Occurrence of sand-dwelling and epiphytic dinoflagellates including potentially toxic species along the coast of Jeju island, Korea

Abstract

Marine benthic (sand-dwelling and epiphytic) dinoflagellates consists of known potentially toxic species which are harmful to marine organisms as well as human by consumption of sea food, alerting scientists, aquaculture industry and government in mostly tropical and subtropical region. Occurrence and distribution of these species are less studied from temperate region. Occurrence and distribution of benthic dinoflagellates in the intertidal zone along the coasts of Jeju Island, Korea was determined by monthly collection of sand sediment and macroalgal samples from eight sampling locations from March 2011 to February 2012. Identification and taxonomic observations were made of the benthic dinoflagellate samples using light and epifluorescence microscopy. Thirty-seven dinoflagellate taxa belong to eighteen genera were identified. Among them, twenty six were found only in sand sediment, seven in macroalgal samples and four in both sand and macroalgal samples. Of the 37 species, nine were potentially toxic. The most frequently occurring species was Amphidinium carterae, followed by A. operculatum, Coolia malayensis and Ostreopsis ovata, occurred at all sampling stations. Gambierdiscus yasumotoi and Gambierdiscus sp. were rarely occurred. Monthly variations in number of occurring benthic dinoflagellates showed that higher number of species could be found during early of spring to early summer (March to June) with moderate to high salinity (26-34 psu) and low to moderate temperature (12-20°C). Epiphytic dinoflagellates did not show specific preference for macroalgal species as host. Potentially toxic species were present throughout the year, however, varied within the stations. These results suggest that diversified benthic dinoflagellates including several potentially toxic species occurring in Jeju Island, which may indicate a potential risk of toxicity in the marine ecosystem. © 2014 Academic Journals Inc.