Reef fish community structure of the Fernando de Noronha Archipelago (Equatorial Western Atlantic): the influence of exposure and benthic composition

• Published in: Environmental biology of fishes 2011-09, Vol.92 (1), p.25-40
• Main Authors: Krajewski, João Paulo, Floeter, Sergio R.
• Format: Article
• Language: English
• Subjects: Agnatha. Pisces; Animal and plant ecology; Animal Systematics/Taxonomy/Biogeography; Animal, plant and microbial ecology; Animals; Archipelagoes; Autoecology; Biological and medical sciences; Biomedical and Life Sciences; Carnivores; Community structure; Coral reefs; Environment; Fish; Freshwater & Marine Ecology; Fundamental and applied biological sciences. Psychology; Habitats; Herbivores; Invertebrates; Life Sciences; Nature Conservation; Omnivores; Vertebrata; Vertebrates: general zoology, morphology, phylogeny, systematics, cytogenetics, geographical distribution; Zoology
• ISSN: 0378-1909; 1573-5133
• DOI: 10.1007/s10641-011-9813-3

We studied the reef fish assemblage of eight reefs within the oceanic archipelago of Fernando de Noronha, off northeastern Brazil. In a total of 91 belt transects (20 × 2 m) we recorded 60 species from 28 families. The 25 most abundant species accounted for about 98% of all fish recorded in this study and most of these species are widely distributed in the Western Atlantic. The majority of fish counted were planktivores (37.0%), followed by mobile invertebrate feeders (28.5%), territorial herbivores (11.3%), roving herbivores (10.5%), omnivores (7.1%), macrocarnivores (6.5%) and sessile invertebrate feeders (0.03%). In terms of biomass, roving herbivores were the most representative (41.8%), followed by mobile invertebrate feeders (19.9%), macrocarnivores (14.3%), omnivores (14.0%), piscivores (8.3%), planktivores (1.4%), territorial herbivores (0.3%), and sessile invertebrate feeders (0.03%). Overall, density and biomass of fishes were positively correlated with coral cover and depth, and negatively correlated with wave exposure. These relationships are probably a response to the habitat complexity provided by the higher coral cover in deeper reefs (>10 m) of the archipelago or to the lower water turbulence below 10 m deep. Carnivores and mobile invertebrate feeders were mainly influenced by depth and non-consolidated substratum, planktivores and omnivores by wave exposure and herbivores by algal cover. Although our results suggest that habitat characteristics may play a role in determining the distribution of some fish species, we also found several habitat generalists, suggesting that the community is dominated by versatile species.