RESPONSE OF PLANKTON COMMUNITIES IN COASTAL LAGOONS TO CHANGES IN NUTRIENT QUALITY AND QUANTITY: CASE STUDY OF FLORIDA BAY

dc.contributor.advisorGlibert, Patricia Men_US
dc.contributor.authorShangguan, Yinien_US
dc.contributor.departmentMarine-Estuarine-Environmental Sciencesen_US
dc.contributor.publisherDigital Repository at the University of Marylanden_US
dc.contributor.publisherUniversity of Maryland (College Park, Md.)en_US
dc.date.accessioned2017-01-24T06:40:54Z
dc.date.available2017-01-24T06:40:54Z
dc.date.issued2016en_US
dc.description.abstractThe Comprehensive Everglades Restoration Plan was initiated to return Florida Bay to a more natural ecological state. The C-111 project, one phase of this plan and initiated in 2012, was designed to increase freshwater flow into northern Florida Bay. However, it also alters the nutrient regime and, potentially, phytoplankton biomass and assemblage. This dissertation investigated the combined effects of changes in discharge and nutrient on phytoplankton biomass and assemblage in several interconnected, mesohaline coastal lagoon systems (lakes) of Florida Bay using field observations, mesocosm experiments, and a statistical box model. Field measurements on nutrients and phytoplankton were performed before and after C-111 implementation. After C-111, increased freshwater flow and phosphorus (P) input, but decreased salinity and nitrogen (N) input were observed. One set of the lagoon lakes, previously highly eutrophic (average chlorophyll a >20 ug L-1), had a nearly 50% decline in overall phytoplankton biomass. The other set of lakes, originally oligotrophic (average chlorophyll a <2 ug L-1), had a doubling of phytoplankton biomass. Phytoplankton assemblage in both sets of lakes shifted to picocyanobacteria. Mesocosm experiments (5 independent experiments, 5-10 day duration, 1000 L tanks) were conducted to test the effects of nutrient additions. Phytoplankton biomass increased 3 to 10-fold in the +P treatments (alone or +N), but did not increase substantially in the +N alone treatments. The +N+P treatments, particularly the +NO3-+P at a +N:P molar ratio of 32 led to a 20-fold increase in diatoms, whereas N in the form of +NH4+ yielded a > 2-fold increase in picocyanobacteria. A statistical box model based on relationships measured in the field under different salinity regimes was developed to simulate flow, nutrients, and phytoplankton changes in the eutrophic lake chain. Model output showed that higher freshwater discharge decreased phytoplankton biomass in the upper of the connected lakes, but the lower lake had a high potential to generate algal blooms, which is consistent with the field data. Also, picocyanobacteria tripled following an increase in dissolved organic nitrogen (DON). This study recommends co-management of both P and N, particularly NH4+ and DON in Florida Bay if picocyanobacteria blooms are to be controlled.en_US
dc.identifierhttps://doi.org/10.13016/M2Q531
dc.identifier.urihttp://hdl.handle.net/1903/18977
dc.language.isoenen_US
dc.subject.pqcontrolledBiological oceanographyen_US
dc.subject.pqcontrolledEnvironmental scienceen_US
dc.subject.pqcontrolledEcologyen_US
dc.subject.pquncontrolledFlorida Bayen_US
dc.subject.pquncontrolledlagoonen_US
dc.subject.pquncontrollednutrienten_US
dc.subject.pquncontrolledphytoplanktonen_US
dc.subject.pquncontrolledrestorationen_US
dc.titleRESPONSE OF PLANKTON COMMUNITIES IN COASTAL LAGOONS TO CHANGES IN NUTRIENT QUALITY AND QUANTITY: CASE STUDY OF FLORIDA BAYen_US
dc.typeDissertationen_US

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