General Fisheries Commission for the Mediterranean - GFCM

Climate change and non-indigenous species

The Mediterranean and the Black Sea already show significant evidence of climate-induced changes. The region is warming 20 percent faster than the rest of the globe, and a number of additional drivers are making impacts in the region. Current predictions identify this region as one of those likely to be most affected by global warming, with changes including increases in sea surface temperature and salinity, more frequent heat waves and other extreme events, sea level rise, decreased precipitation, and changes in oceanographic circulation.  

Another change is an increase in the presence of non-indigenous species, which are species introduced outside their natural past or present range which might survive and subsequently reproduce. They can harm local ecosystems in several ways: by expanding rapidly and outcompeting indigenous species in the quest for space, food or other factors; by preying upon indigenous species; or by introducing diseases to which indigenous species are not resistant. But they also offer opportunities for fishers in a quickly changing ecosystem.

In the Mediterranean and the Black Sea, non-indigenous species mainly enter by different means through the Strait of Gibraltar and the Suez Canal. Climate change, overfishing and habitat degradation sometimes create enabling conditions for these species (e.g. tropical species) to survive and thrive.

Non-indigenous species can have negative impacts on fisheries, for example by outcompeting traditional target stocks; however in some cases the new arrivals can offer potential for commercial exploitation. 

The GFCM drives efforts to study the impacts of climate change on marine habitats and ecosystems in general, and on fisheries and living marine resources in particular. It also works to mitigate the negative impacts of non-indigenous species, while assessing and managing the potential new opportunities they bring. In both cases, the GFCM aims to devise practical adaptation mechanisms to integrate into fisheries management. 


  • Assessment of the vulnerability of fisheries to climate change, according to a standard methodology, through subregional case studies.
  • Compilation of information to create a non-indigenous species (NIS) monitoring network, including work on early detection of new species and significant changes in NIS abundance as well as biological and/or socio-economic impacts at the subregional level.
  • Implementation of regional research programme for rapa whelk fisheries in the Black Sea and research programme on blue crabs in the Mediterranean, to collect data to inform assessments and potential management measures for NIS that become target fisheries.
  • Collaboration on the joint GFCM-UN Environment/MAP pilot project on non-indigenous species in the eastern Mediterranean, to provide a common reference and standard guidance for monitoring NIS through subregional monitoring plans.
  • Study of interactions between NIS and fisheries as well as their linkages with climate change.
  • Development of a regional adaptation strategy for climate change and non-indigenous species. 




  • NIS Pilot & Climate Change Workshop Reports | GFCM