Rockfish with the disease mycobacteriosis can develop lesions and have their scales destroyed. AP/KATHLEEN LANGE OXFORD, Md. -- Biologist Larry Pieper is wearing waterproof overalls and giving dozens of bass from the Chesapeake Bay a tabletop inspection. He's not surprised by what he sees -- many of them look sick.
Pieper is part of Maryland's first effort this year to take a new look at a chronic wasting disease in striped bass, commonly called rockfish or stripers.
Mycobacteriosis, also known as "myco" or fish handler's disease, can slowly eat away at a fish's scales. It can leave nasty lesions and kill the striped bass, the hallmark fish of the Chesapeake Bay. Beyond that, scientists don't know enough about the disease to know how worried they should be.
"We know a whole lot of nothing," Pieper said after examining 80 striped bass, noting lesions and little brown specks that suggest the bacteria are present.
Myco is usually harmless to humans, as long as anglers wash their hands after handling infected fish. However, scientists are startled by the bacteria's spread through the region. State biologists in Maryland and Virginia say that about 60 percent of the bass in the Chesapeake, where most of the East Coast's striped bass come to spawn, are now infected.
But scientists aren't entirely sure whether myco kills all striped bass that get it, or whether some striped bass recover, and why. It's not clear how myco spreads, nor why the disease has increased sharply in recent years.
It could be that there are simply more bass in the bay. After overharvesting nearly wiped out the striped bass, a fishing ban in the 1980s led to a remarkable rebound in the species, with fishing now allowed. Another suggestion is that more bass are getting sick because they're weakened by low food supplies, or because low oxygen levels in cold water drive them to warmer water, where they're more vulnerable to disease.
"When we started, there was lots of anecdotal information, lots of impressions, but nobody knows" exactly how the disease behaves or how it affects the fish, said John Hoenig, a researcher with the Virginia Institute of Marine Science in Gloucester Point, Va.
Bounty hunters
To find answers about the bacteria, biologists are trying a new method to learn about it. Maryland's Department of Natural Resources, along with a federal research group, started a new kind of tagging project this spring.
The research differs from traditional tagging because anglers are asked not just to call the number on the tag and report where and when they caught the fish, but to keep the fish on ice. Fishermen who do so get a $20 bounty, plus authorities will come pick up the fish.
On a tagging trip last week, 11 Maryland biologists tagged and examined 80 fish. Pieper looked at each fish and announced its condition to a notetaker -- "The left side is clear," he called, or, "We have healing on the right-side fin." Then the fish went to a white piece of wood for several photographs on each side, plus close-up shots of any lesions.
After a few moments on board, the tagged fish were tossed back into the Chesapeake.
Scientists hope that when anglers catch the tagged fish months or years from now, they'll be able to match the fish to their original pictures.
"Some of the fish that didn't look so good, they may come back in a year and be healed. We just don't know yet," Pieper said.
Economic impact
Virginia has been doing this type of work for two years, tagging 6,700 bass since 2005, but this is Maryland's first year joining the effort.
The research could yield lucrative findings. Recreational fishing in Maryland is an industry valued at more than $300 million a year, by state estimates. Unsightly lesions on striped bass and public worries about catching fish handler's disease can harm charter boat captains and commercial fishermen who depend on the fish for their livelihoods.
The research could prompt fishery managers to cap harvests or make other arrangements to help the population thrive despite the bacteria.
It's a new approach for officials used to considering only catch data when surveying a fish population. "Historically in fisheries, fishing is the problem," Hoenig said. When disease hits, he added, "We're sort of unprepared for that."
Figuring out clues
DNR biologist Kevin Rosemary, photographer for the striped bass, said that the research could prove valuable even if most fish don't get caught and called in. Dead fish are usually gobbled up quickly by other critters, so if the returned fish in Maryland's study were more likely to be disease-free when tagged, that could mean the sick fish were more likely to die. "We're hoping to learn if fish die of myco or not," Rosemary said.
He said Maryland hopes to tag 1,000 striped bass this year, some in the spring and then again in the fall.
Already the effort has yielded some clues. Hoenig said that when Virginia started its tagging, some people were critical because myco is always fatal in captive fish. Turns out, striped bass in the wild can live years with the bacteria, some plump and alert despite being mottled with lesions.
"Some people said it was silly because we're going to tag them, and then they're all going to die," Hoenig said. Now, as scientists learn more about how the bacteria affects the beloved striped bass, the next step could be clues for how to deal with mycobacteriosis.
"It's hard to convince people to take action if we can't demonstrate that there's problem," he said.
WANTED: STRIPED BASS WEARING GREEN TAGS
WANTED: Striped bass, also called rockfish or stripers, with a small green tag to report the catch.
THE CRIME: Scientists want to know more about mycobacteriosis, a mysterious wasting disease that now infects more than half the Chesapeake Bay's striped bass. Not all the tagged fish have the bacteria. But healthy fish are wanted, too, to see if they've stayed healthy since Maryland biologists tagged them or if they had the bacteria but recovered.
THE EVIDENCE: Some striped bass with the bacteria have mottled scales, or even nasty lesions. Some infected fish have tiny brown dots on some scales. Some infected fish show no outer signs of disease. The bacteria is usually harmless to humans, and if your poor hand-washing skills lead to an infection, the disease is easily treated with antibiotics. In rare cases of untreated mycobacteriosis, arthritis-like symptoms can result.
THE REWARD: Anglers get $5 for calling in a catch, or $20 if they keep the fish on ice for scientists to retrieve.
Source: Maryland Department of Natural Resources
Poster Comment:
When I was a kid my dad would wake my brother and I in the middle of the night so we could be on the fishing pier at Ocean View before sunrise. This pier at the mouth of the Chesapeake bay is one of my fondest memories because it wasn't unusual to catch 100 pan sized spot and croaker, give 60 away and take 40 or so home for a breakfast fish fry.
If you've never eaten a fresh (never frozen) ocean fish then you're letting the best of life pass you by.
But, in the mid 1970's a corporate type was convicted of the crime of dumping Kepone (a poison) into the James River which then proceeded to poison the fin and shellfish in the bay and leading to a years-long moratorium on their harvest. This was the first time someone went to jail for an environmental crime, and the impact on the bay and fishing was immediately obvious. Gone were the days of pulling up young pan fish two at a time, and my soul and the bay are forever damaged.
They still monitor the waters near the bridge tunnel (connecting Hampton and Norfolk) because of the very real threat that hurricanes may release sequestered Kepone.
The mighty striped bass is also a favorite fish here in DE river, where the migration alternates with the Chesapeake bay depending on unknown factors that determine the fish's choice of routes every spawning season. The Chesapeake bay and the Delaware river are connected by the C&D canal on the north end of the bay, so a problem with Chesapeake bay rockfish is a problem with Delaware rockfish.
What I wouldn't give to have lived when the Dutch landed here and the English landed in Jamestown, when clams were so thick that one could rake them from the clear waters all day every day non stop.
My soul is in agony when I read these stories. Words fail me beyond a mere account of the evidence of a crime for which there is no suitable punishment.
And, when Native Americans say that we whites have destroyed the land I have no answer....