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Hays GC, Laloë JO, Mortimer JA, Rattray A, Tromp JJ, Esteban N. Remote submerged banks and mesophotic ecosystems can provide key habitat for endangered marine megafauna. SCIENCE ADVANCES 2024; 10:eadl2838. [PMID: 38381823 PMCID: PMC10881038 DOI: 10.1126/sciadv.adl2838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Accepted: 01/18/2024] [Indexed: 02/23/2024]
Abstract
The importance of some ecosystems remains poorly understood. We showed that mesophotic ecosystems (30 to 150 m) are a key habitat for a critically endangered species, with strong evidence that a globally important population of adult hawksbill turtles (Eretmochelys imbricata) almost exclusively foraged at these depths on remote submerged banks. This discovery highlights the need for such areas to be included in conservation planning, for example, as part of the United Nations High Seas Treaty. We equipped nesting turtles with Fastloc-GPS (Global Positioning System) satellite tags at an Indian Ocean breeding area and they all traveled to deep foraging sites (6765 days of tracking data across 22 individuals including 183,921 dive-depth measurements) rather than shallow coral reef sites. Both chart depths and depth data relayed from the tags indicated that turtles foraged at mesophotic depths, the modal dive depths being between 35 and 40 m. We calculate that 55,554 km2 of the western Indian Ocean alone consists of submerged banks between 30 and 60 m.
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Affiliation(s)
- Graeme C. Hays
- Deakin Marine Research and Innovation Centre, School of Life and Environmental Sciences, Deakin University, Geelong, Victoria, Australia
| | - Jacques-Olivier Laloë
- Deakin Marine Research and Innovation Centre, School of Life and Environmental Sciences, Deakin University, Geelong, Victoria, Australia
| | - Jeanne A. Mortimer
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
- PO Box 1443, Victoria, Mahé, Seychelles
| | - Alex Rattray
- Deakin Marine Research and Innovation Centre, School of Life and Environmental Sciences, Deakin University, Geelong, Victoria, Australia
| | - Jared J. Tromp
- Deakin Marine Research and Innovation Centre, School of Life and Environmental Sciences, Deakin University, Geelong, Victoria, Australia
| | - Nicole Esteban
- Department of Biosciences, Swansea University, Swansea SA2 8PP, Wales, UK
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Martin BC, Giraldo-Ospina A, Bell S, Cambridge M, Fraser MW, Gibbons B, Harvey ES, Kendrick GA, Langlois T, Spencer C, Hovey RK. Deep meadows: Deep-water seagrass habitats revealed. Ecology 2023; 104:e4150. [PMID: 37523230 DOI: 10.1002/ecy.4150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 06/10/2023] [Accepted: 06/15/2023] [Indexed: 08/01/2023]
Affiliation(s)
- Belinda C Martin
- The UWA Oceans Institute and School of Biological Science, University of Western Australia, Crawley, Western Australia, Australia
- Ooid Scientific, North Lake, Western Australia, Australia
| | - Ana Giraldo-Ospina
- The UWA Oceans Institute and School of Biological Science, University of Western Australia, Crawley, Western Australia, Australia
- Marine Science Institute, University of California Santa Barbara, Santa Barbara, California, USA
| | - Sahira Bell
- Department of Biodiversity, Conservation and Attractions, WA Government, Kensington, Western Australia, Australia
| | - Marion Cambridge
- The UWA Oceans Institute and School of Biological Science, University of Western Australia, Crawley, Western Australia, Australia
| | - Matthew W Fraser
- The UWA Oceans Institute and School of Biological Science, University of Western Australia, Crawley, Western Australia, Australia
- Flourishing Oceans, Minderoo Foundation, Perth, Western Australia, Australia
| | - Brooke Gibbons
- The UWA Oceans Institute and School of Biological Science, University of Western Australia, Crawley, Western Australia, Australia
| | - Euan S Harvey
- School of Molecular and Life Sciences, Curtin University, Bentley, Western Australia, Australia
| | - Gary A Kendrick
- The UWA Oceans Institute and School of Biological Science, University of Western Australia, Crawley, Western Australia, Australia
| | - Tim Langlois
- The UWA Oceans Institute and School of Biological Science, University of Western Australia, Crawley, Western Australia, Australia
| | - Claude Spencer
- The UWA Oceans Institute and School of Biological Science, University of Western Australia, Crawley, Western Australia, Australia
| | - Renae K Hovey
- The UWA Oceans Institute and School of Biological Science, University of Western Australia, Crawley, Western Australia, Australia
