Reef Fishes of Saba Bank, Netherlands Antilles: Assemblage Structure across a Gradient of Habitat Types

Abstract

Saba Bank is a 2,200 km2 submerged carbonate platform in the northeastern Caribbean Sea off Saba Island, Netherlands Antilles. The presence of reef-like geomorphic features and significant shelf edge coral development on Saba Bank have led to the conclusion that it is an actively growing, though wholly submerged, coral reef atoll. However, little information exists on the composition of benthic communities or associated reef fish assemblages of Saba Bank. We selected a 40 km2 area of the bank for an exploratory study. Habitat and reef fish assemblages were investigated in five shallow-water benthic habitat types that form a gradient from Saba Bank shelf edge to lagoon. Significant coral cover was restricted to fore reef habitat (average cover 11.5%) and outer reef flat habitat (2.4%) and declined to near zero in habitats of the central lagoon zone. Macroalgae dominated benthic cover in all habitats (average cover: 32.5 – 48.1%) but dominant algal genera differed among habitats. A total of 97 fish species were recorded. The composition of Saba Bank fish assemblages differed among habitat types. Highest fish density and diversity occurred in the outer reef flat, fore reef and inner reef flat habitats. Biomass estimates for commercially valued species in the reef zone (fore reef and reef flat habitats) ranged between 52 and 83 g/m2. The composition of Saba Bank fish assemblages reflects the absence of important nursery habitats, as well as the effects of past fishing. The relatively high abundance of large predatory fish (i.e. groupers and sharks), which is generally considered an indicator of good ecosystem health for tropical reef systems, shows that an intact trophic network is still present on Saba Bank.

Status and trends Saba Bank fisheries: 2015

“…She also presented evidence that ghost fishing by derelict traps might be problem. Finally, Toller et al (2010) studied fish assemblages of the bank and confirmed Meesters et al's (1996) prior suggestion that large groupers were all but absent but also drew attention to the seeming abundance of sharks in the ecosystem. This all meant that further investigation was clearly urgently needed.…”

Unforeseen importance of historical collections as baselines to determine biotic change of coral reefs: the Saba Bank case

“…Another invasive species in the Caribbean (since 1992), the notorious piscivorous red lionfish Pterois volitans Linnaeus, 1758, has not been recorded yet from Saba Bank (Toller et al. 2010; Williams et al.…”

A novel stereo‐video method to investigate fish–habitat relationships

“…Species within a given feeding guild have similar dietary requirements; therefore, relationships with benthic cover have also been found at this level (Friedlander & Parish ; Toller et al . ). The abundance and diversity of fish are often found to be greatest on rocky and coral reefs and decline with increases in the per cent cover of macroalgae and sand (e.g.…”