSI<0.81) and increased mangrove cover, from 11.0 km2 area in 1990 to 14.5 km2 in 2020. However, the Western Delta has undergone massive erosion at a mean rate of -10.09 ± 1.61 m/year with obtrusive salinity (0.7 ≤ VSSI ≤ 1.2) and 70 km2 of mangrove cover loss. In the Middle West Delta and Middle East Delta erosion is observed at an average rate of -28.45 ± 0.55 m/year rate, with high obtrusive salinity (0.43 ≤ VSSI ≥ 1.32) and rapid mangroves cover loss (14 km2). The Eastern Delta was relatively stable and accelerating towards the sea with increasing mangrove cover (629 km2). Our analysis revealed that erosion, which occured due to reduced sediments flow linked to development of water infrastructures as well as climate change, have serious implications for the ecosystem. Future policy and action-plans should priotitise addressing vulnerabilities by integrate nature-based solutions for revival of the Delta.
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Affiliation(s)
- Hafsa Aeman
- State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University, China.
| | - Hong Shu
- State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University, China
| | - Sawaid Abbas
- Smart Sensing for Climate and Development, Center for Geographical Information System, University of the Punjab, Lahore 54590, Pakistan; Department of Land Surveying and Geo-Informatics, The Hong Kong Polytechnic University, Hong Kong
| | - Hamera Aisha
- World Wide Fund for Nature - Pakistan (WWF-Pakistan), Pakistan
| | - Muhammad Usman
- Smart Sensing for Climate and Development, Center for Geographical Information System, University of the Punjab, Lahore 54590, Pakistan
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Thomas GAJ, Santha Ravindranath RR, Jeyagopal S, Thodhal Yoganandham S. Statistical analysis of shoreline change reveals erosion and baseline are increasing off the northern Tamil Nadu Coasts of India. Environ Monit Assess 2023; 195:409. [PMID: 36800075 DOI: 10.1007/s10661-023-11015-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Accepted: 02/09/2023] [Indexed: 06/18/2023]
Abstract
Many tourists have been recently attracted towards the coasts around the world, especially to the large urban centres and economically significant areas. In the last four decades, there is a significant increase in the key coastal developments and tourist's attractions like major ports, minor ports, fishing harbours, desalination plants, shore protection structures, and many more along the southeast coasts of India, in particular, northern Tami Nadu coastal stretches. The shoreline change study of these regions were carried out using the geospatial technologies (satellite remote sensing and geographical information system) to examine potential modifications occurred during the last 32 years between March 1990 and May 2022. This study used Landsat satellite images of spatial resolution 30 m to track the shoreline changes which was extracted using the Digital Image Processing software and techniques. In addition, the United States Geological Survey (USGS) developed Digital Shoreline Analysis System (DSAS) v5.2 software, an add-on tool to ArcGIS used for the statistical analysis to compute the shoreline rate of change. The linear regression rate (LRR) and end point rate (EPR) statistics were used to identify the eroding, accreting, and stable shoreline between Kattupalli coast and Kalpakkam coast of the northern Tamil Nadu coasts. This shoreline study of 106 km was carried out by dividing it into six zones (zone 1 to zone 6), and the DSAS analysis conveys that the shoreline of zone 1 (Kattupalli) and zone 2 (Ennore) shows erosion compared to other four zones. In locations where the coast is vulnerable, national mitigation measures must be implemented.
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Affiliation(s)
- German Amali Jacintha Thomas
- Centre for Remote Sensing and Geo-informatics, Sathyabama Institute of Science and Technology, Chennai, Tamil Nadu, India
- Centre for Ocean Research, Sathyabama Institute of Science and Technology, Chennai, Tamil Nadu, India
| | - Radhika Rajasree Santha Ravindranath
- Centre for Ocean Research, Sathyabama Institute of Science and Technology, Chennai, Tamil Nadu, India
- Faculty of Fisheries, Kerala University of Fisheries and Ocean Studies, Cochin, Kerala, India
| | - Sriganesh Jeyagopal
- National Technology Centre for Ports, Waterways and Coasts, Indian Institute of Technology Madras, Chennai, Tamil Nadu, India
| | - Suman Thodhal Yoganandham
- Centre for Ocean Research, Sathyabama Institute of Science and Technology, Chennai, Tamil Nadu, India.
