EU Science Hub

Invading the Mediterranean Sea: human activities shape biodiversity patterns

Oct 01 2014

A JRC article published yesterday in Frontiers Press investigates how human activities have influenced biodiversity in the Mediterranean Sea through the introduction of alien species.


The key finding of this study is that the composition of marine communities, which in the past was shaped by climate, environment, and oceanographic barriers, now greatly depends on human activities. Activities such as shipping and aquaculture, and large-scale interventions such as the opening of navigational canals, have removed environmental barriers for marine species that can now easily be transferred far away from their natural range. Once arriving in new marine regions, such species are referred to as ‘alien’ species, and may have severe impacts on the ecosystems of these regions.


This study investigated how human activities, by assisting the introduction of alien species, may shape biodiversity patterns: the distribution of species and how they relate as marine communities. Using the Mediterranean Sea as a case study, it was found that the local composition of marine communities is greatly affected by major anthropogenic impacts, such as the Suez Canal that acts as a species introduction corridor from the Red Sea to the Mediterranean. In affected areas, food webs have profoundly changed since they are often dominated by alien species both in abundance and in numbers of species.


Certain groups of alien species were mostly introduced through specific pathways: fish through the Suez Canal, algae by aquaculture, and invertebrates through the Suez Canal and by shipping. Such introductions are expected to continue, and will keep affecting the biodiversity of the Mediterranean Sea. The authors call for further research in order to better understand how these changes will affect the structure and functioning of Mediterranean ecosystems, and ultimately, how they will affect humans via the services that people obtain from the sea.


Further information