| 31 August 2010
Dr. Phil Stevens, FWRI, Charlotte Harbor Field Lab
The Importance of Living Shoreline for Juvenile Snook in Charlotte Harbor
Dr. Phil Stevens, is an advisory council member of the Snook Foundation. Here he provides an overview of his recent studies on the Caloosahatchee River, one of the Florida rivers that may turn out to be critical in restoring Snook populations.
(Click Image To Enlarge) Remote inland creeks that are not accessible by larger fish are the safe havens where juvenile snook can grow. Protecting and preserving these areas is essential for Snook population recovery.
We've done a lot of sampling in the Caloosahatchee River, testing the conceptual model that the Caloosahatchee, which is close to a major inlet, would be a snook nursery.
We were right and what we also found is that snook abundance in the backwater tributaries, oxbows, and embayments in the Caloosahatchee River was 7 times that of the mainstem shorelines.
The point is that common snook juveniles move into the far reaches of coastal wetlands where many of the aquatic predators are excluded. We simply will not find them along open estuarine shorelines.
Below is an excerpt that relates to snook from a paper that will be appearing in an upcoming issue of a leading science journal.
A river transient (a species that uses the river during only a portion of its life cycle) found to be more abundant in the backwaters is one of the most important sport fish in southwest Florida: C. undecimalis (common snook).
Relatively few C. undecimalis nurseries in the Charlotte Harbor estuary have been identified (Adams et al. 2006; Stevens et al. 2007). Those that have been identified are located in coastal wetland ponds, creeks, and island networks, many of which are so remote they are inaccessible to sampling by boat.
Living shoreline is critical for juvenile snook. On the Caloosahatchee, homeowners who incorporate their docks and homes along mangrove or other native plant shorelines help maintain a refuge for juvenile snook to survive to maturity. The close proximity of the Caloosahatchee River to ocean passes used as spawning sites and the availability of coastal wetland habitat in its backwaters are factors that likely explain the presence of juvenile C. undecimalis in the river.
The abundances of juvenile C. undecimalis in the backwaters of the Caloosahatchee River are of the same magnitude (~1 fish 100 m-2) as those described for the few juvenile C. undecimalis habitats found elsewhere in the Charlotte Harbor estuary.
Because the river’s backwaters provide juvenile habitat for E. plumieri, (striped mojarra), L. macrochirus, (bluegill), and C. undecimalis, these morphologically distinct areas of the river should be of prime importance to programs targeting lands for acquisition, management, and conservation.
Editor's note: Dr. Stevens' findings underscore the need to make sure that fish habitat stays at the forefront in development and planning considerations. Out-dated building or homeowner requirements which favor armored seawalls over living shoreline, or require maintenance of non-native grass that requires water and fertilizer, need revision. Builders, regulators and homeowners, need more information about how to easily maintain and protect the natural shorelines that will foster healthy fisheries.
