Fish Kill Event - Bee Branch Detention Basin

The fish kill occurred in the Bee Branch Detention Basin which is located within the City of Dubuque,T89N, R2E. The UTM to the basin is 692592 East and 4708999 North. The Kill occurred in an approximately 24 acre basin that is open to the Mississippi River via a water outlet structure. The main kill seemed to be located in the SE section of the basin but some fish and mussels were found throughout the basin.

The original spill occurred after a pump was left running while transferring fertilizer from a barge on June 18. An estimated 432,000 gallons of liquid fertilizer overflowed from above ground storage tanks near 1200 Kerper Boulevard.

The kill was extensive but only a percentage of the fish and mussels were tabulated. Many dead fish and mussels could be seen exiting the basin through the outlet structure before being counted and many were consumed by the various scavengers that appeared on site. Water was clear and near base flows at the time of assessment. The kill also included crayfish which were not quantified. It is unknown how long fish were dead in the initial investigation but we were able to identify all the species and some fresh dead fish were observed. The second kill consisted of both older and newly perished individuals but all still remained intact enough to identify to species. Twenty-four species were identified in the kill extent.