What is marine connectivity
Connectivity is the extent to which populations in different parts of a species range are linked by the movement of eggs, larvae or other propagules. This movement is important information for marine spatial planning.
Marine plants and animals are not fixed in the seascape but may disperse or migrate from one place to another. If there is a lot of dispersal including genetic exchange between the populations, connectivity is high resulting in metapopulations sharing a (large) gene pool. When dispersal between populations is low, connectivity and genetic exchange is low. Populations will be more isolated and genetic diversity might become depleted.
In the Baltic Sea, many species are locally adapted to the low salinity and due to low connectivity genetically distinct from populations in the North Sea.