A group seeking to clean up Iowa’s waterways says a national report confirms that manure spills are the top source of fish kills in the state. Susan Heathcoat of the Iowa Environmental Council says the report examined fish kills nationwide in a four-year period.An estimated two-point-three million fish were killed in Iowa between 1995 and 1998. Manure spills were the number one source of the killing spills. Heathcoat says a review of more recent information shows a cutback in deadly kills.The Environmental Council compared data from the year after the study and found spills were down to 18 from 39 in last year of the study. Heathcoat says the Iowa Department of Natural Resources has focused on reducing spills and that has helped. She says more could be done to stop spills at large manure holding areas by improving backup systems.While the study looked at spills nationwide, Heathcoat says it’s hard to rank states when it comes to spills, because many don’t keep records that’re as detailed as Iowa’s.Information on spills and fish kills in Iowa can be found on the Iowa Environmental Council’s website at:www.earthweshare.org.