Friday, October 27, 2006

Salt Marsh, Sand Dunes, and a Beach at Galveston


On Wednesday, Alexandra and I went on a field trip with some other homeschoolers to Galveston. We were in a class that visited a salt marsh and then went to a beach that had sand dunes. It was a long day, but it was a lot of fun.

We went to the salt marsh, first, and discussed the purpose of a salt marsh (home for marine life - especially babies, protection, filters the water, holds flood waters) and discussed that estuaries are where salt water mixes with fresh water. Then, we headed off through the mud after being taught the stingray shuffle.

The first thing Alexandra found was a large shell - with a hermit crab in it! We were very excited as we noticed these hermit crabs everywhere! Then, we saw periwinkle snails on the grass - 100's of them! They are about the size of a shooter marble and they were climbing up the stalks of grass.

The mud was hard to walk in even before we got in the water. The first few steps into the shallow water were hard to take - it made you feel like you were just learning to walk. As we got into the water, Alexandra was scared (the fact that we had to learn the stingray shuffle and that they said there was a 99.9% chance that you'd fall in the water didn't help). It was also cold and sprinkling. A kind homeschooling dad offered to carry her and his son gave her his jacket. I was amazed that this gentleman carried her for over an hour!

Some of the kids pulled a large net behind them while another child walked in front of the net to "kick up" whatever was at the bottom of the marsh. We caught: lots of shrimp, lots of small baby fish, a few pike fish, some tongue fish (a lot like a flounder), lots of small baby crabs, one large blue crab, and lots of sea snot - which looks like just what it sounds like.

Again, I was amazed at how hard it was to walk around while shuffling in the mud. There were lots of holes - at time I'd step into one and the water would go up to the bottom of my shorts. Also, at times my foot would get trapped. They warned us not to pull our foot out of our shoe or you'd never find your shoe again. We saw evidence of this - unclaimed shoes that washed up on the beach. A few times I got stuck in mud that came to the top of my socks. You have to wiggle your heal, then pull your toe up first to keep your shoe on your foot.

After the marsh, we went to the beach. At the beach, they discussed the importance of sand dunes - both to the animals that live in it and the people who are protected by it. We looked at some of the different types of plants that grow on them - some are not native.

Then, we combed the beach for shells and whatever else we could find. We found: lots of shells (there'd been some flooding about 9 days earlier), a man-of-war, a dead hawk, lots of pieces of oyster, pieces of sand dollars, and our best find: horse manure. Actually, this was kind of funny. I found it when Alexandra and I were by ourselves. I asked her what she thought it was - it was mainly in little round balls. She said she didn't know and picked some up and it broke up in her hands. I called over the gentleman, David, who'd helped us before. David is a farmer and knew immediately that we'd made a wonderful find: horse manure. Yuck! Thankfully, our guides had hand sanitizer.

Photo #1: a piece of oyster on the left and a piece of a large lightning whelk shell covered in worm tunnels on the right side (we learned to identify some shells and things, too!)
Photo #2: top 3: shell (I don't remember it's name), piece of lightning whelk piece, piece of sand dollar; bottom 3: piece of sand dollar, piece of shark's eye shell (what's really neat about it is the little hole at the top - we learned that when you find a shell like this, it's because the organism had been eaten by a snail the uses its tounge and some acid to "drill" a hole and then eat the organism!), a piece of an angel's wing shell

Here's a great site I came across to help identify shells and other things found in Galveston:
http://www-bioc.rice.edu/precollege/k12resources/fieldguide/resources/shell.htm

I did a little more research online about shark's eyes also known as moon snails. The teacher told us their tongue has little teeth - the teeth are called radula. These types of snails are predators called "drills." They drill a tiny hole in the shell of their prey. They can also be cannibals and I'm guessing our little shell of a shark's eye was eaten by another shark's eye or some other type of "drill."

1 comment:

Robin said...

This was a really facsinating post, Dana. The next time we go to the beach I may actually try to identify some of what we find, rather than just appreciating how "pretty" it is, like I usually do...LOL
I'll have to make Jabem bring his laptop so I can do school at the beach :)

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