Downeast Tomcod Monitoring - Powered by Anecdata.org

Study Extent

Downeast Salmon Federation is conducting a presence/absence survey in Hancock and Washington County in December and January to monitor tomcod (also known as frost fish). This is part of a larger citizen science project gathering information on anadromous fish species. Project Goal: Determine the presence and absence of Microgadus tomcod in Downeast Maine.

Sampling

Maine is home to 12 species of native sea-run (called diadromous) fish that spend part of their lives in freshwater and part in the sea. These fish make astounding migrations each year with significant impacts to the freshwater, estuary, and marine environments that they move through as they complete their life cycles. Because of the widespread and mobile nature of their life histories, much remains to be known about which particular coastal rivers they occupy, the timing and extent of their migrations, and the number of individuals present. Information about these fish has implications for species conservation, restoration, and management. Atlantic tomcod are one such species that migrate up rivers from the ocean to spawn in the winter. Spawning occurs in shallow brackish or fresh water over gravelly bottom. A female can deposit 6,000-30,000 eggs. Egg incubation takes up to 30 days in 30 to 43ºF water. The average adult is 9-12 in. Life expectancy is 4 years. Atlantic tomcod live in the mouths of streams or estuaries and are resistant to sudden changes in temperature and salinity. Their range is southern Labrador to Virginia. Tomcod eat larval copepods, small crustaceans, small mollusks, worms, as well as fish larvae and are eaten by predators such as Striped Bass and Bluefish. Atlantic tomcod populations have declined due to loss of access to spawning grounds, overfishing, and exposure to toxins. Because they typically live year-round in estuaries, tomcod are particularly subject to stresses from pollutants. Since the commercial fishery closed in the 1950s, there is very little known about their current whereabouts or how well they are doing in Maine rivers and streams. We need to learn more about these amazing creatures to better manage our rivers and streams now and into the future. Information collected by this project is designed to create a more complete picture of where, when, and in what numbers tomcod can be found.

Method steps

1. Participants will visually identify Microgadus tomcod sign, including fish and bird activity.

Downeast Maine, United States