After a year working as a marine observer on fishing vessels, monitoring cetacean by-catch levels, and conducting seabird and cetacean surveys, she started working as a marine surveyor for JNCC.
She carried out marine surveys around Ireland for 2 years before writing a report on the distribution of seabirds and cetaceans in the waters around Ireland in 1997.
In 1998, she became Atlantic Frontier team leader, coordinating marine surveys north and west of Scotland for the AFEN project. She also participated in surveys of breeding seabirds on remote Scottish islands, and was joint team leader on an expedition to census breeding seabirds on St. Kilda in 1999, as part of Seabird 2000.
After nearly two years travelling overseas Claire returned to Ireland in 2001 and with Colin Barton, set up Cork Ecology, an independent environmental consultancy based in Cork.