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RICHMOND, Va. (AP)- A chronic bacterial disease that infects more than half of all the striped bass in the Chesapeake Bay is also lethal to the prized game fish, researchers concluded.


Scientists at the Virginia Institute of Marine Science said they are the first to conclusively link mycobacteriosis to the death of rockfish, the more common name for bay stripers.

Although the disease was first detected among bay rockfish in 1977, its virulence was not immediately apparent because the fish weren't dying in large numbers.

"They're just going to drop out of the population one by one," David Gauthier, lead author of the study, said of the infected stripers. "It takes a long time to kill a fish."

The study appears in the October issue of Ecological Applications. It was conducted by researchers at VIMS, based in Gloucester Point, and from Coastal Carolina University and the U.S. Geological Survey's National Wildlife Center.

Mycobacteriosis slowly eats away at a fish's scales, scarring its streamlined, silvery body. The disease is usually harmless to humans, provided they wash their hands after handling infected fish. Handling an infected fish with an open wound can cause lesions.

"It's a common-sense thing," Gauthier said. "It's a really good idea to wear gloves."

Infected fish are also safe to eat, but should be cooked thoroughly, he said.

While up to 60 percent of the striped bass in the bay are now afflicted, older fish are infected at higher rates. The estuary is the primary East Coast destination for striped bass to spawn. The game fish is coveted along the East Coast and is often on the menus of high-end restaurants.

It's not clear how mycobacteriosis spreads, nor why the disease has increased sharply in recent years. The disease, however, has historically been found among farmed fish.

"What makes it unique is you don't see it prevalent in a wild population," said Gauthier, who is now at Old Dominion University's department of biological services.

He said the bacterial infection is a "stress disease," and he cited several theories on what's causing it among bay stripers.

They include the bay's low-oxygen "dead zones," which could be forcing rockfish out of their preferred cold water into warmer waters; and low food supplies.

The study found a higher mortality rate in the summer months.

The mycobacteriosis-death link is based on fishery stock assessments that show an increase in natural deaths among striped bass in Maryland waters since 1999. The scientists used 1,420 stripers in their sample and determined a fish's age, sex and whether it had mycobacteriosis. They then used a mathematical formula to conclude whether the stripers were dying from the disease or from other causes.

Among other findings, the scientists found that older females are more likely than males to die from the disease, a likely toll of spawning and migration.
 

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Another Memory from the Salty Windshield

--Yeh, & Physteria, turned out to be not what 4 years & a large payroll for some Hot Shot Biologests--Studies , studies & more Studies , Free Physicals for every dock rat fron pa. to va. line --Front page Gloom & Doom articles almost every week , I even took the 75.00 paycheck to have myself evalued, when the Smoke & mirrors cleared it turned out it Wasn't Physteria , just a local case of some kinda Mold related problem --This was REPORTED on PAGE 3, in the papers , with no 4" Gloom & Doom headlines like the first articles ---Don't ever jump to concludtions based on Inital Bull $hit --This so called Killer has been here for Centuries--More fish die Choaking on oversize white perch in thier Gullet ,Or get cleaned out by a school of sharks than this ---Gotta go , ruin another fishes day --Caffine, Nicotine & Diesel Smoke --geo.
 

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They need to interview the hook/line guys up near Annapolis.Last summer - some caught 50-60 Rock but could only keep 3-4.The rest were covered in sores :eek2:.

I think the bad water quality in the upper bay is forcing the Rock into tighter schools- almost like they were in a fish farm pen.The disease spreads fast when the fish are tightly schooled.

Farther down the bay- the water is better and only a few sick fish are seen.
 

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What is the evidence that the water in the upper bay is poor quality? Guys who live near the flats say it is choked full of grass, the water is clear and there are many species of bait and fish alive and well but few stripers. Are stripers really fussier about water quality than walleye, large mouth bass, and perch? When I see stripers crashing the surf with sand suspended in the water, it makes me think they are pretty tolerant and durable. Also the fact that they can thrive in fresh water lakes makes me think they are pretty adaptable to a variety of conditions.

