title: PSP toxin levels and plankton community composition and abundance in size-fractionated vertical profiles during spring/summer blooms of the toxic dinoflagellateAlexandrium fundyensein the Gulf of Maine and on Georges Bank, 2007, 2008, and 2010: 1. Toxin levels.
abstract: As part of the NOAA ECOHAB funded Gulf of Maine Toxicity (GOMTOX) project, we determinedAlexandrium fundyenseabundance, paralytic shellfish poisoning (PSP) toxin composition, and concentration in quantitatively-sampled size-fractionated (20-64, 64-100, 100-200, 200-500, and > 500 μm) particulate water samples, and the community composition of potential grazers ofA. fundyensein these size fractions, at multiple depths (typically 1, 10, 20 m, and near-bottom) during 10 large-scale sampling cruises during theA. fundyensebloom season (May-August) in the coastal Gulf of Maine and on Georges Bank in 2007, 2008, and 2010. Our findings were as follows: (1) when all sampling stations and all depths were summed by year, the majority (94% ± 4%) of total PSP toxicity was contained in the 20-64 μm size fraction; (2) when further analyzed by depth, the 20-64 μm size fraction was the primary source of toxin for 97% of the stations and depths samples over three years; (3) overall PSP toxin profiles were fairly consistent during the three seasons of sampling with gonyautoxins (1, 2, 3, and 4) dominating (90.7% ± 5.5%), followed by the carbamate toxins saxitoxin (STX) and neosaxitoxin (NEO) (7.7% ± 4.5%), followed by n-sulfocarbamoyl toxins (C1 and 2, GTX5) (1.3% ± 0.6%), followed by all decarbamoyl toxins (dcSTX, dcNEO, dcGTX2&3) (< 1%), although differences were noted between PSP toxin compositions for nearshore coastal Gulf of Maine sampling stations compared to offshore Georges Bank sampling stations for 2 out of 3 years; (4) surface cell counts ofA. fundyensewere a fairly reliable predictor of the presence of toxins throughout the water column; and (5) nearshore surface cell counts ofA. fundyensein the coastal Gulf of Maine were not a reliable predictor ofA. fundyensepopulations offshore on Georges Bank for 2 out of the 3 years sampled.
authors: US FDA Center for Food Safety and Applied Nutrition, 5100 Paint Branch Parkway, College Park, MD 20740, USA.
authors: Jonathan R
authors: JR
authors: Deeds
authors: School for Marine Science and Technology, University of Massachusetts Dartmouth, 706 South Rodney French Boulevard, New Bedford, MA 02744, USA.
authors: Christian M
authors: CM
authors: Petitpas
authors: US FDA Center for Food Safety and Applied Nutrition, 5100 Paint Branch Parkway, College Park, MD 20740, USA.
authors: Vangie
authors: V
authors: Shue
authors: US FDA Center for Food Safety and Applied Nutrition, 5100 Paint Branch Parkway, College Park, MD 20740, USA.
authors: Kevin D
authors: KD
authors: White
authors: Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA.
authors: Bruce A
authors: BA
authors: Keafer
authors: Department of Applied Ocean Physics and Engineering, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA.
authors: Dennis J
authors: DJ
authors: McGillicuddy
authors: School for Marine Science and Technology, University of Massachusetts Dartmouth, 706 South Rodney French Boulevard, New Bedford, MA 02744, USA.
authors: Peter J
authors: PJ
authors: Milligan
authors: Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA.
authors: Donald M
authors: DM
authors: Anderson
authors: School for Marine Science and Technology, University of Massachusetts Dartmouth, 706 South Rodney French Boulevard, New Bedford, MA 02744, USA.
authors: Jefferson T
authors: JT
authors: Turner
keywords: Alexandrium sp; Georges Bank; Gulf of Maine; Harmful algal bloom; PSP toxins; Vectorial intoxication