HUMBER RIVER AND DUFFINS CREEK 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.

Since 1967, DFO has been collecting spawning-phase sea lampreys from the Humber River, as part of a Lake Ontario network of traps intended to monitor sea lamprey numbers. In the early 1980s, following an extended period of dip-netting and one year of portable trapping, two attractant water traps were installed in the bank-side corners of the Old Mill water control dam. Portable trapping operations, initiated in Duffins Creek in 1976, were replaced downstream in 1981 by a low-head barrier and incorporated attractant water trap.

OBJECTIVE: Operate the two traps incorporated into Old Mill dam on the Humber River in Toronto, ON, and the trap incorporated into the low-head sea lamprey barrier on Duffins Creek in Ajax, ON, conducting mark and release studies 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.