One of the primary public health concerns in regards to water quality is the suitability of the fish in our waters for human consumption. In Iowa, the Fisheries Bureau of the Iowa Department of Natural Resources is responsible for issuing fish consumption advisories. The IDNR Land Quality & Geological Survey Bureau is responsible for coordinating the annual collection of fish tissue for contaminant analysis and is responsible for the preparation of all summaries or reports of this monitoring.

In nearly all cases, the fish in Iowa are safe to eat. The cleaning and or preparation of the meal cause most the problems regarding taste or color of fish meant for consumption. As with all other living creatures, fish are susceptible to diseases, parasites, and other naturally occurring conditions in the water. If you suspect your fish is affected by any of these conditions, it should NOT be eaten.

Routine fish tissue monitoring is conducted in Iowa as part of three long-term programs: (1) U.S. EPA (USEPA) Region VII Regional Ambient Fish Tissue (RAFT) Monitoring Program, (2) water quality studies of the Des Moines River near Saylorville and Red Rock reservoirs, and (3) water quality studies of the Iowa River near Coralville Reservoir. Since 1977, annual fish collection and analysis activities in Iowa have been conducted by IDNR as part of the USEPA's RAFT monitoring program. These samples are analyzed for contaminants by the USEPA laboratory in Kansas City, Kansas, to determine the level of contamination present. Results are transmitted to IDNR in the spring following sampling. Annual fish contaminant monitoring at three of Iowa's federal flood control reservoirs is sponsored by the U.S. Army Corps of Engineers (Rock Island District). This monitoring is conducted by Iowa State University (Saylorville and Red Rock reservoirs) and by the University of Iowa (Coralville Reservoir).

To supplement other environmental monitoring programs and to protect the health of people consuming fish from waters within this state, the IDNR conducts fish tissue monitoring. Since 1977, the IDNR, the USEPA Region VII, and the University of Iowa Hygienic Laboratory have cooperatively conducted annual statewide collections of fish for tissue contaminant analysis. Beginning in 1983, this monitoring effort became the RAFT program. Currently, the RAFT program is the only statewide fish contaminant monitoring program in Iowa. Historically, the data generated from the RAFT program have enabled IDNR to document temporal changes in contaminant levels and to identify Iowa lakes and rivers where high levels of contaminants in fish potentially threaten the health of fish-consuming Iowans. The Iowa RAFT monitoring program incorporates three different types of monitoring sites: 1) status, 2) trend, and 3) follow-up.

The majority of RAFT sites sampled each year determine whether the waterbodies meet the "fish consumption" portion of the fishable goal of the federal Clean Water Act. In other words, these sites are used to screen for contamination problems and to determine the water quality "status" of the waterbodies. Analyses for a variety of pesticides, other toxic organic compounds, and metals are conducted on composited fillet (edible portion) samples of three to five omnivorous bottom-dwelling fish (e.g. carp) and carnivorous predator fish (e.g. bass or walleye). Most status sites on rivers and lakes have either never been sampled or have not been sampled within the last five years (rivers) or 10 years (lakes). Staff of the IDNR divisions of Environmental Services and Conservation and Recreation select status sites. Status monitoring occurs on most types of Iowa waterbodies (interior rivers, border rivers, and manmade and natural lakes) in both rural and urban areas. Lakes and river reaches known to support considerable recreational fishing receive highest priority, but IDNR attempts to sample all lakes and river reaches designated in the Iowa Water Quality Standards for recreational fishing. Approximately one-third to one-half of Iowa RAFT status sites are on lakes; the remaining sites are either on interior rivers or on the border rivers (Mississippi, Missouri or Big Sioux).

In 1994, USEPA Region VII in cooperation with the Region VII states (Iowa, Kansas, Missouri, and Nebraska), identified stations that would be monitored every other year to determine trends in contaminant levels. One composite sample of three to five common carp from each station is submitted for whole-fish analysis. Whole-fish samples are more likely to contain detectable levels of most contaminants than are fillet samples (edible portions). Examination of the trend monitoring results may help identify temporal changes in contaminant concentrations and may expose new contaminants entering the food chain. In Iowa, the following ten locations are part of the RAFT trend monitoring.

Stations first sampled in 1994 and sampled in even years since:

1. Mississippi River downstream from Dubuque, Dubuque County
2. Mississippi River downstream from Linwood, Scott County
3. Wapsipinicon River north of Donahue, Scott County
4. Des Moines River at Keosauqua, Van Buren County
5. Little Sioux River near Washta, Ida County

Stations first sampled in 1995 and sampled in odd years since:

1. Mississippi River at Lansing, Allamakee County
2. Maquoketa River at Maquoketa, Jackson County
3. Iowa River at Wapello, Louisa County
4. Skunk River at Augusta, Lee County
5. Des Moines River at Des Moines, Polk County

If status sample results show elevated contaminant levels, the RAFT program conducts follow-up monitoring to better define the levels of contaminants. In addition, follow-up sampling is conducted every other year at waterbodies with existing consumption advisories.

• 2006 Fish Tissue Monitoring in Iowa fact sheet (*.pdf) (~246k)
• 2005 RAFT Report (*.pdf) (~52k)
• 2004 RAFT Report (*.pdf) (~75k)
• 2003 RAFT Report (*.pdf) (~39k)
• 2002 RAFT Report (*.pdf) (~123k)
• 2001 RAFT Report (*.pdf) (~162k)