Gymnodiniod genera Karenia and Takayama (Dinophyceae) in New Zealand coastal waters

New Zealand has been subject to massive blooms of gymnodinoid dinoflagellates over the last decade and in some instances marine biota mortalities. Respiratory problems for people impacted by aerosols from these blooms have occurred. However, because of the difficulty in definitively identifying gymnodinoid dinoflagellates, the identities of the causative organisms have not always been established with certainty. This paper documents the occurrence of several newly described species in the genera Karenia and Takayama in New Zealand's coastal waters as determined by analysis of DNA sequence data. The species include Karenia umbella de Salas, Bolch & Hallegraeff, Takayama helix de Salas, Bolch, Botes & Hallegraeff, and T. tasmanica de Salas, Bolch & Hallegraeff, which are known to have caused fish kills in Tasmanian (Australia) waters in the past. Liquid chromatography-mass spectrometry analyses of mass cultures of these dinoflagellates have been negative for neurotoxic brevetoxins. The species designation of several unidentified gymnodinoid species (designated Gymnodinium sp.) isolated from New Zealand waters and maintained in the Cawthron Collection of Microalgae were also identified on the basis of their DNA sequences. © The Royal Society of New Zealand 2005.