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Urban Water Quality and Fertilizer Ordinances:Avoiding Unintended Consequences:A Review.... 3 bodies in Florida includes increases in algal growth, role in algal blooms.Further,some algal species can including those algae that produce toxins that can fix nitrogen from the atmosphere,adding another potentially harm aquatic wildlife and humans level of complexity to the nutrient source picture (Anderson,2002;Paerl et al.,2010). The following (Havens,2004).Finally,the impacts of information summarizes the many and varied sources eutrophication differ depending on the algal species of nutrients that should be of concern in any approach (Anderson et al.,2002). addressing the overall urban water quality problem. Distant sources.While nearby land-based Sewage-based nutrients.Water bodies can sources are important,studies have also implicated receive nutrients from several sewage sources long-distance transported nutrients in Florida red including water treatment plant discharges and tides.For example,depositions of Saharan dust, on-site septic systems.Land-based sewage sources containing iron,could relieve iron deficiency of were implicated in algal blooms off the southeast certain aquatic organisms(Walsh and Steidinger, coast of Florida(Lapointe et al.,2005).Paerl et al. 2001). Stumpf et al.,(2008)used thermal and ocean (2010)found that cyanobacteria(one of the bacteria color satellite data to suggest the possible importance associated with red tide)responds to iron,N and P of nutrients from the Mississippi River that travel in a from sewage outfalls,urban wastewater,urban plume to the west Florida shelf,30 to 50 miles from development runoff,and nutrients from groundwater. the coast.The connectivity of the water bodies makes Lapointe et al.(2006),determined that large algal it difficult to clearly distinguish among the many and blooms of Microcystis aeruginosa in the varied sources of nutrients at any single locale. Caloosahatchee estuary in 2005 were likely related to sewage effluent as were red tide blooms off Sanibel Industrial emissions(e.g.,smoke)and fossil Island in 2004.There are examples where the fuel combustion(e.g.,automobiles)adds N oxides to removal of sewage-based nutrient sources was related the air,which can be later deposited onto land or to a subsequent reduction in algal blooms(Anderson water bodies during rainfalls.For example,the et al.,2002). Tampa Bay Estuary Program predicted in 1996 that as much as 33%of nutrients in Tampa Bay by 2010 Land-based N and P discharges.Nutrients from would result from atmospheric deposition(Zarbock a mixture of sources can enter the water stream et al., 1996).An updated report(Janicki et al.,2001), moving off of land toward a water body.N discharges using the methods of Zarbock et al.(1996)predicted from Lake Okeechobee and the Caloosahatchee River that for 2010 conditions,atmospheric deposition following hurricanes of 2004/2005 were implicated would be 20%and non-point contributions of N to in algal blooms in southwest Florida.Nutrient flux Tampa Bay would be 49%.The total annual N load from bays,harbors,and rivers along the west coast of predicted for 2010 in the latter report was 2950 tons, Florida can provide significant amounts of nutrients down from the predicted value of 3670 tons in the to support high-biomass blooms of red tide,Karenia Zarbock et al.(1996)report.Predicted total brevis(Vargo et al.,2008).Land-based N and P quantities of non-point N losses in both estimates sources vary from location to location,and this were similar.The percent loads due to non-point variability leads to a gradient of P-and N-limited sources increased because material losses and phytoplankton communities(Heil et al.,2007). atmospheric deposition were predicted to be lower in Although the ultimate source of nutrient enrichment the later model.A planning and management may be land-based,there can be considerable cycling, document from the Tampa Bay Estuary Program transport,and mineralization of N and P from concluded that the two largest contributors of phytoplankton,and these cycled quantities can be nutrients to Tampa Bay were atmospheric deposition greater than external loadings(Wang et al., 1999). and storm water runoff(Tampa Bay Estuary These authors suggested that,while nutrient load Program,2006). reductions are needed at the source,time will be required before observing impacts of those reductions Fertilizers.Fertilizer has been a common input because cycling of already imported nutrients plays a for managing healthy urban turfgrass and landscape (3- 10