The photo project was done for the organization Fishlove and included some other U.K.-based celebrities posing in the buff with critters ranging from bass fish to sharks. Its goal is to raise awareness of how overfishing is destroying the oceans. The release of Gillian's nearly nude pic, which was snapped by French portrait photographer Denis Rouvre, is timed with a European Parliament vote on banning destructive forms of deep-sea fishing in the Northeast Atlantic. The Fishlove organization is trying to rally voters to sign a petition ending deep-sea trawling – which, according to scientists, is negatively impacting the fish population and their habits – and Gillian solicited signatures in a Twitter post. Photo: “Fish Love” Project by Photographer Denis Rouvre. Gillian Anderson. (Photo by Denis Rouvre)

Lindsay Heimbach goes airborne while sledding down a hill on Mt. Lemmon December 27, 2008. (Photo by James Gregg/Arizona Daily Star)

Young women prepare for Notting Hill Carnival on August 27, 2017 in London, England. The Notting Hill Carnival began with a special ceremony of remembrance following the Grenfell fire tragedy. (Photo by Leon Neal/Getty Images)

Visitors to Kensington Gardens are reflected in Anish Kapoor's sculpture “C-Curve 2007” on September 27, 2010 in London, England. (Photo by Peter Macdiarmid/Getty Images)

A model poses with a motorcycle and a car on a racing track at the Essen Motor Show in Essen, Germany, November 27, 2015. (Photo by Ina Fassbender/Reuters)

Lara Stone at Mark's Club on October 27, 2016 in London, England. (Photo by Mark Milan/GC Images)

A reveller participates in a flour fight during the “O Entroido” festival in Laza village, Spain February 27, 2017. (Photo by Miguel Vidal/Reuters)

Singer Rita Ora enters her hotel on April 27, 2017 in New York City. (Photo by MEGA)