Collapse of an oyster fishery during a historic drought may provide insight into future effects of climate change on estuaries

In 2012 the oyster population in Apalachicola Bay, Florida suddenly collapsed. The catastrophic event, which had severe impacts on the local economy, coincided with two years of record low rainfall over the watershed and the lowest river flows into the estuary in 89 years. Elevated salinity in the bay allowed marine predators, parasites and pathogens from the Gulf of Mexico to increase in abundance and impact the oyster population. Population modeling indicated that the proximal cause of the collapse was high juvenille mortality. Ecosystem modeling (using ECOSPACE) indicated that because the system also had considerably degraded habitat, recovery of oyster harvest to pre-impact levels would require both (a) substantially reduced harvest pressure for a period of two years and (b) restoration of at least 1,000 acres of oyster reef. Given that in the future climate change may result both in greater saltwater inputs (due to sea level rise) and increased frequency and/or intensity of droughts, the effects observed in Apalachicola Bay can provide a 'lens' into the future in regard to estuarine impacts.