Tidepool life has changed dramatically in recent years

        It’s one of my fondest childhood memories — wandering the rocky coastline of Rhode Island and exploring the tidepools to discover whatever creatures may be in residence. It was always exciting to spot a crab or sea urchin or a few minnows, and even better when a starfish made an appearance.
        Yet while those same tidepools remain in the same places, like Brenton Point in Newport, Beavertail in Jamestown or Black Point in Narragansett, the marine life that call those nooks and crannies home have changed dramatically.
        Sure, those little round, blue-black snails — officially called periwinkles — are still in abundance. There might even be more of them now than when I was a kid. But as common as they have been for more than 100 years, they aren’t native to our shores. They were introduced from Europe in the 1800s and may be the reason why we have so many bare rocks along the coast. Before the arrival of the periwinkles, most of those boulders would have been covered in lush green algae. But the snails ate most of it.
        Nonetheless, periwinkles are just about the only reliable creature to be found in our tidepools these days. The crabs that were common back in the day, like hermit crabs and rock crabs, have been mostly replaced by non-native species, especially Asian shore crabs and green crabs. The new arrivals aren’t big, nor are they likely to nip your little fingers. In fact, the shore crabs aren’t aggressive at all, and the green crabs only fight among themselves. They’re both more likely to hide under a rock when approached by human hands than to lash out.
        The same is true of the purple sea urchins, the dome-shaped animals with the spiny shell that are not uncommon in tidepools. They’re slow-moving and feed exclusively on algae and detritus on the seafloor, so there’s nothing to fear from these unique invertebrates either.
        The good news is that researchers think that urchins are resilient to warming temperatures and ocean acidification, so their populations aren’t likely to decline much from the changing climate. A University of Rhode Island researcher is even investigating whether they could be profitably raised in aquaculture facilities in Narragansett Bay to help harvesters diversify their crop.
        The biggest disappointment to tidepool watchers like me has been the disappearance of starfish. Also called eastern sea stars, the once-common starfish was always considered the most prized of the tidepool creatures in my younger days. Their rough texture and hundreds of tiny tube-like feet on their undersides was always fascinating to me. And then to learn that they can regenerate an arm when necessary and pull open the shells of clams and other mollusks was too much to believe.
        Sadly, they, too, have mostly disappeared from our tidepools and shorelines. Back in 2013, a graduate student at URI collected some to study and found that they melted away in her tank and died within days. It was the first observation of a disease that ravaged starfish populations throughout the East and West Coasts. While there is evidence that the animals are recovering slightly, we’re still a long way from those joyous days of commonly observing these wonderful creatures in our tidepools.
        Despite the changing species and populations, however, investigating tidepools remains a fun family activity that everyone can enjoy. To ensure the health of the animals, it’s probably best not to handle whatever you find there. But don’t let that stop you from exploring this amazing marine world.

This article first appeared in The Independent on May 12, 2022.