The aftermath of a mass sponge die-off. Left: Healthy vase sponge Ircinia campana Right: Dead vase sponge after an algal bloom. We are currently studying the mechanism behind the mortality and the ecological feasibility of “jump-starting” sponge community restoration.
ECOSYSTEM RESTORATION AFTER HARMFUL ALGAL BLOOMS
Research in the Behringer lab also focuses on hard-bottom communities in southeast Florida and the Florida Keys with the aim of determining human and environmental impact patterns, and the potential for sustainable use or restoration. In the Florida Keys, we have been studying the impacts of recurring harmful plankton blooms on shallow hard-bottom communities, particularly sponges. These blooms devastate sponges, some > 1 m wide, that form much of the structure in this critical habitat. Many ecologically and economically valuable organisms such as spiny lobsters, stone crabs, snappers, and groupers rely on this habitat for their early ontogeny.We are studying the potential for ecosystem restoration in the wake of these algal blooms. Cyanobacteria blooms blanketed much of central and western Florida Bay during the summer and fall of 2007. This bloom devastated the sponge communities in these areas, which provide much needed water column filtration, while also providing habitat for many ecologically important organisms such as crabs, lobsters, and fish. We are investigating the potential for sponge restoration and developing techniques that can be scaled to an ecosystem-level effort.
MONITORING HARD-BOTTOM ECOSYSTEM AFTER RESTORATION
In areas where we have restored sponges, we are monitoring the effects of our restoration efforts. Because sponges and the hard-bottom are extremely important as nursery habitat, we are measuring recruitment of juvenile crabs, lobsters, and fishes. We collect juveniles in “shag” collectors (photo on right) and identify and enumerate them in the lab. We are also monitoring the trophic ecology of benthic organisms in this habitat using stable isotope analysis. By comparing performance of restored ecosystems to similar hard-bottom ecosystems that have not been affected by algal blooms, we can assess the efficacy of our restoration efforts.