Monday, August 3, 2009

Lovells Island

Everday is a new adventure. After a hectic early morning escapade, it was nice to relax a little bit on the way to the island. It the day was a little gloomy from overcast, but was still relatively warm (probably about 75 degrees) with some light winds throughout the day. Once we arrived on the island I could see a rock filled beach with little sand, which we learned was called a cobble stone beach. This is one of the four types of beaches in the New England region, the others being: rocky, sandy, and mud-flats. From here we walked across to the other side of the island, where we could noticeably see the, I think its called, "wrackline" which consists of all kinds of debris and sea weed. We could also see the line that separated the dry part of the beach from the wet part showing the tide was regressing to low tide. The average of high tide in this area is around 9 feet but can reach up to 12 feet in the summer. It was here that we got to learn about the "Brazil Nut Phenomena" which states that bigger solids come to the top. A variety of things can affect these rocks(both its position and its form) such as: currents, human activity, tides, and storms. On the beach we could see it was littered with blue mussel shells and, as we looked closer in the wet area, could see it was full of periwinkles which were our main focus for the day. We all picked them up and observed them. We tried just about anything to get them out of there shells from rocking them to singing them lullabies. These periwinkles were diverse in that some had strips and some didn't and they varied in color. These animals are harmless to humans, however they are enemy to anyone who likes sandy beaches, because they help turn them into rocky beaches. As we got to look at these snails close up we could see that some of them had little holes in their shells. I think that there could be more than one predator resposnible for this: the Dog Whelk, Oyster Drill, and the, I think, dog snail along with other various kinds of rock whelks. All of which use their teeth like tongues to penetrate the periwinkles very strong shells in order to eat and I think any of these animals could be responsible.

We then walked for a few minutes down the shore to eat lunch. Mr. Berman found some interesting snail shells that were not periwinkles. I think they might be known as a brown-lined snail or something like that. I learned that these shells(the dead ones we found) could be determined older or younger than others. The shell of the older one would be more eroded from weather, scowered, and more faded than the younger ones. Later, we saw similar snails on our hike through a trail. The snail that I found was high on a branch behind on a sumac, I think they are called. I also noticed that one of the teams around me were finding their snails in branches as well. So, clearly they are mor comfortable in a tree than on the ground. This led to the question, how did they end up on beach? It was suspected by some students and hinted stongly by Mr. Berman that they could have ended up there because of the birds. I can totally see that because maybe, just like some of the gulls by the tide pool pick up crabs and drop them and then eat them, maybe they do something similar to the snails. Prior to this part of the trip we took a walk through a marsh, which no longer stays wet consistently due to government interference. We got to see a plant called pepper weed that had a distinguished smell to it. Once through the marsh we came to the tide pool. It was the not best smelling part of the island, but it was filled with all kinds of wildlife. There were several bird in the nearby distance like gulls, sand pipers and oyster catchers. The shallow part of the pool was filled with periwinkles, hermit crabs, green crabs ( main predators of the periwinkles), and some very small shrimp that I am unable to identify. I know the rangers told what they were but I forgot. I assume that many of these animals are not native but maybe hitched a ride by boat, storm, or maybe oven another animal it was latched onto. It was cool to see, when up close, how many of these animals lived so close to each other in this part of the pool. I was not one of the more adventurous who went out to the deeper end of the pool, but thanks to several students, was able to see a lobster from a distance, which was cool.

We concluded the trip by taking the shells and separating them into groups, some larger than others. This must be due to "Natural Selection" that Mr. Berman talked about earlier in class. Maybe the smaller groups were better suited for the island than the other larger ones(because less perished). Or maybe looking at the other way around, there are less snails(the smaller groups) so there must not be very many of them. The main difference I saw between the Barking Crab trip and this one was that there was much more life in this area. Probably due to the fact that we were in a much more wild-like habitat and there was much more growth in both on land and in the water.

-Ryan Santana

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