From a nonscientific perspective, I completely agree that each ecosystem needs to be examined individually, but I still believe that there is a direct relationship between prey and predators. The sea lions or the pelicans survive because they find a new prey on which to feed. It may not be the recognized primary food source when available, but whatever they switch to becomes a forage fish for them.
Yes, I am aware that the Lenfest program is funded by the PEW Foundation and where PEW gets its money. There are a lot of “circular” relationships on every side of the environmental equation. They all bear some level of scrutiny.