Sean joined Channel Islands National Marine Sanctuary in 1997 and serves as the site's resource protection coordinator. He is responsible for developing policies and programs to address industrial, military, commercial, and recreational uses and impacts in and around the sanctuary. He also handles emergency response, enforcement, permits, community relations and is a liaison to the media. In addition, Sean helped create the marine protected area network to restore local fish and invertebrate populations and habitats in the sanctuary and helped the state of California to do the same in state waters on the mainland.

Daily he strives to raise the sanctuary's profile locally, nationally, and internationally through astute communication, media, and negotiation skills.  He has forged trusted partnerships with academia, government agencies, non-government organizations, and sanctuary user groups. Sean has a Master of Marine Affairs degree from the School of Marine Affairs, University of Washington, and a Bachelor of Arts in environmental studies from the University of California at Santa Cruz. In 1998 he was nominated as a presidential management fellow. Sean is an avid outdoorsman who surfs, boats, paddles, scuba and free dives, fishes, hunts, skis, and snowboards throughout California's wildlands. With a multi-agency coalition and community support, he has helped move commercial shipping lanes to protect endangered whales.