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Montero-Hidalgo M, Tuya F, Otero-Ferrer F, Haroun R, Santos-Martín F. Mapping and assessing seagrass meadows changes and blue carbon under past, current, and future scenarios. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 872:162244. [PMID: 36796703 DOI: 10.1016/j.scitotenv.2023.162244] [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: 11/11/2022] [Revised: 02/10/2023] [Accepted: 02/10/2023] [Indexed: 06/18/2023]
Abstract
Seagrasses store large amounts of blue carbon and mitigate climate change, but they have suffered strong regressions worldwide in recent decades. Blue carbon assessments may support their conservation. However, existing blue carbon maps are still scarce and focused on certain seagrass species, such as the iconic genus Posidonia, and intertidal and very shallow seagrasses (<10 m depth), while deep-water and opportunistic seagrasses have remained understudied. This study filled this gap by mapping and assessing blue carbon storage and sequestration by the seagrass Cymodocea nodosa in the Canarian archipelago using the local carbon storage capacity and high spatial resolution (20 m/pixel) seagrass distribution maps for the years 2000 and 2018. Particularly, we mapped and assessed the past, current and future capacity of C. nodosa to store blue carbon, according to four plausible future scenarios, and valued the economic implications of these scenarios. Our results showed that C. nodosa has suffered ca. 50 % area loss in the last two decades, and, if the current degradation rate continues, our estimations demonstrate that it could completely disappear in 2036 ("Collapse scenario"). The impact of these losses in 2050 would reach 1.43 MT of CO2 equivalent emitted with a cost of 126.3 million € (0.32 % of the current Canary GDP). If, however, this degradation is slow down, between 0.11 and 0.57 MT of CO2 equivalent would be emitted until 2050 ("Intermediate" and "Business-as-usual" scenarios, respectively), which corresponds to a social cost of 3.63 and 44.81 million €, respectively. If the current seagrass extension is maintained ("No Net Loss"), 0.75 MT of CO2 equivalent would be sequestered from now to 2050, which corresponds to a social cost saving of 73.59 million €. The reproducibility of our methodology across coastal ecosystems underpinned by marine vegetation provides a key tool for decision-making and conservation of these habitats.
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Affiliation(s)
- Miriam Montero-Hidalgo
- Rey Juan Carlos University, Chemical and Environmental Technology Department, Madrid, Spain.
| | - Fernando Tuya
- Biodiversity and Conservation Research Group, IU-ECOAQUA, Universidad de Las Palmas de Gran Canaria, Telde, Spain
| | - Francisco Otero-Ferrer
- Biodiversity and Conservation Research Group, IU-ECOAQUA, Universidad de Las Palmas de Gran Canaria, Telde, Spain
| | - Ricardo Haroun
- Biodiversity and Conservation Research Group, IU-ECOAQUA, Universidad de Las Palmas de Gran Canaria, Telde, Spain
| | - Fernando Santos-Martín
- Rey Juan Carlos University, Chemical and Environmental Technology Department, Madrid, Spain
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Andréfouet S, Derville S, Buttin J, Dirberg G, Wabnitz CCC, Garrigue C, Payri CE. Nation-wide hierarchical and spatially-explicit framework to characterize seagrass meadows in New-Caledonia, and its potential application to the Indo-Pacific. MARINE POLLUTION BULLETIN 2021; 173:113036. [PMID: 34649208 DOI: 10.1016/j.marpolbul.2021.113036] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 09/26/2021] [Accepted: 10/03/2021] [Indexed: 06/13/2023]
Abstract
Despite their ecological role and multiple contributions to human societies, the distribution of Indo-Pacific seagrasses remains poorly known in many places. Herein, we outline a hierarchical spatially-explicit assessment framework to derive nation-wide synoptic knowledge of the distribution of seagrass species and communities. We applied the framework to New Caledonia (southwest Pacific Ocean) and its 36,200 km2 of reefs and lagoons. The framework is primarily field-based but can leverage various habitat maps derived from remote sensing. Field data collection can be stratified by map products and retrospectively contribute to developing new seagrass distribution maps. Airborne and satellite remote sensing alone do not allow for the spatial generalisation of the finest attributes (species distribution and types of seagrass beds), but staged stratified field sampling provides synoptic views of these attributes. Using three examples, we discuss how the hierarchical and spatial information generated from this framework's application can inform conservation and management objectives.
