Both plants and algae use the process of photosynthesis to absorb carbon dioxide from their environment and use the sun’s energy to convert that carbon into sugar and oxygen. But unlike eelgrass, algae are not plants. Algae lack the specialized tissues (known as xylem and phloem) that plants use to transport water and nutrients. Instead of leaves, algae have blades (sometimes the leaves of grasses are referred to as ‘blades’, however the term ‘leaf/leaves’ is never used for algae and seaweed). Algae do not have root systems like eelgrass. Instead, algae have holdfasts which they use to anchor themselves to rocks, shells, debris and other hard substrates. The holdfast does not aid in nutrient absorption like roots; algae absorb nutrients from the water directly through their blades. You may find holdfasts of some of the larger species of kelp still attached to mussel shells and rocks on the beach.
Although they are different organisms, both eelgrass and algae are incredibly important to our coastal marine ecosystems because of their ability to oxygenate the water, dampen wave energy and provide habitat for hundreds of other species.
If you find something on the beach and want to learn more about it, feel free to reach out and send a photograph to the FISM Coordinator, Connor Jones (email@example.com).