- Department of Environmental Engineering, Changwon National University, Changwon, Gyeongsangnamdo, Republic of Korea.
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Mishra M, Acharyya T, Chand P, Santos CAG, Silva RMD, Santos CACD, Pradhan S, Kar D. Response of long- to short-term tidal inlet morphodynamics on the ecological ramification of Chilika lake, the tropical Ramsar wetland in India. Sci Total Environ 2022; 807:150769. [PMID: 34624284 DOI: 10.1016/j.scitotenv.2021.150769] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 09/29/2021] [Accepted: 09/30/2021] [Indexed: 06/13/2023]
Abstract
The long- to short-term morphodynamic response in low-lying coastal wetlands raises serious concerns worldwide about the loss of their biodiversity and ecological ramifications due to change in tidal amplitude and cyclonic events. One such place worth studying is Chilika lake, India, a prominent Ramsar site, the largest brackish water lagoon in Asia, and the second-largest coastal lagoon in the world. It experiences frequent cyclone landfalls and strong littoral drift that tends to open/close the tidal inlet. The goal of this study was to analyze the response of slow onset events such as long- (1952-2020) to short-term (~annual scale from 1989 to 2020) tidal inlet movement, shoreline change (1990-2020 with almost every five-year interval), spit morphodynamics (~annual scale from 1989 to 2020) on ecological ramification in Chilika lake as well as the implications of sudden onset event such as cyclonic landfall. In this study, we used the Digital Shoreline Change Analysis System (DSAS) to compute the statistics of shoreline change rate by calculating end point rate (EPR) values for short-term shoreline change (1990, 1995, 2000, 2005, 2011, 2016, and 2020) and weighted linear regression (WLR) for long-term shoreline change (1990-2020). The results show that Chilika lake experienced both erosion and accretion processes with a remarkably high erosion rate of 19.87 m year-1 and accretion of 16.91 m year-1 during a long-term scale (1990-2020). The average erosion and accretion rates were 2.25 m year-1 and 4.67 m year-1, respectively, during the past three decades (1990-2020). The short-term analysis suggests that the highest mean erosion of 4.37 m year-1 occurred during 2005-2011, mainly due to cyclonic storms, reduction in sediment discharge, and lunar eclipse, which induced tide with very high amplitude in August 2008. Overall, the annual scale analysis of tidal inlet shows a shifting trend towards the northward side even after the artificial opening of an inlet in 2000. It can be ascribed mainly to the prevalent direction of longshore drift along this coast. This study observed that the landfall of cyclones significantly affects the spit morphodynamics and opening of the tidal inlet, which defines the inflow of the seawater into the lagoon and further substantial impacts on the ecological ramification. The current study's methodology can be extended to comprehend the response of long- to short-term changes of the tidal inlet, shoreline, and spit morphodynamics on the ecological ramification of coastal lagoons worldwide along with impacts of sudden-onset events caused by cyclonic landfall.
