BIOLOGICAL POLLUTION - Marine Pollution: What Everyone Needs to Know - page 203

control the spread of invasive species in the Mediterranean
Sea. The app, which includes an identification guide to the
most important invasive species found in the Mediterranean,
will help to spot invasive species in marine protected areas
so that monitoring and control programs can be put in place
quickly before they damage native species.
What can be done after an invasive species has arrived?
Once a species has arrived in a new area it is important to
locate it and take action very quickly, before it has a chance
to establish and spread. This can be difficult. Eradication suc-
cesses are rare in the marine environment. But if an invader is
found while it occupies a relatively small area, it may be eradi-
cated if the response is quick enough. Surveys are important
and can be site-specific, such as in ports where species may be
introduced, or species-specific (targeting those that are known
to pose high risks). Surveys can be carried out by organiza-
tions with responsibility for detecting invasive species.
An eradication of the brown mussel Perna perna from a
deep soft-sediment area in New Zealand was undertaken
following its discovery among fouling organisms physically
removed from a drilling rig. A total of 227 dredge tows were
undertaken, removing about 35 tons of material that had been
removed from the rig, and which was disposed of in a land-
fill. The removal of these bivalves from relatively deep (>40
m) soft sediments indicates that, with appropriate tools and
other resources (including substantial funding), eradication is
feasible even in challenging environments. They did not claim
to have removed all the mussels, but said that when total elim-
ination is not feasible, density-based success criteria can be
developed that can effectively mitigate risks.
A relatively small Caulerpa infestation in Southern
California was spotted and quickly eradicated by covering the
seaweed with plastic sheets and poisoning it with chlorine.
The cost of this eradication was $2.33 million in 2000-2001,