An extraordinary Karenia mikimotoi "beer tide" in Kachemak Bay Alaska

Publication date: Available online 3 December 2019Source: Harmful AlgaeAuthor(s): Mark Vandersea, Patricia Tester, Kris Holderied, Dominic Hondolero, Steve Kibler, Kim Powell, Steve Baird, Angela Doroff, Darcy Dugan, Andrew Meredith, Michelle Tomlinson, R. Wayne LitakerAbstractIn autumn of 2013 an immense dinoflagellate bloom developed in Kachemak Bay, AK, USA. Much of the Bay was discolored a dark amber color and raised public concerns as small scale fish kills were reported in a few locations. Light microscopy revealed a monospecific bloom of gymnodinoid dinoflagellates that were previously unknown from the Bay. Gene sequencing of SSU rDNA from cells collected from the bloom confirmed the causative species to be Karenia mikimotoi. This represents the first report of a K. mikimotoi bloom in Alaska. After the bloom organism was confirmed, a K. mikimotoi species-specific qPCR assay was developed and used to assess K. mikimotoi abundances in DNA extracted from phytoplankton samples from Kachemak Bay and Lower Cook Inlet (LCI) obtained over a six-year period. The K. mikimotoi abundances were compared with corresponding time series of environmental variables (water temperature, salinity, water column stability, nutrients, precipitation and wind speed) to assess the factors contributing to the development of the bloom. The results showed early bloom development occurred in August when snow melt reduced salinities and increased water column stability during a period of calm winds. ...
Source: Harmful Algae - Category: Environmental Health Source Type: research