Plants/Algae
Seagrasses and marine algae are primary producers, deriving energy from the sun through photosynthesis to form the base of the food web in the ocean. Seagrasses, including eel grass and surf grass, are flowering plants. They have roots, shoots and leaves, and bloom underwater, releasing pollen in long strands and forming seeds. Flowering plants evolved on land; a few genera, like Zostera and Phyllospadix in the temperate zone, returned to the sea. Algae lack true roots, leaves and flowers. They absorb nutrients and light through their blades, cling to the sea floor with holdfasts, and reproduce with spores. There are three groups of algae: brown, red, and green. Brown algae called kelps grow the largest and can be easily viewed from the surface. Giant kelp (Macrocystis) forms amber forests in nearshore habitats throughout the sanctuary. The most extensive forests occur along protected island shores. These kelp forests provide food and habitat for a large community of invertebrate and vertebrate species.