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Marijuana farms in California are killing this adorable weasel

Illegal marijuana farms are putting this little guy at risk.
Illegal marijuana farms are putting this little guy at risk.
Bethany Weeks

Over the past couple weeks, federal agencies have mobilized to address a big, new threat to wildlife in northern California and Oregon — marijuana farms.

Heavy water use and chemical spraying at outdoor pot farms have put animals and ecosystems along the West Coast at risk for years, exposing fish, mammals, and birds to deadly chemicals, and draining streams and rivers necessary for their survival.

The problem is now so grave that federal agencies are moving in to help. On October 6, the US Fish and Wildlife Service released a proposal that would list Pacific fishers, a furry member of the weasel family, as threatened under the Endangered Species Act. On October 1, NOAA Fisheries released a recovery plan for the coho salmon in southern Oregon and northern California.

So what exactly makes marijuana farms so dangerous? Here's a primer on the issue.

How are marijuana farms bad for the environment?

Coho salmon

A young coho salmon smolt, ready to be released to the wild. (Earl Steele)

Marijuana farms can have a number of environmental impacts — though they're mostly related to how the drug is grown, rather than the plant itself or its needs for cultivation. These farms have had notably harmful effects on the Pacific fisher, coho salmon, southern torrent salamander, and other animals of all kinds, particularly in northern California and Oregon.

"It came as a shock that the growth of the marijuana industry in the wake of [California's medical marijuana ballot initiative] in 1996 had actually gotten to the point where it was clearly affecting our fish, salamanders, and, through the toxic substances some growers are using, even mammals and birds of prey," said Scott Greacen, executive director of Friends of the Eel River.

Perhaps the biggest problem, as the Associated Press reported, is the sheer amount of water used by these farms. One study from the California Department of Wildlife and Fish found outdoor farms and greenhouses are sucking millions of gallons from coho salmon streams each year, debilitating the species' natural habitat.

northern spotted owl

The extinction of the fisher could hurt other wildlife along the West Coast, including owls. (John and Karen Hollingsworth / USFWS)

Other problems include clear-cutting forests to create pot farms and petroleum products, sediment, and fertilizers that contaminate roads and rivers — a combination of practices that destroys and poisons the animals' homes.

For Pacific fishers, the biggest threat is prey contaminated with rat poisons and insecticides, including some chemicals banned in the US. In an in-depth analysis, researchers from the Sierra Nevada Adaptive Management Project, UC Davis, and UC Berkeley found 79 percent of 58 autopsied fisher carcasses were exposed to one or more rat poison. These chemicals build over time in a fisher's system, eventually causing it to bleed to death.

The harm done to these environments doesn't stop with fishers, salmon, or salamanders. When an important predator like the fisher dies out, the disruption trickles out through the entire ecosystem and can lead to fluctuations in wildlife populations, more ruined habitats, and, eventually, more deaths.

The fisher "plays a unique role" in keeping the bird and rodent populations under control in the region, said Erin Williams, field supervisor at the Yreka, California, Fish and Wildlife Office. "It's always problematic for an ecosystem when you see those numbers get out of balance."

What can be done about the pot farms?

Pacific fisher

Perhaps the cutest Pacific fisher in the land. (brunop)

Experts and advocates generally frame the solution as having two parts: one for illegal marijuana farms known as "trespass grows," and another for state-legal operations that cultivate pot for medical and recreational purposes.

Trespass grows are illegal operations in which some of the most harmful farming practices, such as the use of rat poison, take place. To deal with these, Greacen of Friends of the Eel River said, law enforcement and wildlife officials need to crack down on the farms and clean up the chemical messes they leave behind. "The horrible reality is we need to spend a lot more than we're spending now on enforcement," he said.

Many of these illegal grows could also be dealt with by legalizing marijuana, according to a report from Scientific American's EarthTalk. Drug policy experts and legalization advocates argue that a legal pot market would be able to offer lower prices, since it wouldn't have to deal with the massive costs of smuggling pot from Latin America to the US, and eventually drive the black market out of business. Over time, that would eliminate the illegal farms.

The legal farms bring their own issues as well, with a severe lack of regulations and oversight under the current legal structure in California and Oregon. Greacen and other advocates have called for regulations on the industry. Greacen listed a few possibilities: a ban on pesticides, requirements for water storage, regular inspections, and a limit on the scale of farms.

Pacific fisher

A Pacific fisher looks around. (US Department of Agriculture)

"Logging is regulated. Vineyards are regulated," Scott Bauer, an environmental scientist on the watershed enforcement team of the California Department of Fish and Wildlife, told the Associated Press. "It is time this industry was willing to be regulated."

Greacen acknowledged that establishing and enforcing regulations will require a very careful balancing act on the part of policymakers. On one hand, the regulations have to be stringent enough that they both protect the environment and appease federal law enforcement officials who regularly crack down on state-legal marijuana businesses that don't meet certain standards. On the other hand, regulations that are too strict would simply push marijuana growers back to the black or gray market and out of sight of regulators.

Greacen noted particular problems with attempts to severely limit how many farms are allowed in California, similar to what Washington did with its caps on shops and farms. "If you do that, you would have done nothing to displace the black market industry and the incentives that create the harms we're dealing with," he said.

Part of the issue is also education. As Greacen described in a 2012 TEDx Talk, some of the water problems could be fixed by simply letting growers know that they can cut how much water they take from streams by installing more storage tanks that would capture some of California's typically abundant winter rainfalls. With that move alone, the threat to salamanders, salmons, and other water-based wildlife in the region could be greatly reduced.

In the coming months, federal agencies will be working with the resources they already have to address the issues facing the fisher and coho salmon in particular. Some of that will involve a lot of data collection to gauge the depth of the problem. But wildlife agencies also hope to raise public awareness and see what can be done right now.

"This presents a great opportunity for us to begin that conversation about what we can do as a society to fix this issue," said Williams of the Yreka, California, Fish and Wildlife Office. "That's certainly something we're interested in, and I'm sure law enforcement and others will be interested as well."

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