Lobster industry Takes on the Exotic Bait Debate
by Laurie Schreiber
The potential incidence of disease with the import of exotic bait in the Gulf of Maine lobster industry was a top topic at the Canadian/U.S. Lobstermen’s Town Meeting in Portland, held on March 23-24.
“The risk of transmission of exotic diseases into Maine on bait fish, needs to be established. The viral hemorrhagic septicemia virus was identified as a particular concern,” said Ian Bricknell, a professor of aquaculture biology at the University of Maine and director of the university’s School of Marine Science’s Aquaculture Research Institute.
Bricknell, Department of Marine Resources (DMR) lead lobster biologist Carl Wilson, and Sebasco Estates-based Purse Line Bait owner, Jennie Bichrest, spoke to a crowd of about 70 attendees about the need to improve biosecurity measures for imported bait.
The discussion landed on the agenda in response to a report provided to the DMR’s Lobster Advisory Council in 2010 by Bricknell and Deborah Bouchard, manager of the university’s Maine Aquatic Animal Health Laboratory.
The report, “Determining the Health Risks of Lobster Bait to Marine Animals,” continues to be a percolating topic for the industry. The report said that, although the Maine lobster fishery is heavily dependent on the herring fishery to supply fresh, salted and frozen bait, recent changes in the status and management of the herring fishery “have created significant concern over the future availability of bait for the lobster fishery.”
Expectations that herring could become too scarce, or too expensive, “have caused increasing interest in alternative baits as supplements or replacements,” the report said.
The demand for alternative lobster baits is rising, and one bait replacement has been fish processing by-products, the report said.
“Two examples of by-products would be the use of carp and salmon heads/ racks (complete fleshed head attached to bone skeleton),” the report said. However, there may be a risk both of introducing “exotic diseases” to Maine’s marine organisms and of lobster become a vector that allows disease to be further distributed.
The report documented the authors’ study of an infectious viral pathogen called viral hemorrhagic septicemia (VHS), “a major bio-security threat to both freshwater and marine aquatic environments in the U.S.”
VHS and related virus strains have been found in European aquaculture operations and in a variety of marine fishes in the North Pacific, North Atlantic, the seas around northern Europe and Japan, and in the Great Lakes, the report said.
In February, the state legislature addressed the issue when it passed an emergency law, LD 1609 "An Act To Ensure the Safety of Bait Used in Maine's Fishery.” Current law prohibits the use of offal as bait to fish for or take lobster or crabs. Offal does not include marine organisms. The new law allows the DMR commissioner to maintain a list of exempt freshwater organisms and prohibited marine organisms. Any exemption or prohibition must list the freshwater organism or marine organism and the location from which that organism is harvested.
In his presentation, Bricknell posed the questions, “What is the risk of introducing exotic diseases to Maine by inadvertently using infected fish heads from elsewhere in the U.S. and Canada as bait? Could these diseases utilize lobsters as a vector, permitting disease to be moved from ocean to pound and then distributed via exports to Canada and other countries which permit live lobster imports? What are the risks of disease from Maine farmed salmon carcasses processed within the state?”
Bricknell has worked with the aquaculture industry for 25 years. In 2007, he accepted the post of Libra Professor of Aquaculture Biology at the University of Maine, and in 2009, he was appointed as the first director of the Aquaculture Research Institute, where he established a new aquatic animal disease research group. According to his biography, he has expanded his research interests to include lobster health.
Bricknell said that his group was asked by the DMR several years ago to assess the possible risk of introducing disease through certain baits, a situation that might be exacerbated by the rising price of herring, due to herring’s reduced availability as bait from the New England. VHS affects fish around the world, he said. Its end stage affects the nervous tissues, especially the brain, of affected fish.
VHS is a disease among both freshwater and marine species, Bricknell said. The study group designed an experiment to assess the survival of VHS in a variety of storage conditions, of the type that might typically be found for lobster bait.
Injected into brain tissue, the virus was stored for 30 days at three regimes, 40 degrees Fahrenheit, or the temperature of a refrigerator; 0 degrees Fahrenheit, the temperature of a freezer; and salted and kept at room temperature. The latter is a popular way to store bait, he said.
At 40 degrees, he said, the virus could be detected in the first three days, but there was none by day 30. However, he said, the bait was a “stinking mess with a lot of bacterial activity.”
At zero degrees, the number of viruses dropped by 90 percent over course of the month, leaving 10 percent.
Salted, there was “lots of viruses” for the first two days, and none detected by day three. By day 30, the tissue had degraded considerably, he said. “So salting bait might be good way to inactivate VHS,” he said.
Dropping the number of viruses by 90 percent might sound like a lot, Bricknell said. However, he said, “It’s not uncommon in tissues of infected animals to have 1 billion viruses or bacteria per gram of tissues. So if you kill 90 percent, that still leaves 100 million. So it’s a huge amount still. The risk is still substantial.”
Bricknell also discussed the white spot virus which, he said, is found on shrimp and is endemic in Asia. It causes white lesions in the hard carapace of marine and freshwater crustaceans, and could potentially affect crabs, lobster and shrimp worldwide, he said.
The white spot virus would be unlikely to kill adult lobsters, but could potentially cause mass mortality in larvae, he said.
“This is a very concerning thing,” he said. “This has been seen in the green crab in France.”
Bricknell called for better biosecurity measures to prevent the advent of diseased bait into the Gulf of Maine. VHS, he said, could potentially afflict Maine’s wild and farmed fisheries, and there would almost certainly be limitations on the export of live animals outside of the state because of the risk of carrying the virus in their holding tanks or packing materials.