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Affiliation(s)
- Serge Andréfouet
- UMR-9220 ENTROPIE (Institut de Recherche pour le Développement, Université de la Réunion, Ifremer, CNRS, Université de la Nouvelle-Calédonie), 101, promenade Roger-Laroque Anse Vata, BP A5, 98848 Noumea, New Caledonia.
| | - Solène Derville
- UMR-9220 ENTROPIE (Institut de Recherche pour le Développement, Université de la Réunion, Ifremer, CNRS, Université de la Nouvelle-Calédonie), 101, promenade Roger-Laroque Anse Vata, BP A5, 98848 Noumea, New Caledonia
| | - Julie Buttin
- UMR-9220 ENTROPIE (Institut de Recherche pour le Développement, Université de la Réunion, Ifremer, CNRS, Université de la Nouvelle-Calédonie), 101, promenade Roger-Laroque Anse Vata, BP A5, 98848 Noumea, New Caledonia
| | - Guillaume Dirberg
- Muséum National d'Histoire Naturelle, UMR BOREA 7208 CNRS-UCN-UA-IRD, Paris, France
| | - Colette C C Wabnitz
- Institute for the Oceans and Fisheries, University of British Columbia, Vancouver, B.C. V6T 1Z4, Canada; Stanford Center for Ocean Solutions, Stanford University, Stanford, CA 94305, United States
| | - Claire Garrigue
- UMR-9220 ENTROPIE (Institut de Recherche pour le Développement, Université de la Réunion, Ifremer, CNRS, Université de la Nouvelle-Calédonie), 101, promenade Roger-Laroque Anse Vata, BP A5, 98848 Noumea, New Caledonia
| | - Claude E Payri
- UMR-9220 ENTROPIE (Institut de Recherche pour le Développement, Université de la Réunion, Ifremer, CNRS, Université de la Nouvelle-Calédonie), 101, promenade Roger-Laroque Anse Vata, BP A5, 98848 Noumea, New Caledonia
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Schwarz JN. Dynamic partitioning of tropical Indian Ocean surface waters using ocean colour data - management and modelling applications. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2020; 276:111308. [PMID: 32891983 DOI: 10.1016/j.jenvman.2020.111308] [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: 06/06/2019] [Revised: 07/16/2020] [Accepted: 08/23/2020] [Indexed: 06/11/2023]
Abstract
Over the past few decades, partitioning of the surface ocean into ecologically-meaningful spatial domains has been approached using a range of data types, with the aim of improving our understanding of open ocean processes, supporting marine management decisions and constraining coupled ocean-biogeochemical models. The simplest partitioning method, which could provide low-latency information for managers at low cost, remains a purely optical classification based on ocean colour remote sensing. The question is whether such a simple approach has value. Here, the efficacy of optical classifications in constraining physical variables that modulate the epipelagic environment is tested for the tropical Indian Ocean, with a focus on the Chagos marine protected area (MPA). Using remote sensing data, it was found that optical classes corresponded to distinctive ranges of wind speed, wind stress curl, sea surface temperature, sea surface slope, sea surface height anomaly and geostrophic currents (Kruskal-Wallis and post-hoc Tukey honestly significantly different tests, α = 0.01). Between-class differences were significant for a set of sub-domains that resolved zonal and meridional gradients across the MPA and Seychelles-Chagos Thermocline Ridge, whereas between-domain differences were only significant for the north-south gradient (PERMANOVA, α = 0.01). A preliminary test of between-class differences in surface CO2 concentrations from the Orbiting Carbon Observatory-2 demonstrated a small decrease in mean pCO2 with increasing chlorophyll (chl), from 418 to 398 ppm. Simple optical class maps therefore provide an overview of growth conditions, the spatial distribution of resources - from which habitat fragmentation metrics can be calculated, and carbon sequestration potential. Within the 17 year study period, biotic variables were found to have decreased at up to 0.025%a-1 for all optical classes, which is slower than reported elsewhere (Mann-Kendall-Sen regression, α = 0.01). Within the MPA, positive Indian Ocean Dipole conditions and negative Southern Oscillation Indices were weakly associated with decreasing chl, fluorescence line height (FLH), eddy kinetic energy, easterly wind stress and wind stress curl, and with increasing FLH/chl, sea surface temperature, SSH gradients and northerly wind stress, consistent with reduced surface mixing and increased stratification. The optical partitioning scheme described here can be applied in Google Earth Engine to support management decisions at daily or monthly scales, and potential applications are discussed.
