Manhattan Under Our Feet: Life in the Tidepools
You’re standing on the rocky shore. While you’re gazing out over the sea, you hear a voice, in a Robert DeNiro accent. “Hey buddy! Watch where you’re standing! I’m trying to make a livin’ here!” You look down, only to see a few million invertebrates yelling at you like drunk fans at Yankee Stadium.
In fact, tide pools are a lot like New York City. They’re crowded, loud, competitive, edgy, full of weird characters, and something is always happening.
If You Can Make it Here, You’ll Make It Anywhere
Tidepools are as tough an environment as the Big Apple. Crashing waves batter you all day, every day. You’re crammed into a few rocks with millions of your best friends and worst enemies. Six hours a day, you’re deprived of oxygen. And you’re expected to make a living and raise kids. But you can always find a meal at 3am, and life is never boring.
Expensive Real Estate
Like apartments on Central Park West, intertidal real estate is phenomenally costly. There’s not much space between the low and high tides, and everyone wants it. Places with protection from waves, access to feeding areas, or crevices to hide from predators are constantly fought over. In a tidepool version of rent-control, barnacles glue themselves to rocks with an adhesive so strong that the US Navy has sought to mimic it (and failed). Colonies of aggregating anemones war with each other, fighting over any unclaimed space on the rocks. Hermit crabs pry each other from their shells. Mussels, urchins, sea stars, limpets, chitons, and other invertebrates live on top of each other, crammed into big housing projects.
And staying attached is critical. Once you’re knocked off the rocks, you’re as exposed as a tourist wandering into the wrong section in the Bronx. You’re likely to get swept in to the tentacles of a sea anemone, devoured by a crab, or swept out to sea.
Like New York, the intertidal is divided into zones. Each neighborhood has its own character. In the outer boroughs, high in the tide zone, you’re less likely to get battered by waves or eaten by predators, but you’re farther away from food and the chances of finding a mate are slimmer. In the mid-tide zone, food, water, and oxygen are available if you can put up with a crowded neighborhood, wave impact, and more predators. Even lower down, the intertidal is like Wall Street. A wealth of food abounds, but predators are everywhere. Here you’re swimming with the sharks, real and metaphorical.
Like the guys on Canal Street trying to sell you a fake Rolex, anemones wave enticing tentacles, only to snatch naïve passers-by with stinging cells. Sea slugs eat the anemones’ stinging cells and use them in their own defense, advertising their poisonous nature with colorful punk hairdos. The weirdest character is the seemingly defenseless sea cucumber—which defends itself by vomiting up its own guts, tangling aggressors in sticky filaments, while it sneaks off to grow new intestines. The weirdos in the East Village have nothing on these guys.
The Ecosystem That Never Sleeps
In tidepool life, one thing is universal: for several hours a day, you’ll be deprived of oxygen and will need to shut down. During that time someone will invariably try to kill you. Sea stars pry open muscles with suction-cupped feet and powerful arms. Surprisingly fast predatory snails (for a snail) drill holes in shells with their tongues. Birds pry critters off the rocks. Crabs and octopi reach into crevices, and eels wait for the unsuspecting to swim by.
Nobody Owns a Car
The costs of being mobile in the tidepool are higher than the benefits. If you’re not securely attached, you’ll get knocked off the rocks and into gaping mouth of a wolf eel. Mussels, barnacles, sea stars, and urchins attach themselves with powerful glue, strong filaments, suction, and hydraulic pressure. The two common free-roaming creatures, crabs and sculpin, protect themselves with armor, claws, spines, and a strong sense of smell to guide them home when the waves sweep them away.
Most of all, the in-your-face, “you talkin’ to me?” attitude is the norm. Virtually every tidepool denizen packs a tough exterior, shells, spines, claws, stinging cells, or poisonous chemicals. Sometimes it’s just a bluff. The Porcelain Crab brandishes a massive set of claws—which are weak and paper-thin. And beauty can be deceptive: the multi-rayed, photogenic sunflower star is a voracious predator.
Next time you’re on the beach, wander over to the rocks at low tide and check out the urban culture of the sea. But try not to irritate the locals.