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)

Belarusian police officers detain an opposition supporter during a rally to protest against the disputed August 9 presidential elections results in Minsk on September 6, 2020. Tens of thousands of Belarusians staged a peaceful new march on September 6, keeping the pressure on strongman Alexander Lukashenko who has refused to quit after his disputed re-election and turned to Russia for help to stay in power. (Photo by TUT.BY/AFP Photo)

An Indian woman performs rituals near the body of her husband who died of COVID-19 in Gauhati, India, Monday, September 28, 2020. India’s confirmed coronavirus tally has reached 6 million cases, keeping the country second to the United States in number of reported cases since the pandemic began. (Photo by Anupam Nath/AP Photo)

A gallery worker poses in front of part of artist Sin Wai Kin's Turner Prize shortlisted artwork “It’s Always You” at the Tate Liverpool in Liverpool, Britain on October 18, 2022. (Photo by Phil Noble/Reuters)

Yuccas catch fire as the Powerhouse fire makes a fast run toward Lake Hughes, south of Lake Hughes, California, on June 1, 2013. The 19,500-acre wildfire destroyed numerous homes overnight. (Photo by David McNew/Getty Images)

The abandoned 77-metre (250-feet) cargo ship MV Alta is pictured stuck on rocks near the village of Ballycotton south-east of Cork in Southern Ireland on February 18, 2020. A “ghost ship” drifting without a crew for more than a year washed ashore on Ireland's south coast in high seas caused by Storm Dennis, the Republic's coast guard said. (Photo by Cathal Noonan/AFP Photo)

A bride gets tested for the coronavirus disease (COVID-19) at a nucleic acid testing site, following the coronavirus disease (COVID-19) outbreak in Shanghai, China on November 15, 2022. (Photo by Aly Song/Reuters)

Anti-frost candles burn in apricot plantations to protect flowering buds and blossoms from frost in the midst of the Swiss Alps, in Saxon, Canton of Valais, Switzerland, 05 April 2019. With an unusually low temperature forecast for the season, fruit growers try to protect their buds from frost damage with two different means, icy water or large candles. (Photo by Valentin Flauraud/EPA/EFE)