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Affiliation(s)
- Jill N Schwarz
- School of Biological & Marine Sciences, University of Plymouth, Drake Circus, Plymouth, PL4 8AA, UK.
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Gulick AG, Johnson RA, Pollock CG, Hillis-Starr Z, Bolten AB, Bjorndal KA. Recovery of a large herbivore changes regulation of seagrass productivity in a naturally grazed Caribbean ecosystem. Ecology 2020; 101:e03180. [PMID: 32882749 DOI: 10.1002/ecy.3180] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 05/19/2020] [Accepted: 07/14/2020] [Indexed: 11/05/2022]
Abstract
What happens in meadows after populations of natural grazers rebound following centuries of low abundance? Many seagrass ecosystems are now experiencing this phenomenon with the recovery of green turtles (Chelonia mydas), large-bodied marine herbivores that feed on seagrasses. These seagrass ecosystems provide a rare opportunity to study ecosystem-wide shifts that result from a recovery of herbivores. We evaluate changes in regulation of seagrass productivity in a naturally grazed tropical ecosystem by (1) comparing Thalassia testudinum productivity in grazed and ungrazed areas and (2) evaluating potential regulating mechanisms of T. testudinum productivity. We established 129 green turtle exclusion cages in grazed and ungrazed areas to quantify T. testudinum growth (linear, area, mass, productivity : biomass [P:B]). In each exclosure, we recorded temperature, irradiance, water depth, nitrogen : phosphorus ratio (N:P) of blade tissue, grazing intensity before cage placement, and T. testudinum structural and nutrient characteristics. Thalassia testudinum exhibited compensatory growth in grazed areas via stimulated blade linear growth, blade area growth, and P:B across seasonal high and low growth periods and in shallow (3-4 m) and deep (9-10 m) seagrass meadows. Irradiance, depth, and N:P ratios had significant roles in regulating mass growth and P:B of T. testudinum in ungrazed areas. Depth was a significant regulating factor of mass growth and P:B in grazed areas; rates were higher and more variable in shallow meadows than in deep meadows. Grazing intensity was also a significant regulating factor for P:B, stimulating tissue turnover with increasing grazing pressure. This study provides important insights into how recovery of a large marine herbivore can result in dramatic, sustainable changes in the regulation of seagrass productivity. We also highlight the need for a historical perspective and use of appropriate indicators, including P:B and grazing intensity, when evaluating seagrass response to green turtle grazing as meadows are returned to a natural grazed state. In an age of green turtle recovery and global seagrass decline due to anthropogenic threats, a thorough understanding of green turtle-seagrass interactions at the ecosystem level is critical to ensure the restoration of seagrass ecosystems and continued recovery of green turtle populations.
