Saturday, August 1, 2009

Gotta Love the Barking Crab.

This afternoon, August 1st, 2009, walking along the Boston Harbor in 80 degree weather, I learned a lot about life in the water that I did not know before. At the pier behind the Barking Crab while working with Chloe and Alexis, I examined a corner under the wooden dock in a shady spot under the bridge. We found mussels hanging off the plastic platforms underneath and after removing one of them we found what looked like tiny bugs crawling out of it. They were constantly moving and curling up and almost looked like extremely tiny shrimp. I am guessing that these were anthropods. After searching my guidebook I found that they had what looked like an exoskeleton, which is a main characteristic of anthropods and which disables an increase in size, explaining why they all looked the same. I also learned from the guidebook that the joints on the exoskeleton enable movement and flexibility which these creatures clearly displayed. In this same spot under the shade we also saw bits of orange hanging at the bottom, closest to the water. I saw this same orange color during the class’s somewhat risky visit to the water by the Rowes Wharf. I had trouble identifying it but it seemed to grow on the tips of what looked like seaweed or some kind of coral. Another dark green creature that I observed in this spot visually resembled dill and looking through the guide, I noticed it resembled the picture of the Wine-Glass Hydroid, although what I saw looked more dense. There were also darker green and dark read bush-like plants floating side by side.
Examining another spot under the dock, which this time was in the sun, I noticed both similarities and differences. Although there were mussels here as well, they were less abundant and only appeared completely beneath the wood, as opposed to appearing dispersed along the border like in the shaded spot. The conclusion I draw from this is that they do not want to be exposed to the sun because of potential harmful or fatal effects.
Another thing I saw in the sunny spot only was a green organism that from its shape looked like either a plantlike animal, coral, or sponge. It resembled the picture of the Eunicea Sea Rock but I don’t think that was it because those are not from this region (Seashore Creatures, 368). After looking at the Hitchhikers Guide I noticed it resembled the Green Fleece Alga, another invasive species originating in Asia.
On the piece that Bruce held in his hand to show the class, we saw many different colors and patterns. The orange appeared again, along with green, brown, blue, and white. There was a small patch among these patterns that looked like sunflowers. From the guidebook I concluded that this might be part of a Golden Star Tunicate because of its black background and white lines. The guide also explained that these are found on rocks, seaweed, and in brackish or shallow waters, all of which we were around (Seashore Creatures, 738). Again, after seeing them on the Hitchhikers Guide it seems that they are one example of an invasive species which originated in Europe.
Finally, Bruce’s picture from last summer looks pretty different from what we saw today. First, the water looks more green in the picture, which makes me think that it is dirtier. The rain is supposed to bring nutrients with it so perhaps the water this summer is cleaner as a result of the heavy rainfall we have been experiencing. However, this difference in color may also have to do with sunlight. The picture from last summer appears brighter which may be the result of greater sun exposure. In the picture from last year we see even more of the orange color which we saw today but the rest seems to be grayish. This differs from today where we saw some reds and a lot of leafy green. This difference could also have to do with the clarity of the water which changes with the rain. Although I observe less variety in the picture from last summer, there is a greater amount of whatever is latching on to the dock. I think this has to do with the current which is stronger when there is more rain, so perhaps there is less grabbing on to this surface.
One experiment we could do to find out what is really behind these differences is to remove some of the things we saw today, the orange substance for example, and split it in half. We could then isolate each half in a container and over an extended period of time, exposing each to different conditions having to do with both sunlight and rain. It would be better, perhaps, to divide it into many different parts so that we may test the effects of each individually instead of simultaneously. This would result in more accurate conclusions about the specific effects of each factor from salinity to bacteria, to the strength of the current.
I hope things become more clear to me tomorrow so I can better explain what I have observed. See you all in the morning.

Leana Ovadia

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