“Many of the pressures have hit here much earlier and more intensely than in other world regions,” said Thorsten Reusch, a marine ecologist based here at Germany’s largest ocean research institute.
That is in part due to the Baltic’s small size: It is roughly the size of California, or 1/250th of the Atlantic. It is also tucked between nine countries — including Sweden to the north, Russia to the east and Germany to the south — whose residents pollute and dump waste into, travel over and swim through its delicate marine ecosystems.
As a result, conditions have been changing rapidly. The temperature of the Baltic has risen at roughly three times the average rate of global oceans over the past decade. It has experienced a tenfold expansion of no-oxygen “dead zones” that wipe out fish and their habitats in the past 115 years. And it is seeing increasing levels of acidification.