Maybe there is something to the disease claims and maybe Omega is taking too many of the menhaden that stripers need to thrive and stay healthy. When I used to fish land locked stripers at Santee Cooper SC, the fish had oily herring to eat.
 

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I'm talking the area near Annapolis.The waters deeper then 35 feet are often so low in O2 that nothing can live there in summer.The Rock prefer to stay in the deeper cooler water in summer.The shallower water is warmer- this might let the disease spread faster.

We often see nasty looking tide lines and somedays the water is a reddish brown color.Once south of Bloody Point- the water quality gets much better and clearer.

It's sad but we can now tell when we hook a sick Rock- they fight very different then a healthy one, almost like hooking a Flounder.

From my own experience - it seems the sick fish are mostly from Baltimore light/Love Point - south to Mattapeake/Tolly Point.This 7 mile stretch of the bay for some reason is bad for them.I've seen them other places but not in the numbers.
 

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I'm talking the area near Annapolis.The waters deeper then 35 feet are often so low in O2 that nothing can live there in summer.The Rock prefer to stay in the deeper cooler water in summer.The shallower water is warmer- this might let the disease spread faster.

We often see nasty looking tide lines and somedays the water is a reddish brown color.Once south of Bloody Point- the water quality gets much better and clearer.

It's sad but we can now tell when we hook a sick Rock- they fight very different then a healthy one, almost like hooking a Flounder.

From my own experience - it seems the sick fish are mostly from Baltimore light/Love Point - south to Mattapeake/Tolly Point.This 7 mile stretch of the bay for some reason is bad for them.I've seen them other places but not in the numbers.
That does sound bad. I do not fish there at all and have not seen it. I fish the flats and then north and south of the Pax.
 

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It worse then most people know.When I go scuba diving in that area- the lower part of the water column in 30 feet and deeper is like a black fog.This fog is about 2-4 feet off the bottom.

In summer- it is rare to see any fish on the meter below 30 feet- no O2 for them.We do see Rock suspended in the channel about 25 feet- my guess is they want to go deeper but can not due to no O2.Only 15 years ago we used to fish lures 40-50 feet down in summer and catch nice 30-36 inch Rock.Not anymore.
 

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Back in 2006 I talked with Steve Early of Maryland's Department of Natural Resources Fisheries Service Cooperative Oxford Lab about Mycobacteria in the Chesapeake Bay and it's effects on Rockfish/Striped Bass. You can listen to my interview with him here. It's a pretty good listen. When you go to the link there will be a little button with and arrow which is the "play" button. It is an MP3 and also on iTunes under Lateral Line Podcasts.

Brandon
 

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last year I went down to my boat in Chesapeake beach while i was cleaning I happened to notice that there was a bunch of crabs stuck on the top of a sunken boat i then looked over to the shore line and crabs were up on shore still alive I thought mabe it was something like whale beaching I did not know went back home came back later and there were dead fish all over the place thousands of them I talked to one of the crabbers and they said they pulled up 25 pots of dead crabs I have heard the stories before but never had seen it first hand
I did not see that this year but I have heard of several other places that had its not a pretty site

to think this is not a problam you would have to have your head in the sand





9rock
 

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The water quality in the bad is bad- as you saw first hand.The crabs can breathe air as long as their gills stay moist.They crawl out onto the beach because the water has no O2 in it.

Dead crabs in pots are another bad sign.We have dropped live Spot to the bottom in 25 feet and after only 15 minutes-we reel up dead ones.No bite marks or scales missing- they died from no O2 on the bottom.The heavy 3 oz sinker kept them in the dead zone.

Heard of guys near the gas dock having the same problem.
 

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John - it has a fancy name but is basically just silt/debri that is suspended near/on the bottom.With no oysters to filter it out- it stays there.

On slack current is almost goes away but as soon as the current picks up - it comes right back.It's not as bad in water 25 feet or shallower.
 
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