Monday, July 15, 2013

Day 3 - The Docks

Today we spent the day wandering around the harbor, looking at different sites, analyzing the habitat and the life that was present therein. We needed to fully understand the area that we were looking at. The first thing that we had to keep in mind is that this area of the harbor sees a lot of human traffic. So, there will be trash and signs of human activity. If you look in the right places though, those signs are harder to see and truly allow life to thrive. I’m not saying by any means that the sites we looked at were in bad shape or that the bay is extremely polluted or anything of that sort. I’m saying exactly the opposite. Though we take care of the Boston Harbor extremely well and keep it very clean, there will still be signs of human traffic, things that we can’t erase. But organisms learn to adapt and learn to thrive in the environment they have available to them.
The first observations we made had to do with the general environment. The date is July 14, 2013. The temperature was in the 80’s (Fahrenheit), and there was little to variable wind (much to many people’s dismay as we walked along the harbor). Now, looking itself, at our first site at Long Wharf at Christopher Columbus Park, behind the Marriot Long Wharf along the rocky seawall, the water was fairly clear, allowing us to see about three to five feet deep. We started at this location at 9:55 am. Today, low tide (one of them, as Boston Harbor has semidiurnal tides) was at 10:04am, so we were pretty much looking at the water at low tide. After making those general observations, we were then able to look deep into the harbor and observe the life that was present and make observations. So, the setting is a rocky seawall with a small rocky beach with rocks ranging from pebbles to cobbles along with some sand. The first thing that was recognized was this plant-like seaweed on the shore. It was brown/black in color and seemed to be on a lot of rocks that would’ve been covered by seawater during high tide. We soon learned that plant is what is commonly known as Rockweed, or Fucus vesiculosus. One of the unique features of rockweed are the small “poppers” that are present on the plant. These poppers are actually air bladders. We also learned that rockweed is a sign of good water quality because rockweed doesn’t grow in extremely polluted areas. We also saw some green leafy seaweed and some reddish/purple seaweed. These all were in the water, with some on the beach as well. Something that we only saw outside of the water a bright (and darker) green mossy material. We saw this at other sites as well and more clearly saw the two different colors. These two colors do not mean that they are two different species though. These might be the same species, just one gets more sunlight than the other, therefore one is a lighter green and the other is a darker green. This looks to me to be some sort of green algae. While we were looking at the site we also saw a couple crabs, and then a seagull, which proceeded to eat these two crabs. Now the crabs were too far to specifically identify what species they were but they were most likely either green crabs or Asian shore crabs based on the reddish brown color. The seagull was more specifically a ring-billed gull (Larus delawarensis), which is a common medium-sized gull. Also, along the beach there were a lot of different shells, most commonly blue mussel shells and clam shells. The way I was able to tell that the mussel shells were blue mussels (Mytilus edulis) is because of the elongated ovular shell and dark blue/black/purple color. Blue Mussels are very common in Boston. The clamshell was harder to identify because of how far away we were, but my best guess would be that it was a soft-shell clam, also known as an Ipswich clam (Mya arenaria), which are common in the area. After this introduction to detailed observations, we moved on to our next site along the harbor.
We then moved on to something called a “Switchback Dock”, which is a floating dock that has two access ramps on it. One is better for high tide and the other is better for low tide. The ramps make it easier for handicap-able people and people with strollers to get onto the boats for cruises and such. The ramps move up and down as the tide raises and lowers the dock. While we were here we made observations again. Here, the general environment hadn’t changed (same weather and visibility conditions as before), but what I noticed was different is that the water bottom seemed more clay-like or muddy. While here we saw some of the same things as earlier, but also some different things. We saw floating rockweed, the same reddish brown seaweed as before, green algae and some crabs. The main difference here was that there were barnacles (small white hard organisms that attach themselves to hard materials, like rocks and such) and a bright orange organism that we had not seen before. But, we weren’t really close enough to be able to tell exactly what it was. Maybe we would see it later on in our journey.
