1
|
Seal S, Bayyana S, Pande A, Ghanekar C, Hatkar PS, Pathan S, Patel S, Rajpurkar S, Prajapati S, Gole S, Iyer S, Nair A, Prabakaran N, Sivakumar K, Johnson JA. Spatial prioritization of dugong habitats in India can contribute towards achieving the 30 × 30 global biodiversity target. Sci Rep 2024; 14:13984. [PMID: 38886526 PMCID: PMC11183059 DOI: 10.1038/s41598-024-64760-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Accepted: 06/12/2024] [Indexed: 06/20/2024] Open
Abstract
Indian coastal waters are critical for dugong populations in the western Indian Ocean. Systematic spatial planning of dugong habitats can help to achieve biodiversity conservation and area-based protection targets in the region. In this study, we employed environmental niche modelling to predict suitable dugong habitats and identify influencing factors along its entire distribution range in Indian waters. We examined data on fishing pressures collected through systematic interview surveys, citizen-science data, and field surveys to demarcate dugong habitats with varying risks. Seagrass presence was the primary factor in determining dugong habitat suitability across the study sites. Other variables such as depth, bathymetric slope, and Euclidean distance from the shore were significant factors, particularly in predicting seasonal suitability. Predicted suitable habitats showed a remarkable shift from pre-monsoon in Palk Bay to post-monsoon in the Gulf of Mannar, indicating the potential of seasonal dugong movement. The entire coastline along the Palk Bay-Gulf of Mannar region was observed to be at high to moderate risk, including the Gulf of Mannar Marine National Park, a high-risk area. The Andaman Islands exhibited high suitability during pre- and post-monsoon season, whereas the Nicobar Islands were highly suitable for monsoon season. Risk assessment of modelled suitable areas revealed that < 15% of high-risk areas across Andaman and Nicobar Islands and Palk Bay and Gulf of Mannar, Tamil Nadu, fall within the existing protected areas. A few offshore reef islands are identified under high-risk zones in the Gulf of Kutch, Gujarat. We highlight the utility of citizen science and secondary data in performing large-scale spatial ecological analysis. Overall, identifying synoptic scale 'Critical Dugong Habitats' has positive implications for the country's progress towards achieving the global 30 × 30 target through systematic conservation planning.
Collapse
Affiliation(s)
- Sohom Seal
- Department of Habitat Ecology, Wildlife Institute of India, P.O. Chandrabani, Dehradun, Uttarakhand, 248 001, India
| | - Sharad Bayyana
- Department of Habitat Ecology, Wildlife Institute of India, P.O. Chandrabani, Dehradun, Uttarakhand, 248 001, India
- Centre for Biodiversity and Conservation Science, School of Environment, University of Queensland, St. Lucia, QLD, 4072, Australia
| | - Anant Pande
- Department of Habitat Ecology, Wildlife Institute of India, P.O. Chandrabani, Dehradun, Uttarakhand, 248 001, India
- Marine Program, Wildlife Conservation Society - India, Bengaluru, Karnataka, 560 097, India
| | - Chinmaya Ghanekar
- Department of Habitat Ecology, Wildlife Institute of India, P.O. Chandrabani, Dehradun, Uttarakhand, 248 001, India
| | - Prachi Sachchidanand Hatkar
- Department of Habitat Ecology, Wildlife Institute of India, P.O. Chandrabani, Dehradun, Uttarakhand, 248 001, India
| | - Sameeha Pathan
- Department of Habitat Ecology, Wildlife Institute of India, P.O. Chandrabani, Dehradun, Uttarakhand, 248 001, India
| | - Shivani Patel
- Department of Habitat Ecology, Wildlife Institute of India, P.O. Chandrabani, Dehradun, Uttarakhand, 248 001, India
| | - Sagar Rajpurkar
- Department of Habitat Ecology, Wildlife Institute of India, P.O. Chandrabani, Dehradun, Uttarakhand, 248 001, India
| | - Sumit Prajapati
- Department of Habitat Ecology, Wildlife Institute of India, P.O. Chandrabani, Dehradun, Uttarakhand, 248 001, India
| | - Swapnali Gole
- Department of Habitat Ecology, Wildlife Institute of India, P.O. Chandrabani, Dehradun, Uttarakhand, 248 001, India
| | - Sweta Iyer
- Department of Habitat Ecology, Wildlife Institute of India, P.O. Chandrabani, Dehradun, Uttarakhand, 248 001, India
| | - Aditi Nair
- Department of Habitat Ecology, Wildlife Institute of India, P.O. Chandrabani, Dehradun, Uttarakhand, 248 001, India
| | - Nehru Prabakaran
- Department of Habitat Ecology, Wildlife Institute of India, P.O. Chandrabani, Dehradun, Uttarakhand, 248 001, India
| | - Kuppusamy Sivakumar
- Department of Habitat Ecology, Wildlife Institute of India, P.O. Chandrabani, Dehradun, Uttarakhand, 248 001, India
- Department of Ecology and Environment, Pondicherry University, Puducherry, India
| | - Jeyaraj Antony Johnson
- Department of Habitat Ecology, Wildlife Institute of India, P.O. Chandrabani, Dehradun, Uttarakhand, 248 001, India.
