By KMAland’s Ethan Hewett

Impacts of a fertilizer spill into the East Nishnabotna River in Montgomery County on fish and wildlife in Northwest Missouri are being realized.

Last week, officials with the Iowa Department of Natural Resources reported nearly 265,000 gallons of liquid nitrogen fertilizer spilled into a drainage ditch before making its way into the Nishnabotna River and eventually into Missouri, where the river flows for roughly 10 miles until it reaches the Missouri River. An investigation determined a valve had been left open overnight before being discovered last Monday.

Matt Combes is the supervisor for the Missouri Department of Conservation’s Ecological Health Unit and the agency’s fish kill program. Combes tells KMA News that his group observed a near-total fish kill along the 10-mile stretch of the Nishnabotna in northwestern Atchison County.

“Especially around the Watson boat ramp and on down to the Missouri River mouth – there were many dead fish on both sides of the river,” said Combes. “They did an official count of one bank of the river for nearly two miles and counted nearly 4,000 dead fish. That allows us to make an estimate of the fish kill in the rest of the river, but we haven’t completed that estimate officially.”

Ultimately, Combes says officials observed 16 different species of fish, primarily non-native silver carp, big-head carp, and grass carp. However, Combes notes that some native fish were also caught up in the spill.

“River Carpsuckers were in high numbers and Red Shiners were killed in high numbers,” he said. “Channel Catfish were in the river and were killed with a lot of them around the 18 to 24 inch range and there was also one 30-inch Blue (Catfish) observed. We also had a few rare fish killed – a Blue Sucker was observed and two Shovelnose Sturgeon were observed dead or dying.”

Additionally, Combes says there is concern about the impacts on other wildlife in the area that consume the fish killed by the nitrogen spill. While ammonia typically doesn’t transfer as easily from animal to animal as other toxins, such as an arsenic spill, Combes notes they did observe a number of animals consuming fish that had washed up on shore.

“I went out Saturday morning with crews who were looking for dying sturgeon, and we observed more than 20 American Bald Eagles on the shores and had been eating the fish – so that certainly is concerning,” Combes emphasized. “There was a lot of tracks of raccoons, otters, and other animals on the shore and evidence of them dragging fish up and over the banks.”

While the Missouri River’s much larger stream size has reduced immediate concerns and impacts, Combes says they plan to monitor the shallower waters behind wing dikes along the river, where ammonia could gather and become an issue for the fish population as temperatures warm up later this spring and summer.

Meanwhile, Karen Rouse is the regional director of the Missouri DNR’s Kansas City office. Rouse says her office notified water supplies pulling off the Missouri River, including Kansas City, roughly 100 miles south of the mouth of the Nishnabotna. From the six sample locations taken off the Nishnabotna and two from the Missouri, Rouse says the ammonia appeared to have significantly diluted once it reached the much larger Missouri River.

“We found elevated ammonia at two locations on the Nishnabotna, but once it reached the Missouri River it had greatly dissolved,” said Rouse. “So, we didn’t find any elevated ammonia once it reached the Missouri (River).”

While resampling along the Nishnabotna could be done at request, Rouse says they do have stations along the Missouri continually monitoring water quality. Combes adds that his department’s investigation remains ongoing.