Photo by Jillian Caom
The time is right for Hillsborough County to pass an ordinance that effectively controls fertilizer applications during the summer rainy season, says Commissioner Mariella Smith.
“We’ve had a summer of red tide with tons of dead fish, Bayshore Boulevard stinking from their odor, and heartbreaking devastation for fishermen,” she said. “There’s a real feeling of ‘Git-R-Done,’ and a real push to control this source of nutrients.
The board of county commissioners voted unanimously to approve an ordinace that would prohibit the application of fertilizer that contains nitrogen or phosphorus, similar to ordinances that have been in effect in Pinellas and Manatee counties and the city of Tampa for 11 years.
While nitrogen is an essential nutrient, excess levels in aquatic ecosystems fuel algal growth, including toxic microorganisms like red tide and the cyanobacteria bloom that followed the release of nutrient-loaded discharges from the defunct Piney Point fertilizer plant.
The excess nutrients in fertilizer also are an important factor in the ongoing loss of seagrass acreage in Tampa Bay. In a balanced ecosystem, the growth of algae is limited by available nutrients. High levels of nutrients fuel the growth of algae, which clouds the water and limits the amount of sun that reaches the bay bottom. Without sufficient light, seagrasses die back. An overgrowth of algae also depletes levels of oxygen at the bay bottom, impacting the fish, crabs and benthos that need it to survive.
The proposed ordinance nearly mirrors the model drafted by the Tampa Bay Estuary Program (TBEP) in 2008, except that the restrictions on the sale of lawn fertilizer during summer months are excluded. “We can’t ban sales of fertilizer because it has been preempted by the state legislature,” Smith said.
Although it’s difficult to tease out the exact impact of summer fertilizer bans, more than half of the nitrogen entering Tampa Bay comes from stormwater runoff in residential and urban areas. Ed Sherwood, TBEP executive director, estimates that nearly 90 tons of nitrogen enter Tampa Bay every year when just 10% of the homeowners in the region fertilized their lawn at recommended rates.
Cleaning it up once it’s released is expensive — an average of $3.500 per pound, according to estimates from the Florida Department of Environmental Protection.
One study shows significantly reduced annual fertilizer use in Pinellas and Manatee, at about 40 pounds per acre, compared to Hillsborough County, where more than 90 pounds of fertilizer are applied per acre. The decrease in fertilizer applications is showing up in 18 Pinellas County creeks where nitrogen concentrations are dropping, he adds
“The biggest thing is that there will be more uniformity in fertilizer applications across the region, and we’re looking forward to promoting the Be Floridian campaign in Hillsborough,” Sherwood said. “It’s a cost-effective approach to improving water quality because an ounce of prevention is worth a pound of cure.”