Posts Tagged: marijuana

Insight into the environmental impacts of cannabis agriculture

As policy liberalization rapidly transforms the multi-billion-dollar cannabis agriculture industry in the United States, the need for regulation and assessment of environmental impacts becomes increasingly apparent. 

A recent study led by UC Cooperative Extension specialist Van Butsic used high resolution satellite imagery to conduct a systematic survey of cannabis production and to explore its potential ecological consequences. 

Published this spring in Environmental Research Letters, the study focused on the “emerald-triangle” in northern California's Humboldt, Mendocino, and Trinity counties, which many believe is the top cannabis-producing region in the United States.

The UC Berkeley-based Butsic and his co-author Jacob Brenner used Google Earth imagery to locate and map grow sites (both greenhouses and outdoor plots) in 60 watersheds. Most cannabis grow sites are very small, and have gone undetected when researchers used automated remote sensing techniques, which are commonly used to detect larger changes such as deforestation.

“We chose to use fine-grained imagery available in Google Earth and to systematically digitize grows by hand, identifying individual plants. Most plants stand out as neat, clear, little circles,” said Brenner, who is on the faculty of the Department of  Environmental Studies and Science at Ithaca College. “The method was laborious — it took over 700 hours — but it proved to be highly accurate.”

Butsic and Brenner paired their image analysis with data on the spatial characteristics of the sites (slope, distance to rivers, distance to roads) and information on steelhead trout and Chinook salmon, both of which are listed as threatened species under the federal Endangered Species Act. These and other species are vulnerable to the low water flows, soil erosion, and chemical contamination that can result from nearby agriculture.

Results of the study show 4,428 grow sites, most of which were located on steep slopes far from developed roads. Because these sites will potentially use significant amounts of water and are near the habitat for threatened species, Butsic and Brenner conclude that there is a high risk of negative ecological consequences.

“The overall footprint of the grows is actually quite small [~2 square kiliometers], and the water use is only equivalent to about 100 acres of almonds,” says Butsic, who is in the Department of Environmental Science, Policy, and Management at Berkeley. According to Butsic, California currently has more than one million irrigated acres of almonds.

He stresses that the issue lies in the placement of the sites: “Close to streams, far from roads, and on steep slopes — cannabis may be a case of the right plant being in the wrong place.”

Last year, California legislature passed laws designed to regulate medical marijuana production, and state voters will weigh in on whether to legalize recreational marijuana this coming fall. Given these changes as well as the profitability of cannabis production, Butsic expects that marijuana cultivation will expand into other sites with suitable growing conditions throughout the region. He and Brenner assert that ecological monitoring of these hotspots should be a top priority.

Bills recently signed into law by Governor Jerry Brown have made some advances in this direction — requiring municipalities to develop land use ordinances for cannabis production, forcing growers to obtain permits for water diversions, and requiring a system to track cannabis from when it is first planted until it reaches consumers.

But the researchers say that regulation will likely be a constant challenge because it will rely on monitoring procedures that are just now emerging, as well as voluntary registration from producers and budget allocation from the state for oversight and enforcement.

“Some of the same fundamental challenges that face researchers face regulators as well, primarily that cannabis agriculture remains a semi-clandestine activity,” says Brenner. “It has a legacy of lurking in the shadows. We just don't know — and can't know — where every grow exists or whether every grower is complying with new regulations.”

Perils of illegal marijuana crops

Rodenticides used on illegal marijuana farms have already been shown to pose serious harm to the fisher—a cat-sized carnivore found in forests across Canada and four regions in the U.S. (Previous news article.)

Mourad Gabriel, a doctoral candidate with the Veterinary Genetics Laboratory at UC Davis School of Veterinary Medicine, provides a more comprehensive look at the situation in the recent issue of The Wildlife Professional, put out by The Wildlife Society. (Article here.)

New information looks at risks to other species and to the ecologists and biologists conducting wildlife research on community and public lands where more of these crops are being cultivated.

