BCNP Wet-Season Aquatic Fauna

2007-11-19T10:56:00.000-08:00

Preserve-wide, we've seen a lot of variation among our sites this wet season. Our Raccoon Point site re-wet in early-July, our L28 site (north of I-75) re-wet in mid-August, and our Bear Island site has essentially remained dry(!). We completed our aquatic fauna sampling (see photo below of our 1-m2 throw trap being used in a Raccoon Point cypress dome) in mid-September and early-November.

Despite the 6-week difference in re-flooding date among sites, water depths and aquatic fauna communities at L28 and Raccoon Point were relatively similar during both sampling events. In general, our samples reflected typical early-wet season Everglades communities and were dominated by eastern mosquitofish (Gambusia holbrooki), flagfish (Jordanella floridae), Everglades crayfish (Procambarus alleni), dragonfly larvae and juvenile sunfish (primarily Lepomis marginatus and L. gulosus). We also noted an absence of tadpoles (tadpoles were numerous one month following re-flooding last year).

In September, one of the plots at our Bear Island site was inundated enough to connect to a small deep-water refuge pond. Using an experimental gill net (30 min soak), we captured ~40 exotic brown hoplo catfish (Hoplosternum littorale; see left) and two Florida gar (Lepistosteus platyrhincus) that were moving from the refuge into inundated portions of the mixed hardwood forest. The density of hoplos we estimated at this site (using a 1-m2 throw trap) was significantly higher than any we've seen in southwest Florida to date. The site dried completely a few weeks following this sampling and we we have been unable to re-sample.

We anticipate at least one more sampling event (mid-December) this season prior to our sites drying completely - which looks like it may be significantly earlier than last year.

Turner River Flows, Sobczak

2007-09-07T12:11:00.000-07:00

Turner River flows update
Robert V. Sobczak

Restoration of the Turner River has been an amazing environmental success story in south Florida. Road and canal building decades ago caused the river to dry up and virtually disappear until the NPS modified the road and canal network in the late 1980s and mid 1990s to re-direct water back into Turner River. Kayakers and canoeists were soon to follow, making this not only an ecological success story, but also a premier example of how scenic, recreational, and educational benefits can flow quickly behind the water; and how restoration success can be achieved with relatively minor re-plumbing actions.

The attached figure shows river flow relative to flows in the adjacent canal, updated through Summer 2007. The original phase of restoration work was completed in 1989, but canal flows still spiked out of system until follow-up restoration work was completed in 1996. River flows have equalled or exceeded flows in the adjacent canal for the past 10 years. Additional restoration work is needed to replenish additional waters into the river's headwater wetlands, to complement restoration flows directed directly into the river's headwater pools.

BCW Science Notepad

BCNP Wet-Season Aquatic Fauna

Turner River Flows, Sobczak