Tuesday, July 12, 2011

The Difference a Few Feet Makes

A couple weeks ago, I finished my main review of my first full year at Bay View. It was eye-opening.

Now, I've taken the time to compare the two zones I work. This has been even more eye-opening.

As a quick refresher, every week I walk two distinct zones at Bay View, I call them "Zone N"(orth) and "Zone S"(outh).
My two zones at Bay View
Each zone is 250 feet long, each starts at the dune line and goes down to the terrace, halfway between low & high tide lines. The big difference? Zone N is right near the parking lot & beach access. It's the popular spot, where all the beachgoers congregate. Zone S, on the other hand, sits beyond a private patio area that encroaches onto the beach. The patio acts like a line of demarcation. A few folks wander down past it to spend time in Zone S, but not many.

In Maine, beach season is pretty much only the summer, maybe a little in the spring. In autumn and especially winter, only the hardiest of solace-seekers hits a Maine beach. So my question when I started was, will there be a noticeable difference in debris between the zones, and will it even out over the winter when the beachgoers have gone?

Well, here's my charts for the four seasons:
Summer 2010
Autumn 2010
Winter 2010-11
Spring 2011
In the summer, the tourist season, Zone N blew Zone S away. This isn't surprising. And in fact, much of the difference between the two could easily be accounted for by beachgoer trash -- cigarettes, food packets, umbrella bits, toys, flipflops.

But look at autumn, winter, and spring. All of them still show a big difference between Zones N & S. In fact, 2 to 2 1/2 times more in Zone N for each season. What does this mean?
Breakdown of finds by zone & category
Well, maybe debris got buried in the summer, and re-exposed by winter storms? A dirtier Zone N in summer may mean more junk uncovered there in winter. But much of what showed up in winter had obviously washed in from far away. Tons of fishing debris, sun-bleached plastic, plastic fouled by marine life. And of course, no cigarette butts. If they'd been buried in summer, they surely would have shown up in winter.

No, what's happening here is weird. Two zones, same beach, same climate & weather, separated by barely 150 feet (if that). And yet during the winter, Zone N consistently doubles the amount of debris washed up.


There's a rock outcrop just north of Zone N that's exposed at low tide. Maybe it changes the current? The beach at Zone S seems slightly narrower, slightly steeper. Not drastically, but maybe enough? What about the trees? You can see from the satellite image that Zone N backs onto open ground, while Zone S is tree-studded. Does that blunt the seabreeze and change the flotsam?

Whatever the reason, I know this: If you think you know how your beach works, take the briefest of strolls up or down it. And then check again.

I love this stuff.

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