At the marine biology day today, the first presentation by Rob Leewis.
His subject was invasive animal species in Dutch sea water.
As, for instance, international shipping increases, more new animal species than before find their way to Dutch waters.
The biggest share, 20%, of those new species arriving, is on ships’ hulls.
Many of those species do not survive in the long run.
Of those that do, only a small minority causes real ecological and/or economical problems.
One of those is the sea squirt Didemnum, which increased dramatically in Zealand province after the harsh winter of 1996 had harmed many of its competitors and predators.
Another new species, the leathery sea squirt, did not increase so strongly.
Invasive seaweed and marine animals in Scotland: here.
Gobies in Pacific coral reefs: here.
Tubesnout fish lays eggs in sea squirts: here.