Southeast Volusia Audubon Society, P.O. Box 46, New Smyrna Beach, FL 32170;   president@SEVolusiaAudubon.org


November 2013 SJRWMD Update


Gizzard shad harvest reduces nutrient pollution in St. Johns River system

The St. Johns River Water Management District's Lake George gizzard shad harvest removed more than 9,000 pounds of phosphorus and 28,000 pounds of nitrogen from the lake in Volusia and Putnam counties that is part of the St. Johns River system.

Removing gizzard shad from Lake George will help to meet the necessary downstream nutrient loading reduction essential to meeting state water quality standards and reduce the severity of algal blooms in the lower St. Johns River.

The gizzard shad harvest took place from June 3 through Sept. 6, 2013, and exceeded the District's expectations by removing 1.17 million pounds of the fish from Lake George, which directly removed thousands of pounds of nutrient pollution from the lake. Removing large numbers of shad from a water body removes the nutrients contained in the fishes' bodies.

Gizzard shad feed on algae on the bottom of the waterway, stirring up sediments and clouding the water. Shad excrete nutrients back into the water, recycling nutrients from the bottom that feed more algae. Thus, by removing the fish, another 31,000 pounds of phosphorus and 93,000 pounds of nitrogen will not be released into the lake to impair its water quality.

The $694,000 project was funded with a 2012 legislative appropriation, which dedicated $5.6 million to St. Johns River restoration projects.

The District's Governing Board on Oct. 8, 2013, approved a contract to remove more gizzard shad from the lake in 2014. Next year's harvest will be funded with $846,000 from a $7 million 2013 legislative appropriation for St. Johns River restoration and protection. District staff anticipate removing 12,000 pounds of phosphorus and 36,000 pounds of nitrogen from Lake George next summer.

Gizzard shad are a native fish found in most Florida waters and account for 5 to 20 percent of the total fish population in healthy Florida lakes. However, in nutrient-rich, algae-dominated lakes, gizzard shad proliferate and can account for more than 90 percent of the total fish population.

Harvesting gizzard shad from Lake George is conducted only during warmer months to avoid potentially catching untargeted species, including American shad, a species that is managed and protected under the Atlantic States Marine Fisheries Commission.

The District hires commercial fishing vendors to net gizzard shad. Sport fish caught in nets during the harvests are immediately released.


Ed. Note. I did not get an update from Ed for this month's eSkimmer News but saw this in one of the regular emails I get from the district.  I thought you might find it interesting.