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Affiliation(s)
- Manoranjan Mishra
- Department of Natural Resources Management and Geo-informatics, Berhampur University, 760007 Berhampur, Odisha, India
| | | | - Pritam Chand
- Department of Geography, School of Environment and Earth Sciences, Central University of Punjab, VPO-Ghudda, 151401 Bathinda, Punjab, India
| | | | | | | | - Subhasis Pradhan
- Project Scientist, SAC-CDA Project, Chilika Development Authority, Palashpalli, Bhubaneswar, 751020 Odisha, India
| | - Dipika Kar
- Department of Natural Resources Management and Geo-informatics, Berhampur University, 760007 Berhampur, Odisha, India
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Mishra M, Kar D, Santos CAG, Silva RMD, Das PP. Assessment of impacts to the sequence of the tropical cyclone Nisarga and monsoon events in shoreline changes and vegetation damage in the coastal zone of Maharashtra, India. Mar Pollut Bull 2022; 174:113262. [PMID: 34968828 DOI: 10.1016/j.marpolbul.2021.113262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 12/10/2021] [Accepted: 12/12/2021] [Indexed: 06/14/2023]
Abstract
The tropical cyclones impact both the eastern and western coasts of India, causing severe socio-environmental problems. This study analyzed shoreline changes and vegetation degradation caused by cyclone Nisarga and monsoon events in Maharashtra coastal zone and Mumbai region, India. In this study, the shoreline change was studied using the Net Shoreline Movement (NSM) statistical technique embedded in the digital shoreline analysis system (DSAS) tool. The effects of the cyclone on the vegetation were mapped using the Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), and the rainfall distribution from Global Precipitation Measurement (GPM) data. The correlation between rainfall data and vegetation loss was analyzed using geographically weighted regression. The results also show that 90% of the events were concentrated in the 80-300 mm classes, being classified as sudden increases. This cyclone caused erosion in 56.32% of the shoreline; the highest erosion level was observed along the coastal zone of Maharashtra (near Mumbai city). Cyclone Nisarga has also impacted the vegetation loss most prominently in the region, with mean EVI in pre-cyclone equal to 0.4 and post-cyclone equal to 0.2. These eco-physical studies using geospatial technology are needed to understand the behavior of changes in shoreline and vegetation and can also help coastal managers plan for resilient coastal systems after the passage of tropical cyclones.
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Affiliation(s)
- Manoranjan Mishra
- Department of Natural Resource Management & Geoinformatics, Berhampur University, India
| | - Dipika Kar
- Department of Natural Resource Management & Geoinformatics, Berhampur University, India
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Rayner D, Glamore W, Grandquist L, Ruprecht J, Waddington K, Khojasteh D. Intertidal wetland vegetation dynamics under rising sea levels. Sci Total Environ 2021; 766:144237. [PMID: 33421788 DOI: 10.1016/j.scitotenv.2020.144237] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 10/29/2020] [Accepted: 11/23/2020] [Indexed: 06/12/2023]
Abstract
Intertidal wetlands have historically been in decline and are increasingly at risk due to climate change, particularly sea level rise (SLR). Different intertidal wetland communities can adapt to SLR via lateral upslope retreat to higher ground, capture and accumulation of allochthonous sediment, and/or organic accretion. In this paper, a case study is presented to assess the impact of the overall sediment accretion rate (i.e. allochthonous and organic accumulation) versus possible SLR rates on wetland species composition. Initially, an eco-hydraulic calculation method is developed to estimate existing spatial and temporal tidal inundation statistics of saltmarsh species at a Ramsar listed wetland on the south-east coast of New South Wales, Australia. SLR and accretion scenarios were then tested using high resolution hydrodynamic models to predict future saltmarsh species composition based on the eco-hydraulic calculation method. Saltmarsh species composition and extents were found to persist if sea levels continue to rise at present-day rates, as observed rates of SLR are similar. However, if the SLR rate accelerates beyond the accretion ability of the wetland, a significant shift in species composition and an increase in open water coverage was predicted. These results indicate that the current rate of sediment capture by wetland species, and the subsequent rate of elevation change, will need to increase significantly to adapt with projected future rates of SLR.