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Affiliation(s)
- Alexandra G Gulick
- Archie Carr Center for Sea Turtle Research and Department of Biology, University of Florida, Gainesville, Florida, 32611, USA
| | - Robert A Johnson
- Archie Carr Center for Sea Turtle Research and Department of Biology, University of Florida, Gainesville, Florida, 32611, USA
| | - Clayton G Pollock
- Division of Resource Management and Research, Buck Island Reef National Monument, National Park Service, Christiansted, U.S. Virgin Islands, 00820, USA
| | - Zandy Hillis-Starr
- Division of Resource Management and Research, Buck Island Reef National Monument, National Park Service, Christiansted, U.S. Virgin Islands, 00820, USA
| | - Alan B Bolten
- Archie Carr Center for Sea Turtle Research and Department of Biology, University of Florida, Gainesville, Florida, 32611, USA
| | - Karen A Bjorndal
- Archie Carr Center for Sea Turtle Research and Department of Biology, University of Florida, Gainesville, Florida, 32611, USA
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Seascape Genetics and the Spatial Ecology of Juvenile Green Turtles. Genes (Basel) 2020; 11:genes11030278. [PMID: 32150879 PMCID: PMC7140902 DOI: 10.3390/genes11030278] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 02/19/2020] [Accepted: 02/28/2020] [Indexed: 11/17/2022] Open
Abstract
Understanding how ocean currents impact the distribution and connectivity of marine species, provides vital information for the effective conservation management of migratory marine animals. Here, we used a combination of molecular genetics and ocean drift simulations to investigate the spatial ecology of juvenile green turtle (Chelonia mydas) developmental habitats, and assess the role of ocean currents in driving the dispersal of green turtle hatchlings. We analyzed mitochondrial (mt)DNA sequenced from 358 juvenile green turtles, and from eight developmental areas located throughout the Southwest Indian Ocean (SWIO). A mixed stock analysis (MSA) was applied to estimate the level of connectivity between developmental sites and published genetic data from 38 known genetic stocks. The MSA showed that the juvenile turtles at all sites originated almost exclusively from the three known SWIO stocks, with a clear shift in stock contributions between sites in the South and Central Areas. The results from the genetic analysis could largely be explained by regional current patterns, as shown by the results of passive numerical drift simulations linking breeding sites to developmental areas utilized by juvenile green turtles. Integrating genetic and oceanographic data helps researchers to better understand how marine species interact with ocean currents at different stages of their lifecycle, and provides the scientific basis for effective conservation management.
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Unsworth RKF, McKenzie LJ, Collier CJ, Cullen-Unsworth LC, Duarte CM, Eklöf JS, Jarvis JC, Jones BL, Nordlund LM. Global challenges for seagrass conservation. AMBIO 2019; 48:801-815. [PMID: 30456457 PMCID: PMC6541581 DOI: 10.1007/s13280-018-1115-y] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Revised: 10/18/2018] [Accepted: 10/23/2018] [Indexed: 05/21/2023]
Abstract
Seagrasses, flowering marine plants that form underwater meadows, play a significant global role in supporting food security, mitigating climate change and supporting biodiversity. Although progress is being made to conserve seagrass meadows in select areas, most meadows remain under significant pressure resulting in a decline in meadow condition and loss of function. Effective management strategies need to be implemented to reverse seagrass loss and enhance their fundamental role in coastal ocean habitats. Here we propose that seagrass meadows globally face a series of significant common challenges that must be addressed from a multifaceted and interdisciplinary perspective in order to achieve global conservation of seagrass meadows. The six main global challenges to seagrass conservation are (1) a lack of awareness of what seagrasses are and a limited societal recognition of the importance of seagrasses in coastal systems; (2) the status of many seagrass meadows are unknown, and up-to-date information on status and condition is essential; (3) understanding threatening activities at local scales is required to target management actions accordingly; (4) expanding our understanding of interactions between the socio-economic and ecological elements of seagrass systems is essential to balance the needs of people and the planet; (5) seagrass research should be expanded to generate scientific inquiries that support conservation actions; (6) increased understanding of the linkages between seagrass and climate change is required to adapt conservation accordingly. We also explicitly outline a series of proposed policy actions that will enable the scientific and conservation community to rise to these challenges. We urge the seagrass conservation community to engage stakeholders from local resource users to international policy-makers to address the challenges outlined here, in order to secure the future of the world's seagrass ecosystems and maintain the vital services which they supply.
