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)

In collaboration with the Pennsylvania Department of Transportation, Allegheny College art students repurpose used street signs as art materials to create the PennDOT Road Sign Sculpture Garden in Meadville, Pennsylvania, USA on August 19, 2017. (Photo by Brian Cahn/ZUMA Wire/Rex Features/Shutterstock)

Jimmy Fallon and Madonna sign the Facebook wall before their livestream interview at the Facebook offices on March 24, 2012 in New York City. (Photo by Dimitrios Kambouris/Getty Images)

Hugo Gonzalez of Lake Worth works to put final strokes on his rendition of a Raksha demon. (Photo by Thomas Cordy/The Palm Beach Post)

Mr. Grindell Matthews with his latest invention, the new photographic gun which is the latest development in sky signs. 1933. It can throw a beam of light 15 miles into the sky. (Photo by Fox Photos)

Model Lily Donaldson flashes the peace sign as she leaves Victoria's Secret Fashion Show China casting in New York City on August 22, 2017. (Photo by Christopher Peterson/Splash News and Pictures)

With less than a week before Election Day, a Halloween skeleton holds a vote sign outside a home in Falls Church, Virginia, October 29, 2020. (Photo by Kevin Lamarque/Reuters)

The Villarrica volcano shows signs of activity, as seen from Pucon, some 800 kilometers south of Santiago, on November 21, 2022. Villarrica volcano is among the most active in South America. (Photo by Mario Quilodran/AFP Photo)