title: Multidimensional approach to invasive species prevention.
abstract: Nonindigenous species (NIS) cause global biotic homogenization and extinctions, with commercial shipping being a leading vector for spread of aquatic NIS. To reduce transport of NIS by ships, regulations requiring ballast water exchange (BWE) have been implemented by numerous countries. BWE appears to effectively reduce risk for freshwater ports, but provides only moderate protection of marine ports. In the near future, ships may be required to undertake ballast water treatment (BWT) to meet numeric performance standards, and BWE may be phased out of use. However, there are concerns that BWT systems may not operate reliably in fresh or turbid water, or both. Consequently, it has been proposed that BWE could be used in combination with BWT to maximize the positive benefits of both management strategies for protection of freshwater ports. We compared the biological efficacy of "BWE plus BWT" against "BWT alone" at a ballast water treatment experimental test facility. Our comparative evaluation showed that even though BWT alone significantly reduced abundances of all tested organism groups except total heterotrophic bacteria, the BWE plus BWT strategy significantly reduced abundances for all groups and furthermore resulted in significantly lower abundances of most groups when compared to BWT alone. Our study clearly demonstrates potential benefits of combining BWE with BWT to reduce invasion risk of freshwater organisms transported in ships' ballast water, and it should be of interest to policy makers and environmental managers.
authors.affiliation: Great Lakes Laboratory for Fisheries and Aquatic Sciences, Fisheries and Oceans Canada, 867 Lakeshore Road, Box 5050, Burlington, Ontario, L7R 4A6. elizabeta.briski@dfo-mpo.gc.ca
authors.forename: Elizabeta
authors.initials: E
authors.lastname: Briski
authors.forename: Lisa E
authors.initials: LE
authors.lastname: Allinger
authors.forename: Mary
authors.initials: M
authors.lastname: Balcer
authors.forename: Allegra
authors.initials: A
authors.lastname: Cangelosi
authors.forename: Lana
authors.initials: L
authors.lastname: Fanberg
authors.forename: Tom P
authors.initials: TP
authors.lastname: Markee
authors.forename: Nicole
authors.initials: N
authors.lastname: Mays
authors.forename: Christine N
authors.initials: CN
authors.lastname: Polkinghorne
authors.forename: Kelsey R
authors.initials: KR
authors.lastname: Prihoda
authors.forename: Euan D
authors.initials: ED
authors.lastname: Reavie
authors.forename: Deanna H
authors.initials: DH
authors.lastname: Regan
authors.forename: Donald M
authors.initials: DM
authors.lastname: Reid
authors.forename: Heidi J
authors.initials: HJ
authors.lastname: Saillard
authors.forename: Tyler
authors.initials: T
authors.lastname: Schwerdt
authors.forename: Heidi
authors.initials: H
authors.lastname: Schaefer
authors.forename: Matthew
authors.initials: M
authors.lastname: TenEyck
authors.forename: Chris J
authors.initials: CJ
authors.lastname: Wiley
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Bailey
mesh_terms: D003247:Conservation of Natural Resources / Q000379:methods*; D016983:Enterococcus / Q000254:growth & development; D004926:Escherichia coli / Q000254:growth & development; D006114:Great Lakes Region; D052836:Heterotrophic Processes; D058865:Introduced Species; D012767:Ships; D018508:Water Purification