Back in 2005, when then-Prince Charles and Camilla touched down in West Marin, they toured what was widely considered the national epicenter of the organic food movement, an agrarian vanguard buoyed by the county’s own in-house organic certifier.

Two decades later, that certifier, Marin Organic Certified Agriculture, operated by the county’s department of Agriculture, Weights and Measures, has ceased to provide organic livestock certification services.

While MOCA will continue to certify organic crops, the shift…