[Coral-List] Impact of nutrient enrichment on coral reefs

arianna bucci ariannabucci at yahoo.it
Wed Mar 19 13:02:56 EDT 2014

Dear all, 
this may be of your interest. In my PhD thesis ("Coastal microphytoplankton and microphytobenthos. Diversity, ecology and implications in silicon biolgeochemical cycle), I carried out a study investigating microphytoplankton and nutrients over a shallow continental shelf in Belize. You can find the abstract here:
Phytoplankton variability across a gradient of habitats over a tropical continental shelf


In Study 1, Phytoplankton variability across a gradient of habitats over a tropical continental shelf, we investigated the species composition and abundance of the microphytoplankton over a shallow Mesoamerican continental shelf (Belize). Samples were collected during dry (December 2005) and rainy season (July 2005), along a presumptive environmental gradient extending from offshore blue water across a succession of continental-shelf habitats (i.e., fore reef, lagoon patch reef, turtlegrass bed and island mangrove). Rich phytoplankton communities occurred in all habitats. Diatoms (127 species) were the most abundant organisms, followed by dinoflagellates (70 species), coccolithophorids (12) and silicoflagellates (1). There were marked seasonal differences in some environmental variables (seawater temperature, irradiance, salinity, rainfall and some nutrients). Accordingly, we detected significant between-season differences in the taxonomic composition
 of phytoplankton, although variations in cell abundances were hardly detectable. Surprisingly, neither the analysis of nutrients in the water column (silicate, phosphate, nitrite+nitrate) nor phytoplankton abundance revealed a clear offshore to inshore gradient in the study area; the lowest values did not always occur in open waters and, even if they did, they increased in a non-lineal, complex pattern across shelf habitats. Each habitat showed a characteristic nutrient composition and a distinctive phytoplankton community, with between-habitat differences being most marked in July. The mangrove habitat, with the highest nutrient concentrations and noticeable abundance of dinoflagellates and coccolithophorids, was the most distinct. The studied environmental parameters did not fully explain the variability in phytoplankton composition, suggesting that additional factors are responsible for the marked between-habitat distinctiveness.

Best regards, 
Arianna Bucci, PhD

Il Mercoledì 19 Marzo 2014 1:45, Eugene Shinn <eugeneshinn at mail.usf.edu> ha scritto:
I have never seen parrot fish eat live /Acropora/ but have watched them 
take bites out of Large live head corals and on calm days leave their 
poop in piles on the same corals.. Is anyone making follow up observation 
to see if algae infests the bite marks ? Their poop, as with many fish, 
also contains Serratia Marcescens as does the human gut. Gene


No Rocks, No Water, No Ecosystem (EAS)
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E. A. Shinn, Courtesy Professor
University of South Florida
College of Marine Science Room 221A
140 Seventh Avenue South
St. Petersburg, FL 33701
<eugeneshinn at mail.usf.edu>
Tel 727 553-1158
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