BULLHEAD CITY — Dead stripers started popping up along the Colorado River on Thursday, shortly after a boat was seen putting something into the water at the Palo Verde Meadows marina.
The boat was believed to have been from the Clark County Vector Control and was thought to be treating the water for blackfly population. No one from Vector Control was available for comment on Friday, though the agency has been treating the Tri-state blackfly population for more than two decades with no previous reports of fish kill.
A resident of Palo Verde Meadows documented the carnage — photos were sent to the Daily News and to several area agencies in hopes of getting an explanation of what happened and why.
So far, there are more questions than answers.
“I swim in the river every day,” said a woman who lives in Palo Verde Meadows. “My neighbor told us to get out of the water, that something was wrong. He said something’s weird today. Something was very weird.”
Indeed, something was.
“Up and down the river, there were dead stripers,” said the neighbor, who estimated he saw between 12 and 20 stripers washed up on the shoreline and other fish floating on the surface in the middle of the river. He said he traveled by personal watercraft for a couple of miles south on the river and had to dodge dead fish along the way.
“The vultures are happy,” he said.
“What bothers me is that they did something to the river and didn’t tell anybody about it,” said one Palo Verde Meadows resident. “If that stuff is killing the fish, what is it doing to pets and humans? Am I going to get sick? Needless to say, I didn’t go swimming (Friday).”
While some officials questioned if the fish kill could have been caused by something else — just coincidentally occurring at about the same time as the boat was treating the water — one witness said he had no doubt.
“These things were alive before they got in here,” he said of the stripers. “Now, they’re all along the shoreline. The vultures are having a field day.”
One witness said other river scavengers, such as raccoons, weren’t taking an interest in the dead fish.
“That makes me wonder right there,” she said.
Bullhead City Manager Toby Cotter said the city had nothing to do with the fish kill. He said the city’s pest management employs trout to help curtail the caddisly population and that, while stripers do consume the trout, the city is having “thousands” of trout introduced through regular stockings. He said that is enough to satisfy the stripers and local trout anglers as well as making a huge dent in the caddisfly population.
“We love the stripers,” Cotter said, noting the city recently conducted a striper derby to draw attention to the popular sport fish that draws fishermen from throughout the area to the Colorado River.
“The City of Bullhead City’s Pest Abatement program did not apply any chemicals into the river directed toward fish removal,” said Michael Cavallaro, the city’s pest abatement manager. “In fact, the city’s program has added thousands of fish into the river.
“A fish removal plan would require comprehensive planning, which would occur over decades throughout the Colorado River watershed. There is an extensive permitting process, which requires the involvement of local, state, and federal agencies for application or modification of any river condition. The motivations or cause of this alleged action is uncertain. I plan to visit the site, write up an evaluation, and contact the appropriate fish and wildlife officials.”
Cotter also said the city will investigate to try to pinpoint the cause of the fish kill.
Clark County Vector Control has treated the river for many years, applying a biological control agent, Bti (Bacillus thuringiensis israelensis), which contains spores that produce toxins that specifically target the larvae of mosquitoes, blackflies and fungus gnats. Bti is an EPA-approved treatment, with five strains of Bti used in various pesticides.