Water use and other actions by the marijuana industry in the Emerald Triangle of Northern California and Southern Oregon are threatening salmon already in danger of extinction, US biologists have said.

Concerns about the impact of pot farming were raised by the NOAA Fisheries Service in its final recovery plan for coho salmon in the region. The full plan was to be posted on the agency's website.A copy obtained in advance calls for determining then decreasing the amount of water that pot growers illegally withdraw from creeks where young fish struggle to survive.

Pot is legally grown in the region for medical purposes and illegally for the black market.

Other threats from the unregulated industry include clear-cutting forests to create pot plantations, building roads that send sediment into salmon streams, and spreading fertilizer and pesticides that poison the water.

Coho salmon have been listed as a threatened species since 1997 in the region. Like salmon throughout the West, they have suffered from loss of habitat from logging, agriculture, urban development, overfishing and dams.

The recovery plan also calls for steps to address many of those issues.

The spotlight on marijuana stemmed from a California Department of Fish and Wildlife study that estimated pot growers suck millions of gallons of water from salmon streams.

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

Armed with new authority from the Legislature, the department is imposing fines for illegal water withdrawals for use on pot plantations, Bauer said.

The recovery plan points specifically to marijuana as a threat in river basins of Northern California, but the same issues exist in southwestern Oregon rivers, said Clarence Hostler, south coast branch chief for NOAA Fisheries in Arcata, California.

The plan marks the second time that Endangered Species Act actions have pointed to marijuana as a threat. The U.S. Fish and Wildlife Service has been looking at rat poison left around illegal pot plantations in California as a factor in whether to list the Pacific fisher as a threatened species.

The Emerald Growers Association represents a few hundred marijuana farmers in the region known as the Emerald Triangle due to the prevalence of pot plantations. Executive director Hezekiah Allen said bringing the industry under regulation would allow legitimate growers to compete more evenly with illegal growers, who have a financial incentive to cut corners.

"We need regulation that's going to make sense to the farmers on the ground," he said. "That is also going to achieve the public safety and environmental goals that we all share."

The recovery plan covers 40 genetically related populations of coho salmon and includes the Eel, Klamath, Smith, Chetco and Rogue river basins.

The area covered by the plan stretches from the Mattole River near Petrolia, California, north to the Elk River near Port Orford, Oregon.