The Roughest Place on Earth

February-March 2006

This is an article from WaveLength Magazine, available in print in North America and globally on the web.
To download a pdf copy of the magazine click here: > DOWNLOAD

by Neil Schulman

Heceta Head pounded by waves.

Your dream finally comes true—you move to a beautiful, rocky, waveswept spot on the Pacific. When you get there, you read the fine print. You’re to glue your head to a rock. For six to ten hours at a time, you’ll be submerged in a medium in which you can’t breathe or eat, while hungry predators try to drill holes in your shell with their sharp tongues. When it’s time to feed, your job is to catch plankton with your feet. All the while, the waves will pound you.

Welcome to life as the barnacle Balanus glandula proving that life at the beach isn’t always relaxing.

I’ve been fascinated by the world between the tides since the age of six, when I turned over a rock in Nova Scotia and saw crabs and eels scurry around. When I started kayaking, I suddenly had constant connection to the intertidal—I humped my boat over seaweedslicked rocks to get ashore, left chunks of gelcoat on barnacle encrusted rocks, and pried urchins off the rocks for lunch.

Tidepools are cities suspended halfway between land and sea. Like Manhattan, Tokyo or London, life is packed in as close as it can get, sea stars on top of mussels on top of something else. And like a lot of big cities, tidepools are full of weird characters, each one trying to make a living according to a bizarre set of rules. Here’s how you can see what’s going on in this rough world. It’s great to visit, but be glad you don’t have to live there.

AIR TODAY, GONE TOMORROW

Living in the intertidal means you’re exposed to both water and air. Whichever one you breathe, you’re going to be without it for hours at a time. Most intertidal critters need the sea to breathe, move, feed, or all three. Our friend the barnacle has a hard shell to keep the moisture in during the long dry periods of the upper intertidal. Rockweed preserves water in oily pouches that kids love to pop (and that can also lubricate stuck rudder pedals.)

SURF’S UP

Having been pitchpoled a few times in the surf, I’m in awe of anything that can withstand that pounding day after day—let alone for 100 years, which is how long some anemones live. In the upper zone, you simply can’t make it without a hard shell. The soft-shelled creatures like anemones and sea cucumbers wedge themselves into crevices, attach themselves to rocks, or live below the surf. And when something does get knocked loose, it won’t last long, because the predators are waiting.

SNAILS, SEA STARS, ANEMONES

The reason barnacles live so high above the average tideline—as far as they can go and still feed—is because they’re on the run from one of the speediest predators around. That’s the snail nucella, which can ‘sprint’ at three inches a minute. (That’s about .5 kph, not bad for a snail!) The barnacle stays high and dry because during the five hours it takes for the snail to drill through the barnacle’s shell, the snail will probably run out of the water it needs to breathe. A foot lower, and the barnacles are toast.

The same pattern repeats itself further down the rock—mussels grow to a certain level on the rock, but not below. Below is the ochre sea star, another voracious predator, that uses water to power its hydraulic system that pries open the mussel shell, inserts its inside-out stomach, and digests the mussel. Further down lurk other fearsome carnivores, sea anemones, and below them, sunflower stars, the fastest and toughest guys in the neighborhood.

A tasty sea urchin graces Neil’s deck.

ZONES

This combination of factors—wave shock, drying out, predators and intense competition for space—divides the intertidal into zones obvious to the most casual observer. Hard-shelled creatures at the top of the zone give way to semihard creatures like sea stars and goose barnacles as you descend, then finally the softbodied seaweeds, anemones, sunflower stars and sea cucumbers. Generally, a creature’s high point in the intertidal zone is dictated by its tolerance to drying out and wave shock, and the low point is dictated by predators lurking below and competition for space. In the protected waters of Washington’s Puget Sound and BC’s Georgia Strait, where wave action is minimal compared to the open coast, the upper zone is more clearly defined, since waves don’t splash high on the rocks.

TIPS FOR TIDEPOOLING

Here are some tips to check out the natives in this weird world: Surge Channels Anyone who’s kayaked in rock gardens knows that when a swell enters a narrow channel, it gets faster and steeper. This is a challenge for kayakers but a bonanza for intertidal life because the surging waves stir up the food. Surge channels have the most biomass in the intertidal zone—big anemones to grab the waterborne food, mussels filtering plankton out of the swirling water, and sea slugs and sea stars eating the anemones and mussels that live along these seafood conveyer belts.

Knee Pads and Patience

To see the most, you’ll need to be patient. Wherever there are that many predators, the prey is going know to how to hide. Sculpins change color patterns to match a particular tidepool. Decorator and kelp crabs actually glue pieces of seaweed and algae to their carapaces, where they continue to grow. Chitons carve themselves a crack in the rock with their tongues (another job I wouldn’t want) and snuggle in there. I’ve spent many hours over the years kneeling next to tidepools, waiting for something to emerge. Polarized glasses will help by blocking the glare off the water.

Current Events

Look for areas with strong currents. Even away from the surf, narrow passages with strong current are rich in marine life in all its forms. Some great examples are Dolomite Narrows in the Queen Charlottes, Browning Passage at the north end of Vancouver Island, and the tidal rapids of the Discovery Islands (northern Georgia Strait).

Sea stars clinging to the rocks.

Not Just the Tropics

In a calm channel in Barkley Sound, I saw some of the most amazing arrays of sea cucumbers and sunflower stars I’ve ever seen in my life. I found myself wishing I’d brought a mask and snorkel, so I could jump out of my boat and swim around in my drysuit. When I got back to camp, two people were doing just that. They were nice enough to share, but now I bring my own.

Eat (But Be Smart)

Crabs, mussels, urchins, seaweed... there’s a lot of sea life, and most of it tastes good. But before you eat any filter-feeders, like clams, mussels, or oysters, check for paralytic shellfish poisoning (also called Red Tide), as it can be fatal. It’s a naturally occurring, deadly toxin contained in the dinoflagellates the bivalves eat. It’s most common in summer, so check with the authorities before harvesting.

BRING AN EXPERT

OK, so you can’t fit an actual marine biologist in your front hatch. But maybe you can fit in (or at least do your pre-trip research with) Marine Life of the Pacific Northwest: a Photographic Encyclopedia of Invertebrates, Seaweeds and Selected Fishes by Andy Lamb and Bernard P. Hanby (see Books, page 41), The Northwest Coast: A Natural History by Stewart Schultz, and two books by Eugene Kozloff: Seashore Life of the Northern Pacific Coast and Seashore Life of Puget Sound, the Strait of Georgia, and the San Juan Islands.

And When the Going Gets Strange....

The strange get going. The intense environment of tidepools has spawned some truly bizarre creatures. Sea cucumbers cough up their digestive tract, hoping predators will eat that while the cucumber escapes and grows a new one. Anemones clone themselves and have territorial wars with other clones. Sea slugs actually eat the stinging cells of anemones, then use them for their own protection, advertising their toxic defense in colorful, waving, punk hairdos. We’re paddling over some wild and crazy creatures. Visit with care.

© Neil Schulman encountered his first regurgitating sea cucumber in 1976 in the Bay of Fundy and has been hooked ever since. He has taught coastal ecology on the Oregon Coast.