Program in Nutrition
Capability/Technical Service - Monitoring and evaluation of contaminants in in fish feeds, hatchery fish, and the hatchery environment.
Contaminants in the aquatic environment, in commercial fish feeds, and in NFH fish are serious concerns to the health of aquatic species and for human consumption. A better understanding of the sources of contaminants in NFH fish, their food, and the aquatic environment will provide a basis for controlling and/or eliminating the problem.
1) Effluent Management Through Nutrition
The Environmental Protection Agency (EPA) is developing new effluent standards and guidelines for aquaculture facilities, including NFHs. New requirements include development of treatment technologies and best management practices for reducing the discharge of total suspended solids and excess feed. These new standards will require feeds that produce less waste via fish excrement or as excess feed. This project proposes to develop and test low polluting diets to be used at National FIsh Hatcheries to assist in the management of solids and excess feed. The feed would be highly palatable, highly digestible, and low in excreted phosphorous. Also, non-friable fecal material would be produced making the solids easier to remove. As diets are developed they will be fed to the fish using standard nutrition study protocols in controlled tank studies to determine which formulations perform optimally. All feeding trials have been completed. Using different fish species Mora Fish Technology Center (FTC) ran one trial, Abernathy FTC ran three trials and Lamar & Bozeman FTCs each ran two. The majority of the analytical work has been completed (proximate and phosphorus analysis of the fish). Abernathy, Lamar & Bozeman FTCs have preliminary data analyses done and Bozeman FTC has a preliminary report completed.
Partners USFWS Bozeman FTC, Mora NFH & TC, and the Northeast Fisheries Center
2) Identification of Contaminats in Commercially Produced Fish Feeds Used at NFHs.
Contaminated commercial fish feed pose both fish and human health hazards. Exposure to contaminants can adversely affect the health and viability of declining, threatened, and endangered fish species reared at NFHs. These fish feeds can negatively affect the quality of fish destined for human consumption. Fish feeds from various suppliers are used at Pacific Region NFH. Some of the same brands of fish feed were found to have elevated levels of heavy metals in the feeds used at Southwestern Region NFHs. The objective of this study was to determine if contaminants were wide spread in fish feeds used by the USFWS. Feeds were sampled from eleven NFHs representing the Pacific, California/Nevada, Great Lake/Big Rivers, Rocky Mountain, and Northeast Regions. Abernathy FTC staff processed feed samples, conducted proximate analyses and sent samples to USGS, Biological Resources Division for contaminants analyses. A final paper was published in the peer-reviewed journal Chemosphere. This paper gives an overall view, in a two year period, of the contaminant load in fish feeds used at NFHs. Polychlorinated biphenyls (PCBs) were the compounds most commonly detected in the feed but at levels lower than previously reported.
Partners: Coleman, Spring Creek, Hagerman, Quilcene, Leavenworth, Garrison Dam, Ennis, Jordan River, Genoa, North Attleboro, and White Sulphur Springs NFHs.
Publication: Maule, A.G., Ann L. Gannam, and J. W. Davis. 2007. Chemical contaminants in fish feeds used in federal salmonid hatcheries in the USA. Chemosphere 67:1308-1315.
3) Investigation of Contaminants in Fish and Fish Feeds at Pacific Region NFHs.
Numerous species of fish are reared at NFHs where they are fed commercial fish feed. Many of those feeds contain contaminants.. Contaminants in fish and fish feeds have been brought to the forefront recently by a paper published in Science (Hites et al. 2004). Contaminants were identified in the feeds tested and were reflected in the flesh of the fish, Atlantic salmon (Salmo salar), in the Hites et al study. While the effect these contaminants on fish health is not completely known, there are health risks associated with consuming fish containing contaminants. The objective of this study is to address the potential occurrence of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), dioxins/furans, heavy metals, including mercury, and organochlorine pesticide (OC) contaminant residues in fish and commercial feeds at NFHs. Fish and feed will be sampled at three Pacific Region NFHs (Warm Springs, Quinault and Quilcene). The fish sampled will be Warm Springs NFH spring Chinook salmon, Quinault NFH steelhead, and Quilcene NFH coho salmon. Fish and feed samples were collected according to study protocols at the three NFHs and submitted for analysis. Whole bodies of returning spring Chinook at the Warm Springs NFH were also sent for analysis because of tribal concerns about contaminants. Results of this study will provide a better understanding of the contaminant levels in fish feed used at NFHs and the concentrations of contaminants in fish reared at NFHs.
Partners: USFWS Warm Springs, Quinualt, and Quilcene NFHs.