424. Why Taunton Bay?

February 5, 2015

Why do members of a small, fringe band of horseshoe crabs live in cold, rocky Taunton Bay when they could be living it easy in Delaware Bay with its much warmer waters and sandy shores? Having monitored horseshoe crabs in Taunton Bay for several years, then witnessing the horde of breeding crabs in Delaware Bay in 2005, I couldn’t help asking that question.

 

Horseshoe Crabs in Delaware Bay

Breeding Horseshoe Crabs on the Warm, Sandy Shores of Delaware Bay

Or, put differently, what draws horseshoe crabs to Taunton Bay in the first place? Why are they here?

I’d lived as a guest of Bob and Mary McCormick on Butler Point for several years after leaving my camp on Burying Island, and laid out a monitoring site divided into 10-meter sectors that wrapped around a point of exposed granite ledge and boulders where horseshoe crabs faithfully came ashore to breed every spring when water temperature reached 56 degrees Fahrenheit (13 degrees Celsius). Patches of sand and gravel were far between around the point, yet that was the soil the crabs needed to lay their eggs. The rest was ledge and fields of glacially-rounded cobbles and boulders.

 

Ledges in Taunton Bay

Ledges and Boulders at the High Tide Line in Taunton Bay

A common saying has it that horseshoe crabs breed in the light of the full moon in May. If that is true, what is it about the full moon that brings them to shore? Could it be the extra light at night? The gravitational pull when moon, sun, and Earth are lined up in syzygy?

In Taunton Bay, breeding horseshoe crabs show up in the daytime at high tide. The shore is so treacherous, I’ve never checked for them at night. But that seems to rule out the light of the moon as the spark that sets off the breeding season. And at full moon, the tide is low at 6:00 a.m. and p.m., high at noon (and midnight), or an hour-and-a-half later in Taunton Bay due to the constriction at Tidal Falls.

 

High-tide line, Butler Point.

Rocky Shores of Butler Point Where Horseshoe Crabs Come to Breed.

It makes more sense to me that water temperature reaching the threshold of 56 degrees is what brings the crabs ashore to lay their eggs. And that the moon’s effect is in drawing an incoming tide over flats and rocks and ledges warmed by the morning sun, sharing the sun’s heat with the water as the tide rises, so warming the water to a maximum at high tide, when the crabs come ashore to breed for a period of a couple of hours.

In my thinking, breeding crabs are attracted to particular sites by the heat given off by sun-warmed ledges and boulders, then imparted to incoming tidal waters, and has nothing to do with the sparsity of suitable breeding habitat, which the crabs find by relentlessly searching and digging wherever they go along their favored breeding sites, no matter how ledgy and stony.

 

High Tide Line, Egypt Bay

Horseshoe Crabs Love the Warm Waters that Cover These Stones & Ledges.

Other horseshoe crab breeding sites in Maine feature sandier shores than does Taunton Bay, where the crabs are hardy enough to eke out a living under stern local conditions in spite of short summers, cold waters, and harsh habitats.

What Taunton Bay does have to offer is two shallow sub-embayments, Egypt Bay and Hog Bay, where incoming waters are warmed by sunlight falling on mudflats and ledges from low tide to high, briefly achieving warm conditions such as are a regular feature of Delaware Bay much farther south where millions of crabs breed on an annual basis.

 

Horseshoe crab breeding habitat, Taunton Bay

Horseshoe Crabs Eke Out the Gravel Between These Boulders & Ledges.

That is my hypothesis, achieved by observing and thinking about why horseshoe crabs have established an outlying population this far to the north of their usual spawning grounds across the world. I offer this as an example of my ongoing engagement with horseshoe crabs. They have established a beachhead in my consciousness, and I carry them everywhere I go, thinking about issues they raise on sleepless nights, dwelling on the predicaments they face, wondering why, against all odds, they cling to two exceptional habitat areas in Taunton Bay.

You might well ask, Who cares? I can only reply, I, for one. Because I engage horseshoe crabs on a daily basis, and have made them part of my life by paying attention to them for much of my time on this Earth. Our regular engagements become parts of our lives because so firmly rooted in our minds through our frequently acting and perceiving in unity.

By engaging, we make lives for ourselves. Those lives are what we are. Each different by nature and by passionate engagement. As we are expectant, observant, attentive, and active, so do we become. No two the same.

Me, I’m taken with horseshoe crabs, eelgrass, rockweed, deep woods, rowing, walking, hiking, and similar natural activities and engagements with my home planet. And now with consciousness as my basic tool for conducting those engagements. As you are taken by the aspects of that same planet as they affect you and draw out your lifetime engagements.

So are we all, products of the lives we actually lead, because those lives are in our minds to live out as we do. We can’t help it. That is our destiny. To be ourselves because it is beyond our abilities to be anyone else.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: