Seaweeds in the intertidal zone at Cabrillo National Monument are very important to the sea life. They provide food for most of the sea slugs, snails and crabs. Equally important, these aquatic (non-vascular) plants also provide shelter for the animals. Most often the seaweeds are homes for juvenile animals. Seaweeds protect the young from strong currents, crashing waves and foraging predators, while surrounding them with plenty of food.
Seaweeds have also adapted to their environment. These aquatic plants are exposed to dry air during low tide and are submerged during high tide. To adjust to changing conditions, different plants have developed different adaptations. To keep from being eaten, some plants have developed tough branches that are hard to bite into – some have adapted so well that they have a calcareous shell that cannot be bitten into by small snails and crabs. Some plants are very dense and spongy, keeping in the moisture; others are succulent and sometimes woody, preventing moisture loss; and some are so small and grow so close to one another that they keep each other moist by storing water in their “colony.”
Last updated: January 4, 2016