Oysters are stationary filter feeders and live their whole lives in one estuary. This means that changes in water
quality and the availability of their food supply can affect the health of the oysters. Changes in the health of
the oysters can indicate a change in the ecosystem. The health of Apalachicola Bay and the oysters is important to
the residents of Franklin County as the oyster industry is a large part of the economy and employs a good portion
of the community.
Apalachicola National Estuarine Research Reserve started an oyster growth monitoring project in Spring 2004.
Sample sites are located next to the two most commercially-important oyster bars in the Bay: Dry Bar and Cat
Point. Each site contains 60 oysters of varying sizes which are measured monthly.
Researchers have discovered that the smallest oysters have the fastest growth rate and their growth rate slows as
they grow into the larger size classes. This suggests that larger oysters could be more vulnerable to decreased
nutrients. Of the sites, the oysters at the bar closest to the mouth of the Apalachicola River grow slightly
faster than those at the bar further from the river. The river provides the oysters with most of their nutrients
and food so these results are expected.
Researchers are now comparing oyster growth rates in drought conditions to those in non-drought conditions, as
reduced freshwater flow is a major threat to the Apalachicola Bay ecosystem. During Summer 2007, the Apalachicola
River experienced the lowest flow levels ever recorded.