Despite media reports describing a rash of red snapper with lesions caught off Alabama in the Gulf of Mexico, such fish proved difficult to catch during 4 days of intensive fishing off the Alabama coast by a team of researchers from the Dauphin Island Sea Lab.
Meanwhile, a scientist who examined a few of the fish purported to have lesions described them as having simple, and relatively minor, bacterial infections of the skin, which he said were common in the Gulf.
Recent Sea Lab research trips netted about 900 apparently healthy red snapper, grouper and red porgies. One snapper with a small, eggplant-colored patch was caught during that time. Scientists described it as having a “small, healed wound” at the base of the dorsal fin.
The issue of sick snapper was initially raised by Jim Cowan, a Louisiana State University fisheries scientist. Cowan, who has since been quoted in multiple media accounts, said he received the carcasses of several diseased fish from a commercial fisherman. In early May, he made a research cruise off Alabama looking for fish with lesions. He provided 5 fish from that trip to John Hawke, a fisheries pathologist at LSU.
Hawke said last week that he had examined those fish and would not characterize any of them as sick.
Hawke described some of the lesions as “barely visible abnormalities of the skin.” He said that he did find bacteria, including Vibrio vulnificus, on the fish. Vibrio is commonly found in Gulf waters, and is the bacteria blamed for occasional sickness or death associated with eating oysters.
‘These are not what I would call sick fish’
“It is hard to think there is any kind of infectious disease spreading through the population. I really don’t see it being anything like that,” Hawke said. “These are not what I would call sick fish. The organisms we are looking at are very common marine bacteria. The fish have infections on the skin, but that does not equate to an overall disease state. Otherwise, they are healthy.”
Will Patterson, a biologist at the University of West Florida who regularly studies snapper populations, said he has seen about 30 fish with lesions this spring. Some were seen in underwater video surveys and some were provided by commercial fishermen. He said he felt the issue had been “sensationalized” in the media.
He said it is important to document any abnormalities in fish in light of last summer’s Gulf oil spill, but cautioned that all research going forward will be handicapped by what he termed “a dearth of information” about the health of snapper before a BP-owned well spewed 200 million gallons into the Gulf.
Patterson said the fact that several ongoing scientific sampling efforts have located few fish with the abnormalities raised several possibilities. “Perhaps this was sort of an ephemeral issue and it has passed. Or perhaps fish are moving. Or, worse yet, perhaps fish are dying,” Patterson said.
He said he was particularly disturbed by fish he saw during the video surveys.
“We’ve actually seen fish on our video samples that have fin rot and other issues. Things we’ve never seen before,” Patterson said. “We have videotaped 50,000 to 60,000 fish in the past eight years and never seen anything like that. The fact that we’ve seen these problems alone should raise some concern.”
Ongoing research will determine percentage of fish affected
Patterson said ongoing research by university scientists and the federal government would determine what percentage of the fish population had been affected.
In emails to other scientists, LSU’s Cowan wrote that 10 percent of fish he sampled were affected. Patterson said his research indicates the total would be somewhere below 2 percent.
Bob Shipp, head of marine sciences at the University of South Alabama, led the recent Dauphin Island Sea Lab trips. Shipp said that the group he works with had caught 3,000 snapper in the last year. Just one fish — representing a fraction of 1 percent of the total caught — showed any sign of infection, he said.
Last week, Shipp conducted multiple video surveys of artificial reefs that had been singled out as “hotspots” for diseased fish by the same commercial fisherman who provided fish samples to Cowan. No sign of infection was seen on any of the fish that swam past the camera, he said. The videos are posted at www.vimeo.com/disl. (Or view one below.)
One thing has been notably absent on the many video surveys conducted by the Sea Lab over the last several months. “We haven’t seen any oil on the bottom or on the reefs at any of our sites,” Shipp said.
He said fish are often injured when they are caught, then released. Given the fact that red snapper are off limits to fishermen for most of the year, that’s a common occurrence.
“A lot of fish that came up during our sampling had signs of immediate injuries that had happened within the 10 minutes prior to coming on the boat,” Shipp said. “That can happen as the fish is fighting the hook, its body rubbing on the line. Anyone calling a fish with those kinds of injuries a sick fish, that is not appropriate.”
Bonnie Ponwith, who heads the fisheries science center for the National Oceanic and Atmospheric Administration’s Southeast region, said federal scientists have yet to catch an infected fish despite an ongoing, Gulfwide survey that began a month ago.
However, she encouraged anyone catching a fish with lesions to discard it at sea. That should be common practice, she said, because of the possibility of infection.
“If a human being comes in contact with a fish that has an infection of this species of Vibrio, and a person has open wounds or a puncture that comes in contact with Vibrio, they could get sick from it,” Ponwith said.
(Click here to link to the original Press Register story.)