The Effects of Freshwater Flushing on Marine Heterotrophic Protists – Implications for Ballast Water Management

• Published in: Marine pollution bulletin Vol. 42; no. 11; pp. 1082 - 1086
• Main Authors: Hülsmann, N, Galil, B.S
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.11.2001; Elsevier
• Subjects: Animal, plant and microbial ecology; Animals; Applied ecology; ballast management; ballast water; bioinvasions; Biological and medical sciences; Cochliopodium bilimbosum; Condylostoma arenarium; Conservation, protection and management of environment and wildlife; Eukaryota; Food Chain; Freshwater; freshwater flushing; Fundamental and applied biological sciences. Psychology; General aspects; heterotrophic protists; Labyrinthula; Marine; open-ocean exchange; Platyamoeba murchelanoi; Pontifex maximus; Population Dynamics; Protista; Ships; Thecamoeba orbis; Water Movements; Water Pollutants; Pacific Ocean; North Atlantic; Atlantic Ocean; North Pacific; heterotrophic protists; open-ocean exchange; ballast management; bioinvasions; freshwater flushing; ballast water; Marine animal; Protozoa; Fresh water; Environmental factor; Environmental management; Survival; Invasion; Salinity; Marine environment; Rhizopoda; Aquatic environment; Faunal survey; Ciliata; Ballast tank
• ISSN: 0025-326X; 1879-3363
• DOI: 10.1016/S0025-326X(01)00087-X

Survivorship of ballast-entrained marine heterotrophic protists was examined following freshwater flushing. The recovered taxa, including typical marine rhizopods such as Platyamoeba murchelanoi, Labyrinthula spp, Pontifex maximus, Thecamoeba orbis, and the ciliate Condylostoma arenarium, were reared in waters of various salinities. After 2 months, the original salinity subsample retained five protist taxa, the freshwater six, including the amoeba Cochliopodium bilimbosum, the brackish water 22 taxa, and the seawater 19 taxa. Since protists form a major component of marine microbial food webs, their survival may be instrumental in supporting complex ballast-entrained food webs. Our study raises questions as to the reliability of open-ocean exchange (OOE) or freshwater flushing as effective control measures.