After nearly 20 years in a legal gray zone, medical marijuana in California is being brought under regulation. But clandestine pot cultivation continues. Illegal grows on public land are especially notorious for causing a range of environmental problems. Now, there's new research that zeroes in on the toll these trespass grows take on threatened wildlife.
Several years ago, federal wildlife managers wanted to find out whether Pacific fishers qualified for protection under the Endangered Species Act. For years, the weasel-like cousin to the wolverine has been declining throughout California, Oregon and Washington.
While studying how fishers are dying, researchers found something unusual in the tissues of dead fishers: anti-coagulant rodenticides 鈥� rat poison. Dr. Robert Poppenga describes how these poisons work.
鈥淭hey prevent the blood from clotting by interfering with Vitamin K, so if you don鈥檛 have it, there鈥檚 nothing to stop the hemorrhage, so these animals basically bleed to death,鈥� he says.
Poppenga is a veterinary toxicologist with the University of California Davis. Since 2007, Poppenga鈥檚 lab has examined the bodies of 167 fishers. He says about 10 percent of them died by poisoning, and many more were contaminated at less-than-lethal levels.
鈥淚n about 85 percent of these animals we find at least one anticoagulant rodenticide present in their bodies,鈥� he says. 鈥淚n many of these animals we actually find more than one.鈥�
Dr. Mourad Gabriel -- with the non-profit Integral Ecology Research Center in Humboldt County, California 鈥� says the team began looking for the source of the poisons. They eliminated government agencies, power companies, timber companies, private landowners.
Then, Gabriel says, law enforcement officers invited the researchers to come along on raids of trespass marijuana grows on public lands.
Bingo 鈥�
鈥淥ur team has collectively visited close to 200 sites in California,鈥� Gabriel says. 鈥淎nd about 95 percent of those sites have some type of rodenticide present.鈥�
Gabriel says these illegal grow operations are typically way in the back country, and the workers who live there often leave a huge toxic mess on the landscape.
鈥淭he human waste, the garbage, the food, the rodenticides 鈥� and then you now take that picture of one site and then you extrapolate that to thousands of sites in California.鈥�
When law enforcement officers raid these back country grows, they destroy the marijuana crop, but there鈥檚 often no money to clean up the trash and poisons left behind. Gabriel says these sites could easily contaminate soil, waterways, even entire food webs.
鈥淚f we don鈥檛 do something about this sooner than later, we鈥檙e going to leave a legacy effect,鈥� he says.聽 鈥淎nd it鈥檚 going to occur not just for the wildlife or the fisheries, but the indirect and direct impacts are going to affect everybody,鈥� he says.
Jim Wood agrees. Wood is a Democratic member of the California Assembly whose district encompasses much of the state鈥檚 prime pot growing territory. He鈥檚 sponsoring a bill that would create a fund to pay for enforcement of water and land use regulations and cleanup of toxic trespass grows.
鈥淲e鈥檙e asking for the legitimate cannabis cultivators to pay a fee based on their crop to help us to go after the people who are creating a problem for them and a problem for our environment,鈥� he says.
Wood estimates his bill would generate about $20 million a year for cleanup. And the legitimate cannabis cultivators seem to be on board with that.
Hezekiah Allen, head of the California Growers Association, says they鈥檙e very much in favor of cracking down on irresponsible marijuana operations.
鈥淲e absolutely agree that there needs to be an investment in cleanup and remediation first,鈥� he says. 鈥淏ut we would also like to see a long-term investment into conservation and restoration.鈥�
Allen notes the region鈥檚 environment was damaged by reckless mining, ranching and timber extraction long before abusive pot growers began contributing to the problems, and that many of those impacts persist.
鈥淎nd we don鈥檛 just want to clean up the messes that this industry has made. We want to be part of a long term solution to restore those watersheds, to restore those fisheries,鈥� he says.
That would go well beyond the scope of Assembly member Wood鈥檚 pending bill.
That bill is expected to be considered after the Assembly reconvenes in January.
