Thursday, July 24, 2014

An exploration of the Harbor & Islands in style, or, Fishing as Ecosystem immersion

An exploration of the Harbor & Islands in style, or, Fishing as Ecosystem immersion
Erik Wilke

On Friday the 18th, we explored the Boston harbor with Captain Charlie. We found the water to be relatively clear (I could see the fish when we reeled them in several feet down before they were pulled up).
One of my favorite pieces of information was from Professor Berman as were just getting to where we were going to fish. We were told that the cormorants don't have oily bodies, and as such don't really have much insulation (they are diving birds, so that makes sense). Therefore, they only spend time in the water that they can use to fish, so if you see a cormorant in the water diving, there’s a good likelihood of fish.
We first ‘met’ some sea worms, which we promptly put on fishing hooks, but not before observing their fin-like appendages all along their body in a ruddy orange color against the body’s light grey to brown.
The first fish we caught was a Black Sea bass (Centropristis striata), about 14-15 inches long and a male. The hump above its head showed that it was completing the process of switching genders, as Black sea bass start off in the world as female (to maximize breeding). Patrick caught the one pictured below. This one had beautiful green scale pigmentation as well as they gray blue black coloration (hence the name) and a white underbelly.
However, they weren’t the only fish in the sea. Classmates caught two flounder and a silver hake. The flounder were about a foot and a foot and a half respectively (from right), with one of them having green-brown coloration and the other having a light brown coloration. Both of them were right eye flounder—meaning that they originally had eyes on both sides but gradually the left eye moved to their right side, allowing them to look all around them and above, because they feed around the bottom.

Then, a striped bass (Morone saxatilis) was caught. It was about 3’2’’ in length and had green-gray coloration on its top and sides as well as defined gray stripes along its side, leading to a white underbelly. Inside the gills (it was large enough to see inside the hole), were several red frond-looking gills which filtered and drew oxygen from the water. I’d imagine if you took them out and compared them to lung tissue, you might find some similarities.

Then we went to Lovell’s island. Upon reaching the island, we encountered some fauna on our way to the beach. On the beach, however, we came across a stretch of tide pools, wherein we found periwinkles (sea snails), Asian shore crab (which is invading from long island coast to near Portland, Maine), as well as some small fish that swam in schools (see video). I had a hard time attempting to get a closer look at them but they could be very small mummichogs or gobies or some other similarly shaped and sized fish. Interestingly enough, I did not see any tunicates like we did on the docks. Perhaps a further excursion would find them, I bet they need to be submerged more often to survive. The crab was around 2 inches long and the sea snail was about the size of a pea or about ½ inch in diameter. We also encountered some hermit crabs roughly the same size or slightly bigger than the sea snails. Additionally,we found and sampled some slipper shell clams, ranging from 2  inches across to about 4 inches. 

Part 2

We also found and discovered some land snails (Cepaea nemoralisalso in the mollusca family like the slipper shell clams) , which would have had to have been dispersed to the island. A friend of mine from Harvard (he works with the Dept. of the Interior on invasive species) thinks that birds carried him, while his daughter thinks that campers on the island would have brought them via tents and equipment on land. I like both hypotheses and I’d bet that both have occurred in the past.

Bonus: Striped Bass encountered in my kitchen, alongside what appears to be lemon, garlic, a bit of an herb such as oregano. 

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