As we continued to walk along the harbor we saw a group of five molting Mallard ducks (Anas platyrhynchos), two chicks and three males. They didn’t seem to be fazed by our presence at all. We then continued to walk around the wharf and on the South of Long Wharf, next to the Frederick L. Nolan Jr. boat we fed a large Striped bass (Morone saxatillis), which was really fun to see. As we continued to walk, we not only saw more things in the harbor, but we learned about the buildings on the harbor as well. For example, we learned that Harbor Towers is the last building that was built on the harbor that doesn’t provide a public use on its first floor (like a restaurant or coffee shop or something). I found that very interesting. We also learned what the intertidal, subtidal and benthic zones are. The intertidal zone is the area that is above water at low tide and under water at high tide. The subtidal zone is the area that is always submerged, even at low tide. The benthic zone is the bottom-most layer of the ocean.
The next major place where we stopped was at Rowes Wharf, where we looked at the pillars under the dock as well as a rope that was covered in life. On the pillar that my group chose, the top of it was covered in barnacles, but because we are so far away it is difficult to tell the exact type. My guess is that the barnacles were the Northern Rock Barnacle (Balanus balanoides) as they are very common. But, I don’t know for certain as I was too far away to look at them close enough to make an accurate prediction. It could have been both types of barnacle that are common to the Boston Harbor. While here we also saw live blue mussels attached to the pillar along with more green and brown algae. Again, the orange organism was seen here. There was both orange and a pale yellow organism here. While I was too far away to observe it closely, I was able to determine that these two organisms were Tunicates. Later I was able to finally identify the specific tunicate types that were present.
We then continued around Rowes Wharf (seeing some sea stars on other pillars we walked by) to look at rope that is attached to the floating dock, but has been lowered into the water to allow organisms to flourish here. On this rope there were lots of blue mussels and more of the orange tunicates and brown algae. This rope was very compacted, but shows a diverse community within the water. Every year more organisms add on to the rope, and after roughly two years of being in the water, the rope would be too heavy to even lift out.
Finally, we continued on to the docks at the Barking Crab. This was the last site that we visited this day, and the site where we were able to finally get up close and personal with the organisms we’ve been seeing all day. On the plastic underside of these docks, there is an abundant community of marine plants and animals that thrive here. Many of the same species that we had all been seeing all day were present here as well, but it was much easier to officially identify the organisms around us. First, there was some reddish/purple (red algae, Grateloupia turturu) seaweed along with the bright green leafy seaweed we had seen before. This green seaweed looks an awful lot like lettuce. Interestingly enough, the actual name is sea lettuce (Ulva lactuca). It really looks like the lettuce that you can buy in the store. Along with those two seaweeds, there was the same brown algae on he dock that we had seen before. Attached to the side of the dock were many blue mussels (both alive and dead). But, when pulled the mussels off of the edge of the dock to closer examine them, there were little, what seemed like bugs, that were crawling all over it. These were not bugs. They almost looked like mini crawfish. In actuality these were what I believe to be Red-Eye Amphipods (Ampithoe rubricata). These little amphipods were a grayish, brownish green in color and extremely small. There were tons of them too. They seemed to be a very common species on this dock. They had two really long antennae that were about the same size as the body (which is really small in general), 7 legs and two larger claw legs at the front. This to me matched the Red-Eye Amphipod description. There were also these flatter organisms (again insect sized) that were floating around. They were a blackish brown color, with seven legs and two antennae. This to me seemed to be a Northn Sea Roach (Ligia oceania). These also seemed to be in abundance and were floating all around. Finally, I was able to identify and closely look at the two different types of tunicates that we had seen earlier. The orange tunicate was a larger shape, with small little colonies all grouped together. When you closely look at this tunicate, it looks like there is a clearish jelly that encases these flat smaller orange flower shaped organisms. This is what is known as an Orange Sheath Tunicate (Botrylloides spp.). The yellow tunicate was very similar except the flowers were yellow and more spread out, still in a colony though. This is a Golden Star Tunicate (Botryllus schlosseri). Finally, while we were at the dock, Professor Berman caught a crab. We were able to identify the crab as a Green crab because of it’s darker brownish green color and slightly bumpy shells towards its face. We were also able to identify it as a female because when you flip the crab over, it’s underside had a broad triangle, which indicates that it is a female. Males have a much smaller triangle, that is more line-like. Now though Green crabs are thought to be native, they are actually an invasive species. But, they have been in the Boston Harbor for roughly 300 years, so it’s hard to differentiate the Green crab as a non-native crab.
Overall it was a fun filled day with lots of discoveries. Being able to be up close and personal with these intertidal and subtidal organisms is very fun and I can’t wait to see what tomorrow brings.

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