It’s officially summer, which means the second year of our Casco Bay Aquatic Systems Survey (CBASS) is now underway. With a new team of interns to help us, there’s plenty of energy in our lab to fuel our research over the next few months.
CBASS is a long-term ecosystem monitoring study. We use a variety of sampling methods to measure what is happening in the whole ecosystem, not just a single site. Then, we repeat the sampling multiple times per year, over the course of many years, so we can record and learn from changes we observe.
With the help of our interns, who join us from universities across the country to work on this project, the CBASS team will spend the summer exploring and sampling at our sites in the river, estuary, and outer bay areas.
These sites stretch from the Presumpscot River to West Cod Ledge, located three miles off the shore of Cape Elizabeth. Depending on the site, we may be working in two feet of fresh water, or 200 feet of salt water, so we have a range of techniques to handle the different challenges these varying conditions present.
This year, our sampling season is off to an exciting start. While fishing in the outer bay with hook and line, we caught nearly 100 fish. Six different species were represented in our sample, with cod making up about a third of the catch.
Through CBASS, we also monitor alewives running up the Presumpscot. At this time, it appears the fish are mostly done with that part of their migration. Now, instead of going to the river to catch fish, we will spend more time analyzing the fish we sampled, according to their length, age, and maturity.
A surprise visit from a 20-foot basking shark was perhaps our most exciting moment on the boat so far this summer. Basking sharks, while harmless, are often confused with Great White sharks. While there have been several reported shark sightings in the news recently, we think many of them are probably basking sharks.
Like most ocean environments, Casco Bay is a dynamic place. By using a variety of sampling techniques across many different sites, we hope to better understand the patterns of life here. As we record these patterns, the long term nature of the project will help show how the ecosystem changes over time.