Pesticide-Laden Runoff Kills Blue Crabs

BATH — Hilton Waters was picking through baskets of live blue crabs a few weeks ago, counting them as he culled out peelers to put in his shedding tanks. It was about 5:30 p.m. on a Friday, and he and his wife were leaving for a much-needed vacation the next day.  But something looked wrong.

“We just noticed the crabs seemed to be acting funny,” Waters said in a telephone interview on Friday, recounting the Aug. 10 incident.

By about 7 p.m., he said, some of the crabs in the shedding tanks were flipping end over end — something he had never seen before. Two hours later, most of the crabs were flipping continuously.  At about 11 p.m., all 2,000 or so of the crabs in the tanks were on their backs, quivering. Then, during the night, their claws and, sometimes, entire legs were falling off.

By morning, Waters said, every crab was dead.

“Everything hit wrong,” he said.  “It came with a heck of a downpour at the same time the runoff came with a very low tide.”A lifelong waterman, Waters immediately suspected pesticide poisoning of the canal at the mouth of St. Clair’s Creek, which empties into the Pamlico River at his operation between Bath and Belhaven.  A neighboring farmer had ground sprayed his cotton fields with a pesticide the day before, and there had been a rain deluge of 1.5 inches that afternoon. The farm field drains into a ditch that drains into the canal, which supplies water for his tanks.

Waters saved a water sample, and froze some of the dead crab. The next morning, he called a state environmental emergency number and he was soon contacted by Lynn Henry, a marine biologist at the state Division of Marine Fisheries office in Elizabeth City.  A report was taken, Waters said, but Henry did not visit the site.

But a person from the state Department of Agriculture and Consumer Services did come out that Monday to look around, he said, and came back the next day to collect the samples.

Jennifer Almond, pesticide operations specialist with the agriculture department, confirmed that an inspector visited the site on Aug. 13, and found that the pesticide bifenthrin, which is highly toxic to crab, shrimp, and other aquatic life, had been used by the farmer, Mike Godley of Bath.  The matter is still under investigation and she said she could not comment further.

Henry said that there is no indication that the pesticide was applied improperly. “I think it was just the timing was terrible,” she said. “I have not heard that the farmer did anything wrong.”

Pesticide poisonings seem to be isolated in the crab operations in the Albemarle-Pamlico estuaries, said Anne Deaton, section chief of habitat protection with the division. But lately, she said, she has heard that crabbers proactively take their pots out of the water when there’s a heavy rain.

“The question for us — we see a bunch of adult crabs dying — so what’s happening below the surface to the juvenile or post-juvenile crabs?” Deaton said. “The important thing is to figure out how much of these chemicals are getting into the water.”

Crabs are already stressed out when they’re shedding, said Henry, and crabbers always try to get the best water quality possible. Oxygen content, temperature and handling are also issues in mortality, so crabbers are vigilant in keeping watch on the potentially lucrative crabs in the tanks.

A kill like Waters suffered, Henry said, is a concern to anyone who cares about the water quality in that agricultural region.

“If these chemicals are doing this to him, what is it doing to all the other critters in the environment?” he said. “What is this stuff doing to the aquatic environment in these small creeks and nursery areas?”

Apparently, no one really knows. Thanks to a combination of government budget cuts and entangled bureaucratic regulations, there appears to be no clear-cut understanding of the impacts of pesticide use near estuarine waters or who is in charge of oversight.

In 2010, the state eliminated funding for “rapid response teams” in the Neuse and Pamlico river basins, and along with that, the emergency phone number to call about fish kills or water pollution was eliminated. Now, calls about all environmental emergencies go to the state Division of Emergency Management (800-858-0368) and the appropriate agency is notified.

With the Waters case, after consulting with the Division of Marine Fisheries and the Division of Water Quality, it was decided that because it was pesticide-related, it should be handled by the state Department of Agriculture and Consumer Services, said Steve Lewis, the emergency response coordinator for the Division of Water Quality.

Lewis said that under the federal Clean Water Act, stormwater runoff from agricultural operations is not subject to the act’s regulations, even if the runoff contains enough pesticides to kill crabs.

And if the farmer applied the pesticide according to the label, there may be very little recourse even if there is a kill.

What happened in this incident, Lewis said, it that the pesticide, which is relatively non-toxic to mammals, was washed from the cotton into the waterway where it was not intended to go. There, it became very deadly to invertebrates in the water.

“It wasn’t that it was super-concentrated,” he said about the pesticide. “It’s just that it was so toxic.”

The bottom line is that it is difficult to regulate pesticide use that may result in accidental pollution of waterways, said Matt Matthews, chief of surface water protection for the division in Raleigh.

“In order to address the situation in some way, we’re trying to address this with outreach and education,” he said.

Matthews said he has found that farmers try to use the “least environmentally impactful” chemical available, but it can be a balancing act finding the right herbicide and pesticide.

There are 323 monitoring stations located in waterways throughout the state that look for indications of chemical, physical and biological contamination, but Matthews said he is not aware of any targeted state studies of agricultural pesticide effects on estuarine aquatic life.

“We do not have those kinds of resources right now,” he said.


Dan Rittschof

A 2009 Duke Marine Lab study by Dan Rittschof, prompted by a large blue crab kill in Swan Quarter, studied varying degrees of toxicity to crabs during their life stages of four commonly-used pesticides, with the one in the same chemical family as bifenthrin considered the most toxic.

Rittschof is one of five authors of a 2012 report on the toxicity of pesticides to crabs published in the Journal of Experimental Marine Biology and Ecology.

“The sensitivity of molting blue crabs to these pesticides makes frequently molting juveniles particularly vulnerable to pesticides in estuaries,” the report said.

If Waters has anything to be grateful for, he said, it’s that his operation was not at its maximum of 5,000 crabs. It’s still not known whether he’ll be able to collect insurance money from Godley, who Waters characterized as a “good guy” who would not intentionally hurt anything.  Not only is he out of about $4,500 for the crabs, it is unclear when it will be again safe to use the canal and when his shedding operation will fully recover.

But he said he is disappointed in the state’s slow response to his calls, and says that no one was there fast enough to see the hundreds of dead grass shrimp lining the quarter-mile canal after the rain, not to mention the crabs that were not in his tanks — because all the poisoned creatures soon sank to the bottom, unseen and unknown.

“From my standpoint, that’s just my word,” he said.  “It’s never been documented. It’s not just my shedders; it’s killing everything.”

 

About the Author

Catherine Kozak

Catherine Kozak has been a reporter and writer on the Outer Banks since 1995. She worked for 15 years for The Virginian Pilot. Born and raised in the suburbs outside New York City, Catherine earned her journalism degree from the State University of New York at New Paltz. During her career, she has written about dozens of environmental issues, including oil and gas exploration, wildlife habitat protection, sea level rise, wind energy production, shoreline erosion and beach nourishment. She lives in Nags Head.