Reef fish structure and distribution in a south-western Atlantic Ocean tropical island

Abstract

The community structure of the reef fish fauna of Trindade Island, a volcanic oceanic island located 1160 km off the coast of Brazil, is described based on intensive visual censuses. Seventy-six species were encountered in 252 censuses, with mean ± S.E. of 99 ± 3 individuals and 15.7 ± 0.3 species 40 m(-2) transect. The average fish biomass, calculated from length-class estimation, was 22.1 kg 40 m(-2) transect. The species contributing most to biomass were, in decreasing order, Melichthys niger, Cephalopholis fulva, Kyphosus spp., Holocentrus adscensionis, Sparisoma amplum, Sparisoma axillare, Acanthurus bahianus and Epinephelus adscensionis. Carnivorous fishes were the largest trophic group in terms of biomass, followed by omnivores and roving herbivores. The two predominant types of reef habitat, fringing reefs built by coralline algae and rocky reefs made of volcanic boulders, showed significant differences in the biomass and the abundance of the trophic guilds. Within each habitat type, significant differences in species richness, density and biomass were detected among crest, slope and interface zones. Although similar in overall species composition to coastal reefs in Brazil, the fish fauna of Trindade Island shares certain characteristics, such as a high abundance of planktivores, with other Brazilian oceanic islands. Despite comparatively high fish biomass, including the macro-carnivorous species habitually targeted by fisheries, signs of overfishing were evident. These findings highlight the urgency for a conservation initiative for this isolated, unique and vulnerable reef system.

Spatial distribution and diet of Cephalopholis fulva (Ephinephelidae) at Trindade Island, Brazil

“…Since Trindade Island is reasonably far from the continent, environmental issues as pollution, introduction of non-indigenous species and habitat loss are expected to be less intense than they are for more coastal areas and islands. In fact, the coney has been shown to be more abundant in oceanic banks and islands (Atol das Rocas, Fernando de Noronha and Trindade Island) than in the continental coastal regions (Floeter et al, 2007;Krajewski & Floeter, 2011;Pinheiro et al, 2011). Thirdly, fisheries at Trindade Island are mostly focused on larger fish species such as Carcharhinus perezii, Xiphias gladius, Mycteroperca venenosa, Ephinephelus adscensionis (Pinheiro et al, 2010), which may also contribute to reduced competition and predation over C. fulva.…”

“…(1) The reef crest is located at the surf zone, with depths of about 3-6 m; (2) the reef slope, with depths varying between 6-20 m; and (3) the reef plate, the deepest habitat sampled, with depths >20 m and limited in the deepest portion by non-consolidated substrata. Structural complexity was assessed visually by classifying the substrate rugosity according the following three categories: high complexity (rocks and holes > 1 m in length and depth), medium complexity (rocks and holes < 1m), low complexity (lack of rocks and holes) (Floeter et al, 2007;Pinheiro et al, 2011;Simon et al, 2011).…”

“…Despite its ecological and commercial importance, there are only few studies focusing specifically on the population dynamics of C. fulva in Brazil (Araújo & Martins, 2006, 2009Freitas et al, 2011). Due to its high abundance in Trindade Island (Pereira-Filho et al, 2011;Pinheiro et al, 2011) , C. fulva stands out as a model organism to evaluate ecological issues such as diet and habitat preferences. In this study, the relationship between diet and distribution of C. fulva at coastal reef areas of Trindade island, was evaluated, focusing particularly on its preferences for different habitat types and microhabitats with varying levels of structural complexity.…”

Upper and lower mesophotic coral reef fish communities evaluated by underwater visual censuses in two Caribbean locations

“…Thus, two to six 30-m transects were obtained per site, totaling 14 visual censuses in Bermuda (three at 45-50 m; nine at 60-65 m; two at 70-80 m) and 22 in Curaçao (five at 45-50 m; four at 60-65 m; four at 70-80 m; four at 85-90 m; five at 105-130 m). All species were counted within 1 m of each side of the transect tape for a total area of 60 m 2 per survey (e.g., Lesser and Slattery 2011;Pinheiro et al 2011Pinheiro et al , 2013. Abundance and body size (5 cm size classes) were estimated for each species observed along the transects.…”

A new species of Anthiadinae (Teleostei: Serranidae) from São Pedro and São Paulo Archipelago, Brazil, Equatorial Atlantic

“…Intensive studies of the fish fauna of the Brazilian oceanic islands are relatively recent (Gasparini & Floeter, 2001;Feitoza et al, 2003;Pinheiro et al, 2009Pinheiro et al, , 2011Pereira-Filho et al, 2011). Prior to 2008, many different types of fishes were recorded in the São Pedro and São Paulo Archipelago (SPSPA), also known as St. Paul's Rocks, Brazil, of which 100 were identified to species level, eight to genus, and eight to family (Vaske Jr. et al, 2005).…”