Sunday, March 26, 2006

VIMS: Pfiesteria bloom never happened


Anybody remember Pfiesteria hysteria? It was a raging crisis in the Chesapeake in 1997, when schools of menhaden pocked with sores went belly up in the Pocomoke River. The toxic dinoflagellate Pfiesteria piscicida was suspected of killing them, and of making people sick, too. Scientists and health officials swarmed in, concerned the affliction would spread. Nine years and millions of dollars later, here's what researchers at the Virginia Institute of Marine Science have to say about Pfiesteria:

Never happened. "My best scientific consideration is that Pfiesteria is not an issue in the Chesapeake and never was," says Wolfgang Vogelbein of VIMS. After extensive research, he suspects a fungus-like organism was to blame.

"The researchers were never able to isolate the [Pfiesteria] toxin," says Harley Speir of Maryland's Department of Natural Resources. "We do know those ugly sores were from a fungus, not Pfiesteria."

We bring up old news because a new affliction with a weird name looms in the nation's largest estuary. It's mycobacteriosis, a sickness caused by bacteria from the same germ family that produces tuberculosis and leprosy in humans. VIMS says up to 70 percent of rockfish (striped bass) in the bay are infected, and though there's no way to estimate subsequent mortality in the wild, myco is considered 100 percent fatal when it strikes rockfish in aquaculture ponds.

It's a slow "wasting disease" like TB that leaves stricken fish skinny and weak. It affects internal organs first. By the end, rockfish are emaciated and covered in red sores. A strain of myco also causes "fish handler's disease," a nasty hand infection resulting from exposure through cuts or nicks. In severe cases it gets deep into joints, forcing doctors to amputate digits or even limbs.

Mycobacteria is clearly no joking matter. Resource managers have been aware of its presence in bay rockfish for nearly a decade and believe it may be getting more prevalent. Some believe overall natural mortality for rockfish is increasing and myco may be a cause. Many think declining water quality and declining food sources in the bay stress fish to the point they are more susceptible to these naturally occurring bacteria.

On the other hand, coastal stocks of stripers are at a record high and some think the crisis is overblown. There are opinions of every stripe but little solid information. Worried officials reassure anglers and seafood-eaters that rock, the bay's premier sport and table fish, is safe to eat. But they also caution diners to stay away from raw rockfish and tell anglers to handle fish carefully, particularly if they show lesions, as a small percentage of rockfish do.

A front-page story on myco in The Post two weeks ago sent rockfish market prices plunging by half. It came at a rough time for the sportfishing industry. Charter skippers worry that apprehensive anglers now won't book spring trips. Rockfish season opens April 15 in Maryland and in the lower Potomac, May 1 in the District and May 15 in Virginia's portions of the bay.

It seems like a decade doesn't go by without a crisis on the bay. In the 1970s it was Kepone, a poison dumped into the James River that afflicted fish; in the '80s it was acid rain, thought to be ruining rockfish spawning success; in the '90s it was Pfiesteria. Now comes myco.

"When I saw that headline ["Chesapeake's Rockfish Overrun by Disease," Post, March 11], I thought 'Here we go again,' " said Mike Slattery, assistant secretary of Maryland's DNR.

But officials are far from unconcerned. Almost a decade after myco was first detected in rockfish, there are many more questions than answers. Vogelbein, who is seeking federal grants to ramp up research at VIMS, lists these unanswerables atop the list:

What is the extent of rockfish mortality? Does the disease go dormant? Can rockfish get over it? Does it affect spawning success? Can it spread to other species?


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