Habitat modeling of Irrawaddy dolphins (Orcaella brevirostris) in the Eastern Gulf of Thailand
Abstract Aim The Irrawaddy dolphin (Orcaella brevirostris) is an endangered cetacean found throughout Southeast Asia. The main threat to this species is human encroachment, led by entanglement in fishing gear. Information on this data‐poor species’ ecology and habitat use is needed to effectively in...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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Wiley
2020-03-01
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| Series: | Ecology and Evolution |
| Subjects: | |
| Online Access: | https://doi.org/10.1002/ece3.6023 |
| _version_ | 1818455019743084544 |
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| author | Justine Jackson‐Ricketts Chalatip Junchompoo Ellen M. Hines Elliott L. Hazen Louisa S. Ponnampalam Anoukchika Ilangakoon Somchai Monanunsap |
| author_facet | Justine Jackson‐Ricketts Chalatip Junchompoo Ellen M. Hines Elliott L. Hazen Louisa S. Ponnampalam Anoukchika Ilangakoon Somchai Monanunsap |
| author_sort | Justine Jackson‐Ricketts |
| collection | DOAJ |
| description | Abstract Aim The Irrawaddy dolphin (Orcaella brevirostris) is an endangered cetacean found throughout Southeast Asia. The main threat to this species is human encroachment, led by entanglement in fishing gear. Information on this data‐poor species’ ecology and habitat use is needed to effectively inform spatial management. Location We investigated the habitat of a previously unstudied group of Irrawaddy dolphins in the eastern Gulf of Thailand, between the villages of Laem Klat and Khlong Yai, in Trat Province. This location is important as government groups plan to establish a marine protected area. Methods We carried out boat‐based visual line transect surveys with concurrent oceanographic measurements and used hurdle models to evaluate this species’ patterns of habitat use in this area. Results Depth most strongly predicted dolphin presence, while temperature was a strong predictor of group size. The highest probability of dolphin presence occurred at around 10.0 m with an optimal depth range of 7.50 to 13.05 m. The greatest number of dolphins was predicted at 24.93°C with an optimal range between 24.93 and 25.31°C. Dolphins are most likely to occur in two primary locations, one large region in the center of the study area (11o54′18′′N to 11o59′23′′N) and a smaller region in the south (11o47′28′′N to 11o49′59′′N). Protections for this population will likely have the greatest chance of success in these two areas. Main Conclusions The results of this work can inform management strategies within the immediate study area by highlighting areas of high habitat use that should be considered for marine spatial planning measures, such as the creation of marine protected areas. Species distribution models for this species in Thailand can also assist conservation planning in other parts of the species’ range by expanding our understanding of habitat preferences. |
| first_indexed | 2024-12-14T22:04:07Z |
| format | Article |
| id | doaj.art-6490a427bddc4ae08785fd90550e68bb |
| institution | Directory Open Access Journal |
| issn | 2045-7758 |
| language | English |
| last_indexed | 2024-12-14T22:04:07Z |
| publishDate | 2020-03-01 |
| publisher | Wiley |
| record_format | Article |
| series | Ecology and Evolution |
| spelling | doaj.art-6490a427bddc4ae08785fd90550e68bb2022-12-21T22:45:54ZengWileyEcology and Evolution2045-77582020-03-011062778279210.1002/ece3.6023Habitat modeling of Irrawaddy dolphins (Orcaella brevirostris) in the Eastern Gulf of ThailandJustine Jackson‐Ricketts0Chalatip Junchompoo1Ellen M. Hines2Elliott L. Hazen3Louisa S. Ponnampalam4Anoukchika Ilangakoon5Somchai Monanunsap6Department of Ecology and Evolutionary Biology University of California Santa Cruz Santa Cruz CaliforniaDepartment of Marine and Coastal Resources Marine and Coastal Resources Research and Development Center, The Eastern Gulf of Thailand Rayong ThailandEstuary & Ocean Science Center San Francisco State University Tiburon CaliforniaNOAA Southwest Fisheries Science Center, Environmental Research Division/Department of Ecology and Evolutionary Biology University of California Santa Cruz Monterey CaliforniaThe MareCet Research Organization Shah Alam MalaysiaMaharagama Sri LankaDepartment of Marine and Coastal Resources Southern Marine and Coastal Resources Research Center Songkhla ThailandAbstract Aim The Irrawaddy dolphin (Orcaella brevirostris) is an endangered cetacean found throughout Southeast Asia. The main threat to this species is human encroachment, led by entanglement in fishing gear. Information on this data‐poor species’ ecology and habitat use is needed to effectively inform spatial management. Location We investigated the habitat of a previously unstudied group of Irrawaddy dolphins in the eastern Gulf of Thailand, between the villages of Laem Klat and Khlong Yai, in Trat Province. This location is important as government groups plan to establish a marine protected area. Methods We carried out boat‐based visual line transect surveys with concurrent oceanographic measurements and used hurdle models to evaluate this species’ patterns of habitat use in this area. Results Depth most strongly predicted dolphin presence, while temperature was a strong predictor of group size. The highest probability of dolphin presence occurred at around 10.0 m with an optimal depth range of 7.50 to 13.05 m. The greatest number of dolphins was predicted at 24.93°C with an optimal range between 24.93 and 25.31°C. Dolphins are most likely to occur in two primary locations, one large region in the center of the study area (11o54′18′′N to 11o59′23′′N) and a smaller region in the south (11o47′28′′N to 11o49′59′′N). Protections for this population will likely have the greatest chance of success in these two areas. Main Conclusions The results of this work can inform management strategies within the immediate study area by highlighting areas of high habitat use that should be considered for marine spatial planning measures, such as the creation of marine protected areas. Species distribution models for this species in Thailand can also assist conservation planning in other parts of the species’ range by expanding our understanding of habitat preferences.https://doi.org/10.1002/ece3.6023Gulf of ThailandhabitatIrrawaddy dolphinOrcaella brevirostrisspatial managementspecies distribution model |
| spellingShingle | Justine Jackson‐Ricketts Chalatip Junchompoo Ellen M. Hines Elliott L. Hazen Louisa S. Ponnampalam Anoukchika Ilangakoon Somchai Monanunsap Habitat modeling of Irrawaddy dolphins (Orcaella brevirostris) in the Eastern Gulf of Thailand Ecology and Evolution Gulf of Thailand habitat Irrawaddy dolphin Orcaella brevirostris spatial management species distribution model |
| title | Habitat modeling of Irrawaddy dolphins (Orcaella brevirostris) in the Eastern Gulf of Thailand |
| title_full | Habitat modeling of Irrawaddy dolphins (Orcaella brevirostris) in the Eastern Gulf of Thailand |
| title_fullStr | Habitat modeling of Irrawaddy dolphins (Orcaella brevirostris) in the Eastern Gulf of Thailand |
| title_full_unstemmed | Habitat modeling of Irrawaddy dolphins (Orcaella brevirostris) in the Eastern Gulf of Thailand |
| title_short | Habitat modeling of Irrawaddy dolphins (Orcaella brevirostris) in the Eastern Gulf of Thailand |
| title_sort | habitat modeling of irrawaddy dolphins orcaella brevirostris in the eastern gulf of thailand |
| topic | Gulf of Thailand habitat Irrawaddy dolphin Orcaella brevirostris spatial management species distribution model |
| url | https://doi.org/10.1002/ece3.6023 |
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