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Tracking New England River Herring

We monitored river herring spawning migration to investigate challenges presented by past cranberry bog farming and urbanization along the Coonamessett River in Falmouth, MA.

On this chilly April morning, river herring make a run from the sea to their freshwater spawning grounds via the Coonamessett River and a short detension at our tagging station.

Did you know that the term "River Herring" refers to not one, but two different species of fish? Blueback (Alosa aestivalis) and Alewife (Alosa psuedoharengus).

Urban ecosystems provide an opportunity to study rapidly occurring adaption and contribute to understanding the fundamental processes of selection. Dams along the highly populated northeastern seaboard contributed to the extirpation of many anadromous fish runs by altering aquatic connectivity and restricting access to historic spawning grounds, yet simply removing barriers does not guarantee return of historic populations. River herring populations have been in sharp declined since the late 1960s largely due to overfishing, habitat degradation, and restricted access to spawning streams by dams and road

culverts. Working closely with the town of Falmouth, MA and a local non-profit the Coonamessett River Trust, we used PIT tags and remote PIT tag detecting arrays to monitor fish movements during the spring spawning migration. We found that herring in the Coonamessett River tend to move at night likely as a local adaptation to high daytime bird predation influenced by the removal of trees along the river for the last 100 years to facilitate farming. This river section was restored in 2018 and combined with ongoing restoration of another river section provides opportunities to study and evaluate the effects of river and

marsh restoration on migratory fish, local adaption, and life-history strategies.

Many dedicated volunteers help count, tag, and track river herring in the Coonamessett River and other rivers in New England. Today my team includes my daughter Rachel, my husband Andrew, and my good friends, Kate and Jason McCreas. Yup! The caramel guys!
Nothing beats the feeling of sending a newly tagged herring on its way upstream to spawn.

...except, perhaps, the feeling of tagging so many herring that you use up ALL the tags! : )

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