Volunteer Angling Survey of Anadromous Brook Trout in Maine

Brook trout that live in coastal streams may spend part of their lives in salt water and come back to fresh water to spawn, a life history strategy called "anadromy". Anadromous brook trout may leave their fresh water environment for periods ranging from a few months to over a year. Typically, they migrate from fresh to salt water at an early age, probably to take advantage of the more abundant food resources of salt water estuaries. Research in two Maine streams with anadromous brook trout found that their migration from fresh to salt water occurred mainly from April through June. Their return to fresh water starts in May and can last until early August. When brook trout return to streams from salt water they have a silvery color, which fades after only two weeks in fresh water.

Not all brook trout in coastal streams adopt an anadromous life history. It is not known why some brook trout head to salt water and some stay in fresh water. Anadromous populations of brook trout appear to be declining throughout their range. This decline is believed to be due to over fishing, habitat degradation and loss, in-stream barriers (dams, culverts, etc.) or predation. There has never been an intensive survey of Maine's anadromous brook trout populations, so their current status in Maine is uncertain.

This lack of information has prompted Inland Fisheries and Wildlife to start a volunteer angling survey of coastal brook trout waters. Recruiting anglers to aid in this effort greatly increases our ability to gather data over a wide area. By taking a small sample of scales from brook trout caught in coastal rivers, chemical analysis will be able to tell us whether a trout is anadromous or "resident" (non-anadromous). This information, when combined with a simple volunteer logbook detailing the amount of time spent fishing and the number of fish caught, will give MDIF&W valuable data for an initial assessment of anadromous brook trout populations in Maine.

If you would like to participate, please contact Maine IF&W Fisheries Research Section: Merry Gallagher at (207) 941-4381, or merry.gallagher@maine.gov