“Look at that boat right yonder. They’re going around picking up dead fish,” says a man who identifies himself on YouTube as Kyle McGee.
McGee is battling a stiff wind as he records cell phone video May 7 on a dock at White Lake, N.C. The picture pans toward the shoreline while McGee points out a line of small dead fish that runs the length of the dock. The fish get bigger as he walks toward a lake house.
“Every one of them… dead. I just picked up that bass a minute ago. He was about ten pounds,” McGee says. “I was wondering why there weren’t no fish in this lake. There was. Not no more.”
White Lake Turns Green
White Lake is a resort town in Bladen County, N.C., about halfway between Fayetteville and Wilmington. The lake has attracted visitors for decades with a white sand beach and crystal-clear water fed from an underground aquifer. Local officials have estimated the lake alone represents 10 percent of the county’s revenue.
But since 2013, persistent algae blooms have left residents continually searching for a way to restore their piece of paradise. They could no longer brag about being able to see straight to the bottom of their lake. White Lake Mayor Goldston Womble and his family, like many White Lake residents, own lakefront homes and businesses.
“The appearance of it was not good," Womble said. "It had turned basically a dark green.”
That started to change in early May. The town, led by Womble, hired the Nebraska-based company HAB Aquatic Solutions at a cost of $500,000 to apply aluminum sulfate, more commonly called alum. The company has applied the chemical in other lakes with no reported fish kills.
“The reason we did the alum treatment is that people who had businesses at the lake… folks were not wanting to come and go into the lake. People were canceling their reservations to stay at White Lake,” Womble said.
Alum is designed to improve water clarity, lower pH levels, and eliminate algae blooms. Crews started the treatment on May 3 and there were signs the water would be clear in time for White Lake’s annual Water Festival, which started on May 18.
Four days later, on May 7, McGee picked up his dead ten-pound largemouth bass. It was one of nearly 115,000 that died in a fish kill involving nine different species at a hatchery value of $634,132, according to an 18-page report from the North Carolina Wildlife Resources Commission released June 11.
Searching For Answers
While there is no stated cause of death for the fish kill, officials at the state Department of Environmental Quality say the Wildlife Resources Commission's report is strong evidence to suggest alum played a part.
“I think that was the one thing that kind of jumped out at me was just how comprehensive the fish kill was,” said Brian Wrenn, ecosystems branch supervisor in the Division of Water Resources, a branch of DEQ.
“There were seven- to ten-pound largemouth bass out there and that’s a pretty tough fish. When you start seeing them die off in the numbers that we saw, it tells you something was really going wrong in the lake,” Wrenn said.
Mike McGill, a spokesman hired by White Lake, does not dispute that conditions at the lake had deteriorated around this time.
“Nutrient levels being high and algal blooms are involved in many cases in fish kills,” McGill said. “Since we did have high nutrient levels and we did have algal blooms in the lake, we can say those were factors to the fish kill.”
DEQ staff sent more than a dozen fish to Mac Law, a pathologist at N.C. State University, for a necropsy. The report ruled out particular diseases like Largemouth Bass virus, and said based on an examination of fish gills, “it is unlikely that chronic/long-term poor water quality was a cause of death in the White Lake fish kill.”
Law did not make a definitive call on the cause of death, but he did not rule out the alum treatment as a contributing factor.
“Combined with the stresses caused by probable wide fluctuations in dissolved oxygen due to the algae bloom, it is possible that acute exposure to [a]lum in this case was a cause of this multi-species fish kill in White Lake, NC,” his report says.
“The problem is there’s just not that much known about the effects of alum on animals,” Law said in an interview, adding there are no markers in a necropsy that would point directly to alum toxicity. “I can say the application of the alum in combination with hypoxic stress is probably the cause of this fish kill. That’s putting evidence together and saying, ‘I think it is likely the alum contributed to the kill.'"
McGill sparred with officials at DEQ over what might have killed the fish shortly after the agency halted the alum treatment on May 8, and let it continue on May 10. McGill cited DEQ officials as saying the algae bloom was responsible. Jim Gregson, interim deputy director for DEQ’s Division of Water Resources, sent a letter to White Lake calling McGill’s statements inaccurate or misleading. McGill consistently points to the lake’s ongoing water quality issues as the culprit of the fish kill.
“An algal bloom was already underway as HAB began their work, and the bloom resulted in a fish kill,” McGill said in a statement released May 29, after the necropsy and Gregson’s letter were released. “State scientists stated earlier this month that they did not find any data tying the alum treatment to the fish kill, so it was allowed to be resumed and completed. The alum treatment has been a success. There has not been any additional fish mortality, pH levels have dropped, and water clarity has greatly improved,” the statement said.
A 'Co-Stressor' Situation?
Mark Vander Borgh is a water quality biologist and environmental specialist at DEQ who has been studying issues at White Lake since 2013. He says the North Carolina Wildlife Resources Commission’s report strongly suggests it was not simply the algae bloom.
“We haven’t seen a fish kill of this magnitude actually in my whole 20 years of experience dealing with fish kills in North Carolina,” Vander Borgh said. “It can’t be a coincidence that the alum treatment would have gone into the system and not have any effect on the fish. The sheer quantity of chemical in addition to the bloom could not have had negligible or no effect on the actual fish kill.”
“Was it the only reason that the fish kill occurred? I don’t think so,” said Wrenn, of the Division of Water Resources. “It was a co-stressor situation, but the alum played some role in the fish kill.”
Vander Borgh, Wrenn and Law all acknowledge that there is no direct evidence to show a cause of death, whether it was an algae bloom, exposure to alum, or both. But their opinions continue to contradict those of White Lake Mayor Goldston Womble, McGill and others the town has hired.
“I think they’re clearly wrong. I don’t think alum was a contributing factor at all,” Womble said. “If they want to show you some data to the contrary, I would be glad to look at it. In all sincerity, I don’t think you can say, ‘Well, there was a fish kill, so we think the alum contributed to it.’”
McGill called DEQ's opinions "caveated statements" that do not show proof.
“You need to have scientific data to show that the alum treatment was connected to the fish kill. There isn’t any,” McGill said.
“If you want to talk about other circumstantial evidence, you have actions by the state allowing the alum treatment to resume, you have the fact that there wasn’t any additional fish mortality following the alum treatment and there hasn’t been any since because the water quality of the lake improved with the alum treatment.”
Without a "smoking gun," Wrenn admitted it is hard to determine what happened.
"We have a situation where we have a pretty intense algal bloom going on, the fish are stressed, there's not a lot of refuge, and then you have an alum treatment that is applied to the lake that either had some low-level toxic effects that are not typically observed in a fish population but it was just enough to push the fish over the edge, or there was some sort of avoidance response to the alum application; the fish moved into shallower, warmer areas where the algal bloom was really intense," Wrenn explained.
"It's a very complicated system. It's a very complicated situation and we just don't have any direct-line evidence to show what the actual cause was."
In the coming months, Vander Borgh and Wrenn say the Department of Environmental Quality will continue analyzing data to determine the source of the nutrients they believe are feeding White Lake’s algae blooms. Some of those numbers are coming from Bald Head Island Conservancy, which is testing water quality at the town’s request.
DEQ is also trying to determine whether crews properly applied the May alum treatment.
It might shed more light on why so many fish died at White Lake.