American media personality Paris Hilton (L) and American rapper Megan Thee Stallion are seen onstage during NYLON Nights: NYFW x Paris Hilton Infinite Icon Album Release Party presented by Hey Dude at Hall Des Lumieres on September 05, 2024 in New York City. (Photo by Roy Rochlin/Getty Images for NYLON)

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)

A s*x worker (C) stages a performance to denounce what they say is abuse and social stigma against them in Madrid, Spain, October 14, 2015. Placard reads "Prostitutes are the ones that make the streets dirty". (Photo by Andrea Comas/Reuters)

Photographer Jamie McCarthy and Lori Levine attend Moto X presents Heidi Klum's 15th Annual Halloween Party sponsored by SVEDKA Vodka at TAO Downtown on October 31, 2014 in New York City. (Photo by Mike Coppola/Getty Images for Heidi Klum)

Sharni Edwards, 27, and Robyn Peoples, 26, a Belfast couple who are the first known same-s*x couple to get married in Northern Ireland, kiss after being married, in Carrickfergus, Northern Ireland on February 11, 2020. (Photo by Phil Noble/Reuters)

In this Wednesday, August 20, 2014 photo released by Red Bull, Maikel Melero of Spain warms up prior to the fifth stage of the Red Bull X-Fighters World Tour in the South African savanna of Pretoria, South Africa. (Photo by Joerg Mitter/AP Photo/Red Bull)