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Affiliation(s)
- Duncan Rayner
- Water Research Laboratory, School of Civil and Environmental Engineering, UNSW Sydney, NSW, Australia.
| | - William Glamore
- Water Research Laboratory, School of Civil and Environmental Engineering, UNSW Sydney, NSW, Australia.
| | - Lisa Grandquist
- Advisian, 141 Walker Street, North Sydney, NSW 2060, Australia
| | - Jamie Ruprecht
- Water Research Laboratory, School of Civil and Environmental Engineering, UNSW Sydney, NSW, Australia.
| | - Katrina Waddington
- Water Research Laboratory, School of Civil and Environmental Engineering, UNSW Sydney, NSW, Australia.
| | - Danial Khojasteh
- Water Research Laboratory, School of Civil and Environmental Engineering, UNSW Sydney, NSW, Australia.
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9
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Mehdi B, Schürz C, Grath B, Schulz K. Storm event impacts on in-stream nitrate concentration and discharge dynamics: A comparison of high resolution in-situ measured data with model simulations. Sci Total Environ 2021; 755:143406. [PMID: 33203562 DOI: 10.1016/j.scitotenv.2020.143406] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 10/12/2020] [Accepted: 10/23/2020] [Indexed: 06/11/2023]
Abstract
The relationship between nitrogen and discharge (N-Q) in a stream can be captured with high frequency nitrate nitrogen (NO3--N) samplers. In Austria, the Raab catchment (998 km2) has high frequency NO3--N data measured with a spectrometer probe. This study evaluated if the widely-used and typically calibrated eco-hydrological model Soil and Water Assessment Tool (SWAT) can reproduce the hysteresis loop direction and the dilution or accretion effects of NO3--N dynamics during storm events in this agricultural catchment. The daily aggregated NO3--N measurements were compared with the daily SWAT simulated discharge and NO3--N concentrations of 14 storm events by computing hysteresis indices - loop direction and area (h index), loop direction (HInew) and solute gradient (∆C). Overall, the SWAT model was able to replicate the predominant anticlockwise hysteresis and dilution effect of NO3--N in the Raab catchment. The loop direction was simulated correctly in 9 and 10 events, for the h and HInew indices, respectively. The hysteresis direction inferred from both indices did not always concur due to the differences in the calculation methods. The dilution or accretion effect was simulated correctly in 9 of the events. However, the SWAT model only correctly simulated the N-Q relationships for all three hysteresis criteria in 5 of the 14 events. Due to the aggregation of measured data to the daily time step, information pertaining to the hysteresis shape was sometimes lost, particularly if the storm event was <4 days in duration. Structural limitations of the SWAT as well as specific relevant basin parameters (parameters that have one value for the entire catchment) may restrict simulating N-Q dynamics. An enhanced calibrated and validated model would possibly improve the results, since the events during the better calibrated period more often reproduced the measured hysteresis indices.
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Affiliation(s)
- Bano Mehdi
- University of Natural Resources & Life Sciences, Vienna (BOKU), Department of Water-Atmosphere-Environment, Institute for Hydrology and Water Management, Muthgasse 18, 1190 Vienna, Austria; University of Natural Resources & Life Sciences, Vienna (BOKU), Department of Crop Sciences, Institute of Agronomy, Konrad-Lorenz Str. 24, 3430 Tulln, Austria.
