A Match to the Heart by Gretel Ehrlich

tides are strewn with red algae and green mermaid’s hair—seagrass, surfgrass and eelgrass—which is brushed back and forth in undulating waves. In the splash zone, village life seems to prevail: both shelled and soft creatures hide under rocks, between rocks, or fasten themselves to rocks in colonies, rigid in sweeping waters and in the continual flux of tides. Barnacles, anemones, jellyfish, starfish, sponges, hydroids, worms, chitons, mussels, clams, snails, octopuses, shrimps, crabs, lobsters, sea spiders, urchins, sea squirts and salps, algae, kelp, lichens and grasses—all crowd together in urban densities. Aggregate anemones often live in concentrations of three thousand individuals per square meter of rock; they are marine apartment dwellers.
    A tide pool is perhaps the one place where creatures can prosper by becoming completely sedentary and permanently attached. Barnacles spend their youths floating free before coming home to a rock and, once glued, they never leave again, never have to go in search of food because room service is provided by the waves bringing it to them. They merely extend legs to capture floating plankton; these legs are also the apparatus through which they breathe. Mussels are “gill-netters” They catch prey, pump water, and breathe through fleshy tubes that extend from the rear of their hinged shell.
    Because sessile creatures—ones that are permanently attached—are unable to “go with the flow,” they thrive on extremes : they’re either underwater or desiccating in hot sun. To avoid drying up during low tide, periwinkles and limpets keep so tightly closed that their respiration stops. They literally hold their breath until covered by water again.
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A regimen of daily walks took me into the middle of January. With each high tide more sand was removed, more rocks exposed, more sea creatures revealed. In dense fog a single red starfish, bright on wet sand, was the only thing visible and seemed to stand for the whole unseen galaxy. Up close they’re less than romantic. If barnacles and mussels represent tenacity—not only are they unmoving, but also very long-lived—then starfish are known for their voraciousness. Known as the “walking stomachs of the deep,” they eat continually, devouring everything in their path: oysters, clams, barnacles, and they sift through sand and mud for any bits of bottom garbage and carrion.
    A starfish eats by pushing his stomach out through his mouth, located at the center of his body. That’s how greedy it is: it eats everything whole, shell and all. And just so nothing is missed, the branching tubes in the arms, where its eyes and respiratory system are located, are put to work picking up any dropped morsels. The efficiency of the starfish’s stomach is twofold: waste products are ejected from the same opening through which the meal was ingested.
    Brittle stars, blood stars, ocher stars, leather stars, variable and shallow-water sand stars—the ones seen around here—as well as 3,600 other species, all start out as one of thousands of eggs shed from the underarms of a mother/father (they are hermaphroditic). Once released, they glue themselves to kelp. From “stardust” they turn into odd-shaped punctuation marks until the rays finally emerge; they grow from stardust to gluttony in a matter of weeks.
    Sea stars, as biologists like to call them, since they’re not fish, have an extremely complex nervous system and are famous for regenerating lost arms. They can cast off a wounded ray and regrow a new one, or else grow a whole new body if part of the central disk is included in the cut-off arm. With such powers, starfish numbers could get out of control, but this problem is solved by sex changes—no operation needed. Males can turn into females, and vice versa, an art that regulates population dynamics.
    As I poked through tide pools, Sam began stalking