title: Phytoplankton biomass and composition in a well-flushed, sub-tropical estuary: The contrasting effects of hydrology, nutrient loads and allochthonous influences.
abstract: The primary objective of this study was to examine trends in phytoplankton biomass and species composition under varying nutrient load and hydrologic regimes in the Guana Tolomato Matanzas estuary (GTM), a well-flushed sub-tropical estuary located on the northeast coast of Florida. The GTM contains both regions of significant human influence and pristine areas with only modest development, providing a test case for comparing and contrasting phytoplankton community dynamics under varying degrees of nutrient load. Water temperature, salinity, Secchi disk depth, nutrient concentrations and chlorophyll concentrations were determined on a monthly basis from 2002 to 2012 at three representative sampling sites in the GTM. In addition, microscopic analyses of phytoplankton assemblages were carried out monthly for a five year period from 2005 through 2009 at all three sites. Results of this study indicate that phytoplankton biomass and composition in the GTM are strongly influenced by hydrologic factors, such as water residence times and tidal exchanges of coastal waters, which in turn are affected by shifts in climatic conditions, most prominently rainfall levels. These influences are exemplified by the observation that the region of the GTM with the longest water residence times but lowest nutrient loads exhibited the highest phytoplankton peaks of autochthonous origin. The incursion of a coastal bloom of the toxic dinoflagellate Karenia brevis into the GTM in 2007 demonstrates the potential importance of allochthonous influences on the ecosystem.
authors.affiliation: Fisheries and Aquatic Sciences Program, SFRC, University of Florida, 7922 NW 71st Street, Gainesville, FL 32653, USA.
authors.forename: J A
authors.initials: JA
authors.lastname: Hart
authors.affiliation: Fisheries and Aquatic Sciences Program, SFRC, University of Florida, 7922 NW 71st Street, Gainesville, FL 32653, USA. Electronic address: Phlips@ufl.edu.
authors.forename: E J
authors.initials: EJ
authors.lastname: Phlips
authors.affiliation: Fisheries and Aquatic Sciences Program, SFRC, University of Florida, 7922 NW 71st Street, Gainesville, FL 32653, USA.
authors.forename: S
authors.initials: S
authors.lastname: Badylak
authors.affiliation: Guana Tolomato Matanzas National Estuarine Research Reserve, 505 Guana River Road, Ponte Vedra, FL 32082, USA. Electronic address: nikki.dix@dep.state.fl.us.
authors.forename: N
authors.initials: N
authors.lastname: Dix
authors.affiliation: Guana Tolomato Matanzas National Estuarine Research Reserve, 505 Guana River Road, Ponte Vedra, FL 32082, USA.
authors.forename: K
authors.initials: K
authors.lastname: Petrinec
authors.affiliation: Georgia Southern University, Department of Biology, Statesboro, GA 30460, USA. Electronic address: alorenmathews@gmail.com.
authors.forename: A L
authors.initials: AL
authors.lastname: Mathews
authors.affiliation: St. Johns River Water Management District, 4049 Reid Street, Palatka, FL 32177, USA. Electronic address: wgreen@sjrwmd.com.
authors.forename: W
authors.initials: W
authors.lastname: Green
authors.affiliation: Fisheries and Aquatic Sciences Program, SFRC, University of Florida, 7922 NW 71st Street, Gainesville, FL 32653, USA.
authors.forename: A
authors.initials: A
authors.lastname: Srifa
mesh_terms: D044822:Biodiversity; D018533:Biomass; D063366:Estuaries; D005068:Eutrophication; D005431:Florida; D062070:Hydrology; D010839:Phytoplankton / Q000145:classification / Q000502:physiology*; D012621:Seasons
keywords: Climate change; Eutrophication; Guana Tolomato Matanzas estuary; Karenia brevis; Red tides; Water residence time