"California sea lions have found plentiful salmon -- and easy to catch -- at the foot of the Bonneville Dam." Image and caption credit:Thomas Boyd/The Oregonian
To be clear at the outset, I am in favor of doing whatever it takes to sufficiently reduce Sea Lion predation of salmon at the base of Bonneville Dam. Sea Lions populations are well recovered from their seriously endangered status; whereas the future of wild salmon is seriously in doubt - likely worsening. Humans put both species in jeopardy and humans have a responsibility to assist in recovery of both. (An assertion make purely on sunk costs and ethics - I like salmon and sea lions equally.)
The Oregonian has excellent coverage of the controversy over managing the Sea Lion predation - about which no one is satisfied. Blogging can not do it justice. A short excerpt follows but please read the whole thing if you have time.
To be killed, a sea lion has to be seen eating salmon at the dam between Jan. 1 and May 31, be identified at the dam for five days and be shown to return after it's subjected to nonlethal hazing.
When the program began in 2008, estimates were that 30 California sea lions a year would be killed or taken to zoos or aquariums. About three years in, the total stands at 35, counting four that accidentally died in traps in 2008.
The Case of San Francisco's Disappearing Sea Lions :