Harbor porpoises on the decline in the German North Sea

The harbor porpoise population is declining in the German North Sea, according to a recent study which surveyed the species over a 20-year time period. Harbor porpoises are known as a “sentinel species” – animals which indicate the health of an ecosystem and point to potential risks (think of the canary in the coal mine) – and their decreasing numbers indicate the extent to which human activities have affected marine wildlife.
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