A statewide task force aimed at disrupting illegal marijuana grow operations discovered and eradicated fewer than half as many marijuana plants in 2018 than in 2017, state Attorney General Xavier Becerra said Thursday at a news conference in San Diego.

The most obvious difference? This is the first year cannabis has been legal in California.

During the 2018 Campaign Against Marijuana Planting program, law enforcement task forces eliminated 254 illegal grow operations and eradicated 614,267 marijuana plants, Becerra said. CAMP task force teams also made 52 arrests and seized 110 weapons statewide.

But the number of plants eradicated during the 12-week operation this year was less than half of the 1.26 million plants eradicated by CAMP in 2017 and the more than 1.5 million illegal marijuana plants eradicated by CAMP in 2016.

A spokeswoman for Becerra’s office said the year-to-year changes depend on several factors though, and it’s unclear after just one year if legalized cannabis caused the huge drop in the number of plants discovered by the CAMP task force.

What likely did play a role in the big drop were the state’s wildfires, Becerra spokeswoman Jennifer Molina said.

The Mendocino Complex and Carr fires, which started four days apart at the end of July, burned more than 688,000 acres combined in Northern California, where state authorities said illegal marijuana grows are more common.

And while the number of plants eradicated this year was down more than half from the two prior years, it was not far behind 2015, when CAMP task forces eradicated 832,085 plants, according to The Press Democrat in the Bay Area.

“The majority of these grow sites are in protected wilderness areas, like the Trinity Alps Wilderness area in Norther California, or the Palomar mountains not far from where we are today in San Diego,” Becerra said Thursday during the news conference at the local office of the California Department of Justice. “These areas have been preserved so that California families can enjoy them, not so that criminals can profit from illegal activity.”

This year, in Southern California — defined by CAMP as the 10 counties between the border and San Luis Obispo, Kern and San Bernardino to the north — the CAMP task force eliminated 47 illegal grows, eradicated about 127,000 plants, made 23 arrests and seized 13 weapons.

The Southern California task force discovered and eliminated 11 illegal grow sites in San Diego County, including nine on public lands and two on private property, Becerra said. Those 11 sites resulted in 17,745 eradicated cannabis plants.

Authorities believe most of the marijuana grown illegally in California is shipped out of the state. But the product that’s grown here and stays here undercuts legal dispensaries and licensed growers, who have strict rules and regulations they must follow, authorities said at Thursday’s news conference.

“The only reason marijuana is grown on public lands is for profit; it’s circumventing California state law,” said Karen Flowers, special agent in charge of the Drug Enforcement Agency’s San Diego Field Division. “The grower does not have to get a permit. They do not have to follow health inspections or meet any type of county code or state law. They operate with impunity. It’s low cost and it’s very high reward.”

Flowers said that by conservative estimates, the more than 614,000 marijuana plants eradicated resulted in “$2.4 billion of revenue denied to drug traffickers.”

“These aren’t, in general, California drug traffickers,” Flowers added. “These are Mexican national drug traffickers who are working on behalf of Mexican drug cartels.”

Becerra and Flowers also pointed to the effects that illegal grows have on public lands and stressed the need to continue battling those who grow the crop illegally.

“Illegal planting on public land hurts everyone,” Becerra said. “It hurts Californians who want to enjoy our state and national forests. It hurts farmers who depend on access to safe water and healthy soil.

“It hurts families, including drinking water that’s contaminated by illegal pesticides used on these sites, and it hurts every Californian that wants to play by the rules in our state when it comes to the use and grow of cannabis,” he said.

© 2018 The San Diego Union-Tribune. Visit The San Diego Union-Tribune at www.sandiegouniontribune.com. Distributed by Tribune Content Agency, LLC.