A participant in costume poses for a photo during a Halloween event in Kawasaki, south of Tokyo, Japan on October 28, 2018. (Photo by Toru Hanai/Reuters)

Black-headed gulls sit on pickets at a riverside in Tokyo, Japan, December 27, 2015. (Photo by Toru Hanai/Reuters)

People are reflected in a shop window as they walk along a street in a shopping district in Tokyo, Japan June 25, 2015. (Photo by Thomas Peter/Reuters)

A white whale wears a wreath at the Hakkeijima Sea Paradise aquarium-amusement park complex in Yokohama, Japan, on October 3, 2012. (Photo by Associated Press)

A family of children share a bath in Japan, circa 1965. (Photo by Three Lions/Hulton Archive/Getty Images)

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)

Jun Sato (2nd L), founder of Japan's first parkour educational institute SENDAI X-TRAIN, demonstrates his parkour skill with other practitionners at a park in Tokyo, Japan November 2, 2016. (Photo by Kim Kyung-Hoon/Reuters)

Japan's electronics equipment maker MuRata Manufacturing Co., Ltd's showcased their bicycle-riding robot “MuRata Boy” during the CEATEC Japan 2006 exhibition on October 3, 2006 in Chiba, Japan. The “MuRata Boy” robot can ride up a 25-degree slope, stop without losing its balance and make an S-curve without falling. (Photo by Koichi Kamoshida/Getty Images)