Were the animals sunk to hide the dead bodies, or were they sunk as they had been experimentally drugged causing their death?
This seems to have been well hidden and not mentioned in any of the Penn Cove capture information, I have never seen it in any other document other than this one done by SeaWorld. SeaWorld also strangely question Mitchell's research on the size and sex of the captures, detailed in Table 2.
The Southern Resident community of the Northeast Pacific lost 48 of its members to captivity. By 1976, only 80 killer whales were left in the community, which remains endangered. With subsequent captures, the theme parks learned more about avoiding injury during capture and subsequent care of killer whales, and discovered that they could be trained to perform tricks, a great attraction to visitors. As commercial demand increased, growing numbers of Pacific orcas were captured, peaking in 1970.