COBOURG BROOK SEA LAMPREY TRAPPING CONTRACT

BACKGROUND
DFO has played a vital role in the sea lamprey control program since 1955.  It is a binational program that is coordinated by the Great Lakes Fishery Commission (GLFC) and serves to protect the fisheries of the Great Lakes, which have an estimated economic benefit of $7 billion annually.  Control is achieved primarily by extensive treatment of streams to eliminate larval sea lampreys. To measure how effective the control program is each year, DFO estimates the populations of adult sea lamprey in each lake on an annual basis.  This is done by using traps to estimate populations in streams and then extrapolating to the entire lake.  The results help to direct sea lamprey management.

DFO has been collecting spawning-phase sea lamprey from Cobourg Brook since 1976, as part of a Lake Ontario network of traps intended to monitor sea lamprey.  Initially carried out irregularly with portable traps, a low-head barrier with fishway and trap inserts was installed for the 1997 trapping season.  


OBJECTIVE:
Operate the sea lamprey trap on Cobourg Brook, conducting a mark and release study with the sea lamprey captured, and collect and supply raw data to be used to generate a population estimate in this stream.  This population estimate will be used along with that of other streams to estimate the population in all of Lake Ontario.