Every year, a small group of harbour porpoises traverses a narrow strait from the Black Sea to the Sea of Asov, then returns again, in a natural migration cycle. Since prehistory, these Black Sea porpoises have been isolated, evolving separately from other porpoises, becoming smaller, but with larger snouts. They’re sleek and cute, with eyes and mouths that have the perpetual hint of a smile.
The small but spectacularly beautiful comb jelly Mnemiopsis leydyi, can reproduce at a dismaying speed, and copes with warm and cold water and even different amounts of salinity. And when it spreads to areas where it isn’t naturally found, it can cause devastating damage. As in the Black Sea in the 1980s.
