Saturday, August 2, 2008
Field Work...Day 1
Today we investigated the surprising biodiversity of the Barking Crab Wharf. Our materials were limited to our eyes, our fingers, a magnifying glass and a pen to poke with. In pairs, we hung off the wharf upside down to get a close look at the organisms that make this floating intertidal zone their home. The first sample we pried off of the wharf consisted of two mussels tightly bound with thread like substances, and hundreds and hundreds of tiny, squirming, shrimp like creatures. I believe the mussels are common blue mussels, but I have no idea what the shrimp creatures are. I could not find a shrimp like organism in my guidebook with a pointed tail like the ones I observed. The shrimp like creatures were abundant and their sizes varied greatly which led me to believe that they were of different ages and clearly establishing a healthy colony. Upon closer inspection of our clump, my partner and I found a small crab hiding inside one of the open mussels. Though I only caught a glimpse of the crab I venture to guess that it was a rock crab. There were a couple of different types of seaweed among the mussels, I think they may have been sea lettuce, rockweed, kelp and perhaps Irish moss. We also observed a different kind of shrimp like creature that was long, red and very active (until dried out). I believe these were longhorn skeleton shrimp. I saw one anemone that I think was a frilled anemone. The most mysterious organisms were the spongy layers which covered mussels and also floated freely, attached by a slim thread. I could not find anything quite like what I saw in my guidebook that looked exactly like the red/orange spongy substance but after reading earlier posts and doing some further research I agree that it could have been orange sheath tunicate. The other sponge like organism was bluish and had a flower or star pattern inside each small section. I think these were colonies of golden star tunicates. I gathered these conclusions from reading my fellow students blog entries, the National Audubon Society Field Guide to Seashore Creatures, the Hitchhikers excerpt, and the Boston Harbor Seaside Educator's Manual.