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Management strategy and

actions against invasive species

The relationship with all the different activities performed The methods for addressing invasive alien species in
within or in close proximity to MPAs which may act as MPAs need to be site specific and appropriate to the
dispersal vectors for potentially damaging species is the key particular conditions of each site and to the species
to the management of present and future introductions of concerned. Eradication of some species may be possible
when an introduced species is identified at an early stage
alien species in protected areas. Regulations, monitoring
of colonization and still has a limited spatial distribution.
and awareness raising among fishing and recreational boat
owners may help greatly to reduce the establishment of new
species. Awareness is particularly important not only within
MPAs but also in their surrounding areas to reduce
continuous spillover effects from adjacent areas. Educational
displays addressing aquarium retailers and hobbyists can
also help to prevent escapes from aquariums.

Preventing the establishment of new invasive species
should be treated as the top priority. Experience has
demonstrated that, once a species is established, prompt
control measures may still be effective although they are
time consuming and require considerable effort.

The National Park of Port Cross has explored a variety of
methods to control the spread of the killer alga Caulerpa
taxifolia, and now follows a well-structured planning and
management protocol to control and eradicate it in different
areas of the park (Cottalorda et al., 2010). As the alga can be
spread by vessel anchors, diving equipment and fishing nets,
management regulations aimed at restricting the further
propagation of Caulerpa include a ban on anchoring by
recreational vessels and on fishing in high-risk areas, the
restricted use of buoys for mooring and diving, and
awareness-raising activities.
Management also involves a good monitoring programme
with volunteer divers and technicians that every year mark out
the newly colonized zones so that more experienced workers
can then work to eradicate the new colonies through manual
harvesting and the use of opaque plastic sheeting to restrict
the plants’ photosynthesis. These measures have made it
possible to significantly slow down the expansion of Caulerpa
taxifolia within the National Park boundaries.

Eradicating Caulerpa taxifolia in Port Cros MPA (France).
Photo: A. Rosenfeld - Port Cros National Park

Monitoring. Photo: S. Ruitton - Port Cros National Park

Monitoring Marine Invasive Species in Mediterranean MPAs: A strategy and practical guide for managers 23