From the SCCF (Sanibel Captiva Conservation Foundation)
October 30, 2009
Red Tide Event, Shellfish Harvest Closure, Fish Kill
A variety of agencies and organizations are currently surveying the waters in the Gulf of Mexico and Pine Island Sound to determine the extent and impacts of a Red Tide Event.
The Florida Department of Agriculture and Consumer Services has issued a Shellfish harvest Closure Statement for Pine Island Sound.
Dr Rick Bartelson reported from SCCF's Marine Lab that the Florida Wildlife Research Institute's and Lee County's Wednesday October 28th samples at South Seas had 80,000 Karenia cells per liter of water and Tarpon Bay Rd Bch had 30,000.
Karenia brevis is the name for the microscopic, single-celled organism (Dinoflagellate) that causes our Red Tides. The number of cells per liter of water is the standard method for determing their concentration and level of impact.
Thursday at Tarpon Bay Rd Beach, the surf zone out 100 meters or so was brown partly due to the Karenia. There was large concentration of detritus in the brown water and many Karenia cells- live and dead- stuck to the detritus. A sample in the surf zone had 260,000 total Karenia cells/liter . A sample out 40 meters where it was still chalky had 560,000 cells/l.
Over 100,000 cells per liter means probable fish kills.
This bloom may have moved in from offshore, or a seed population was left by the patch found offshore on October 10th.
At the end of August, 2009, we had a fish and crab kill between Bowman's Beach and Blind Pass. Water samples taken at the beach showed no /Karenia brevis/, but no samples were taken farther out. /Karenia brevis/, the red tide dinoflagellate produces neuro and hemotoxins that can kill fish and other aquatic organisms. When benthic suspension feeders ingest Karenia cells, they can become very toxic to benthic grazers such as fish, crabs, and manatees. The late August kill may have been caused by this method.
Today , October 30th our sample from the Sanibel boat ramp had 310,000 cells/liter, so the bloom is entering the Pass. Unfortunately, temperatures and salinities are favorable for survival of Karenia in San Carlos Bay and Pine Island Sound.
In 2006 and 2007, concentrations at the beach were about this level. In 2006, concentrations increased dramatically in the Sound, and in 2007, the bloom dissipated quickly, but over 20 manatees were killed by ingestion of seagrasses which probably had contaminated suspension feeders attached.
Events such as these continue to demostrate the need to control nutrient sources which can fuel these blooms.
We will keep you apprised as more information is obtained.
The Florida Department of Agriculture and Consumer Services is temporarily closing the following shellfish area at sunset on _Thursday October 29, 2009 for the harvest of oysters, clams, and mussels. In this context, shellfish does not include scallops, shrimp, or crabs.
Basis for action:
Precautionary emergency closure due to possible presence of red tide and conditions defined in Chapter 5L-1.003(8), Florida Administrative Code
The portion of Pine Island Sound Western Conditionally Approved shellfish harvesting area located West of a line that runs generally north/south through Pine Island Sound beginning at channel marker 8 located west of Bokeelia Island, then south to channel marker 7 located east of Patricio Island, then south to ICWW channel marker 52 then south along the ICWW to ICWW channel marker 22 located west of York Island.
The closure is based on a change in conditions specifically required under the management plan. Water samples will continue to be collected and analyzed for the area until the sample results conform to the management plan.
You will be notified as soon as the shellfish area can be re-opened. If you have any further questions concerning the closure of shellfish harvesting areas please contact Chad Evers or Yamilet Santana (941)833-2552. The Division of Aquaculture’s Daily Status report is found on the internet at www.FloridaAquaculture.com under the shellfish harvesting tab. In the event the daily status report cannot be accessed due to server problems, a detailed pre-recorded message of open and closed shellfish harvest areas is available 24 hours a day by calling (941)833-2552. For questions concerning scallop harvesting, please call the Florida Fish and Wildlife Conservation Commission at (850)487-0554.