Pubdate: Sat, 14 Jul 2012
Source: Times-Standard (Eureka, CA)
Copyright: 2012 Times-Standard
Author: Thadeus Greenson
Bookmark: (Environmental Issues)
Note: On the Web: To read the complete study, or view a video about 
it, visit


Study Find Marijuana Grows Likely Responsible for Mammal Deaths

Potent rat poisons used on large-scale illegal marijuana farms 
sprinkled through forest lands throughout the state may be killing 
off a rare forest carnivore, according to a groundbreaking study 
released Friday.

"This could be a game changer," said Arcata City Councilman Mark 
Wheetley of the study produced by biologists from University of 
California Davis documenting the deaths of fishers, reclusive members 
of the Mustelid family that are candidates for protection under the 
Endangered Species Act.

"I think this whole study should serve as a wake up call for the 
public to understand the magnitude of the impact of what's being done 
to what we consider sacred, protected public lands," continued 
Wheetley, who holds a day job as a senior biologist for the 
California Department of Fish and Game.

Law enforcement and environmental officials have long complained of 
the environmental degradation associated with large-scale marijuana 
cultivation on forest lands. But the evidence has been almost 
exclusively anecdotal, limited to stories of diverted streams, 
networks of irrigation piping, piles of trash and large amounts of 
commercial fertilizers, insecticides and rodenticides.

The study released Friday documents the scientific data behind the 
stories for the first time, quantifying the environmental impacts of 
illicit grows.

Mourad Gabriel, lead author of the study and president of Blue Lake's 
Integral Ecology Research Center, said the study sprang from efforts 
to identify and study threats to California's fisher populations. 
Because the reclusive forest predators live in coniferous and 
hardwood forests -- mostly forest, park and tribal lands -- far away 
from urban population centers or agricultural fields, Gabriel said 
researchers were shocked to find they were being poisoned by 
toxicants at an alarming rate.

The study found that almost 80 percent of fishers found dead by 
researchers between 2006 and 2011 had been exposed to high levels of 
anticoagulant rodenticide -- commonly referred to as rat poison. 
Because these fishers were being monitored and lived in remote areas, 
Gabriel said researchers were initially stumped as to what could be 
the potential exposure points for them.

Then, Gabriel said, it clicked: Researchers realized that all these 
fishers' habitats overlapped with illegal marijuana farms that often 
used high levels of commercial pesticides and rodenticides to protect 
their crop. Further, the study notes, all the deaths of exposed 
fishers occurred between mid-April and mid-May, the optimal time 
period for planting marijuana outdoors, when growers are most likely 
to use large amounts of poison to protect their seedlings.

The study describes a grow site discovered by law enforcement less 
than 7.5 miles from one of the fisher study areas, where large 
amounts of rodenticide were found sprinkled around plants and lining 
plastic irrigation lines, presumably to keep rats from chewing them.

The anticoagulant rodenticides inhibit mammals' ability to recycle 
vitamin K, making their blood incapable of clotting, leading to 
uncontrollable internal bleeding and, ultimately, death. The 
second-generation poisons can be lethal with a single dose, the study 
notes, but can take up to a week from ingestion to be lethal.

Gabriel said some of the rodenticides are treated with "flavorizers" 
to make the poisons taste like bacon, cheese or peanut butter, which 
could also cause fishers and other animals to eat the poison 
directly. The most likely -- and troubling -- conclusion, however, is 
that the fishers were exposed through their prey: small rodents.

This is a troubling notion for biologists and conservationists for 
several reasons. First, because fishers have the same prey groups as 
federally protected, threatened or endangered species like condors, 
spotted owls and martens, those groups may be just as likely to be 
impacted. Second, these poisons could wipe out a whole prey group -- 
wood rats, deer mice and other small scavenging rodents -- in the 
region, leading to the collapse or partial collapse of a food chain.

Rodenticides, however, are far from the only troubling items found at 
illicit marijuana growing sites. In a separate paper, Gabriel and 
others outline what they found during a brief visit to an abandoned 
marijuana garden in one of their fisher project areas. In addition to 
pounds of rodenticide, they reported finding 575 pounds of 
fertilizer, including 200 pounds of fertilizers with 46 percent 
nitrogen levels, 24 pounds of slug bait and 32 ounces of Malathion, a 
potent pesticide.

Such findings come as no shock to law enforcement.

Humboldt County Sheriff's Office Sgt. Wayne Hansen, who currently 
heads the county drug task force and has spent years heading 
marijuana eradication efforts for the county, said the large-scale 
grows believed to be tied to drug trafficking organizations -- the 
ones most likely to be on remote public lands -- often utilize huge 
amounts of poisons and fertilizers, in addition to diverting streams 
and clear-cutting swaths of forest.

Gabriel said his study simply brushes the tip of the proverbial 
iceberg. The next step for him and fellow researchers, Gabriel said, 
is to look at whether the use of rodenticides at grow sites on public 
lands is depleting the prey pool for fishers and other carnivores. 
But, Gabriel said, there are a tremendous amount of questions 
associated with these growing operations that warrant scientific 
attention, including the impacts of pesticides, fertilizers and 
stream diversions. The hope, Gabriel said, is that his study and the 
ones that follow help inform the discussion.

One thing for sure is that the study is already getting loads of 
attention, having circulated through some professional circles before 
its public release Friday.

Tommy Lanier, director of the White House-funded National Marijuana 
Initiative, said Friday he's very familiar with the fisher study and 
hopes it will serve to educate the public about some of the ancillary 
impacts of the marijuana market. To that end, Lanier said, he's 
trying to get Sen. Barbara Boxer, who heads the U.S. Senate Committee 
on the Environment and Public Works, to hold a congressional hearing 
on illegal marijuana cultivation on public lands. He said he plans on 
asking Gabriel to come back and address Congress.

"The environmental impacts are huge and have to be a huge part of the 
discussion," Lanier said. "(This study) is a great example of some of 
the effects."
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MAP posted-by: Jay Bergstrom