Highlights include: 

• Newly documented fisher mortalities (necropsies done at UC Davis’ California Animal Health and Food Safety Laboratory System)
  
  
• New data documenting just a glimpse of potential environmental degradation possibly occurring on our public lands
  
  
• First mention of toxicants like carbamates and organochlorides (DDT etc...) that are being found in California grow sites
  
  
• Provides readers with information on how some of these toxicants are placed at grow sites to maliciously poison wildlife
  
  
• New info and discussion points of "what are" the potential effects of ...such as damming water courses, putting toxic slurry of chemicals in dammed creeks, cutting riparian zones, human feces (affects salmon and many other species)
  
  
• First-hand accounts of ecologists and biologists conducting wildlife research being shot at, chased and threatened
  
  
• Quantifies the loss of project area access, and data from fisher projects in California public lands

There is also a link to a video that offers a first account visual representation of what a fisher looks like, the unfortunate visual effects of toxicosis and the realistic outcome to wildlife from these illicit activities on tribal and public lands.

For more information, contact Mourad Gabriel, mwgabriel@ucdavis.edu or Trina Wood, tjwood@ucdavis.edu 

Evidence of rodenticide poisoning of wildlife found in the Sierra

There is a new predator in the forest these days. It has arisen quietly over the years. Any wildlife feeling hungry when they come upon it in the Sierra is vulnerable. This predator is amazingly small for the scope of its damage; it can’t run fast or climb high.

This new predator is rodenticide in pellet form, used in violation of all safe-use regulations in our national forests by large-scale marijuana growers. Rodenticides are being used to protect young and tasty marijuana seedlings from wildlife roaming through the forest looking for a meal. Chemicals never meant to be used more than 50 feet from homes are now scattered across forest hillsides. Piles of poisons are left around hundreds of plants even though only a few pellets can be lethal. Miles of water pipe are lined with these pellets to protect the stolen water source. Camps are circled with pellets to protect human food sources and sleeping areas.

University of California scientists originally became aware of this problem when Rick Sweitzer, associate professor in the Department of Environmental Science, Policy and Management at UC Berkeley, and his wildlife research team retrieved a radio-collared fisher whose cause of death was unclear. Sweitzer and his team are researching are studying the fate Pacific fishers as part of the Sierra Nevada Adaptive Management Project (SNAMP).

Necropsy (an autopsy for animals) of the fisher carcass by Mourad Gabriel of UC Davis and the Integral Ecology Research Center found rodenticide poisoning to be the cause. With these new findings, the livers from previous fisher mortalities in the SNAMP study were reexamined for evidence of rodenticide exposure. They discovered that more than 80 percent of dead fishers examined had been exposed to rodenticide. These toxicants can persist in animal tissues or the environment for potentially hundreds of days. At least five dead fishers found by researchers in SNAMP and a second fisher study in northern California have been confirmed to have died of rodenticide poisoning, the scientists reported in the science journal PlusOne.

Considering the hundreds of marijuana grow sites found every year on public lands, the scale of the damage to California’s natural resources may be unprecedented. Grow sites are also found containing massive amounts of fertilizers, herbicides and pesticides, all of which are being used without concern for run off or aquatic species nearby. Marijuana plants are removed from these plots when found, but these chemicals are often left behind.

Although this problem might seem overwhelming, there are efforts to address it. The non-profit Environmental Reclamation Team has cleaned up hundreds of grow sites since 2005. They remove and document all of the poisons found along with the miles of plastic irrigation line and piles of trash. More efforts like this are needed if we are to maintain rare animals like the Pacific fisher as well as all the other species who have the potential of coming in contact with these poisons.

Poisons on public lands put wildlife at risk

Rat poison used on illegal marijuana farms may be sickening and killing the fisher, a rare forest carnivore that makes its home in some of the most remote areas of California, according to a team of researchers led by University of California, Davis, veterinary scientists.

