BY MAGGIE BEAMGUARD, Insider Editor
The term “fish kill” has the ominous ring of a horror movie, but people witnessing this natural occurrence around Lake Auman and Lake Sequoia in spring and early summer do not have cause for worry.
A “fish kill” is an event in which fish die, usually in a localized area, and the reason is usually natural enough.
Casey Joubert, a Fisheries Biologist with the NC Wildlife Resources Commission (WRC), says there is no need for alarm if you witness a fish kill.
“There can be many reasons for a fish kill to occur but, in the spring, the most common reason is low dissolved oxygen,” he said. “This low dissolved oxygen level occurs because of increased water temperatures. Warmer water contains less dissolved oxygen.
“Fish are coming out of winter, a time in which they have been stressed with difficult conditions and little food. They are also preparing to spawn, which uses a lot of energy, and leaves them more vulnerable to stressors such as low dissolved oxygen.”
“Water can do without fish,” the proverb goes, “but fish cannot do without water.” Or the right balance of conditions. This natural phenomenon can happen anywhere, at any time, but in this area, spring is the most common time for fish kills on local water bodies due to changing conditions.
“Fish kills are often seen after periods of heavy rain and sustained cloudiness,” Joubert said. “Rain can cause an increase of nutrients to run into our lakes and rivers, causing an increase in algae and plant growth. This growth seems like it should be positive, but it can have negative impacts on dissolved oxygen because overnight the plants are not able to photosynthesize and instead consume dissolved oxygen. This consumption of dissolved oxygen by plants means there is less dissolved oxygen available for fish. Fish are most frequently seen gasping for air or dying in the early morning hours.”
Because many factors contribute to why and when a fish kill occurs, these events should always be reported to the NC Department of Environmental Quality (DEQ).
Moore County fish kills should be reported to the Fayetteville Regional office at (910) 433-3300. The WRC and biologists like Joubert assist the DEQ with fish kill investigations.
Knowing where and when fish kills occur helps experts determine if the kill was caused by natural or non-natural influences. Says Joubert, “If caused by something such as chemical run-off, it is very important to stop this pollution and investigate further. It is also important to understand if an area is more susceptible to fish kills and if something can be done to help mitigate fish kills in the future.”
Anticipating another possible fish kill this spring, Bruce Runyan, the director of lakes and dams for the Seven Lakes Landowners Association, has already alerted the Management Office in case they start receiving phone calls.
In an updated 2020 memo, Runyan says they have observed that brim and blue gill seem less tolerant, washing up more frequently, than the bass and carp. He notes “… blue gill (sunfish family) will not wander from their nests to find food, and simply starve. Lastly, there is little natural food.
“Our lakes are some of the very cleanest lakes in the state. We do have fish food in the office and encourage folks to feed the fish where possible up until October.”
Runyan also rejects speculation that fish are being impacted by chemical treatments: “Our lake management company complies with every EPA requirement regarding product safety, and EPA product approval.”
Steve Short, chair of the Lake Committee in Seven Lakes West, assures that this is a “phenomenon of nature” after researching previous events at Lake Auman.
“This seems to be an annual event but variable in scope, with some years experiencing a greater number of fish succumbing to the environmental and spanning stresses than in other years.”
Short also points out that because the Lake Auman events are typically observed in ponds where power boats are not allowed, they are independent of boating activity.
Brandon Roberts, of Foster Lake and Pond Management, observed last year’s fish kill around Lake Auman and attributes the die-off primarily to spawning stress.
In a report, he wrote: “I have a history of experiencing this same event at Seven Lakes North on Sequoia Lake. The spawn is a very stressful time for sunfish and the cold weather we experienced over Memorial Day weekend most likely contributed to that stress. Sunfish spawn in groups not like bass where beds are usually isolated. This close proximity to each other can contribute to the spread of any bacteria that they are more susceptible to during this weakened state.”
There are also positive effects to fill kills, experts say.
“These kills can be distressing,” Joubert acknowledges, “but can ultimately have a positive impact on fish populations. Fish with infections or diseases can be most susceptible to low dissolved oxygen, and these fish may die off before being able to infect other fish.”
As spring rains and warmer weather bring more people outside, don’t panic if you observe a fish kill, but do report it as soon as possible, Joubert says.
If you have any questions about fish or wildlife, reach out to the Wildlife Resources Commission at any time. To report violations, call (800) 662-7137.
For fish related questions, contact Casey Joubert at casey.joubert@ncwildlife.org or call (910) 729-0872. You can also view the Fish Kill and Algal Bloom Map at ArcGIS Dashboards.
Contact Maggie Beamguard at maggie@thepilot.com.
