Little Harbor

I was calf-deep in water, wearing jeans and thick rubber boots. The sunlight draped over my shoulders and reflected back up at my face from the shimmering surface below. To my left and to my right, I could see the faint black shadows of land surrounding Buzzards Bay, but in front of me was only the sea. It started out clear near my feet, then took the color of the sand in front of me, and finally deepened in shades of blue toward the horizon. I waded through the water, careful not to splash over the top of my boots. Beside me, I half-dragged, half-carried a 5-gallon bucket on the surface of the water. The mess of green algae in the bottom was already home to ~150 limpets, my catch for the day. Not a bad day at work!   

My trip to the idyllic sand flat known as Little Harbor was motivated by a singular need for Crepidula fornicata. The little slipper limpet is common in New England and a great model species for experiments. I'm starting a new study now that it's spring (and most of my coral DNA work is finished), so over the next few months, I plan to become intimately acquainted with Crepidula.

Codium algae on top of Crepidula in Little Harbor

The limpets like to live in shallow water, either in the intertidal zone or in the subtidal, just below the water line. Where there are rocks and shells available, they adhere themselves to the substrata, but they can also live in sandy and muddy environments by settling on the empty shells of limpets past. Crepidula like to live in stacks, so when you find one, you'll find many. In Little Harbor, most of the stacks are covered in the alga Codium, which settles on Crepidula and uses the shells as its anchor. We went at low tide, when the sand flat is covered by a foot of water or less, and scanned the white-yellow sand for clumps of green Codium. Sure enough, at the base of each one was a stack of Crepidula fornicata.

In just 20 minutes, I managed to fill my bucket. We brought the limpets back to the lab and set them in flowing seawater overnight. It was a successful collection trip, and I look forward to the coming experiment!