Researchers discovered commercial rodenticide in dead fishers in Humboldt County near Redwood National Park and in the southern Sierra Nevada in and around Yosemite National Park. The study, published July 13 in the journal PLoS ONE, says illegal marijuana farms are a likely source. Some marijuana growers apply the poisons to deter a wide range of animals from encroaching on their crops.

Fishers in California, Oregon and Washington have been declared a candidate species for listing under the federal Endangered Species Act. Fishers, a member of the weasel family, likely become exposed to the rat poison when eating animals that have ingested it. The fishers also may consume rodenticides directly, drawn by the bacon, cheese and peanut butter “flavorizers” that manufacturers add to the poisons.

Other species, including martens, spotted owls, and Sierra Nevada red foxes, may be at risk from the poison, as well.

“Our findings were very surprising since non-target poisoning from these chemicals is typically seen in wildlife in urban or agricultural settings,” said lead author Mourad Gabriel, a UC Davis Veterinary Genetics Laboratory researcher and presid

ent of the Integral Ecology Research Center. “In California, fishers inhabit mature forests within the national forest, national parks, private industrial and tribal community lands – nowhere near urban or agricultural areas.”

“I am really shocked by the number of fishers that have been exposed to significant levels of . . . anticoagulant rodenticides,” said pathologist Leslie Woods of the UC Davis California Animal Health and Food Safety Laboratory System.

Exposure to the poison was high throughout the fisher populations studied, complicating efforts to pinpoint direct sources. The fishers, many of which had been radio-tracked throughout their lives, did not wander into urban or agricultural environments. However, their habitat did overlap with illegal marijuana farms.

Gabriel said fishers may be an “umbrella” species for other forest carnivores. In ecology, an umbrella species is one that, if protected, results in protection of ot

her species, as well.

“If fishers are at risk, these other species are most likely at risk because they share the same prey and the same habitat,” said Gabriel. “Our next steps are to examine whether toxicants used at illegal marijuana grow sites on public lands are also indirectly impacting fisher populations and other forest carnivores through prey depletion.”

In addition to UC Davis, the study involved researchers from the nonprofit Integral Ecology Research Center, UC Berkeley, United States Forest Service, Wildlife Conservation Society, Hoopa Tribal Forestry, and California Department of Fish and Game.

(This article was condensed from a UC Davis news release. Read the full press release and watch a flash video of fishers in the wild.)

Urban chickens are fun and a current fad

Cities throughout the United States and Canada are reforming land-use and health policies to allow and encourage urban agriculture - including raising chickens, wrote Josie Garthwaite in the New York Times.

Among her sources for the story was the director of UC Cooperative Extension's Statewide Master Gardener Program Pamela Geisel, who keeps 10 hens at her own rural home west of Chico.

She said enthusiasm for homegrown hens in urban areas may be close to peaking.

“It’s sort of a fad,” she said. Still, “it’s easy to buy chicks, and they’re cheap."

Most of the potential problems tend to arise from having too many chickens in too little space, she said, so regulations for the size and housing of backyard flocks can “help chicken keepers be better chicken keepers.”

She cautioned that keeping chickens involves a significant effort.

“The poop just doesn’t go away — it’s a constant daily cleanup,” she said. “They get sick, they get parasites. For many people it’s just not worth the effort.”

California's growing marijuana business impacting agriculture
Harry Cline, Western Farm Press

California has the dubious distinction of being America’s biggest marijuana supplier. Approximately 75 percent of the marijuana sold in the U.S. is grown in California — not Mexico.

Michelle Le Strange, UCCE farm advisor in Tulare County, said she has been warned by county officials and law enforcement officers that she should be alert in driving a county vehicle in rural areas because marijuana plantation tenders might think she is a law enforcement officer, and she could be in danger.

Any government officials driving vehicles with government plates should be concerned because these marijuana plantations are operated by Mexican drug cartels, the same lawless gangs who are responsible for thousands of murders each year in Mexico. These cartels actually scour the U.S. Forest Service lands in search of ideal growing sites, often adjacent to running streams. The cartels stock these plantations with people, drip irrigation tubing and chemicals to farm the illegal weed.

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