When you think of seaweed, you probably don't think of forests. But if you could walk along the bottom of the ocean, somewhere off the coast of northern California, into an area where giant kelp grows, you would describe that area as an underwater forest.
Kelp is a brown seaweed, and giant kelp is the largest seaweed in the world. Some kelp grows more than 300 feet longthe height of a good-sized redwood tree.
A giant kelp is not a tree, of course. (Although a few kinds of trees grow in water, no tree grows underwater.) But a giant kelp looks something like a tree. It has a thick stem with leaf-like blades growing along it. A root-like structure called a holdfast is at the base of the stem, holding the kelp to rocks on the ocean floor. As the ocean water moves, the giant kelp sways with it, just as trees sway in the wind.
A community of giant kelp is called a forest because so many of these large plants grow so close together over large areas. A human swimmer would seem tiny in comparison to these plants and the areas that they cover.
Just as many animals are part of a forest on land, many animals are part of the giant kelp forest, too. Sea otters live in this forest, diving down into the water to collect their food. A favorite food item is the abalone, a kind of snail that holds tightly onto rocks on the ocean floor.
A sea otter, which looks somewhat like a seal, so loves to eat abalone that it will work very hard to get some. It must dive down deep to find one, and then pry it off its rock. Once the otter has this prize, it clasps the abalone to its belly and floats upward through the giant kelp to the surface. There, while floating on its back, the otter uses a rock to smash the abalone shell and enjoy the fleshy abalone meat inside.
BONUS: Color the Sea otters eat abalone