Long-term watershed urban development and climatic influences on the north central Gulf of Mexico lagoon ecosystems
Anthropogenic and climate stressors impact the health of coastal ecosystems, but the synergistic effects of both kinds of stressors are not well understood. A 12-year (2000 – 2011) water quality and biological dataset that collected from three shallow lagoons in the Perdido Bay system, Florida, was analyzed. These lagoons have similar physical and hydrological characteristics and experienced a total of 22 climatic events, but cover a wide gradient of human watershed development. Here we examine (1) long-term water quality and biotic trends and responses to increasing watershed developments, and (2) the interactions between the urban stress and climate events.
All the 16 analyzed ecological parameters had significant interactions between lagoon and sampling time. The most urbanized system (i.e., Gongora) had the highest incidences of higher light attenuation, major nutrient species (e.g., nitrate, ammonia, phosphate), and both water column and benthic algal biomass, but lower salinity and dissolved oxygen. Of the 22 climatic events, only a few of them (e.g., the 2002, 2004, 2008, and 2011 storms) had significant impacts on these ecological parameters. These results indicated that the climatic events had limited impacts on the health of these lagoon ecosystems, which was primarily driven by the watershed urban development.