| | - Christoph Schürz
- University of Natural Resources & Life Sciences, Vienna (BOKU), Department of Water-Atmosphere-Environment, Institute for Hydrology and Water Management, Muthgasse 18, 1190 Vienna, Austria
| | - Benedikt Grath
- University of Natural Resources & Life Sciences, Vienna (BOKU), Department of Water-Atmosphere-Environment, Institute for Hydrology and Water Management, Muthgasse 18, 1190 Vienna, Austria
| | - Karsten Schulz
- University of Natural Resources & Life Sciences, Vienna (BOKU), Department of Water-Atmosphere-Environment, Institute for Hydrology and Water Management, Muthgasse 18, 1190 Vienna, Austria
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10
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Wu W, Biber P, Mishra DR, Ghosh S. Sea-level rise thresholds for stability of salt marshes in a riverine versus a marine dominated estuary. Sci Total Environ 2020; 718:137181. [PMID: 32105940 DOI: 10.1016/j.scitotenv.2020.137181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 02/05/2020] [Accepted: 02/06/2020] [Indexed: 06/10/2023]
Abstract
We studied the ecological resilience of salt marshes by deriving sea level rise (SLR) thresholds in two estuaries with contrasting upland hydrological inputs in the north-central Gulf of Mexico: Grand Bay National Estuarine Research Reserve (NERR) with limited upland input, and the Pascagoula River delta drained by the Pascagoula River, the largest undammed river in the continental United States. We applied a mechanistic model to account for vegetation responses and hydrodynamics to predict salt marsh distributions under future SLR scenarios. We further investigated the potential mechanisms that contribute to salt marsh resilience to SLR. The modeling results show that salt marshes in the riverine dominated estuary are more resilient to SLR than in the marine dominated estuary with SLR thresholds of 10.3 mm/yr and 7.2 mm/yr respectively. This difference of >3 mm/yr is mainly contributed by larger quantities of riverine-borne mineral sediments in the Pascagoula River. In both systems, sediment trapping by the above-ground vegetation appears to contribute more to marsh platform accretion than organic matter from below-ground biomass based on the medians of the accretion rates. However, below-ground biomass could contribute up to 90% of accretion in the marine dominated estuary compared to only 60% of accretion in the riverine dominated estuary. SLR thresholds of salt marshes are more sensitive to vegetation biomass in the marine dominated estuary while biomass and sediment similarly affect SLR thresholds of salt marshes in the riverine dominated estuary. This research will likely help facilitate more informed decisions on conservation/restoration policies for these two types of systems in the near-term needed to minimize future catastrophic loss of these coastal marsh habitats once SLR thresholds are exceeded.
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Affiliation(s)
- Wei Wu
- Division of Coastal Sciences, School of Ocean Science and Engineering, The University of Southern Mississippi, 703 East Beach Dr., Ocean Springs, MS 39564, USA.
| | - Patrick Biber
- Division of Coastal Sciences, School of Ocean Science and Engineering, The University of Southern Mississippi, 703 East Beach Dr., Ocean Springs, MS 39564, USA
| | - Deepak R Mishra
- Center for Geospatial Research, Department of Geography, University of Georgia, Athens, GA 30602, USA
| | - Shuvankar Ghosh
- Department of Geospatial Monitoring and Information Technology, French Institute of Pondicherry (IFP), 11, St Louis St, White Town, Puducherry 605001, India
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11
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Abstract
Rock coasts are perceived to be stable, however, recent occurrence of stacks of rocks and subsequent loss of some rocky coasts poses a challenge for research. This study sought to assess the impact of waves on the compressive/tensile strength of the rocks and further investigated the lithological properties of coastal material that influence shoreline change along the heterogeneous rock coast of the western region of Ghana. The study determined how the petrology and mineralogy of the various rocks types influence the stability of rocky shoreline. Data used included available historic topographic maps and images, Geological map, directional wave data, field measurements of rock hardness and rock samples collected for laboratory investigations. Schmidt's hammer was used to measure in-situ rock hardness. Shoreline features for the study period (1974–2005) were extracted from multi-temporal dataset into a geodatabase, and change statistics computed by end point rate method using DSAS, an extension of Arc GIS software. Thin sections were produced from rock samples collected from the field, and petrographic and microscopic analyses were carried out on them. It was found that wave impact was minimal compared with the tensile strength of the rocks in the study area; thus wave is not the key geomorphic agent in the study area. The results showed shoreline accretion at few sites, whereas other parts of the rocky shoreline are eroding at varying degrees. It was observed that the site lithology of the rock coast as well as the quartz feldspar ratio content of the rocks influence the shoreline change rates, as quartz bearing rocks are often more resistant to weathering. It was also noted that the strength of the intact rock had moderate correlation with the shoreline change rates; instead the mineralogy, state of weathering and textural properties of the rocks explains the shoreline change rates along the coast.
