Bibliography Background About KRIS

Nutrients  in Gulf of Maine Atlantic Salmon DPS Watersheds

Nutrients are recognized as a threat to DPS Atlantic salmon survival only in the Sheepscot River (Dill et al., 2002). Nutrients impact fish and water quality mainly through side effects of the algae blooms they trigger, including low D.O. Phosphorous (P) is usually the nutrient that limits aquatic plant growth, so total phosphorous (TP) is a useful measurement for assessing the potential for blooms. Nitrogen is also a good indicator of nutrient enrichment and has the potential to stimulate plant growth. It is most available to plants in the form of ammonium ions, but is measured as nitrates in studies of the Sheepscot River. According to Arter (2004): "Nitrates in water generally originate from precipitation, human, and animal waste, residential and agricultural fertilizers and bedrock."

Arter (2004) noted that the Maine Volunteers Lake Monitoring Program data indicated that three lakes in the Sheepscot basin, Clary Lake and Long Pond and Dyer Long Pond, all had elevated levels of phosphorous and high chlorophyll levels indicative of algae blooms and eutrophication. NOAA Fisheries collected pH data in the lower Sheepscot River that showed nocturnal-diurnal fluctuations of pH indicative of algae blooms (Arter, 2004), with day time highs reaching 8.5. One concern about elevated pH is that, in combination with elevated water temperature, it may trigger a shift in available nitrogen from the ammonium ion to dissolved ammonia (Goldman and Horne, 1983), also know as unionized ammonia, which is lethal to fish life at concentrations as low as 0.025 mg/L (U.S. EPA, 1986). So far, no amonia data has been collected in the Sheepscot River. (Whiting, personal communication)

Table 3. Percent of total ammonia converted to unionized or dissolved ammonia in response to temperature and pH. From Goldman and Horne (1983).

Temperature (F) Temperature (C) pH 6.5 pH 7.0 pH 7.5 pH 8.0 pH 8.5
68 20 0.13 % 0.40 % 1.24 % 4.82 % 11.2 %
77 25 0.18 % 0.57 % 1.77 % 5.38 % 15.3 %
82 28 0.22 % 0.70 % 2.17 % 6.56 % 18.2 %
86 30 0.26 % 0.80 % 2.48 % 7.46 % 20.3 %


According to MDEP data, the total phosphorous (TP) in the lower mainstem Sheepscot and lower West Branch is highest (max 160 µg/L) during low flow conditions but also shows a smaller peak (max 91 µg/L) during storms (Arter, 2004). Arter (2004) postulated that the concentrations were highest in the lower rivers due to "an accumulation, or downstream, effect" stemming from non-point source pollution. Information on nitrates in the Sheepscot River (Arter, 2004) is consistent with the hypothesis that nutrients are accumulating in the lower river: "Nitrates are generally higher in both the WB and MS than other salmon rivers. The Sheepscot ranges from < 1.0 µeq/L (essentially zero) to 29.9 µeq/L whereas the Narraguagus ranges from < 1.0 to 5.6 µeq/L."  

dag_nps_dps_strategy.jpg (163071 bytes)The Maine Department of Agriculture, in cooperation with other state agencies, helped abate non-point source pollution problems, including nutrients, in DPS rivers in the last few years. At left: Diagram of Non-Point Source Pollution assessment and abatement on Maine DPS rivers. From the Maine Dept. of Agriculture (2002).

The DAG formed a statewide Nutrient Management Board and hired a Nutrient Management Coordinator. Other specialists have been trained in nutrient control throughout the state and 341 nutrient management plans had been certified as of 2002 (MDAG, 2002). Two million dollars were spent on pollution control structures and a ban on winter spreading of manure was implemented. Nutrient abatement is approached as follows (MDAG, 2002):


Arter, B. S., 2004. Sheepscot River Water Quality Monitoring Strategic Plan: A guide for coordinated water quality monitoring efforts in an Atlantic salmon watershed in Maine. Prepared for the Project SHARE: Research and Management Committee. 84 pp. [975kb]

Beland, K., N. Dubé, M. Evers, R. Spencer, S. Thomas, G. Vander Haegen, and E. Baum.1995. Atlantic salmon research addressing issues of concern to the National Marine Fisheries Service and Atlantic Sea Run Salmon Commission. Maine Atlantic Sea Run Salmon Commission Final Project Report NA29FL0131-01.

