Biological community structure on patch reefs in Biscayne National Park, FL, USA

Abstract

Coral reef ecosystem management benefits from continual quantitative assessment of the resources being managed, plus assessment of factors that affect distribution patterns of organisms in the ecosystem. In this study, we investigate the relationships among physical, benthic, and fish variables in an effort to help explain the distribution patterns of organisms on patch reefs within Biscayne National Park, FL, USA. We visited a total of 196 randomly selected sampling stations on 12 shallow (<10 m) patch reefs and measured physical variables (e.g., substratum rugosity, substratum type) and benthic and fish community variables. We also incorporated data on substratum rugosity collected remotely via airborne laser surveying (Experimental Advanced Airborne Research Lidar-EAARL). Across all stations, only weak relationships were found between physical, benthic cover, and fish assemblage variables. Much of the variance was attributable to a "reef effect," meaning that community structure and organism abundances were more variable at stations among reefs than within reefs. However, when the reef effect was accounted for and removed statistically, patterns were detected. Within reefs, juvenile scarids were most abundant at stations with high coverage of the fleshy macroalgae Dictyota spp., and the calcified alga Halimeda tuna was most abundant at stations with low EAARL rugosity. Explanations for the overwhelming importance of "reef" in explaining variance in our dataset could include the stochastic arrangement of organisms on patch reefs related to variable larval recruitment in space and time and/or strong historical effects due to patchy disturbances (e.g., hurricanes, fishing), as well as legacy effects of prior residents ("priority" effects).

The influence of seafloor terrain on fish and fisheries: A global synthesis

“…High relief, and complex, terrain features (e.g. pinnacles, ledges, caves) often support a diversity of apex predators because they provide important resting points on long‐distance migrations, aggregation sites for spawning and abundant feeding opportunities (Farmer et al., 2017; Kuffner et al., 2010; Morato et al., 2010; Pirtle et al., 2017). It is likely that these higher‐order predators also exert strong top‐down effects in local ecosystems, via both direct predation and elevated predation risk effects, which alter the distribution, abundance and behaviour of their prey and cascade through food webs to shape the composition of benthic assemblages (Atwood et al., 2015; Baum & Worm, 2009; Estes et al., 2011).…”

Responses of the tropical gorgonian coral Eunicea fusca to ocean acidification conditions

“…Their findings suggest that coral tissue might be involved in the resistance of some species of octocorals to ocean acidification. Octocorals are important in reef ecosystems, providing space and habitat for several other reef organisms (Sánchez et al 1998;Kuffner et al 2010). In shallow and exposed fore-reef zones in the Caribbean region, the diversity and biomass of gorgonians could be higher than scleractinian corals (Sánchez et al 1998;Villamizar et al 2013;Ruzicka et al 2013).…”