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12
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Caetano-Anollés G, Aziz MF, Mughal F, Gräter F, Koç I, Caetano-Anollés K, Caetano-Anollés D. Emergence of Hierarchical Modularity in Evolving Networks Uncovered by Phylogenomic Analysis. Evol Bioinform Online 2019; 15:1176934319872980. [PMID: 31523127 PMCID: PMC6728656 DOI: 10.1177/1176934319872980] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 08/08/2019] [Indexed: 01/15/2023] Open
Abstract
Networks describe how parts associate with each other to form integrated systems which often have modular and hierarchical structure. In biology, network growth involves two processes, one that unifies and the other that diversifies. Here, we propose a biphasic (bow-tie) theory of module emergence. In the first phase, parts are at first weakly linked and associate variously. As they diversify, they compete with each other and are often selected for performance. The emerging interactions constrain their structure and associations. This causes parts to self-organize into modules with tight linkage. In the second phase, variants of the modules diversify and become new parts for a new generative cycle of higher level organization. The paradigm predicts the rise of hierarchical modularity in evolving networks at different timescales and complexity levels. Remarkably, phylogenomic analyses uncover this emergence in the rewiring of metabolomic and transcriptome-informed metabolic networks, the nanosecond dynamics of proteins, and evolving networks of metabolism, elementary functionomes, and protein domain organization.
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Affiliation(s)
- Gustavo Caetano-Anollés
- Evolutionary Bioinformatics Laboratory,
Department of Crop Sciences, C.R. Woese Institute for Genomic Biology, and Illinois
Informatics Institute, University of Illinois, Urbana, IL, USA
| | - M Fayez Aziz
- Evolutionary Bioinformatics Laboratory,
Department of Crop Sciences, C.R. Woese Institute for Genomic Biology, and Illinois
Informatics Institute, University of Illinois, Urbana, IL, USA
| | - Fizza Mughal
- Evolutionary Bioinformatics Laboratory,
Department of Crop Sciences, C.R. Woese Institute for Genomic Biology, and Illinois
Informatics Institute, University of Illinois, Urbana, IL, USA
| | - Frauke Gräter
- Heidelberg Institute for Theoretical
Studies, Heidelberg, Germany
| | - Ibrahim Koç
- Department of Molecular Biology and
Genetics, Gebze Technical University, Gebze, Turkey
| | - Kelsey Caetano-Anollés
- Division of Biomedical Informatics,
College of Medicine, Seoul National University, Seoul, Republic of Korea
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13
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Rodriguez-Delgado C, Bergillos RJ, Ortega-Sánchez M, Iglesias G. Wave farm effects on the coast: The alongshore position. Sci Total Environ 2018; 640-641:1176-1186. [PMID: 30021283 DOI: 10.1016/j.scitotenv.2018.05.281] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 05/22/2018] [Accepted: 05/23/2018] [Indexed: 06/08/2023]
Abstract
For wave energy to become a fully-fledged renewable and thus contribute to the much-needed decarbonisation of the energy mix, the effects of wave farms (arrays of wave energy converters) on coastal systems must be addressed. The objective of this work is to investigate the effects of wave farms on the longshore sediment transport and shoreline evolution of a gravel-dominated beach and, in particular, its sensitivity to the longshore position of the farm based on eight scenarios. Nearshore wave propagation patterns are computed by means of a spectral wave propagation model (SWAN), variations in sediment transport rates induced by the farm are calculated, and a one-line model is applied to determine the shoreline position and dry beach area. The significant wave height at breaking is reduced in the lee of the wave farm, dampening sediment transport. We find that changes in the dry beach area induced by the wave farm are highly sensitive to its alongshore position, and may result in: (i) erosion relative to the baseline scenario (without wave farm) in three of the eight scenarios, (ii) accretion in three other scenarios, and (iii) negligible effects in the remaining two. These results prove that the alongshore position of the wave farm controls the response of the beach to the extent that it may shift from accretionary to erosionary, and provide evidence of its effectiveness in countering erosion if appropriately positioned. This effectiveness opens up the possibility of using wave farms not only to generate carbon-free energy but also to manage coastal erosion, thus strengthening the case for the development of wave energy.
