Monday, July 15, 2013

Sarah Grose - Dock Observation

Blog #3: Observing the Harbor

Today we traveled around the Boston Harbor, observing the creatures and plants that live in the surrounding areas. We started at 9:45 at the waterfront by Christopher Columbus park. It was low tide (low tide was set for 10:05) which we could tell not only from looking it up, but also the sand further up the beach was wet, meaning the water was still retreating. There was a light breeze. The beach was made of a range of rocks from pebbles to cobbles, with the smaller pieces by the water and the larger chunks up by the stonewall. The stonewall was covered with a green mossy looking plant in the inter-tidal zone. There was rockweed attached to the stones in the inter-tidal zone, as well as floating in the water. They are able to float because of the little pods that grow among the leaves of the plant. Rock weed can only grow in waters that have little pollution, so their presences here is a good indication of the water quality. There was also green seaweed. This could be found floating in the water, and dotting the beach close to the waters edge. There was a lot more rock weed at this section than there was sea lettuce. The water visibility was between 3-5 feet. There were some sea and land birds spotted feeding on the creatures living at this water front. We spotted one hermit crab as well as another crab from afar that was promptly eaten by a sea gull (species unknown, as it was too far away).

We moved from the water front by Christopher Columbus park, to the far right of the main switchback dock. We observed much more of the bright green moss-like plant growing on the rocks here. Here, we learned about fouling organisms, those that live on floating structures and enjoy a high light and water exposure. We also spotted an orange sponge-looking organism that we identified later as an orange sheath tunicate. As we moved farther down the harbor walkway, we came across a rocky outcropping that was home to five mallard ducks. There was one older looking male, accompanied by two young females and two young males. They were sunning and pruning themselves on the rocks. We observed a more spiked or horned seaweed in this area. The water was much more shallow, with fewer large rocks. We continued around the harbor, and stopped to feed striped bass. Here, the water looked murkier, but we did not come up with a reason for this. Perhaps the water was simply deeper, automatically allowing us less visibility. However, we fed the bass some bread, and observed them splash and flip in the water to grab the food we tossed them. We walked down the ramp to a private docking area and observed a shaded piling and doc section. By this point, it was nearing midday, but we were sheltered by the slightly overhanging pier. On the piling we observed thousands of barnacles. They were whiter in color at the top of the pole, and a darker blue brown at the water line and below. We observed between 20-40 mussels attached to the piling, yet most were on the side of the pole facing the shore (not out to sea). My hypothesis for this finding is that when behind the piling, there is shelter from the waves and tide smashing into the mussel and potentially dislodging it from its home. There were more orange sheath tunicates mostly below the water line, and they increased in numbers as the pole went down into the water. There were what looked like tentacles growing from the piling about two feet below the surface. They were round in shape, about 4 inches long and a brownish blue color. They looked almost like large sea squirts. The water here was visible for 4-6 feet. On the dock itself, there were many more mussels attached. There was sea lettuce right at the surface, and below it we observed the mussels and other attached organisms. Some of the mussels were covered in what looked like brown moss and had a ridged texture. We observed two anemones that were a pearly white color. They recoiled and shrunk to the touch. We observed one snail living on the dock float.

At the Barking Crab dock, we were able to observe a few more creatures than at our previous sites. We found a mussel with a whitish purplish anemone attached to the shell. It had a short half inch shaft, and then another half inch of flowing tentacles that swayed and bloomed with the movement of the water. Like the others observed prior, they shrunk to the touch.  When we took it out of the water, what looked like the "flower" part of the anemone completely disappeared. The sea lettuce was a translucent but bright green color. It had broad leaf, with rounded edges. It was anchored to the dock, very close to the waters surface. Above the big flowing plants, I could see smaller, new leaves growing. We observed a red seaweed. This plant had many more folds within the leaf itself, making it appear thicker in total. It was a deep maroon red color, and not nearly as translucent as the green sea lettuce. We observed a reddish brown plant made of a branching leaf with thin whispy strands that separated and became smaller from base to tip. This was found anchored to the dock as well as on the mussel shells. We found a few pieces of rock weed floating between two of the docks. It was blackish green in color. The pods were in pairs and allowed it to float. We observed the golden star tunicate on mussel shells. It is made of very small (less than 1/8 of an inch across) stars with anywhere from 5-8 arms. These stars are brownish green in color, and they are set in a clear gelatinous substance that spreads across the mussel shell making a sort of blob. In addition, we found orange sheath tunicates growing on mussel shells as well. This was also a blob-like jelly, but it was a bright bright orange color. We observed the orange stars on the shell, but as it expanded off the shell (by almost 2 inches) there appeared to be more layers of the stars, making it appear like one big orange blob. The barnacles we found here had one slit opening, were about 1/4 in wide or smaller and they were very clustered. We found a few just on a mussel shell, or on the sea lettuce, but the majority were on the dock itself in large groups no smaller than 10. They looked like the little striped barnacle, but I am not absolutely confident in that classification. We found a 2-3 in fish swimming and feeding among the sea lettuce. The top half of its body was a brown and yellow speckle pattern. Below that, it had a silver underbelly. Its two side fins were almost wispy, moving many directions at once. This fish preferred the shade (this was observed when I caught it in the container and it would only stop swimming around when I placed a leaf over it for shelter). Last but not least we observed a female crab as it ate the sea worm bate it was caught with. It was missing one right leg and had two pincers, one on each side.

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