Linking regional initiatives to improve predictions of drought impacts on living marine resources in the U.S. Southeast: Apalachicola Bay oyster fishery as a potential test case

In 2007, the U.S. Southeast experienced one of the worst droughts on record. Since 1970, moderate-to-severe droughts in the Southeast have increased by 12-14% and annual average temperature has risen over 1°C. Several global climate models also project warming across the Southeast and an increased rate of warming through the end of the century. The Southeast has also undergone unprecedented growth, with some counties of Florida and Georgia populations increasing by over 500% in the last several decades, further increasing the demand for water resources during times of drought. Two regional efforts are currently underway to help inform constituents about adaptation to climate variability and change in the Southeast region. The first effort is the National Integrated Drought Information System (NIDIS), led by NOAA. NIDIS serves as an early warning system for drought through the consolidation of physical/hydrological and socioeconomic impact data, engages those affected by drought, integrates observing networks, and delivers decision-support tools to end-users. The second effort is the USGS’ National Climate Change and Wildlife Science Center, which will facilitate linking global and regional climate models to ecological and biological responses at spatial and temporal resolutions that will inform resource management decisions. Both efforts will be operating in the Apalachicola-Chattahoochee-Flint (ACF) River Basin. During the 2007 drought, one of the most publicized impacts was on the oyster fishery in Apalachicola Bay. Reduced regional precipitation along with associated higher demands for water uses in the ACF reduced downstream flow into the Bay, producing harmful effects on the oyster fishery and associated ecosystem. Changes in estuarine salinity resulting from alterations in streamflow can lead to impacts on species abundance and community composition. Drought can also lead to changes in predator-prey interactions, as marine predators typically move into estuaries when salinity is high. Experiments have shown that Apalachicola oysters suffer significant mortality due to increased disease load and higher predation pressure under high-salinity, drought conditions. There is currently little information, however, on how drought will influence species interactions, distributions, and abundances in estuarine ecosystems, and how this in turn will affect biodiversity and ecosystem function. Improved linking of hydrologic and climatic models to biological systems is needed in order for resource managers to better predict and mitigate ecosystem changes resulting from drought and climate change. There now exists an opportunity to link the NIDIS and USGS regional efforts to gain a better understanding of how interrelated factors, such as competing demands for water resources in the ACF Basin, changes in the frequency and duration of drought, and management of the reservoirs will affect downstream ecosystems such as the estuarine environment and the oyster fishery in Apalachicola Bay.