Bibliography Background About KRIS

Chemical Pollutants in Gulf of Maine Atlantic Salmon DPS Watersheds

There are many different types of chemicals that may pollute water, including organic chemicals such as pesticides, inorganic chemicals, and petrochemicals. Some of these substances have been more closely studied than others because they are recognized as potential limiting factors for Atlantic salmon in Gulf of Maine DPS rivers (Dill et al., 2002).

Organic Chemicals: Pesticides fall under this category, and some substances used agriculturally in Maine have found their way into the waters of DPS rivers giving rise to concern about effects on Atlantic salmon. Dill et al. (2002) were particularly concerned about organic chemicals because of potential endocrine disruption, which changes sex hormone systems (see more on endocrine disruption). Fish at any life stage can be affected but the greatest concern, based on the work of Fairchild et al. (1999) and McGee (2001), is how endocrine disruption interferes with smolting. The Maine Atlantic Salmon Technical Advisory Committee (Dill et al., 2002) arrived at the following conclusion: "Given the widespread occurrence of known endocrine disrupting chemicals in Maine Atlantic salmon rivers, the committee concludes that endocrine disrupting chemicals have a high probability of adversely affecting Atlantic salmon restoration." Hexazinone is recognized as a particular problem because it is used widely on low bush blueberries and it has been found in tributaries of the Pleasant and Narraguagus rivers (Beland et al. 1995; Chizmas 1999). 

The ESA listing notice for the DPS Atlantic salmon (USFWS/NOAA, 2000) noted existing and potential impacts to the species from "chronic exposure to insecticides, herbicides, fungicides, and pesticides" and said that "discharging (point and non-point sources) or dumping toxic chemicals, silt, fertilizers, pesticides, heavy metals, oil, organic wastes or other pollutants into waters supporting the DPS" would be a potential "take".

The Maine DAG has worked cooperatively to abate recognized problems related to pesticides in DPS watersheds as part of Atlantic Salmon Conservation Plan for Seven Maine Rivers (MASTF, 1997). Their closest partners in monitoring, not only pesticides but also nutrients and sediment, are the Maine DEP, Soil and Water Conservation Districts and the University of Maine Cooperative extension. Pesticide pollution reduction includes the following steps (MDAG, 2002):

MDAG (2002) noted the following success with regard to Hexazinone: "Studies have shown that Hexazinone decreased in Maine ground water from 1994 to 1999 as a result of a specific plan for this chemical being devised. This is important to Atlantic salmon conservation efforts because these ground waters may be connected to surface waters in some DPS rivers. Stricter regulations were combined with grower education. Practical solutions that worked for growers were 1) lower application rates, 2) switching to granular versus liquid products, switching to less toxic herbicides and skipping application cycles."

Inorganic Pollutants: Aluminum is known to contribute to fish toxicity or stress associated with acid precipitation and runoff (see pH section above). Chlorine can also be a companion problem with acid rain because its toxicity is elevated.

Chlorine: Dill et al. (2002) note the elevated risk of chlorine toxicity in conditions of low pH or increased water temperature. The risk area is a reach of the Narraguagus River where local drainage conditions limit the effectiveness of typical septic systems and where overboard discharge (OBD) systems are used. These alternative wastewater treatment systems use chlorine to kill potentially harmful bacteria but chlorine, if released into streams is highly toxic to fish. Consequently, risk to Narraguagus Atlantic salmon from chlorine in the effected reaches would be elevated during acid runoff conditions or during periods of low flow and elevated temperature. 

See the general KRIS background page for more information about chemical pollutants.


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]**

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]