FLORIDA

Removing Rodman dam would be manna from heaven for manatees


Robert Knight
Tue, February 1, 2022


The Sun recently published an opinion piece by Kip Frohlich and David Hankla, two of Florida’s top manatee experts, on the science and protection of this iconic Florida marine mammal. They rightly decry the state government’s failure to protect water quality in the Indian River Lagoon and the state’s equally poor response to the growing crisis facing the future of these precious wild animals.

Manatees are starving to death by the thousands. I have looked into the innocent eyes of these massive but gentle giants. Yet I cannot possibly understand the pain and agony of the starvation they are enduring.

Perhaps it is just a coincidence that manatee and manna have the same root. The definition of “manna” is an unexpected aid, advantage or assistance, as in the biblical phrase “manna from heaven,” referring to the miraculous food The Lord provided to the Israelites as they wandered in the wilderness. In Florida’s springs, there is indeed manna for manatees.


In the mid-1980s I censused the manatees living in the Lower St. Johns River from Jacksonville upstream to Palatka. From a light airplane, manatees were quite visible even in the tannic waters and it was possible to record their numbers and favored habitats by flying up and down the study area.

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I especially remember seeing manatees nibbling on boat anchor lines while the fishermen appeared to be unaware the large animals were so close. At that time, manatee populations in the St. Johns were expanding from their historic lows due to increased awareness of the need for manatee no-wake zones to reduce motor boat impacts to the slow-moving mammals.

The recovered St. Johns River manatee population is now one of the most productive and successful in the state. Just last month, the Volusia Blue Spring winter manatee population set a new record of 663 individuals in the spring run.


But seagrasses have disappeared over much of the St. Johns River. The same problems decimating eelgrass in the Indian River Lagoon are occurring in the Lower St. Johns — elevated nutrient pollution, blooms of floating algae and shading of the submerged aquatic plants that manatees favor.

Manatees may soon be starving in the St. Johns River due to similar issues observed in the Indian River Lagoon. One way to support and maintain the St. Johns River manatee population is to make sure the springs and their ample aquatic plant communities and warm water refugia are accessible to the manatees.

Silver Springs, the Silver River and the 20 “lost springs” of the Ocklawaha River must be opened to succor these manatees. The Rodman/Kirkpatrick Dam must be breached to allow more manatees as well as other migratory aquatic species such as striped bass to reclaim this historic habitat area.


Like manna from heaven, the entire Silver River and much of the Ocklawaha River are full of rapidly growing submerged aquatic vegetation favored by manatees. The outdated and on-the-brink-of-structural-failure Rodman dam is the only obstacle to this manatee Garden of Eden.

Florida’s artesian springs are likely the principal reason the state has long had a year-round, breeding population of manatees. Thermal effluents from coastal power plants have offered refuge from winter cold stress but have not provided suitable food resources.

With increasing pollution of these waters by Florida’s growing human population and lax water quality enforcement, manatees are not able to thrive. Continued reliance on power plant thermal effluents and lettuce buffets is not a long-term assurance of a healthy manatee future.

Accessible springs are an important part of the solution to the plight of starving manatees. And breaching the Kirkpatrick dam to allow manatee access to extensive feeding areas is a critical next step for manatee viability.

Dr. Robert Knight is director of the Howard T. Odum Florida Springs Institute in High Springs. His newest book, “Saving Florida’s Springs – A Prescription for Springs Health,” is now available at www.floridaspringsinstitute.org.
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This article originally appeared on The Gainesville Sun: Robert Knight: Removing Rodman dam would help manatees, other species