Seaweed Critical To Creatures' Survival

Kelp is really the largest form of algae, known as brown algae, and it really isn't dangerous despite my reaction at the time. Other marine algae include green and red varieties, and all algae living in saltwater are commonly referred to as seaweed. Not all the plantlike organisms in the sea are seaweed and some seaweed isn't really a plant. The sea grass common near Caribbean coral reefs and fed upon by sea turtles isn't seaweed; it's really a land plant living in water that possesses aquatic pollen. To make things even more complicated, kelp is one of the few forms of algae that isn't a plant! What all the above seaweedlike organisms have in common is that they use sunlight and carbon dioxide to make glucose (food) and oxygen in a process called photosynthesis, just like plants on land. The two products of photosynthesis make up two of the three reasons why seaweed is so important to fish and sea creatures. Fish, as with all animals, need to "breathe" oxygen and, of course, all animals need to find food to survive; they can't make their food like plants. Many smaller fish, sea urchins and mollusks feed on algae and then they in turn are fed upon by larger marine predators such as sea otters and seals. Unlike in a rain forest or even within a coral reef, most seas of the world are open habitats and organisms living in them are exposed to attack by predators...