Marine dinoflagellate cysts in the ballast tank sediments of ships entering the Laurentian Great Lakes

摘要: One of the greatest threats to ecological health Laurentian Great Lakes is introduction non-indigenous species (Mills et al. 1993). The have a long history introductions with significant and economic consequences. Since opening St. Lawrence Seaway in 1959, approximately 65% all into been attributed ballast water release (Ricciardi 2006). Because concern its potential for species, U.S. Coast Guard promulgated regulations 1993, requiring ships inbound exchange open ocean water. Despite these new regulations, discovery rate increased after mandatory controls were implemented (Holek 2004). Unfortunately, most entering are exempt from 1993 regulations. majority since loaded cargo declared as ‘no on board’ (NOBOB) ships. These NOBOB carry residual sediments their tanks. Once discharge sediment during off-loading loading outbound cargo. represent greater risk than ballasted (Duggan 2005). found tanks contain variety live organisms, resting stages, cysts, spores, andeggsofalgaeand invertebrates Resting stages ofmany algaemay remain viable decades or even centuries (Sicko-Goad 1986) can germinate under favorable environmental conditions. Dinoflagellate cysts already reported tank ports saltwater (Hallegraeff& Bolch 1992,Hamer 2001). non-indigenous, toxic dinoflagellate Gymnodinium catenatumGrahamwas introduced Tasmania, Australia, caused closure Tasmanian shellfish farms 1986 1987 (Hallegraeff & 1992). purpose this study was examine presence marine dinoflagellates. Marine dinoflagellates common component marine-going ships, but abundance composition has not determined freshwater ports, such those Lakes.