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Abstract Overfishing remains a threat to coral reef fishes worldwide, with large carnivores often disproportionately vulnerable. Marine protected areas (MPAs) can restore fish populations and biodiversity, but their effect has been understudied in mesophotic coral ecosystems (MCEs), particularly in the Coral Triangle.Videos were analysed 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: an uninhabited, fully no‐take MPA enacted in 1988 (Tubbataha Reefs Natural Park) and an archipelagic municipality surrounded by an extensive but not fully no‐take MPA declared in 2016 (Cagayancillo). Taxa focused on were groupers (Serranidae), snappers (Lutjanidae), emperors (Lethrinidae), jacks (Carangidae) and the endangeredCheilinus undulatus(Labridae).Mean abundance and species richness were not greater in TRNP than in Cagayancillo regardless of depth despite long‐term protection in the former. Limited impacts of fishing in Cagayancillo may explain this result. Differentiation of fish assemblages was evident between TRNP and Cagayancillo but more obvious between depths at each location, probably due more to habitat than MPA effects. In Cagayancillo, overall carnivorous reef fish, grouper and jack mean abundance were 2, 2 and 10 times higher, respectively, at mesophotic depths, suggesting that MCEs can serve as deep refugia from fishing.These findings of differentiation between depths and higher abundance of certain taxa in mesophotic depths emphasize that MCEs are distinct from shallow reefs, serve as important habitat for species susceptible to overfishing and, thus, must be explicitly included in the design of MPAs. This study also highlights the value of maintaining strict protection of MPAs like TRNP for the Coral Triangle and an opportunity to safeguard intact fish assemblages in Cagayancillo by expanding its no‐take zones.
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This content will become publicly available on October 14, 2026
Community structure and microhabitat associations of cryptobenthic reef fishes in Veracruz, Mexico
Local habitat availability can strongly affect animal communities. On coral reefs, the biodiversity of small, bottom-dwelling (‘cryptobenthic’) reef fishes and drivers of their community assembly have yet to be explored in many locations. Here, we investigate how local and regional factors shape the structure and composition of cryptobenthic reef fish communities in the Veracruz Reef System National Park (VRS) in the Gulf of Mexico (GoM). Focusing on five reefs in the VRS, we surveyed cryptobenthic reef fish communities at scales of reef outcrops (~ 3–5 m2) and isolated microhabitats, while also quantifying the benthic composition of each reef to determine microhabitat availability. We found no significant differences in species richness or abundance across park regions and reef zones, but community composition differed qualitatively across reef zones. Furthermore, we discovered strong differences in cryptobenthic reef fishes’ preferences for various microhabitats, which are likely to drive community assembly and provide evidence for species-specific vulnerabilities to reef degradation. Caves harbored the highest biodiversity and abundance of cryptobenthic fishes, while gorgonian soft corals and algae supported the fewest species and individuals. The endemic gobies Tigrigobius redimiculus and Elacatinus jarocho both showed high abundance and occurrence but displayed opposite patterns of microhabitat specialization; T. redimiculus was categorized as a microhabitat generalist, while E. jarocho was revealed as a cave-dwelling specialist species. Overall, our quantitative exploration of the cryptobenthic reef fish community in the southwest GoM provides a crucial baseline for habitat and biodiversity monitoring in the region and highlights E. jarocho as an emblematic, endemic indicator species that will be vulnerable to extinction if further reduction of habitat complexity occurs.
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- Award ID(s):
- 2210200
- PAR ID:
- 10644929
- Publisher / Repository:
- Coral Reefs
- Date Published:
- Journal Name:
- Coral Reefs
- ISSN:
- 0722-4028
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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