An interesting factor in coastal areas is kelp. Kelp beds are overgrazed, and they're a spawning ground and haven for many little critters. It's not relevant for salmon, who spawn upstream in rivers, but it is for their fry and a lot of other species.
Here's some info about efforts to replant. Kelp is a very interesting plant:
"Kelp beds are known as the rainforest of the ocean."
http://www.acfnewsource.org/environm...ting_kelp.html