Monday, July 15, 2013

Day 4: Lovell's Island

On our fourth day of class, we went on the Boston Belle. We departed from the dock adjacent to the John Joseph Moakley Courthouse at about 8:35 am. The water clarity in the harbor appeared have improved from the day before, which had to do with the fact that the sky was clear and blue. By 9:00, we were fishing at our first fishing location, where we could see the dying diatom; we could tell the diatom was dead because it was floating on the top of the water, and looked like brown pollen. At our first fishing location, we caught several black sea bass in rapid succession. The first black sea bass I saw was about 9” long, and the next one was significantly larger, at about 15” long. Caption Charlie informed us that these two black sea bass were female because they were a brighter turquoise shade of blue, and did not have lumps on their head. I was surprised today to learn how interesting black sea bass actually are. Black sea bass are hermaphroditic fish; they are born female and later in life, as they age, became male. During their transition from female to male, their turquoise shade darkens and their color becomes closer to black. Also during their transition, they grow a lump on their heads. By looking at their color and their heads, it is pretty easy to tell if the black sea bass are male, female, or in transition. Early on at our first fishing location we caught a few bregal or coners. The first one was about 5” long and was a nice light blue, almost pearl color. The number of black sea bass was very telling of the relatively healthy conditions in Boston Harbor. According to Bruce, black sea bass were not found in any large numbers in the Harbor until about 3 years ago, which signals that things are changing, and that perhaps they are migrating here because the water is getting warmer than it used to be. At our first fishing location, the depth was about 20’ and the visibility was fairly good.

En route to our second fishing location, Bruce dissected a black sea bass. The scales of the bass were fairly small and thin. In the bass’ stomach were a few shrimp. We were also able to tell that the bass was just transitioning into male.

At our second fishing location, we were off Long Island and near Spectacle Island. The first striped bass we caught was very large compared to the black sea bass; it was 30” long. The striper was covered in sea lice, which is important because sea lice only live on fish in open water; the sea lice indicate that the fish was migrating in open water, and probably came into the harbor to feed.

After our second fishing location, we went to Lovell’s Island, which I loved. I found the tide pools incredibly interesting and had a good time examining the species present within them (while swimming!). The tide pools were fairly rich and clean, as indicated by the presence of sea life there. The tide was getting higher and higher quite rapidly during our time on Lovell’s, and it was actually shocking to see how different it was from the time we arrived to the time we left. When we left, you could not even see the tide pools any longer, because the water was so high around the rocks that they were no longer visible. We got to the first tide pool at about 11:30, and by 12:20 the water was coming in more rapidly. As the tide was rising, the water got cooler and less transparent. I was able to glean from the appearance of the green algae that the tide zone was going to be pretty high (because the green algae is present in the intertidal zone), but I was still surprised by how quickly it changed.

At the first tide pool we saw many different species. There was an abundance of the invasive Asian shore crabs, which are blue in color. We also saw periwinkle, rockweed, fledging birds, green algae, North Atlantic barnacles, and hermit crabs—all of which, other than hermit crabs, we saw yesterday at the docks,. The species looked less lively though, because they were much more spread out because they were not confined to the limited space on the side of a dock; the intertidal zone of a tide pool is much more spacious than that of a dock. At the second tidal pool we saw most of the same species as the tide was getting higher and higher; however, I noticed two tiny patches of orange sheath tunicate. On the docks we were at yesterday, orange sheath tunicate was in abundance, which was quite a contrast from what was found in the tide pools. Tunicate are a species that start off swimming and smack into rocks or other hard surfaces and attach themselves and grow, so the larger hard-surface area at the dock could be one of the reasons for this. Also, the extreme weather conditions we had in Boston in the past twelve months could also explain how few orange sheath tunicate there were.

On the way back to the Barking Crab, Captain Charlie dissected and filleted the striper. The striper was a female and contained roe (fish eggs) inside. The stomach contents were a few shrimp, but not many.

This day was very informative and I enjoyed all of the hands-on activities we participated in. I went out of my comfort zone by eating the ceviche Bruce prepared for us right on the boat, and by touching all of the fish and even the crabs!

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