An Oregon State researcher is raising some new scientific doubts about the National Marine Fisheries Service Sea Lion biological opinion. Markus Horning has been tagging Sea Lions in Prince William Sound and finding that predators like Killer Whales and Sharks are killing a larger proportion of their pups than expected.
Based on this he has re-examined the data on the Aleutians population segments that are not recovering, and says predation could actually explain it.
“So the same data that past models have used, but we analyze it and look at it in a different way, and lo and behold, our model suggests that what in the past has been interpreted as a decline in birth rate may in fact have been driven by predation. It’s important to remember that all of these are models we are talking about, so they’re somewhat speculative. Including past models. So the past models that have suggested a decline in birth rate are models, and those suggestions or hypotheses have never been tested.”
Horning thinks he could do a tagging study to prove his theory, but federal officials haven’t permitted it because of concerns that it might harm the animals.