Bait Leech, Nephelopsis Obscura Culture And Economic Feasibility

The need for basic biological research on the bait leech, Nephelopsis obscura, became apparent in the late 1970's. As a bait organism gaining popularity with midwest walleye fishermen, the total harvest in Minnesota approached 70 tons with an annual revenue of over $3 million. This does not include the commerce involved with terminal tackle. The scarcity of this excellent bait during the late summer, when not obtainable by natural harvest, and the alarming potential for overharvest prompted the Minnesota Sea Grant Institute to fund a project on the biology, management, and economic feasibility for culture of the bait leech. The research efforts to date have yielded information regarding idealized diet, temperature, water quality, light conditions and space needs for the successful culture of leeches. Growth rates have been measured and reproductive data for culture production and survival rates of young leeches have been determined. This report represents the results of an economic feasibility study based on findings of previous biological research. A comparison of the revenues and costs suggests that commercial bait leech production is indeed economically feasible. A more detailed discussion of this conclusion is provided in this report. Grant no. NA81AA-D-00114