Dolphins causing porpoise deaths in Monterey

[Cetacea]

Monterey Bay researchers say dolphins are causing porpoise deaths

For the past five years, the growing number of dead harbor porpoises washing up on California shores has been a marine mystery — until now.

In September, marine biologists with Okeanis, a nonprofit conservation group based in Moss Landing, captured the only video footage taken in Monterey Bay of bottlenose dolphins attacking and killing a porpoise.

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Not a novel behaviour as such but confirms that it's a global occurence rather than a rare behaviour in an isolated population.