Sadly for the fish in Veterans Memorial Lake last week, it was a perfect storm.
State health officials are blaming an explosive toxic blue-green algae bloom for the massive fish kill at the lake last Thursday. The indiscriminate event claimed the lives of thousands of fish, regardless of size or species, leaving only a handful alive.
“The algae sucked all the oxygen out of the water,” said Dan Wells, Kansas Department of Health and Environment district environmental administrator. The KDHE sent a team to Great Bend Friday to investigate the incident.
“It’s been calm, warm and sunny,” Wells said. “The algae love that.”
These ideal conditions allowed the organisms to multiply and the bloom to form very rapidly. This happened just about overnight, which is not uncommon.
Readings taken Friday showed oxygen levels in Vets were between one and three milligrams of dissolved oxygen per liter of water. “That’s low,” Wells said, adding five or higher is considered normal.
There have been smaller fish kills each year for the past few years, ever since the algae problem first started to plague the park, Wells said. But, these were no where near the scale of the one seen last week.
“The good news is that the City of Great Bend is taking steps to restore the lake,” he said. But, “this is not a quick and easy process. There is no quick answer.”
Another plus is that there were no other contributing factors, such as vandalism, said Terry Hoff, acting Great Bend director of public lands.
After city crews had the smelly and tedious job of hauling buckets full of dead fish out of the lake last Thursday and Friday, there have been no significant occurrences since then, Hoff said. “There are still a few fish in there, but not many.
“We are still working the consulting firm,” Hoff said. In fact, just days before the kill, city employees were taking water and sediment samples in an effort to collect data for the firm, CH2M Hill out of Wichita.
The samples have been sent off to a lab for analysis, but the results have not come back yet. These were going to be used to determine a dosage of chemical that would be introduced into the water to kill the algae, but would be safe for humans, pets and fish.
However, the fish kill happed first.
Now, “they are going to map out a strategy for us,” Hoff said. “I am confident they can come up with some good ideas.”
The first step will likely be “shocking” the lake with a chemical. It may take repeated applications to clear the water and kill the algae.
Then, the issue of chemical run-off from nearby yards and the perennial problem of migratory Canada geese will have to be addressed. The waste from these birds is seen as a key contributor to the toxic blue-green algae problem.
The algae has led the KDHE to place the lake under a warning status that encourages people and pets to avoid prolonged contact with the water. This has been an on-again-and-off-again issue at the lake since 2010.