Environmental Engineering Reference
In-Depth Information
The Transfer of Harmful Aquatic Organisms
and Pathogens with Ballast Water and Their
Impacts
Stephan Gollasch , Dan Minchin , and Matej David
Abstract
The annual number of new species records world-wide has paralleled
shipping and is increasing. For example, in ICES member countries a new introduc-
tion forming a new population beyond its natural range occurs approximately every
9 weeks. The introduction of non-indigenous species by ships' ballast water is
known since more than 100 years, but it was not until 1970s that the fi rst biological
samples from ballast water were taken. Since, more than 1,000 species were identi-
fi ed from ballast tanks, including human pathogens. It was estimated that 3,000-
7,000 different species are moved each day around the globe by ships and it was
concluded that shipping is the prime species introduction pathway with each vessel
having the potential to introduce a species. However, not all species fi nd a suitable
situation in the new environment, but it was suggested that >2,000 aquatic non-
indigenous species have been introduced world-wide, of which in minimum 850 are
likely introduced by ships. Not all introduced species are considered harmful, in
some cases this is quite the reverse, as some support important industries. However,
a number of introduced species had almost catastrophic and seemingly irreversible
impacts and all of the summed impacts amount to considerable costs of billions of
Euro annually. Consequently, a precautionary approach suggests that every vessel
transporting ballast water should be treated as a potential risk by enabling introduc-
tions of harmful species. This chapter summarises key aspects of the current knowl-
edge on species transfers with vessels ballast water.
Keywords
Non-indigenous species Cryptogenic species Harmful aquatic organ-
isms Human pathogens Impact Invasion rate Shipping Ballast water
Biofouling
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