Monterey Bay researchers say dolphins are causing porpoise deaths
An organization called Okeanis has been observing the same group of 600 dolphins for almost 20 years. In September, they captured video of a group of dolphins ganging up and brutally killing a porpoise.
The dolphins corral the porpoise, ram it with their beaks, scrape or rake it with their teeth and drown the porpoise by jumping on top of it. The dolphins then bring the carcass up to the Okeanis researchers, watch them bring it on board and then swim away.
What surprises me most is not the attack, nor the techniques used to kill the porpoise, but the fact that the dolphins then brought the carcass to the researchers. Did Okeanis lure them to do so with a fish reward? How many other interactions have they had with these dolphins in the course of their years-long "observation" of these supposedly wild creatures? The Okeanis website does not give much information on their methodology.