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Affiliation(s)
| | - Rafael J Bergillos
- Andalusian Institute for Earth System Research, University of Granada, Avda. del Mediterráneo, s/n, Granada 18006, Spain
| | - Miguel Ortega-Sánchez
- Andalusian Institute for Earth System Research, University of Granada, Avda. del Mediterráneo, s/n, Granada 18006, Spain
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14
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Rodriguez-Delgado C, Bergillos RJ, Ortega-Sánchez M, Iglesias G. Protection of gravel-dominated coasts through wave farms: Layout and shoreline evolution. Sci Total Environ 2018; 636:1541-1552. [PMID: 29913615 DOI: 10.1016/j.scitotenv.2018.04.333] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 04/24/2018] [Accepted: 04/24/2018] [Indexed: 06/08/2023]
Abstract
The impacts of wave farms (arrays of wave energy converters, or WECs) on the nearshore must be fully understood for wave technology to develop and thus contribute to a sustainable, carbon-free energy mix in the near future. The objective of this work is to investigate the role played by the farm layout on the wave propagation patterns leewards and the implications for longshore sediment transport (LST) and shoreline evolution on a gravel-dominated deltaic coast. Changes in wave propagation in four scenarios, corresponding to as many wave farm layouts, are computed by means of a spectral numerical model (Delft3D-WAVE) under (i) low-energy and storm conditions, and (ii) westerly and easterly waves - the two prevailing wave directions. On this basis, sediment transport rates are computed and changes in the shoreline position assessed using a one-line model. To quantify the impact of the wave farm on the nearshore wave conditions, sediment transport and shoreline, we define three ad hoc indicators: the non-dimensional wave height reduction, the non-dimensional LST rate reduction and the non-dimensional shoreline advance. Significant wave heights decrease in the lee of the wave farm, with the consequent reduction in LST rates. As a result, the dry beach area increases in every scenario under both westerly and easterly waves. We find that case studies with the WECs arranged on fewer rows but covering a greater stretch of coastline provide better coastal protection. These results confirm that wave farms can be used not only to generate carbon-free energy but also to protect gravel-dominated coasts.
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Affiliation(s)
| | - Rafael J Bergillos
- Andalusian Institute for Earth System Research, University of Granada, Avda. del Mediterráneo, s/n, Granada 18006, Spain
| | - Miguel Ortega-Sánchez
- Andalusian Institute for Earth System Research, University of Granada, Avda. del Mediterráneo, s/n, Granada 18006, Spain
| | - Gregorio Iglesias
- School of Engineering, University of Plymouth, Plymouth PL4 8AA, UK.
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15
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Bremner JG, Slater AM, Mason UC, Spring J, Johnson SP. Perception of occlusion by young infants: Must the occlusion event be congruent with the occluder? Infant Behav Dev 2016; 44:240-8. [PMID: 27490421 DOI: 10.1016/j.infbeh.2016.07.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 07/19/2016] [Accepted: 07/21/2016] [Indexed: 11/20/2022]
Abstract
Four-month-old infants perceive continuity of an object's trajectory through occlusion, even when the occluder is illusory, and several cues are apparently needed for young infants to perceive a veridical occlusion event. In this paper we investigated the effects of dislocating the spatial relation between the occlusion events and the visible edges of the occluder. In two experiments testing 60 participants, we demonstrated that 4-month-olds do not perceive continuity of an object's trajectory across an occlusion if the deletion and accretion events are spatially displaced relative to the occluder edges (Experiment 1) or if deletion and accretion occur along a linear boundary that is incorrectly oriented relative to the occluder's edges (Experiment 2). Thus congruence of these cues is apparently important for perception of veridical occlusion. These results are discussed in relation to an account of the development of perception of occlusion and object persistence.
