another of that sea cucumber
It was getting tossed about in the surf, so it was hard to get a good photo, in focus and not washed over by a wave. So I took a bunch. (Another photo.)
I knew nothing about sea cucumbers before reading about them after seeing this one. Apparently the California sea cucumber is the largest on the Pacific coast of North America-- and this one seems to be about as large as they get, approaching two feet long. The bright red spikes look dangerous, but apparently they are soft and harmless. If the spikes don't keep predators away, the cucumber's last ditch defensive is-- so I've read-- "ejecting its digestive tract" and/or its respiratory system (some websites just said "internal organs). It seemed to me that was not "defensive" at all, but the idea, apparently, is that the predator will be "distracted" by the ejected organs (perhaps eating them?) while the cucumber makes its escape. They can regrow their organs, although I think in some cases they can't manage to recover.
Equally surprising, to me, was reading that people eat California sea cucumbers, or at least their "muscles". In fact, I repeatedly read that the California sea cucumber is the only sea cucumber commercially harvested in the Pacific Northwest.
Finally, I think I read that sea cucumbers prefer "rich waters", as in, I assume, nutrient rich. This one was in Saratoga Passage, the part of Puget Sound between Camano Island and Whidbey Island. Since the freshwater of the Skagit River, Puget Sound's largest, has to flow through Saratoga Passage to reach the main basin, I'm guessing it is likely a particular "rich" area.