For the first time, today we were able to sleep in just a little bit. Because low tide was around 1 pm, we gathered at the MIT Sea Grant office around 9:30 before heading out to the harbor. After spending yesterday on Lovells Island, we returned to the (less interesting) Spectacle Island. Once again, we took the ferry, hiked across Spectacle Island, and trekked down perilous boulders to get to the beach site, but eventually we arrived at our destination. Today, our quadrat surveys were around the second transect line we set up at Spectacle during our site visit on Monday. Today’s transect line was 80 meters long, our longest transect line yet. Because we arrived at the beach about an hour before low tide, setting up the transect line was difficult. The location of our end coordinate was several meters into the ocean. The water was almost knee deep, and my pants were soaked when I tried to set the end point down.
Our transect line extended 80 meters all the way to the waterline.
While we waited for low tide to start our quadrat surveys, we measured the beach profile and water quality of the ocean water. We have been analyzing water quality at each of our locations. Our water quality probe allows us to measure temperature, salinity, conductivity, and dissolved oxygen (in two different units). We also measured turbidity and took some water samples back to the lab to incubate; we’ll later use them to measure the water’s biological oxygen demand.
The water quality probe occasionally gives us some trouble, but it is one of our most valuable tools for measuring water quality.
To measure turbidity, we compare a sample of ocean water to a sample of tap water.
The hydrometer is another piece of equipment we use to measure salinity in addition to the probe. Occasionally, we also use a refractometer to get a third salinity measurement as well.
The quadrat surveys went by a lot faster today because after two days of staring at squares, we’ve gotten a lot better at them. In addition, there were fewer organisms to find on Spectacle Island in comparison to Lovells Island. On the other hand, today we encountered a new species of clam that we had not seen before. It was exciting, but we eventually were able to identify the clam in our field guide.
We found an Atlantic Surf Clam for the first time.
We finished our surveys pretty early, so a few of us swam at the beach while we waited for the ferry to take us back to Boston. Thus came the end of yet another exhausting day. Tomorrow is going to be another long day, and we’ll be returning back to Lovells Island. It’s Friday though, so it’ll be the last day of our long week in the field.
–Jeffrey