Bryozoans are colonies of individual little animals that look like moss or weed, and each has tentacles and cilia for food gathering. Here they are growing on a sea squirt. Oyster - All over everywhere, especially on pilings and spread over mud flats. Very much edible, and there are still a few beds around where shellfishing is allowed. Some are red, some yellow.
Different species occur during different seasons.
Sea Spider - Not a real spider, this black bunch of legs in the center of the picture is attached the the skinniest body you can imagine. They feed on amemones, corals and byrozoans.