Water Quality Assessment for Salmon Production and the Salmon Products Facility at the St. Croix Indian Fischeries

Abstract

This report summarizes one year of study of water quality in Loon Creek and the Yellow River near Danbury in Burnett County, Wisconsin. Loon Creek, a tributary of the Yellow River, is the proposed site of an Atlantic salmon fish farm. Field studies and laboratory analysis were conducted monthly tb measure selected physical and chemical characteristics of both streams. Measurements included pH, temperature, conductivity, hardness, dissolved oxygen, ammonia and nitrate nitrogen, phosphorus (orthophosphate), chloride, fluoride, sodium, copper, lead, potassium, calcium, and magnesium. In addition, volume of flow of Loon Creek was determined. Results from this study reveal the volume of flow in Loon Creek ranged from 8,430 to 14,000 gals./min. Loon Creek water was slightly acidic to . slightly alkaline, and was well aerated, with dissolved oxygen levels from 7.4 to 13.3 mg/L. Except for optimum temperature range, Loon Creek water is within suggested limits for raising Atlantic salmon in fresh water. Based on results of a preliminary study, similar conclusions can be drawn about local ground water. Water temperature fluctuations in stream water will not limit growth of salmon, because the water will be heated or cooled as necessary to maintain the 58-60F (14.5-15.6C) temperature required for optimum growth. Data from the study of Loon Creek is being used in the facility design by Butler Research International to determine production capacity, aeration requirements and water recycling potential. Present estimates are that 50% of the water can be recycled. Recycling will reduce the cost of temperature modification and conserve stream water. Levels of chemical constituents are consistently lower in Loon Creek than the Yellow River, thereby, creating a "dilution effect" as the former discharges into the latter. Water quality data on these two streams may be used as a basis to assess possible changes in water quality resulting from operation of the salmon fishery.