Oyster farmers in the state are finally getting their business back with oyster harvest areas now reopening along Louisiana’s coast following Hurricane Katrina.
But the farmers are still dealing with a long-running problem, and it’s not related to contaminated waters.
Black drum, a species of saltwater fish, is getting to oysters before the farmers can. Louisiana Department of Wildlife and Fisheries surveys show 80 percent of oyster farmers said the fish severely threaten their harvest.
University researchers for the past six years have studied how to reduce the black drum population surrounding oyster reefs.
After testing several methods, they said the best solution they have found to reduce the fish population is illegal.
The research team found in the spring that gill nets catch fish by their fins and can effectively increase oyster survival by catching surrounding black drum.
Researchers said Louisiana oyster farmers, the biggest oyster producers in the United States, see the nets and lines as the key to sustaining their business.
But gill nets have been illegal since 1995 because the trapped fish will die if left in the nets.
The Louisiana chapter of the Gulf Coast Conservation Society – a political action group devoted to banning gill nets – said its concern is the nets’ expanded use in commercial fishing will be unregulated severely impact the state’s redfish population.
“Gill nets are indiscriminate killers,” said Jeff Angers, the local chapter’s executive director. “They catch and kill most everything they come into contact with.”
Angers admitted gill nets are the most effective weapon against black drum.
But he says there are other methods – one in particular the state legislature passed this year.
House Bill No. 587 allows staking down “devices” to the ocean floor to protect oyster beds as long as the material in no way resembles a gill net.
University researchers found trot lines – long lines of baited hooks – can also be effective at keeping away black drum.
“Neither scent nor sound worked,” said Kenneth Brown, biological sciences professor and principal investigator for the research project, of other methods tested to keep away black drum. “But you don’t even really have to use gill nets. You can use trot lines.”
The study found trot lines mainly caught the fish swimming along the sea floor near the bedded oysters, including the black drum, and did not harm the redfish swimming above.
Not everyone agrees trot lines are the answer.
“Trot lines are not nearly as much of a hot issue,” said John Supan, research coordinator for the federal Office of Sea Grant Development at LSU. “But they’re inefficient because you’re hoping the fish will bite the hook.”
Sea Grant, the nationwide network of university-based programs under the National Oceanic and Atmospheric Administration, funded the research project.
In applying this research, Supan suggested the use of gill nets exclusively around oyster beds with well-enforced fishing regulations and a limited number of fishing licenses for those that catch black drum.
“[LSU’s research] shows what works and doesn’t work. Repellants don’t. What does work is catching them,” Supan said.
Brown’s research team is now placing radio tags on black drum near the coast to determine where they go and how long they stay in certain areas.
 
Contact Chris Day at [email protected]