Casco Bay Monitoring Project Wraps Second Year

In Stewarding the Ecosystem

As the second year of our Casco Bay Aquatic Systems Survey (CBASS) project comes to a close, we’re reflecting on a successful summer. With a fresh team of interns on board to help, the research team undertook an ambitious sampling effort throughout Casco Bay.

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 joined us from universities across the country to work on this project, the CBASS team spent 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.

In deeper water, we sample using simple hook and line. While fishing in the outer bay early in the season, 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. After the fish complete that part of their migration, the team spends 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 this summer. Basking sharks, while harmless, are often confused with Great White sharks. While you may have noticed several reported shark sightings in the news this summer, 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.

These observations contribute to our growing knowledge of changing climate conditions in the Gulf of Maine. Moreover, the tools we develop for recording and sharing these data will eventually be publicly available, helping our coastal communities adapt to changing conditions in Casco Bay and elsewhere.

For more regular updates on our work, follow us on Twitter and Facebook, or visit the CBASS project page on our website.