Copyright (c) 2013 All rights reserved. http://works.bepress.com/pamela_hallock-muller Recent documents in Pamela Hallock-Muller en-us Thu, 31 Jan 2013 17:16:36 PST 3600 http://works.bepress.com/pamela_hallock-muller/2 http://works.bepress.com/pamela_hallock-muller/2 Thu, 12 May 2011 10:27:25 PDT A harmful algal bloom (red tide) and associated anoxic/hypoxic event in 2005 resulted in massive fish kills and comparable mortality of epibenthic communities in depths <25 m along the central west Florida shelf. There is a robust body of information on the etiology of red tide and human health issues; however, there is virtually no quantitative information on the effects of red tide on epibenthic macroinvertebrate and demersal fish communities. Ongoing monitoring of recruitment and succession on artificial reef structures provided a focused time series (2005 to 2007) before and after the red-tide disturbance. Radical changes in community structures of artificial reefs were observed after the red tide. Scleractinian corals, poriferans, and echinoderms were among the epibenthos most affected. Fish species richness declined by >50%, with significant reductions in the abundances of most species. Successional stages were monitored over the next 2 yr; stages tended to follow a predictable progression and revert to a pre-red tide state, corroborating previous predictions that the frequency of disturbance events in the shallow eastern Gulf of Mexico may limit the effective species pool of colonists. Substantial recovery of the benthos occurred in 2 yr, which was more rapid than predicted in previous studies.

]]> Jennifer M. Dupont et al. http://works.bepress.com/pamela_hallock-muller/1 http://works.bepress.com/pamela_hallock-muller/1 Thu, 12 May 2011 10:27:21 PDT Regeneration rates of coral lesions reflect the ability of colonies to repair damage and therefore can be useful indicators of coral health and environmental conditions. We quantified regeneration rates of boulder corals Montastraea spp. at four, 6 m deep patch reefs within Biscayne National Park (BNP) and the upper Florida Keys National Marine Sanctuary (FKNMS), and along a 3 to 18 m depth transect in FKNMS. Coral lesions (approx. 2 cm(2)) created during sampling for cellular-diagnostic analysis were monitored quarterly in 2001 and 2002, and in February 2003. Regeneration was a dynamic process, continuing longer than previously reported (> 300 d after lesion formation). Geographic location was the strongest factor affecting regeneration rate at our study sites. Lesion regeneration differed significantly among 6 m deep sites; sites offshore from John Pennekamp Coral Reef State Park (Algae Reef and White Banks) consistently had the highest regeneration rates, with colonies exhibiting exponential declines in lesion size and a high percentage of completely healed lesions. Along the depth gradient, corals at the 3 m site regenerated significantly faster than corals at 6, 9, and 18 m. These results suggest that corals sampled at FKNMS 6, 9 and 18 m sites and BNP were in poor physiological condition or were exposed to suboptimal environmental conditions, as evidenced by highly variable and overall low regeneration rates, a low percentage of healed lesions, and a high occurrence of breakage or Type II lesions (lesions that increased in size by merging with areas of denuded tissue on the colony).

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