Taking the Pulse of Nature's Rhythm

Today was, I’m sad to report, my last afternoon (for the next few weeks, at least) at the Harry McDonough Sailing Center in South Boston. While I had originally meant to write a blog entry about how much I loved getting to know the kids at the site, I find myself writing an entry about how much I’m going to miss exploring Pleasure Bay with Sean, Olivia, Julia, and the rest of our gang of anglers and crab-catchers.

Pleasure Bay is an especially great place to observe the effects of the tides—because there are only a few channels through which tidal currents can enter and leave the harbor, the tide tends to rise and fall faster in the main harbor than in the enclosed bay. As a result, there’s almost ways a difference between the water level in Boston Harbor and Pleasure Bay; this difference produces a strong, rushing current. Along most of the coast, the tides rise and fall too slowly to produce forces this dramatic—but at South Boston, the effects of the sun and moon’s gravitational tug-of-war are not only visible, they’re almost impossible to ignore.

The tides move more than just water at South Boston. The level of the tide determines which sea creatures you can expect to catch or trap, and also where you can find them. Low tide, for example, is a prime time to venture to the rocky shore past the swimming beach. Green Crabs and Asian Shore Crabs virtually swarm out from under every rock you turn over, scuttling frantically for any shelter—even the shadow under your shoes! Our Boston Harbor Explorers quickly learned that catching crabs at low tide is, if you’ll excuse my pun, child’s play!

At high tide, however, crabs venture into deeper water. While hunting for bait at high tide, we hardly found any crabs at all, even though we left no stone unturned. High tide, on the other hand, is the perfect time to go fishing. The water beneath the fishing pier at Castle Island is too shallow during low tide, but it’s an excellent place to cast a rod while the tide is high. Exploring the harbor at Pleasure Bay was a crash course in learning to plan our activities around the natural rhythm of the tides, for us instructors as well as our young Boston Harbor Explorers.

Aaron