Question

These ocean "forests" are thought to have been very important to the first people who came down the coast.

Answer 1

An "Ocean forest" is kelp

Step-by-step explanation:

Kelp is a large ocean plant that grows in Arctic and shallow temperate waters around the world, forming “forests” that grow up from the “soils” of the seabed. Kelps are found along coastlines of all continents except Antarctica.