The Mediterranean, Black, and Caspian Seas represent three fragments
of the former Tethys Sea, and are thus of great interest to
understanding the evolution of the entire region where Eurasia,
Africa and the Arabian Peninsula meet. Fishing activity and maritime
traffic through the Dardanelles and Bosporus, and via the Lenin Canal
to the Caspian Sea, have greatly intensified. Moreover, all major
European rivers are now linked by canals, meaning that ships can
navigate from the mouth of the Volga to the Baltic, from the Danube
to the Rhine, and from there to all other major European Rivers. Such
an anastomosed system not only allows ships to pass between basins:
biota follow in their wake, and thus the Black Sea and Caspian fauna
and flora, long sequestered in their closed basins, are suddenly
given an opportunity to "escape". On the other hand, alien invaders
increasingly find their way to the three seas,as stowaways in ballast
water tanks or attached to the hulls. Some of the newcomers expanded
to enormous numbers in the receiving ecosystem, where they may cause
great economic damage. The book provides an up-to-date overview of
the situation in the Ponto-Caspian with regard to the jelly invasions
that have been perturbing the local pelagic ecosystems since the
early 1980s, contrasting that with biological invasions elsewhere, to
try and identify general underlying principles.