Abstract
Serranilla is a protected island of the Seaflower Biosphere Reserve, far from dense human population. These characteristics could help sustain structurally complex coral reefs, often associated with higher biodiversity, abundance, and biomass of reef-associated organisms, including reef fish. However, the multiple threats present in Serranilla, including intense illegal fishing, can impact coral ecosystems generally and also specific key groups, such as the parrotfish, in particular. During the “Seaflower Research Expedition 2017”, we assessed how structural habitat complexity influences reef fish assemblages. In addition, we explored differences in parrotfish species (family: Scaridae) between Serranilla and San Andrés, the most populated island in the Archipelago. On Serranilla, we found that habitat structure, rugosity, and coral cover accounted for up to 66% of variation in reef fish diversity, abundance, and biomass, with values being higher on more complex reefs. Parrotfish species differed between the islands, with larger species supporting higher biomasses at Serranilla, by comparison with San Andrés; however, the abundance, biomass, and lengths of parrotfish species were low in both areas compared with those reported from other protected Caribbean reefs. Our study indicates that despite the evident relationship between structurally complex habitats and reef fish, other threats in Serranilla could be affecting parrotfish populations, such as illegal fishing, a widespread activity in the area.
Highlights
Coral reefs are widely recognized as one of the most diverse marine ecosystems, providing essential habitats for numerous species; coral reefs cover only 0.02% of the ocean’s surface, they are believed to harbor nearly 30% of all known marine species [1,2,3,4].Reef ecosystems provide multiple ecosystem services [5,6,7], including coastal protection [8,9] and the provision of food and livelihoods through fishing activities [10]
66% of variation in the abundance of small parrotfish species was explained by the combination of all six measures of habitat structure (Table 1)
We found that Serranilla BR had larger parrotfish than San Andrés, though the biomass in Serranilla BR was lower (143 kg·ha−1 ) than those values reported from other Caribbean Marine Protected Areas (MPAs) with adequate protection and low local human populations, in which parrotfish biomass values can exceed 500 kg·ha−1 [70]
Summary
Coral reefs are widely recognized as one of the most diverse marine ecosystems, providing essential habitats for numerous species; coral reefs cover only 0.02% of the ocean’s surface, they are believed to harbor nearly 30% of all known marine species [1,2,3,4].Reef ecosystems provide multiple ecosystem services [5,6,7], including coastal protection [8,9] and the provision of food and livelihoods through fishing activities [10]. In recent decades, coral reef ecosystems worldwide have been facing degradation due to multiple environmental and human stressors [11,12]. In the Caribbean, by 2003, at least 80% of the coral cover registered in the 1970s was lost [14,15], while in the Atlantic, 75% of coral reefs are considered at risk [12]. This loss of coral cover has often produced a decline in the reef’s
Published Version (Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have