CBASS sampling includes surveying the coastal fishery ecosystem from the Presumpscot River to the West Cod Ledges, and everything in between. In the river, we sample adult river herring (primarily alewife) during spring spawning runs to monitor changes in migration timings as well as demographics (e.g., age, sex, and energetic condition).
In western Casco Bay, from the mouth of the Presumpscot to Portland Head Light, we use beach seining to assess variations in littoral fish communities; littoral fish are small, inshore fish like Atlantic silversides and mummichogs. We also encounter juvenile alewife in our seine hauls.
In the outer bay and out to the West Cod Ledges we use hook-and-line fishing to conduct a jig survey for groundfish including cod, pollock, redfish and sculpins, among others.
In addition to fish surveys we also deploy temperature loggers at various sites throughout western Casco Bay to monitor changes in water temperature. Since 2019, CBASS has been an invaluable experience for our REU students, as it introduces them to a variety of field sampling techniques.
Starting in 2020 we are excited to pair CBASS efforts with our work on environmental DNA, to compare traditional survey results (e.g., seining) to variations in eDNA for the purpose of validating eDNA as a viable survey approach.
These are the nine most commonly caught fish when using hook-and-line fishing to conduct jig surveys in our region.
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Gulf of Maine, Explained
Read on for an inside look at what we've learned in our summer 2023 Gulf of Maine warming update.