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Updated: Jul 6, 2026

Visualizing Oceanographic Data to Depict Long-term Changes in Phytoplankton
Published on: July 28, 2023
Changes in zooplankton abundance and diversity after ballast water exchange in regional seas
Tracy McCollin1, Aileen M Shanks, John Dunn
1Fisheries Research Services, Marine Laboratory Aberdeen, PO Box 101, 375 Victoria Road, Aberdeen AB11 9DB, United Kingdom. T.A.McCollin@marlab.ac.uk
Abstract:
A study of the efficiency of ballast water exchange (BWE) in regional seas was carried out to assess this management method in reducing the risk of introducing non-native species. Zooplankton samples were taken before and after exchange on ten voyages where BWE took place (North Sea, English Channel, Irish Sea and Bay of Biscay). Zooplankton abundance was always reduced after exchange, but diversity increased on eight occasions. The greatest changes occurred when the source port water was of low salinity and when exchange took place in deeper waters further from land. However, it was clear that BWE did not remove all the source port taxa and this method is unlikely to provide a consistent and effective method of managing ballast water in regional seas.
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