Transfer of marine organisms: a challenge to the conservation of coastal biocoenoses.

1. The global transfer of species across the world’s oceans is an increasing threat to the
biodiversity of the sea and particularly of coastal areas: the magnitude of this peculiar aspect of
global change and the significance of its effects on ecosystems are currently debated.
2. The paper addresses, with reference to the Mediterranean situation, the main research needs
in coastal ecosystem conservation, such as the availability of baseline assessment of native and
non-indigenous species (including biogeography, taxonomy and historical records). Studies on the
transfer mechanisms and on the predictability of successful settlement by alien species are also
important.
3. Finally, management actions applicable to conservation issues are mentioned and discussed