| |
Collapse
|
2
|
Thibault M, Letourneur Y, Cleguer C, Bonneville C, Briand MJ, Derville S, Bustamante P, Garrigue C. C and N stable isotopes enlighten the trophic behaviour of the dugong (Dugong dugon). Sci Rep 2024; 14:896. [PMID: 38195771 PMCID: PMC10776846 DOI: 10.1038/s41598-023-50578-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 12/21/2023] [Indexed: 01/11/2024] Open
Abstract
The dugong (Dugong dugon), a large marine mammal herbivore of the Indo-Pacific, is vulnerable to extinction at a global scale due to a combination of human-related threats including habitat degradation. The species forages on seagrass habitats (marine phanerogams) and plays a key role in the functioning and sensitivity of these declining coastal ecosystems. The trophic behaviour and plasticity of dugong populations in response to extrinsic and intrinsic factors are therefore crucial features to both dugong and seagrass conservation. Yet, this knowledge remains limited to few visual observations and analyses of mouth, stomach or faecal contents of stranded individuals. We take advantage of a long-term monitoring of stranded individuals from the endangered New Caledonian population to depict features of dugongs' trophic ecology from Carbon and Nitrogen stable isotopes. A total of 59 dugong skin samples were used to portrait the stable isotope niche of dugongs according to their sex and maturity. In light of previous work conducted in New Caledonia, a subset of these samples was used to model the trophic mix of dugong males and females. Our stable isotope mixing models used C and N isotope values of 10 taxa bbelonging to five divisions of metazoans, plants, and chromists. Our results represent the first estimate of the species dietary niche in the isotopic space. They suggest that the diet of dugong calves overlaps more with that of adult females (δ13C: - 6.38 ± 1.13 ‰; δ15N: 2.49 ± 1.10 ‰) than males (δ13C: - 5.92 ± 1.10 ‰; δ15N: 3.69 ± 1.28 ‰). Further, we highlight differences in the expected trophic mix of dugong adult males and females. From these, we formulate a sex-specific foraging behaviour hypothesis in dugongs, whereby lactating females could forage over smaller spatial ranges but more diverse food sources thanmales. The study emphasizes the importance of long-term stranding monitoring programs to study the ecology of marine mammals.. Finally, it depicts an ecological feature that may contribute to the sensitivity of vulnerable dugongs to ongoing changes on tropical coastal ecosystems.
Collapse
Affiliation(s)
- Martin Thibault
- Centre d'Écologie et des Sciences de la Conservation (CESCO), Muséum National d'Histoire Naturelle, Station de Biologie Marine, 1 Place de la Croix, 29900, Concarneau, France.
- UMR ENTROPIE (UR-IRD-IFREMER-CNRS-UNC), Labex-CORAIL, 98800, Nouméa, New Caledonia.
