Aquaculture 2022

February 28 - March 4, 2022

San Diego, California

OBSERVATIONS OF AN Akashiwo sanguinea BLOOM IN COASTAL GEORGIA USA AND ITS IMPACT ON OYSTER LARVAE

Elizabeth L. Harvey, Elizabeth Pfeiler , Justin Manley, Thomas Bliss

elizabeth.harvey@unh.edu



Harmful algal blooms (HABs) are a growing concern worldwide. In the state of Georgia, USA harmful algae have been observed in coastal estuaries, however bloom concentrations have not been observed. In the summer of 2017, in response to significant oyster larvae mortality at the University of Georgia’s Shellfish Research Laboratory (UGA SRL), a large, novel bloom of the dinoflagellate Akashiwo sanguinea , was recorded.  In 2017,  bloom concentrations peaked at ~2.5 x 105 cells L-1 in early July, followed by enhanced abundance in August. In 2018, peak abundance was significantly lower (~2.7 X 104 cells L-1) , and no bloom occurred in 2019. Abiotic and biotic factors were  also  investigated to explore drivers of  A. sanguinea  accumulation in the SRE, including transparent exopolymer particles (TEP), temperature, and concurrent community abundance . Investigation of past documentation found that periods of  enhanced  A. sanguinea abundance were coincident with previous oyster larvae mortality events experienced by the UGA SRL.  The work presented here highlights the importance of understanding the ecology of harmful algal bloom species in the Skidaway River Estuary, in light of the growing oyster aquaculture industry in coastal Georgia.