Thursday, September 1, 2011

A Craft-less Post: "Our" Barrier Beach

I set myself a fairly narrow focus when it comes to this blog, but sometimes I can't resist sharing something non-crafty. I've mentioned here before how much I love living so close to the coast and how much I enjoy all the coastal animals my children and I are lucky enough to interact with in their natural environment. This summer, we've been visiting a barrier beach in our town. Barrier beaches protect what's behind them, in this case, the largest salt pond in the state. I've found this very good explanation of barrier beach/island ecology online (that's a PDF link) in a teacher's guide produced by The Wetlands Institute in New Jersey. Because they're focusing on New Jersey, they talk mainly about barrier islands versus beaches, but much of the information applies. Beaches are meant to shift and move over time; sand isn't static. Pages 11-12 of the PDF explain how the natural effects of wind and waves are only a "problem" when humans try to impose their will on the sea.

All this to say, the kids and I were very interested to see how Tropical Storm Irene may have changed "our" beach. This isn't usually a crowded beach and seems to be more popular with out-of-state visitors than Rhode Islanders. The parking lot is very small, so you have to get there early, and there are no "amenities." Since we bring our own food, don't mind compostable toilets with no running water, and don't need a shower because we live so close, this is all fine with us. We think a salt pond full of critters is a fine amenity anyway. So the beach isn't very built up, but the parking lot is between the dunes and the pond, and a road runs along the dunes, with houses on the opposite side (part of the way). In the other direction, a beach road open to permitted vehicles runs the length of the beach, behind the dunes, to the permanent breachway. In other words, enough is going on that the barrier beach and pond are no longer left to do what they want on their own.

When we arrived, a backhoe was scooping up the sand that had washed into the parking lot and depositing it back onto the beach. During the storm, the waves had crested the dunes and water had flowed into the lot. (The big concern on the coast here during Irene was the storm surge coupled with an astronomical high tide caused by a new moon.) The beach itself was scoured. Instead of a covering of soft sand, the hard-packed, moister sand was revealed, full of iron. We've been bringing magnets to the beach all summer, and at this beach, the sand had scant iron (except on the pond side), but now we could see the darker patches everywhere. The topography of the beach was different, too. There was a sort of sand bar, which the waves sometimes washed over, and in front of that, between the sand bar and the dry sand, were pools of water.

When I took this picture, I was standing where the waves were hitting the sand. In front of me is the sandbar, then a pool of water, in which my two younger kids are playing. (At high tide, some of these pools got as deep as my daughter's chest in spots.) Behind them, you can see the dry sand and the backhoe. Behind the backhoe, you walk down the back of the dunes on a path to the parking lot.

This is the same view, with a wave gently flowing over the sandbar.

As high tide approached, currents developed along the edge of the dry sand, like a visible rip current. A channel flowed right to left (in the photo), and another one down the beach flowed left to right. Where they met, they flowed back into the ocean with a very strong current, so strong that I wouldn't let go of my daughter's hands or let my sons wade out too far. It wasn't deep, just fast. The lifeguard told me it probably could bring the boys out up to their necks.

Over time, the waves will change the sand again, and it will level out. But it was really, really fun yesterday. That big pile of sand was a blast, too. Once the backhoe was done, the kids climbed it and jumped, climbed and jumped.

The beach was also different in that it was full of rocks and shells. Except for our very first visit in the early summer, we haven't found much to collect here. Usually the sand is clean. We find things in the salt pond, but not on the beach. Irene changed that, depositing all manner of rocks, shells, and animals onto the beach (including thousands of comb jellies). After my younger son found a moon snail shell--not something I've ever found on our south shore beaches--I began paying even more attention, and I found a really large one myself, buried in the sand at the bottom of one of the pools. We later discovered the shell was housing a dead hermit crab.

Well. We like the shell, but we can't keep it with a decomposing hermit crab in there. They don't just fall out though, so my husband collected an assortment of small pliers, I found one that would fit, and I gently pulled it out. I can tell you that hermit crabs are far more attractive with their borrowed shell (and also, alive), but of course I'm going to show you, too, because aren't you at least a little curious about what they look like in there?

That large thing at the back that looks like a tail is, I think, what keeps it clamped in its borrowed snail shell--it began to uncurl after I pulled it out, which was kind of freaky. This is the larger species of hermit crab found around here, not the tiny ones we find in tide pools. It lives in deeper water, and I assume it was brought in by the enormous waves, poor guy. I can't imagine that was a fun ride.

The PDF I linked to above has a section on how storms affect barrier beaches and how it will roll over on itself as the sand is moved behind the dunes (like it was in this storm), but obviously that's not going to be allowed to happen at this beach. Still, it was an incredible experiential demonstration on the effects of wind and water on a beach, all the better because my kids "know" this beach. And I hope you feel like you know it a little now, too.

(School now starts the day after Labor Day, which is how it should have been all along.)


Donna Lee said...

I've never seen a hermit crab that large. They are strange little creatures. We had an influx of horshoe crabs. Those are some odd looking crabs.

I love the changes in the beach year after year and people who try to keep things the same are doing more damage to the environment. It's natural for sand to shift around and we should allow it instead of replenishing beaches for the sake of tourism.

Michelle said...

It's huge!!! Ew. Yeah, not the most attractive guys.

Very cool. I love seeing the land change like that. Especially through the eyes of a fellow Wetlands Girl. :)

Bells said...

what an interesting study, to see how the change in the weather changes "your" beach. I love it.

Great shot of the hermit crab. A naked crab in fact!