Thursday, October 29, 2009

Of ponds and puddles

Hawksnest State Park has some very nasty puddles.  There's the Godzilla Puddle just above the beach at Hawksnest Pond.   If that puddle rises only a foot more, it will break through to the pond.  When this happens, muddy runoff from the parking lot, and from Round Cove Road will be able to run into the pond.  Goodbye crystalline waters.

"Godzilla Puddle" at Hawksnest, with abusing off-road vehicle. Why does the puddle last?

The Mystery
Cape Cod has very sandy soil, thanks to the glaciers.  Standing water quickly sinks into the porous sand... right?  So the puddles should disappear shortly after a rain.  But that's not the case at Hawksnest, where puddles in the road, along with Godzilla Puddle, persist for weeks.  Why doesn't the water sink in?  It's a mystery!

Solving this mystery could reveal some fascinating things about the lives of ponds.

Clue #1
In the spring and early summer, pines of the Cape release vast quantities of pollen.  It settles on the ponds, and is blown by the wind, where it collects on the beach.  Sometimes you can find up to an inch of beautiful golden pollen on the shore.  As a child digging in the sand, sometimes I would find a layer of golden pollen burried an inch or two deep under the sand.

Pollen scum on a puddle--beautiful and complex

What does pollen have to do with puddles?  Pollen falls on Round Cove Road.  Long stretches of road collect pollen and concentrate it in puddles.  Pollen is microscopic--it clogs the pores between the grains of sand.  So the pollen (and other organic debris) acts like clay, lining the puddles, and making the bottom watertight.  That's why Hawksnest puddles last forever.

OK, hold on, I'm getting to the pond connection.  

Clue #2
There's a curious thing about Hawksnest Pond.  Hawksnest is deep, and unlike the mucky ponds on either side, has few pond lilies or other aquatic plants.  The bottom is sandy, not mucky.  But one spot on Hawksnest has a mucky bottom with lots of aquatic vegetation--that's the cove--the beak of the hawk that gave Hawksnest its name.

The tip of the cove in Hawksnest Pond (green, lower left) is the only mucky part of the pond. source

This part of Hawksnest has lots of decayed organic matter.   But how did that muck get to the cove, and only to the cove?  There are no streams to wash organic stuff into the pond.

"Elementary, my dear Watson"
My guess is that the muck in the cove came from pollen and leaves and anything else that could be blown there.  The cove is on the NE side of the pond, just the place where the prevailing SW winds would blow floating organic matter.

Getting back to Godzilla Puddle
There's a lot of pollen and other muck in that puddle.  If it finally breaks through to the lake, all that muck is is headed for the pond.  Goodbye water quality.  Pollen is natural, but it does contribute to the eutrophication (fertilizing) of the pond, as we see in the cove.  When Godzilla Puddle breaks through, Hawksnest Pond will receive a lot more pollen and other debris, every time it rains.

This little mystery illustrates how Hawksnest State Park, with its three different ponds, could be an ideal laboratory for children from surrounding schools.  Children love puddles... and ponds.

Children playing in a puddle covered with pollen. Better than TV.

What you can do
Write Jon Peterson and ask him to fix this puddle, and to post signs delimiting parking ASAP, before the puddle breaks through!  It's more than a puddle--we're talking about an eroding road and eroding parking lot, all of which are about to drain into the pond.
Jon Peterson
Supervisor, Nickerson State Park
3488 Main St., Rte. 6A
Brewster, MA  02631-1521  

A cry for help...Godzilla Puddle says: "Help me, before I kill a pond!"
Threatened Hawksnest Pond is just behind the puddle.

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