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Affiliation(s)
| | | | | | - Jo Spring
- Lancaster University, United Kingdom
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16
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Puymège A, Bertin S, Guédon G, Payot S. Analysis of Streptococcus agalactiae pan-genome for prevalence, diversity and functionality of integrative and conjugative or mobilizable elements integrated in the tRNA(Lys CTT) gene. Mol Genet Genomics 2015; 290:1727-40. [PMID: 25832353 DOI: 10.1007/s00438-015-1031-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 03/17/2015] [Indexed: 11/27/2022]
Abstract
Streptococcus agalactiae is the first cause of invasive infections in human neonates and is also a major bovine and fish pathogen. High genomic diversity was observed in this species that hosts numerous mobile genetic elements, in particular elements transferable by conjugation. This works aims to evaluate the contribution of these elements to GBS genome diversity. Focusing on genomic islands integrated in the tRNA(Lys) (CTT) gene, a known hotspot of recombination, an extensive in silico search was performed on the sequenced genome of 303 strains of S. agalactiae isolated from different hosts. In all the isolates (except 9), whatever their origin (human, bovine, camel, dog, gray seal, dolphin, fish species or bullfrog), this locus carries highly diverse genomic islands transferable by conjugation such as integrative and conjugative elements (ICEs), integrative and mobilizable elements (IMEs), CIs-mobilizable elements (CIMEs) or composite elements. Transfer of an ICE from an ST67 bovine strain to a phylogenetically distant ST23 human isolate was obtained experimentally indicating that there was no barrier to ICE transfer between strains from different hosts. Interestingly, a novel family of putative IMEs that site-specifically integrate in the nic site of oriT of ICEs belonging to Tn916/ICESt3 superfamily was detected in silico. These elements carry an antibiotic resistance gene (lsa(C)) already described to confer cross-resistance to lincosamides, streptogramins A and pleuromutilins. Further work is needed to evaluate the impact of these IMEs on the transfer of targeted ICEs and the mobility and the dissemination of these IMEs.
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Affiliation(s)
- Aurore Puymège
- Faculté des Sciences et Technologies, INRA, UMR1128 DynAMic, Bd des Aiguillettes, BP70239, 54506, Vandœuvre-lès-Nancy, France.,Faculté des Sciences et Technologies, Université de Lorraine, UMR1128 DynAMic, Bd des Aiguillettes, BP70239, 54506, Vandœuvre-lès-Nancy, France
| | - Stéphane Bertin
- Faculté des Sciences et Technologies, INRA, UMR1128 DynAMic, Bd des Aiguillettes, BP70239, 54506, Vandœuvre-lès-Nancy, France.,Faculté des Sciences et Technologies, Université de Lorraine, UMR1128 DynAMic, Bd des Aiguillettes, BP70239, 54506, Vandœuvre-lès-Nancy, France
| | - Gérard Guédon
- Faculté des Sciences et Technologies, INRA, UMR1128 DynAMic, Bd des Aiguillettes, BP70239, 54506, Vandœuvre-lès-Nancy, France.,Faculté des Sciences et Technologies, Université de Lorraine, UMR1128 DynAMic, Bd des Aiguillettes, BP70239, 54506, Vandœuvre-lès-Nancy, France
| | - Sophie Payot
- Faculté des Sciences et Technologies, INRA, UMR1128 DynAMic, Bd des Aiguillettes, BP70239, 54506, Vandœuvre-lès-Nancy, France. .,Faculté des Sciences et Technologies, Université de Lorraine, UMR1128 DynAMic, Bd des Aiguillettes, BP70239, 54506, Vandœuvre-lès-Nancy, France.
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