Two meetings planned this week in Okeechobee will collect public input on two issues of great concern to area fishermen: changes to the lake level schedule and control of invasive aquatic …
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Meetings to discuss lake level, aquatic spraying
By Katrina Elsken
Two meetings planned this week in Okeechobee will collect public input on two issues of great concern to area fishermen: changes to the lake level schedule and control of invasive aquatic plants.
On Wednesday, Feb. 6, from 6 to 8 p.m., the U.S. Army Corps of Engineers will host a meeting in the Indian River State College Williamson Conference and Education Center, 2229 N.W. Ninth Avenue, to discuss changes to the Lake Okeechobee Regulation Schedule (LORS).
Repairs are currently underway to the Herbert Hoover Dike, a 143-mile earthen berm that encircles Lake Okeechobee. The repairs are expected to be completed in 2022. In anticipation of the reinforcement of the dike, the corps will consider changes to LORS. LORS allows for dry-season low levels of 12.5 feet, and wet-season highs of 15.5 feet.
While some coastal officials who oppose releases of excess freshwater water to the Caloosahatchee River and the St. Lucie Canal are asking for a higher maximum level to prevent releases to the coastal esturies, Florida Gov. Ron DeSantis has proposed a lower dry-season level to ensure that the lake has more available capacity at the start of the wet season.
According to “A Brief History of Lake Okeechobee Ecosystem Responses to Water Level Management,” by Paul Gray, Ph.D, of Audubon Florida, water levels of 16 feet or higher damage the lake’s ecosystem by killing off the marshes that provide habitat for fish and wildlife.
The marsh plants also help clean the water. “A deeper lake is a dirtier lake,” Dr. Gray notes. “Deep dirty water can drown submerged aquatic vegetation (SAV), depleting their ability to absorb nutrients and perform local water quality functions. Once lost, SAV cannot recover until drought conditions lower the lake enough for reestablishment. And the high nutrient inflows associated with deep water events set the stage for cyanobacteria blooms.
“Deep dirty water impacts marsh health. At levels above about 15.5 feet, nutrient-rich water from the middle of the lake flows into the marsh, degrades water quality, shades out desirable plant communities and encourages noxious plants such as cattails to expand. Conversely, low phosphorus levels in the lake occurred after a multi-year period of relatively low water conditions.
Phosphorus levels in 2012 in the middle of the lake dropped to 92 parts per billion (ppb) total phosphorus, and near-shore levels dropped to 41 ppb total phosphorus, the lowest values in a decade. This low phosphorus period followed low inflow years of 2007, 2008 and 2011. When lake inflows and levels subsequently increased, phosphorus levels increased again.”
Dr. Gray stated the lake needs natural water level fluctuations.
“Lowering the lake during the dry season facilitates decomposition of dead plants, wading bird feeding and seed germination (some seeds germinate only on mudflats while others need light penetration to the bottom to germinate). Prey fish are concentrated during the dry season, allowing other fish and wildlife access to an abundant food source. Beneficial prescribed or natural burns can occur. But just as holding the lake too high can have devastating impacts, drawdowns or lake schedules that drop water levels too low, for too long, or too often are harmful.”
In a related matter, the Florida Fish and Wildlife Conservation Commission (FWC) is reviewing procedures for management of harmful aquatic plants.
According to the FWC, invasive plants degrade and diminish Florida’s waterways by displacing native plant communities. Some invasive aquatic plants pose a significant threat to human welfare and cause economic problems by impeding flood control and affecting recreational use of waterways.
In response to concerns from anglers who claim the herbicides used by FWC to control harmful invasive plants are killing the natural aquatic vegetation, on Jan. 28, FWC suspended aquatic spraying statewide. FWC officials have maintained their spraying program targets the harmful invasive plants, and that without the chemical spraying, the invasives would quickly take over the waterways.
On Thursday, Feb. 7, from 5:30 to 8:30 p.m., FWC will host a public meeting to gather community input about the agency’s aquatic plant herbicide treatment program.
Comments about changes to the lake level schedule may be sent via email to: LakeOComments@usace.army.mil or by mail to: Dr. Ann Hodgson, U.S. Army Corps of Engineers Jacksonville District, P.O. Box 4970, Jacksonville, FL 32232-0019.
Comments about the FWC aquatic spraying program may also be sent to Invasiveplants@MyFWC.com.