Environmental Engineering Reference
In-Depth Information
Table 2 Anthropogenic introduction vectors of aquatic organisms
Anthropogenic vectors
Vessels Accidental with vessel fouling (including boring into wooden hulls)
Accidental with ballast water
Accidental with solid ballast (e.g., rocks, sand)
Accidental with anchor chains and in chain lockers
Fisheries Deliberate translocations of fi sh and shellfi sh to establish or support
aquaculture
Accidental with deliberate translocations of fi sh and shellfi sh (e.g.,
epi- and endobionts as well as parasites and disease agents)
Accidental with discharge of material from fi sh and shellfi sh processing
plants
Accidental with seaweed packing material for bait and fi shery products
Plant introductions Deliberate translocation of plant species (e.g., for erosion control)
Accidental with deliberate plant translocations
Biocontrol Deliberate translocation for biocontrol
Accidental translocation with deliberate biocontrol release
Canals Range expansion through man-made canals
Individual release Deliberate and accidental release by individuals (e.g., from aquaria)
Equipment used for recreation (e.g., diving bags, boats)
Scientifi c release Deliberate and accidental release as a result of research activities
Enhanced after Hewitt and Hayes ( 2002 ). With kind permission of Springer Science+Business
Media
In different world regions the importance of species introduction vectors var-
ies. Nevertheless, in all regions considered the most important three vectors are
(possibly in different order): ballast water, hull fouling, and aquaculture, so that
shipping is considered to be the worldwide principal pathway by which species
are spread (see chapter The Transfer of Harmful Aquatic Organisms and
Pathogens with Ballast Water and Their Impacts ). The vector identifi cation for
each species is extremely challenging as several species may be related to more
than one vector. Vectors overlap which makes many of them indistinctive (Minchin
2007 ), as shown in Fig. 1 .
All these overlapping vectors and multiple possibilities often create uncertainties
regarding the vector identifi cation and assignment. However, this information is
very critical for vector management purposes. Different levels of certainty can be
assigned to each vector (e.g., in the non-indigenous species database of the DAISIE 3
project three levels of certainty (i.e., direct evidence, likely, unspecifi ed) are avail-
able for each transfer vector). This database is currently being updated and expanded
during the EU-funded VECTORS project and it is expected that the new database,
named AquaNIS, 4 will become publicly available in 2015. A vector identifi cation is
important to make vector management effi cient, i.e., to regulate the most important
species introduction vector fi rst.
3 Delivering Alien Invasive Species Inventories for Europe (DAISIE).
4 http://www.corpi.ku.lt/databases/index.php/aquanis . last accessed December 2013.
 
Search WWH ::




Custom Search