Dr. Robert Knight has written a special article for the Gainesville Sun describing the the danger of losing Silver Springs. Continue reading for the article, or click HERE for the original piece, published in the Sun on Sept. 28, 2008.
Dr. Robert L. Knight: Saving Silver Springs can’t wait foreverBy DR. ROBERT L. KNIGHT
Special to The Sun
Published: Sunday, September 28, 2008 at 5:04 p.m.
Last Modified: Sunday, September 28, 2008 at 5:05 p.m.
I first visited Silver Springs in August 1953. I was only 5 years old and little did I know that a three-year landmark ecological study was under way under the direction of a new, young professor at the University of Florida named Howard T. Odum.
I remember the crystal clear waters, giant catfish and beautiful underwater “grasses.” I took away an almost dream-like memory of Silver Springs that has stayed with me since that day.
Fast-forward to my last undergraduate semester at the University of North Carolina, during the spring of 1970. On the advice of a friend I signed up for Systems Ecology being taught by the same Dr. H.T. Odum. The course inspired me to pursue a career in environmental science and aquatic ecology.
I also had my first exposure to Dr. Odum’s acclaimed work at Silver Springs from the 1950s, a 57-page monograph that was known world-wide as one of the most complete and intuitive descriptions of any aquatic ecosystem in the world. In his most famous publication, Dr. Odum noted how constant Silver Springs had been throughout recorded history (about 100 years) and probably over the past 10,000-plus years that people had lived next to the springs. This consistency of extremely high flow (nearly 600 million gallons per day) water clarity, unrivaled in any other natural aquatic environment in the world, and rich and abundant biological.
I couldn’t have been more excited when Dr. Odum suggested I restudy Silver Springs, with the intention of repeating many of the measures he had made about 25 years previously. In his seven years back in Florida he had already seen that Silver Springs was changing. My two years of graduate research found that this giant of springs was still highly productive and relatively resilient to the more intensely developed surroundings. But disturbingly I also found that the fish community at Silver Springs had declined by 78 percent during the intervening 25 years, and the changes were linked in time to the construction of Rodman Reservoir downstream on the Ocklawaha River.
Much later in my career I once again was offered a chance to work at Silver Springs. With funding from the Florida Springs Initiative and collaboration with the St. Johns River Water Management District and UF faculty I helped prepare a 50-year retrospective evaluation of the ecological health of Silver Springs. What I saw in the springs and what our data showed was alarming and did not bode well for Silver Springs’ future.
Fish populations had continued to decline (an estimated 92 percent reduction in their biomass over 50 years), nitrate nitrogen concentrations had increased by 200 percent, great masses of filamentous algae were now covering the sand and limerock bottom, flows were lower, water clarity had declined, dissolved oxygen in the river was lower, and overall ecosystem productivity was reduced by 27 percent.
All of the old timers I spoke to at Silver Springs had been lamenting visible changes for years.
The recent Silver Springs study also forecasted the condition of Silver Springs 50 years in the future (2055) as a result of continuing development in Marion County. These estimates predict an additional 84 percent increase of nitrate concentrations, an 18 percent additional decrease in flows, and further degradation of the biological community in Silver Springs.
The three Silver Springs studies described above ended with numerous conclusions and recommendations, one of which was to continue to collect more quantitative ecological data in order to track the changing health of this complex and unique ecosystem. Even more importantly, these studies found that immediate action needed to be taken to stop the rate of decline of this living masterpiece while knowledge caught up.
Those recommended emergency actions include the adoption of local land use restrictions in the immediate springshed to reverse the alarming trends of increasing nitrates in the spring, re-evaluation of permitted consumptive water uses in the vicinity of the spring to preserve spring inflows from the aquifer, and accelerated evaluations of removing the Kirkpatrick Dam downstream on the Ocklawaha River to re-enable the free passage of fish and aquatic wildlife such as manatees between Silver Springs, the St. Johns River and the Atlantic Ocean.
Some may not think that there is enough science to move forward with actions critically needed to begin to restore Silver Springs to its previously pristine condition.
Do we really know that the social costs of land use changes such as reduced fertilizer use, restricted wastewater disposal practices, capping of consumptive uses, and restoration of a prime fishing lake are really worth an attempt to save the life of this spring? Should we wait until there is more science, more people living and recreating near and in the spring, and more degradation?
Are we really going to take a wait-and-see approach?
Dr. Robert L. Knight is an adjunct professor at the University of Florida and president of Wetland Solutions, Inc., an environmental consulting firm in Gainesville.