Up-to-Date Biodiversity Changes in the Benthic Communities from the English Channel Under Climatic and Anthropogenic Pressures

Like most of the North Atlantic marine coastal area, the seawater temperature in the English Channel (EC) is showing an increase that began in the middle of the 1980s. Similarly, during the same period, there has been an increase in human activities (extraction of aggregates, harbour sediment dredging and spoil disposal, Offshore Wind Farms). This point of view examines and analyses the changes in biodiversity of benthic species and communities from the EC under climatic and anthropogenic pressures during the four last decades. Four main changes have been recorded: (1) additions to the checklist of benthic species, due to new prospections; (2) changes in the structure of benthic communities, due to human activities; (3) an increase in diversity due to the arrival of non-indigenous species, some of which have effects on the structure of benthic communities; and (4) eastward progression of temperate species, while some boreal species tend to disappear. Situated in temperate mid-latitudes bordering the North-eastern Atlantic, the EC is an excellent open laboratory to observe and understand the impact of climatic change and human activities on marine coastal ecosystems. Today, the increase in seawater temperature and the introduction of non-native species appear to be the main factors that explain the changes in benthic diversity in the EC.