Carl Wilson said the increasing use of exotic baits in Maine started about a decade ago, but not because of any lack of herring.
“People were starting to use mostly hide baits as a way to extend the fishing power of their long sets, especially in the fall and winter months,” Wilson said. “We slowly started to get reports of consumers who would sit down to their $40 lobster in New York City or wherever, and they’d open up their lobster and find a ball of hair that the lobster consumed off the hide. It doesn’t take many calls to start to think maybe there’s problem with lobsters consuming cowhide.”
The legislature soon passed a law to limit the use of offal, any animal rendering parts, as bait. The exception was hide, as long as the hair was removed.
Despite the exception, Wilson said, “For the most part we’ve seen a dramatic decline in the amount of hides used as bait within the lobster fishery.” Just five or six years ago, he said, herring was used as bait in most trap hauls. Today, it’s used in about 75 percent of the traps.
“The herring is being replaced with exotic baits,” he said. At one time, it might be that a couple of truckloads of exotic bait would arrive in Maine.
“Now some areas are almost exclusively using bait not coming for Gulf of Maine,” he said. “That brings up a biosecurity issue. It’s not necessarily a lobster health conversation, although white spot would make any lobster health biologist scared. But it runs into more, what are the unintentional impacts to the lobster fishery in the Gulf of Maine ecosystem?”
Jennie Bichrest said that, as a bait dealer, she has seen out-of-state carp become a popular bait in the lobster industry. She said the disease risk in exotic baits “scares me to death. I think there could be some really devastating consequences. I’m hoping we can work together to have baits that we need but do it responsibly. I think there are some huge dangers and I’m looking to the state to help us because there’s a lot more coming on the market. I’m not an expert, so I’m looking to the experts to determine what we should be using.”
Native menhaden, redfish and herring “still work” for the lobster fishery, Bichrest said. And they’re safe for the rest of what’s growing out there. So I look forward to moving ahead with safety concerns.”
According to an article by Maine Lobstermen’s Association staffer Melissa Waterman in the MLA’s newsletter, Landings, “Where once locally caught herring or menhaden were the mainstay baits used by Maine lobstermen, today baits used in Maine may come from the four quarters of the globe. Asian carp, black cod racks, tuna heads from Ghana—the list of bait products currently coming into the state resembles the roster of the United Nations.”
The list of exotic baits mentioned by Waterman also includes rockfish, flat fish, orange roughy heads and alfonsino from New Zealand.
Jim Dow of Bass Harbor wanted to know if a test had been developed for fishermen or dealers to be able to determine whether bait is diseased or not.
“There are tests available for virtually all these pathogens,” said Bricknell. “One option is for dealers to send a subset to lab, to do a quick molecular or culture test, which would be ready in three to five days. It’s a good way to reduce the risk.” However, he cautioned, “There’s a cost involved in the test.”
Bouchard said the average cost of a test would be $50 to $60 per sample.
“If you’re testing two tons, it isn’t too much, but if testing smaller portions, it adds up,” Bouchard said.
With regard to white spot virus, Dr. Michael Gillespie of the New England Aquarium said that experiments in 2002 determined that the virus could not be transferred to juvenile lobsters. However, he said, lobsters are vulnerable to “multiple stressors. So sometimes, if you hit them with one thing, it doesn’t affect them, but if you hit them with two or three things, they don’t fare that well.”
White spot virus has not been detected in the Gulf of Maine, Wilson said.
Guy Torrey of Portland noted that Maine does not allow non-native firewood to be brought into the state. He wanted to know why the state allows non-indigenous species of bait in.
“I don’t think there’s enough fish being landed in Maine to supply the lobster fishery in Maine,” responded Wilson. “I think the demand exceeds the supply.”
“Shouldn’t we prove it’s safe before we use it?” asked Casco Bay fisherman Steve Train.
“That’s not a question for me,” said Wilson, who added, “But I think the reality is that the industry has too much of a desire for bait. I think, when push comes to shove, they want to have their traps filled with bait and if it’s exotic bait, ‘Great,’ and if it’s locally supplied bait, ‘Great.’ I don’t think the science is there to say we should block this bait versus that bait. Today it’s VHS as a pathogen that we’re concerned about. Tomorrow, it might be something else. We’re always playing catch-up.”
DMR Commissioner Pat Keliher said: “The issue regarding this law and the safety of bait spins back to how much risk the state is willing to take dealing with exotic bait. [The new law] allows the state and the commissioner’s office to use Maine’s Fish Health Technical Committee and New England’s Fish Health Technical Committee to identify bait within the U.S. and, actually, around the world – to identify areas where these pathogens exist. And then we can ban the use of baits from those areas. We’ve got more work to do with the law. That’s in process now.”
Bichrest said the issue is complicated not only because bait can be transported from anywhere in the United States and the world, but also because bait might be harvested in one area, and then transported to a second area to be processed.
Bricknell said that salting has proven to be effective for killing viruses. But Bichrest and others said that, practically speaking, it may be impossible for dealers to thaw out thousands of pounds of frozen bait, spread it out, and salt it.
“The chance of being able to salt a product in Vietnam is iffy,” Bichrest said, by way of example. “To salt it on this end is, I think, pretty impossible. I don’t think any bait dealer has the room; I know I don’t have the room. Grand Manan fisherman Laurence Cook said that, first and foremost, fishermen need information.