Florida's Harmful Algae Blooms Threaten Human Health?
By Donald Sutherland
A fish killer single cell organism has emerged in Floridan waters and is raising health concerns for residents exposed to its toxins.
13 people are being treated and observed by Florida doctors for symptoms similar to the toxic harmful algae bloom (HAB) species Pfiesteria piscicida responsible for killing millions of fish in North Carolina and Maryland and human health warnings issued by the Environmental Protection Agency, according to officials at the Florida Department of Health.
See: http://www.acnatsci.org/erd/ea/pfiester.htm and http://www.ncsu.edu/unity/lockers/project/aquatic_botany/pfiest.htm and http://www.epa.gov/OWOW/estuaries/pfiesteria/index.html.
During 1998, Floridian doctors diagnosed the 13 patients (ranging in age from 12 to 70) to have the condition called Estuarine Associated Syndrome with symptoms of skin lesions, nausea, diarrhea, memory and neurological problems similar to those suffered by fisherman, scientists, and tourists in Maryland and North Carolina who came in contact with waters contaminated by Pfiesteria, according to Alan Rowan, an epidemiologist with the Florida Department of Health (FDEP).
"The syndrome is being studied in seven states under a program funded by the Center for Disease Control and Prevention, and the Florida study represents the state's first examples of a syndrome of illnesses similar to the Pfiesteria outbreaks which hit North Carolina's and Maryland", says Rowan.
Officials from the FDEP's Florida Marine Research Institute insist Pfiesteria piscicida has not been found in the state despite the recent outbreaks of fish kills with lesions similar to those found on fish in North Carolina and Maryland.They claim a similar HAB species called Cryptoperidiniopsis brodyi found in the St. Lucie, St. Johns, and Indian Rivers is possibly to blame for the fish deaths.
"Pfiesteria has not been found in Florida, and no health standard for harmful algae blooms health threat are warrented," says Leigh Demateis, spokeswoman for the FDEP Florida Marine Research Institute.
Some scientists suggest Florida government officials don't want to incite harmful algae bloom hysteria in the public, and hurt the state's pristine image for its tourist and seafood related industries.
"In Maryland the public overreacted to 2 or 3 small lesion fish kills, and it cost the state $43 million in lost revenue to seafood related industries," says Dr.Kevin Sellner, the Ecology and Oceanography of Harmful Algal Blooms (ECOHAB) Coordinator under NOAA's Coastal Ocean Program.
See: http://es.epa.gov/ncerqa/rfa/ecohab.html and http://www.fmri.usf.edu/ecohab/scientists.htm and http://www.redtide.whoi.edu/hab/nationplan/ECOHAB/ECOHABhtml.html
Florida historically has experienced harmful algae blooms for millions of years, and until recently the only species to receive media attention is Gymnodinium breve, commonly known as Red Tide.
In the last 22 years there has been 21 outbreaks of Red Tide in Florida and millions of dollars have been lost in seafood and tourist industries according to the FDEP. The frequency of Red Tide outbreaks and fish kills have scientists concerned that human sewage pollution from bulging coastal populations and farm chemical runoff could be contributing factors.
Over 400 million gallons of municipally treated sewage are injected underground daily through Florida's 120 coastal Class 1 underground injection control (UIC) wells and according to FDEP monitoring tests the waste effluent is migrating into the state's largest underground source of drinking water, the Floridan Aquifer, which discharges along the coastlines.
Dr.JoAnn Burkholder, research coordinator for the Aquatic Botany Laboratory at North Carolina State University, and her team of researchers confirmed Pfiesteria and other harmful algae blooms are associated with nitrate/phosphate runoff from hog and poultry farms and human sewage.
"In North Carolina there is a connection between nutrients in human waste and Pfiesteria outbreaks, and nutrients from this waste can be highly stimulatory to HABs," Dr.Burkholder says.
The Mote Marine Laboratory in Sarasota, Florida has been closely monitoring and researching Red Tide outbreaks and scientists there say although Gymnodinium breve forms miles offshore it can be effected by the municipal Class 1 UIC well sewage as it nears shorelines.
See: http://www.mote.org and http://www.redtide.whoi.edu/hab
"Red Tides thrive in nutrient deficient waters, but our research indicates nutrient seepage from underground swells might be feeding these organisms and Class 1 UIC sewage migrating offshore certainly isn't helping the situation," says Dr.Richard Pierce, Director of Mote Marine Laboratory.
The big question is how many of the state's 55 different toxic species can be stimulated to grow by the nitrates and phosphates found in human sewage and farm runoff according to Dr.Jan Landsberg, a research scientist with the FDEP's Florida Marine Research Institute.
"There does seem to be more outbreaks in shore regions, but it could be due to numerous factors and science has a long way to go to tie up the loose ends ," says Dr.Landsberg.
Currently, state environmental and health departments rely on common sense and local communities to warn the public of the health risks associated with Red Tide, and neither government agency has ever issued a state human health advisory for harmful algae blooms. The FDEP does ban shellfish harvesting in beds exposed to Red Tides because the organism's toxins become concentrated in the mollusks which feed on them.
"There are no federal standards for Red Tide contaminated shrimp or fish because they don't concentrate the toxin in their bodies, and we don't have the knowledge to tell the public whether fish caught in a Red Tide are safe or not safe to consume," says David Heil, Bureau Chief of the FDEP's Bureau of Marine Resource & Regulation & Development.
"There has never been anybody I know who got ill from eating fish caught in a Red Tide," he says.
Red Tide does cause respiratory and eye irratation problems, and the FDEP advises people suffering from asthma and the elderly to avoid beaches where it comes ashore. In the last several years the Florida Marine Research Institute found over 204 manatees which died from respiratory suffocation due to Red Tide exposure.
"Right now we are advising people not to consume or touch sick or dead fish in Red Tides and other fish kill waters," says Alan Rowan.
"Further research needs to be done before we would issue a health advisory to avoid waters where sick or dead fish are found in HAB waters," he says.
Highlighting the human health threats from the increasing Red Tide and other species of harmful algae blooms would devastate Florida's coastal economies according to officials at the Mote Marine Laboratory and Florida Marine Research Institute.
"What's not well documented is the Red Tides impact on our state's economy," says Dr. Carmelo Thomas, research scientist at the Florida Marine Research Institute."The impact of fish kills from these algae blooms to the multi-billion dollar tourist economy has a halo effect with cancellation of reservations all along the coasts and people stop buying seafood," says Thomas.
Dr.Sellner cautions Florida's nutrient loads from sewage and farm runoff to coastal waters should be as low as practically possible to minimize the chances for HAB outbreaks, and their negative impact on the state's marine reliant economies.
"Yes, more nutrients from sewage should support more activity, and yes there is more pollution, but the research is divided on whether these organisms are being stimulated by land pollution activities or other causes outside of nutrient loading," says Dr. Sellner.
"It's completely up to Florida to develop a checklist of HAB indicators for closing rivers and beaches, however, I wouldn't let my children swim in Red Tide or enter those waters where those 13 Florida residents contacted Estuarine Associated Syndrome", he says.
(C)Donald Sutherland 1999
Member of the Society of Environmental Journalists