Chizmas, J. S. 1999. Study of pesticide levels in seven Maine rivers. Maine Board of Pesticides Control. 14 pp [6.2 Mb]

Dill, R., C. Fay, M. Gallagher, D. Kircheis, S. Mierzykowski, M. Whiting, and T. Haines. 2002, Water quality issues as potential limiting factors affecting juvenile Atlantic salmon life stages in Maine rivers. Report to Maine Atlantic Salmon Technical Advisory Committee by the Ad Hoc Committee on Water Quality. Atlantic Salmon Commission. Bangor, ME. 28 pp. [162kb]

Goldman, C.R. and A.J. Horne. 1983. Limnology. McGraw-Hill, Inc. New York . 464 pp.

Halsted, M., 2002. Effects of stream flow on the stream temperature, E. coli concentrations and dissolved oxygen levels in the West Branch of the Sheepscot River. Alna, ME. 15 pp. [450kb]

Haines, T., and J. Akielaszek. 1984. Effects of acidic precipitation on Atlantic salmon rivers in New England. U.S. Fish and Wildlife Service FWS/OBS-80/40.18.

Haines, T., S. Norton, J. Kahl, C. Fay, S. Pauwels, and C. Jagoe. 1990. Intensive studies of stream fish populations in Maine. U.S. Environmental Protection Agency, Office of Acid Deposition, Environmental Monitoring and Quality Assurance, EPA/600/3-90/043.

Kroglund, F., and M. Staurnes. 1999. Water quality requirements of smolting Atlantic salmon (Salmo salar) in limed acid rivers. Can. J. Fish. Aquat. Sci. 56: 2078-2086.

Magee, J. 2001. Agrochemical monitoring and potential effects on Atlantic salmon in eastern Maine rivers. National Marine Fisheries Service Report.

Maine Department of Agriculture. 2002. Report on activities in Atlantic Salmon Conservation Plan Rivers 2002. Maine Dept. of Ag. 

Maine Department of Environmental Protection. 2002. Water quality concerns and effects from state fish hatchery discharges. Unpublished Report. Augusta, ME.

Maine Department of Environmental Protection. 2004. 2002 Section 303(d) Report: Total Maximum Daily Load (TMDL) Waters. Augusta, ME.

National Research Council, 2003. Atlantic Salmon in Maine. The Committee on Atlantic Salmon in Maine, Board on Environmental Studies and Toxicology, Ocean Studies Board, Division on Earth and Life Sciences. National Research Council of the National Academies. National Academy Press. Washington, D.C. 260 pp. [3.5Mb]**

Pugh, L., 2002. Analysis summary of water quality monitoring data, 1994-2001. Sheepscot Valley Conservation Association . Alna, ME. 6 pp. [225kb]

Robinson, K. W., J. P. Campbell, and N. A. Jaworski, 2003. Water quality trends in New England rivers during the 20th century. United States Geologic Service. Water-Resources Investigations Report 03-4012. Pembroke, NH. 29 pp. [950kb]

State of Maine. (1998). Maine Section 303(d) Waters list.

U.S. Environmental Protection Agency, 1986. Quality criteria for water 1986: EPA 440/5-86-001. Office of Water Regulations and Standards,  Washington D.C.

U.S. Fish and Wildlife Service and National Oceanic and Atmospheric Administration, 2000. Endangered and Threatened Species; Final Endangered Status for a Distinct Population Segment of Anadromous Atlantic Salmon (Salmo salar) in the Gulf of Maine. Federal Register Notice Vol. 65, No. 223 / Friday, November 17, 2000 / Rules and Regulations. Pages 69459-69483 [225kb]

Whiting, M., 2001a. Year 2000 Progress Report for DEP Water Quality Monitoring Plan - Maine Atlantic salmon rivers. Maine DEP, Bangor Regional Office. Bangor, ME. 4 pp. [25kb]

Whiting, M., 2001b. Progress report: A summary of water quality monitoring results from Spring 2001, Maine Atlantic Salmon Rivers Project. Maine DEP, Bangor Regional Office. Bangor, ME. 6 pp. [775kb]**

Whiting, M., 2002. Maine Salmon rivers water quality monitoring progress report for 2002 field season. Maine DEP, Bangor Regional Office. Bangor, ME. 22 pp. [2.25Mb]**

Whiting, M. 2004. Personal communication

Williams, S. 2002. Maine Volunteer Lake Monitoring Program Annual Report 2002. Maine Volunteer Lake Monitoring Program, Auburn, Maine. 52pp. [7 Mb]

Williams, S. 2003. Maine Volunteer Lake Monitoring Program Annual Report 2002. Maine Volunteer Lake Monitoring Program, Auburn, Maine. 52 pp. [8 Mb]