Evaluating intact assemblages and potential for depth refuge at Tubbataha Reefs Natural Park and Cagayancillo MPAs, Philippines
Abstract/Contents
- Abstract
- Overfishing remains a threat to coral reef fishes globally, with large carnivores often the most vulnerable. Marine protected areas (MPAs) can restore fish populations and biodiversity, but often their implementation and scientific study do not consider mesophotic coral ecosystems (MCEs – extensions of shallow reefs between the water depths of 30-150 m), which may be critical as a depth refuge for large carnivorous reef fish from fishing and large storms. I analyzed 65 videos recorded from baited remote underwater video systems deployed in 2016 to investigate the assemblage structure of large carnivorous fishes at shallow (4-12 m) and mesophotic (45-96 m) depths in two of the largest and most isolated MPAs in the Philippines: Tubbataha Reefs Natural Park (TRNP), a fully no-take MPA enacted in 1988; and Cagayancillo, an archipelagic municipality surrounded by an extensive but not fully no-take MPA declared in 2016. I identified and recorded the abundance and species richness of individuals within the taxa groupers (Serranidae), snappers (Lutjanidae), emperors (Lethrinidae), jacks (Carangidae), and the endangered Cheilinus undulatus (Labridae). Mean fish abundance and species richness were not greater in TRNP than in Cagayancillo, regardless of depth, despite long-term protection in the former. According to the PERMANOVA and nMDS, fish assemblages were distinct between the study locations TRNP and Cagayancillo, but more distinct between shallow and mesophotic depths at each location. In Cagayancillo, grouper and jack mean abundance were higher at mesophotic depths than at shallow depths. SIMPER analysis also showed that abundance of the most influential species in Cagayancillo were more abundant in mesophotic depths. Similar abundance and species richness observed at TRNP and Cagayancillo are likely due to limited impacts of fishing within Cagayancillo. Fish assemblages were more distinct between depths than between study locations, more likely due to habitat differences than MPA effects. Groupers and jacks having higher abundance in mesophotic depths may indicate that they are benefiting from depth refuge in Cagayancillo, which suggests that MCEs can serve as deep refugia. Overall, my findings emphasize that MCEs may be acting as critical habitat for fished species, and thus, they should be explicitly included and designated as a part of present and future MPAs.
Description
| Publication date | June 9, 2023 |
|---|
Creators/Contributors
| Author | Salvador, Mikaela |
|---|---|
| Author | Abesamis, Rene |
| Thesis advisor | Crowder, Larry |
| Thesis advisor | Palumbi, Stephen |
| Data contributor | Utzurrum, Jean Asuncion |
| Compiler | Murray, Ryan |
| Compiler | Delijero, Kymry |
| Compiler | Conales, Segundo |
| Advisor | Bird, Christopher |
| Advisor | Gauthier, David |
Subjects
| Subject | Baited camera |
|---|---|
| Subject | Deep reefs |
| Subject | Mesophotic reefs |
| Subject | Predatory fish |
| Subject | Video analysis |
| Genre | Other |
| Genre | Word document |
Bibliographic information
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- License
- This work is licensed under a Creative Commons Attribution Non Commercial 4.0 International license (CC BY-NC).
Preferred citation
- Preferred citation
- Salvador, M. (2026). Evaluating intact assemblages and potential for depth refuge at Tubbataha Reefs Natural Park and Cagayancillo MPAs, Philippines . Stanford Digital Repository. Available at https://purl.stanford.edu/wc719km3101. https://doi.org/10.25740/wc719km3101.
Collection
Undergraduate Honors Theses, Doerr School of Sustainability
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- salvadormik9@gmail.com
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