An Eastern Shore legislator held a news conference yesterday to call attention to a scientific study that questions whether the lesions found on dying fish on the lower Eastern Shore in 1997 were primarily caused by blooms of the toxic microbe Pfiesteria piscicida or by a fungus now attacking fish in the Eastern Pacific.
A team led by Vicky S. Blazer of the U.S. Geological Survey argues in a paper scheduled for publication that the deep, bloody sores on schools of menhaden were triggered by infection with a fungus called Aphanomyces.
Other scientists, led by North Carolina Pfiesteria researcher JoAnn Burkholder, believe that the fungus infections occurred after Pfiesteria toxins ate away the skin of the fish.
State Sen. J. Lowell Stoltzfus, a conservative Republican from Somerset County, said in a news conference at the Senate Office Building in Annapolis that the study linking the lesions to a fungus points out the need to continue scientific research into the fish kills.
"My concern is did Pfiesteria indeed kill the fish?" Stoltzfus said. "That is a question I believe that still lingers today."
Some Shore legislators have pointed to disagreements among scientists as proof that tightened restrictions on fertilizer runoff from farms are not needed, or are at least premature.
Blazer warned against interpreting her study in that light.
"When we first came out with this stuff, I had calls from the agricultural industry saying, 'Well, this means that the controls on nutrients shouldn't be put on,' " she said.
But she cautioned that the fungus seems to grow in areas of high nutrient pollution.
Blazer also said Pfiesteria could have been responsible for fish kills.
"A fish kill and presence of high numbers of menhaden with lesions are two different things," she said.
The study is scheduled for publication in the Journal of Aquatic Animal Health in December, although the bulk of the research was discussed last year at a conference in Maryland.
At the time, Burkholder said she had watched while fish exposed to the microbe in the lab developed lesions similar to those found on fish in the Chesapeake.
Kim Coble, Maryland's senior scientist with the Chesapeake Bay Foundation, called the Blazer paper a "scientific nuance," one that does not question the efforts by the state to control farm runoff.
"Nutrients make things grow, whether they be Pfiesteria or Aphanomyces or whatever," she said. "This paper doesn't say anything about that."
Liz Kalinowski, spokeswoman for the Maryland Department of Natural Resources, said the paper is not the definitive word on the 1997 outbreaks.
"We can't ignore the other suspects at the scenes of the crimes in 1997, given that we have confirmed toxic Pfiesteria piscicida at three locations where we also found dead menhaden," she said.
In the wake of the 1997 Pfiesteria outbreaks, the Maryland General Assembly enacted a law requiring farmers to write nutrient-management plans to restrict pollution from fertilizer runoff. The legislation requires them to plan to limit nitrogen runoff by 2002 and phosphorus runoff by 2005.
Blazer's study does not address Pfiesteria's health effects on humans.
A team led by the University of Maryland found that several people who came into contact with Pfiesteria-contaminated waters in 1997 suffered a severe, though temporary, loss of short-term memory. Victims also complained of fatigue, headaches and skin rashes.
The federal government has awarded a $2 million grant to the University of Maryland to further study Pfiesteria's health effects.