Pfiesteria

New evidence confirms a strong connection between toxic Pfiesteria piscicida and water polluted with animal or human waste, top experts said at a scientific meeting in Baltimore yesterday. Since 1997, when the rivers of Maryland's lower Eastern Shore suffered their first known outbreaks of the microorganism that can kill fish and make people sick, scientists have strongly suspected a link between the outbreaks and tainted runoff from poultry manure, spread as a fertilizer on the region's farm fields.

Proposed regulations that would make Maryland's poultry processing companies responsible for helping their growers get rid of excess chicken waste have stirred a storm of opposition from farmers and poultry companies and staunch support from environmental groups. A public hearing on the regulations scheduled for Monday night in Easton promises to be contentious. Chicken farmers, fearful that the regulations would hurt them, have mailed a blizzard of form protest letters to the Maryland Department of the Environment.

GLOUCESTER POINT, Va. - Virginia Institute of Marine Science scientists Kimberly Reece and Nancy Stokes have developed molecular diagnostic tools to detect Pfiesteria piscicida and related organisms in water samples. The tools were developed using funds for Pfiesteria research provided to VIMS by the Virginia General Assembly and a grant from Environmental Protection Agency. The researchers used the tools to look for Pfiesteria in water samples collected during September and October by the Department of Environmental Quality.

Pfiesteria piscicida was present in a tributary of Rehoboth Bay when about 200,000 juvenile menhaden died last month, Delaware officials have said. But they don't know whether the Pfiesteria was in its toxic state. Maria Taylor, a spokeswoman for the Delaware Department of Natural Resources and Environmental Control, said yesterday scientists suspected the fish kill July 19 in Arnell Creek was the result of a lack of dissolved oxygen in the water because the fish did not have lesions. But tests by two independent laboratories have confirmed the presence of Pfiesteria.

AYER CREEK - As they have many times during the past three years, a team of Maryland scientists was trolling meandering, marshy waters yesterday, casting handnets for sick menhaden, the 2- to 3-inch silvery bait fish that have come to be seen as a potential warning sign of toxic Pfiesteria piscicida. This time - for the first time - fish with bloody sores and ulcers have begun to turn up in the brackish waters of Maryland's coastal bays near Ocean City. Department of Natural Resources researchers were quick to say there is no evidence the single-celled dinoflagellate, which in 1997 was blamed for one of the state's largest recorded fish kills, has transformed into its toxic form, believed capable of making people sick.

For the first time, Maryland biologists have found fish with lesions and possible signs of pfiesteria in a tributary of one of the state's coastal bays, according to a spokesman for the Department of Natural Resources. DNR biologists conducting routine sampling in Ayer Creek, which flows into Newport Bay in Worcester County on the Eastern Shore, found lesions on 33 menhaden of 120 netted Monday. Water samples taken at the location were tested by two pfiesteria experts, said DNR spokesman John Surrick.

A fish pest previously unknown to science has been found infesting menhaden taken from the site of Maryland's most notorious fish kill: the 1997 Pfiesteria outbreak on the Pocomoke River. U.S. Department of Agriculture fish pathologist Renata Reimschuessel found the unnamed attacker while using a high-powered microscope to look at Pocomoke River menhaden found with bloody sores. Alongside the newly discovered cells she also found the distinctive four-petaled spores of a previously known parasite, called kudoa, which sometimes infests menhaden and its relatives, alewives and Atlantic herrings.

When New Jersey environmental officials discovered Pfiesteria in one of their rivers last year, they handled it differently than their Maryland counterparts had. They didn't tell anyone. New Jersey Department of Environmental Protection officials discovered in October that the micro-organism, which has been linked to human health problems in Maryland and North Carolina, was in the waters of the Tuckahoe River within three weeks of a fish kill there. But they couldn't be sure whether the September 14 fish kill was caused by Pfiesteria.

DEPENDING on your viewpoint, single-cell Pfiesteria piscicida may or may not be the primary culprit in Maryland's summer fish kills. Other possible causes of these outbreaks, such as lack of oxygen in water, were cited by scientists at a Pfiesteria conference held in Annapolis last week. But researchers noted that Pfiesteria, which destroys fish in its virulent stage, was always present in seven major fish kills in Maryland in the past three years, a strong sign of causal association.

A Virginia scientist has killed fish in a laboratory after creating toxic Pfiesteria piscicida, giving additional credibility to the work of other scientists who say the dinoflagellate was involved in 1997 fish kills on the lower Eastern Shore. Harold Marshall, a researcher at Old Dominion University in Norfolk, reproduced the same experiments that Joanne Burkholder, the North Carolina State University scientist who helped discover Pfiesteria, had done in her laboratory. Burkholder's critics have argued that her research was flawed because no one else had produced the toxic strain of Pfiesteria after it was connected with fish kills three years ago in the Pocomoke and Manokin rivers.