MONTEGUT — Wayde Bonvillain watched his future spill from a plastic tub and disappear into the murky waters of Bayou Terrebonne.
“Yes, that’s my future. That’s my daughter’s future,” the 57-year-old crab buyer said of the hundreds of crustaceans that came to his plant alive but ended up as food for catfish and other crabs. They should have died in boiling pots at Lenten suppers or fried as delicacies after shedding their shells. But when they died on his lawn and in his sheds, Bonvillain said, he had no choice.
Scientists at the state Department of Wildlife and Fisheries are trying to figure out why crabs like the ones Bonvillain dumped are dying before reaching market but so far have come up with no solid answers.
They have taken samples from him and other crab buyers, but an explanation remains elusive.
What they do know will be shared today at a meeting of the department’s Crab Task Force, scheduled for 4:30 p.m. at the agency’s headquarters on Quail Drive in Baton Rouge.
Some crab buyers and fishermen say they are certain the problem is related to the BP oil spill, which they suspect has cut down the populations of crabs overall, and weakened those that remain. But there is no proof, and scientists are leaning more toward the potential of a local infestation of parasites, though that remains uncertain at this point.
Louisiana’s blue crab fishery — the nation’s largest — was worth nearly $36 million in 2009 when more than 23,000 metric tons were caught in the state’s waters. Catches were relatively steady over the decade but showed dips in 2005, the year of Hurricane Katrina, and 2008. That’s when Louisiana’s crab-basket took a hard hit from the double threat of hurricanes Gustav and Ike.
The numbers are not ready for 2010, but crab fishermen already know they will be low, with much of the water they fished shut down because of the Macondo spill and now — in Terrebonne Parish at least — the problem of die-offs after the crabs have been harvested.
State officials say the issue is not universal in Louisiana. Crabs are doing well, they said in the state’s eastern zone and west of Dularge. There has been no red flag raised about health problems for people, just for the crabs. And crab die-offs are not unheard of in Louisiana, for reasons difficult if sometimes impossible to explain.
Fishermen dismiss the suggestion that weakened crabs are nothing new. Those who fish Lake Boudreaux, Lake Pelto and the bayous that empty into them say they’ve never seen anything like this, and that bothers them.
Paul Orr is the Lower Mississippi “riverkeeper.” Riverkeepers are part of a national environmental network that keeps watch over the quality of rivers and other waterbodies. Orr works closely with the Louisiana Environmental Action Network, and is among advocates who say that if fishermen are baffled, people in charge need to listen carefully.
“Those guys know crabs and if they think something is not right then somebody needs to pay attention,” said Orr. “We have done sampling from the western edge of Terrebonne through the delta and we found high levels of petroleum hydrocarbons.”
But Orr, as well as scientists who have done recent studies on blue crabs, say it is difficult to use such readings to make a determination.
“It has been really difficult to find any sort of existing information about what is acceptable and what is not,” Orr said. There is a lack of hard data.”
High levels of hydrocarbons — compounds that include such petroleum-related substances as toluene — are not good for crabs or other living things when they reach certain levels. But the baseline for those levels in terms of what can make crabs sick is difficult to establish. There are few studies, and scientists say mostly observing and waiting.
Marco Kaltofen, a consulting engineer affiliated with Wooster Polytechnic Institute who owns a firm called Boston Chemical Data, tested Gulf crabs, including some from Terrebonne, for hydrocarbons from January through October.
He acknowledges that parasites — the direction state scientists are leaning toward — could be a cause of the die-offs. But caution should be taken, he said, to pay close attention to the hydrocarbons.
“We know that over the past year there was a big change in water quality because of the oil spill,” he said. “But there is no machine you can put the crab into and say this is what killed it.”
Kaltofen is careful not to jump to conclusions, however, either toward or away from the potential that hydrocarbons could play a role.
“Gross hydrocarbon contamination in an ecosystem is a plausible cause for die-offs, enough effect on the system for toxicity that it could be a cause,” he said.
Scientists observed small crabs — the babies — making it into estuaries over the past few months. But those sightings were limited to Corpus Christi, Grand Isle, Mississippi, Alabama and Florida. Some of the richest areas of crab country — the coasts of Terrebonne and Lafourche — were not part of those studies.
Some of that data will be presented at today’s meeting.
Crabbers may be disappointed when they hear some of the presentations, since hard facts about why their catches aren’t making it to market may not be forthcoming.
Scientists say they are doing their best, however, and that all options are open for consideration.
Julie Anderson, a marine fisheries specialist at Louisiana SeaGrant, will give a presentation at the meeting. She is aware of die-offs that have happened in coastal Louisiana during past years.
“In the past, through all of coastal Louisiana there is a pocket that pops up limited to specific water bodies, when the crabs have very high mortality and poor survival in transit,” she said. “The researchers have looked at water quality, checked for parasites and come up with nothing in those situations. You can have two bodies of water right next to each other, and one will have a die-off and the other one not. Overall we really don’t know.”
Pockets of low dissolved oxygen, whether or not related to the spill, could also be a cause.
“Some do have evidence of parasites,” she said of the crabs currently being tested. “If there is a sudden outbreak of parasites it could be water temperatures. This year it did get colder and the temperatures did keep dropping down. Any of those could have matched perfectly for outbreaks.”
State researchers, Anderson said, could well determine there is a huge problem.
“We just don’t know yet,” she said. “I know the state and the researchers are looking into everything.”
Senior Staff Writer John DeSantis can be reached at 850-1150 or firstname.lastname@example.org.