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Affiliation(s)
- Richard K. F. Unsworth
- Seagrass Ecosystem Research Group, College of Science, Swansea University, Wallace Building, Swansea, SA2 8PP UK
- Project Seagrass, 33 Park Place, Cardiff, CF10 3BA UK
| | - Len J. McKenzie
- Centre for Tropical Water & Aquatic Ecosystem Research, James Cook University, Cairns, Australia
| | - Catherine J. Collier
- Centre for Tropical Water & Aquatic Ecosystem Research, James Cook University, Cairns, Australia
| | - Leanne C. Cullen-Unsworth
- Project Seagrass, 33 Park Place, Cardiff, CF10 3BA UK
- Sustainable Places Research Institute, Cardiff University, 33 Park Place, Cardiff, CF10 3BA UK
| | - Carlos M. Duarte
- Red Sea Research Center (RSRC), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900 Saudi Arabia
| | - Johan S. Eklöf
- Department of Ecology, Environment and Plant Sciences, Stockholm University, 106 91 Stockholm, Sweden
| | - Jessie C. Jarvis
- Department of Biology & Marine Biology, Center for Marine Science, University of North Carolina Wilmington, 601 South College Rd, Wilmington, NC 28403 USA
| | - Benjamin L. Jones
- Project Seagrass, 33 Park Place, Cardiff, CF10 3BA UK
- Sustainable Places Research Institute, Cardiff University, 33 Park Place, Cardiff, CF10 3BA UK
| | - Lina M. Nordlund
- Natural Resources and Sustainable Development, NRHU Department of Earth Sciences, Uppsala University, Campus Gotland, Sweden
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Hwang C, Chang CH, Burch M, Fernandes M, Kildea T. Effects of Epiphytes and Depth on Seagrass Spectral Profiles: Case Study of Gulf St. Vincent, South Australia. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:ijerph16152701. [PMID: 31362358 PMCID: PMC6696022 DOI: 10.3390/ijerph16152701] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 07/20/2019] [Accepted: 07/21/2019] [Indexed: 01/14/2023]
Abstract
Seagrasses are a crucial indicator species of coastal marine ecosystems that provide substratum, shelter, and food for epiphytic algae, invertebrates, and fishes. More accurate mapping of seagrasses is essential for their survival as a long-lasting natural resource. Before reflectance spectra could properly be used as remote sensing endmembers, factors that may obscure the detection of reflectance signals must be assessed. The objectives in this study are to determine the influence of (1) epiphytes, (2) water depth, and (3) seagrass genus on the detection of reflectance spectral signals. The results show that epiphytes significantly dampen bottom-type reflectance throughout most of the visible light spectrum, excluding 670–679 nm; the depth does influence reflectance, with the detection of deeper seagrasses being easier, and as the depth increases, only Heterozostera increase in the exact “red edge” wavelength at which there is a rapid change in the near-infrared (NIR) spectrum. These findings helped improve the detection of seagrass endmembers during remote sensing, thereby helping protect the natural resource of seagrasses.
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Affiliation(s)
- Charnsmorn Hwang
- Department of Environmental Engineering, National Cheng Kung Chung University, Tainan City 701, Taiwan.
| | - Chih-Hua Chang
- Department of Environmental Engineering, National Cheng Kung Chung University, Tainan City 701, Taiwan.
- Global Water Quality Research Center, National Cheng Kung University, Tainan City 701, Taiwan.
| | - Michael Burch
- Department of Ecology & Evolutionary Biology, The University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Milena Fernandes
- Australian Water Quality Centre, SA Water, Adelaide, South Australia 5000, Australia
- College of Science and Engineering, Flinders University, Adelaide, South Australia 5001, Australia
| | - Tim Kildea
- Australian Water Quality Centre, SA Water, Adelaide, South Australia 5000, Australia
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Keulen MV, Nordlund LM, Cullen-Unsworth LC. Towards recognition of seagrasses, and their sustainable management. MARINE POLLUTION BULLETIN 2018; 134:1-4. [PMID: 30236411 DOI: 10.1016/j.marpolbul.2018.08.046] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Affiliation(s)
- Mike van Keulen
- Centre for Sustainable Aquatic Ecosystems, Harry Butler Institute, Murdoch University, Murdoch, WA6150, Australia.
| | - Lina Mtwana Nordlund
- Natural Resources and Sustainable Development, Department of Earth Sciences, Uppsala University, Villavägen 16, 75 236, Uppsala, Sweden
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