Diatom survivorship in ballast water during trans-Pacific crossings

• Published in: Biological invasions Vol. 12; no. 5; pp. 1031 - 1044
• Main Authors: Klein, Georgia, MacIntosh, Kayleigh, Kaczmarska, Irena, Ehrman, James M
• Format: Journal Article
• Language: English
• Published: Dordrecht Dordrecht : Springer Netherlands 01.05.2010; Springer Netherlands; Springer Nature B.V
• Subjects: Algae; Bacillariophyceae; Bacillariophyta; Ballast; ballast water; Biodiversity; Biomedical and Life Sciences; Biota; Developmental Biology; ecological invasion; Ecology; Freshwater & Marine Ecology; geographical distribution; Harbors; hydrochemistry; invasive species; Life Sciences; mid-ocean ballast water exchange; mortality; Nonnative species; Original Paper; Plant Sciences; population density; Sea transport; seawater; shipping; ships; Species composition; species diversity; Species richness; Survival analysis; trans-Pacific crossing; Water exchange; water temperature; British Columbia; Pacific Ocean; INE, Canada, British Columbia, Vancouver, Vancouver Harbour; Ballast exchange; Ballast water chemistry; Propagule pressure; Diatoms; Ballast water
• ISSN: 1387-3547; 1573-1464
• DOI: 10.1007/s10530-009-9520-6

Ship ballast water is believed to be responsible for global dispersal of alien biota; mid-ocean ballast water exchange is most commonly used to mitigate this process. Diatoms are among the most abundant biotic-component in ballast water, yet their invasive biology is poorly understood. To test effectiveness of MOE we examined diatom species composition and cell density in two sets of samples. First, we examined samples collected daily during one 24 days long trans-Pacific crossing in tanks with and without ballast exchanged. Second, we used samples from 23 trans oceanic vessels arriving at Vancouver harbour where diatoms were collected on arrival. Up to 86,429 live diatom cells/l were found in the tanks, ~50% of the samples share up to eight species consistently present. Cell densities and species richness declined over time and with replacement of coastal ballast water by mid-oceanic water. In both data sets diatoms survive in the tanks for as long as 33 days despite ballast exchange.