February 21

Afternoon temperatures are in the low 60’s under sunny skies as I make my way along a section of southern California shoreline, southeast of White Point Park, for my annual solo tide pool exploration. At the first pool, I pause to watch a small snail shell, occupied by a Hermit crab, crawl along the sandy bottom. Since these crabs (stock photo) lack a hard carapace, they use empty shells for partial containment and protection from predators. Nearby, I spot a Sunburst Anemone clinging to the rocks. These colorful creatures feed by firing harpoon-like filaments into their prey when they touch their tentacles, injecting a paralyzing neurotoxin and guiding them into their mouths. However, out of the water, these colorful creatures fold in their tentacles and expose their adhesive sides that are covered with bits of shell, rock and seaweed. Moving down the beach, I notice the parallel layers in the rocks at my feet and realize these are the eroded ends of a sedimentary formation that had been laid down millions of years ago and subsequently uplifted, folded by tremendous geological forces and now exposed by an ebb tide. At another tide pool, I notice a patch of reddish Coralline algae and a clump of Kelp with its air-filled bladders that keep their long stems afloat. Along the exposed beach, I watch an immature gull foraging for whatever the intertidal zone has to offer. Exploring rock faces near shore, I come upon a cluster of Mussels. These bivalve mollusks secrete protein fibers, called byssal threads. from a gland in the foot that secures them to hard surfaces and to each other. Another rock displays a few tiny Limpets. These small herbivorous marine snails feed by scraping the rock’s surface with a strong, toothy organ called a radula. It is very difficult for sedentary animals or plants to become established in their territory because they scrape it clean in a relatively short period of time. Soon, I observe a rock displaying a variety of organisms including a ½ inch Chiton with its coat-of-mail shell resembling the segmented armor on a knight's gauntlet. These marine mollusks have a relatively good fossil record, stretching back 400 million years. On my last rock face, I see more limpets along with masses of tiny barnacles. These creatures feed through feather-like appendages called cirri. As the cirri rapidly extend and retract through the opening at the top, they comb the water for microscopic organisms. 

Ocean recedes

Ebb the tide

Shallow pools

Creatures reside

Anemones

Tiny crabs

Piles of kelp

Rocky slabs

Water floods

Surging flow

Nature’s cycle

What a show!

D. DeGraaf