| | - Yves Letourneur
- UMR ENTROPIE (UR-IRD-IFREMER-CNRS-UNC), Labex-CORAIL, 98800, Nouméa, New Caledonia
| | - Christophe Cleguer
- Centre for Tropical Water and Aquatic Ecosystem Research (TropWATER), James Cook University, Townsville, Australia
| | - Claire Bonneville
- UMR ENTROPIE (UR-IRD-IFREMER-CNRS-UNC), Labex-CORAIL, 98800, Nouméa, New Caledonia
| | - Marine J Briand
- CRIOBE, USR 3278 EPHE-CNRS-UPVD, LabEx « Corail », PSL Research University, Université de Perpignan, Avenue Paul Alduy, 66860, Perpignan Cedex, France
| | - Solène Derville
- UMR ENTROPIE (UR-IRD-IFREMER-CNRS-UNC), Labex-CORAIL, 98800, Nouméa, New Caledonia
- Opération Cétacés, BP 12827, 98802, Nouméa, New Caledonia
| | - Paco Bustamante
- Littoral Environnement Et Sociétés (LIENSs), UMR 7266, CNRS-La Rochelle Université, 2 Rue Olympe de Gouges, 17000, La Rochelle, France
| | - Claire Garrigue
- UMR ENTROPIE (UR-IRD-IFREMER-CNRS-UNC), Labex-CORAIL, 98800, Nouméa, New Caledonia
- Opération Cétacés, BP 12827, 98802, Nouméa, New Caledonia
| |
Collapse
|
3
|
Khamis A, Alcoverro T, D'Souza E, Arthur R, Pagès JF, Shah J, Al-Qahtani T, Eweida AA. Identifying conservation priorities for a widespread dugong population in the Red Sea: Megaherbivore grazing patterns inform management planning. MARINE ENVIRONMENTAL RESEARCH 2022; 181:105762. [PMID: 36208505 DOI: 10.1016/j.marenvres.2022.105762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 09/24/2022] [Accepted: 09/26/2022] [Indexed: 06/16/2023]
Abstract
Extensive home ranges of marine megafauna present a challenge for systematic conservation planning because they exceed spatial scales of conventional management. For elusive species like dugongs, their management is additionally hampered by a paucity of basic distributional information across much of their range. The Red Sea is home to a wide-spread, globally important but data-poor population of dugongs. We surveyed the north-eastern Red Sea in the waters of NEOM, Kingdom of Saudi Arabia, to locate feeding sites and determine priority areas for dugong conservation. We conducted large-scale in-water surveys of dugong feeding trails across 27 seagrass meadows that span 0.7 degree of latitude and recorded nine seagrass species and 13 dugong feeding sites. Spread over ∼4'061 km2 of nearshore and offshore waters, many of these sites clustered around five main core feeding areas. Dugong feeding trails were mostly recorded at sites dominated by the fast-growing pioneer seagrasses Halodule uninervis, Halophila ovalis and/or H. stipulacea. Multispecific meadows with pioneer seagrasses tended to be sheltered and shallow, reflecting a similar spatial pattern to the identified dugong feeding sites. Often close to hotels and fishing harbours, these high-use dugong areas are subject to high boat traffic, fishing, and coastal development which places considerable pressures on this vulnerable mammal and its seagrass habitat. The rapidly accelerating coastal development in the northern Red Sea directly threatens the future of its dugong population. Although our sampling focuses on feeding signs in early successional seagrasses, the results are valuable to spatial conservation planning as they will trigger overdue conservation interventions for a globally threatened species in a data-poor area. Urgent dugong conservation management actions in the northern Red Sea should focus on shallow waters sheltered by coastal lagoons, bays and the lee of large islands.
Collapse
Affiliation(s)
- Abdulqader Khamis
- Faculty of Biology, University of Barcelona, Av. Diagonal, 643, 08028, Barcelona, Spain.
| | - Teresa Alcoverro
- Centre d'Estudis Avançats de Blanes (Spanish National Research Council, CEAB-CSIC), Blanes, Girona, Spain; Oceans and Coasts Programme, Nature Conservation Foundation, Amritha 1311, 12th Cross, Vijayanagara 1st Stage, Mysore, 570017, India.
| | - Elrika D'Souza
- Oceans and Coasts Programme, Nature Conservation Foundation, Amritha 1311, 12th Cross, Vijayanagara 1st Stage, Mysore, 570017, India.
| | - Rohan Arthur
- Oceans and Coasts Programme, Nature Conservation Foundation, Amritha 1311, 12th Cross, Vijayanagara 1st Stage, Mysore, 570017, India.
| | - Jordi F Pagès
- Centre d'Estudis Avançats de Blanes (Spanish National Research Council, CEAB-CSIC), Blanes, Girona, Spain.
| | - Junid Shah
- Ajaz Environment Consultants, United Arab Emirates.
| | - Tareq Al-Qahtani
- National Center for Wildlife, P. O. Box 61681, Riyadh, 11575, Saudi Arabia.
| | - Ameer Abdulla Eweida
- NEOM, Saudi Arabia; Rosenstiel School of Marine and Atmospheric Sciences, University of Miami, USA.
| |
Collapse
|