Friday, July 27, 2012

One if by land, two if by sea, three if by... tree?

Lovell's Island was an interesting place, it reminded me of my early childhood when we used to go search for crabs in the tide pools on the cape beaches and build sand castles for them. To start the day off yesterday we met at Starbucks at our usual time of 8:30a, from there we proceeded to board a boat to George's Island at 9:00a. Once we got to George's Island we came to realize that our boat was cancelled, so Professor Berman set us up with another boat, Abigail, from the DCR. They were so graciously willing to take us over to Lovell's Island. During the twenty minute layover we had, we decided to explore the fort, and take a look at the "nude beaches" on the backside of Lovell's.

Once we arrived to Lovell's Island we quickly realized it was a sandy beach, different from the beach types we noticed at Peddock's Island. As we walked the wrack line down the beach we began to see many periwinkles and hermit crabs shells washed up, as well as muscles, oysters, slipper shells, and crab limbs. From this point we decided to get away from the wracklines and search the tidepools. In the tidepools we found many live periwinkles as well at hermit crabs. Both of these animals were non existent on the docks, and were not as common on Peddocks.


In these pictures here we can see some examples of both smooth periwinkles and rough periwinkles. We saw both of these on the rocks. When we pulled them out and put them on our hand, they took about 20 seconds before they would stick and come back out of their shell as long as we stayed very still. In these rock bed tide pools we also saw many different types of sea weed, rock weed, sea lettuce, and others that were able to stay there because of how moist the environment stays. As shown below we had a number of interesting types of seaweed.

 Seaweed was not the only thing that we found in the rocks, we also had green crabs, and the rise of the tunicates again. These tunicates were sitting on the underside of rocks in order to constantly be wet as such they may survive. Unlike the dock environment however we did not see them all over everything. They were clustered in small areas and there was a much smaller percentage of them.

As we ventured back up the beach we looked at a rock an noticed a number of broken shells that looked very different from the ones that were in habited by the periwinkles. They were brighter in color, thiner, lighter, and had a more defined spiral. When we walked into the woods we found one of these snails up on a tree.

when looking closer at the shells that were left on the rocks we can see that they have a brown ring around the edge of the shells. Based on this color, and some research I have come to the conclusion that they are, brown lipped tree snails. These snails had a much brighter and tanner color then the periwinkles, and they also did not have a trap door to protect them from the elements.

These shells I believe ended up on the rocks in a similar way that the oyster shells we have seen ended up on the rocks, I believe they were dropped there by the small black birds that we saw and heard chirping in the trees. They most likely dropped them there in hopes to crack the shell and get the snail out of them for dinner. These snails sit on the underside of leaves for two reasons, first to protect themselves from the direct rays of the sun, and second to protect from predators. If you are an easy target then you will surely be lunch.

I hope everyone had as much fun at Lovell's as I did, and I look forward to gutting some stripped bass in class today.

Trevor O'Leary

No comments: