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)

This picture taken on January 1, 2014 shows giant panda “Li Li” sleeping on a tree in Hangzhou Wild Animal World in Hangzhou, east China's Zhejiang province. Giant pandas, notorious for their low s*x drive, are among the world's most endangered animals. Fewer than 1,600 pandas remain in the wild, mainly in China's Sichuan province, with a further 300 in captivity around the world. (Photo by AFP Photo)

This picture taken on January 12, 2014 shows pet dogs, a yellow duck and a chicken in a skiing resort for a skiing competition in Sanmenxia, north China's Henan province. A tortoise beat a rabbit in a skiing competition held for pets and their owners in northern China, a report said on January 14. Cats and dogs faced off against a menagerie including a rooster and a yellow duck in a race to the finish line on snowy slopes in China's Hebei province, the state-run China News Service said. (Photo by AFP Photo)

A protester throws a stone towards a burning police bus in front of him, during clashes with police, in central Kiev, Ukraine, Sunday, January 19, 2014. Hundreds of protesters on Sunday clashed with riot police in the center of the Ukrainian capital, after the passage of harsh anti-protest legislation last week seen as part of attempts to quash anti-government demonstrations. The violent scenes further escalated this ex-Soviet republic's political crisis and showed a rift among opposition leaders, one of whom fought bravely to stop the violence, while others condemned the events from afar. (Photo by Evgeny Feldman/AP Photo)

A man rides a horse through a bonfire as part of a ritual in honor of Saint Anthony, the patron saint of animals, in San Bartolome de Pinares, about 100 km west of Madrid, Spain on Thursday, January 16, 2014. On the eve of Saint Anthony's Day, hundreds ride their horses through the narrow cobblestone streets of the small village of San Bartolome during the “Luminarias”, a tradition that dates back 500 years and is meant to purify the animals with the smoke of the bonfires and protect them for the year to come. (Photo by Emilio Morenatti/AP Photo)

This is a bearded tit bird, diving for food. Photo by Edwin Kats.

BASE jumper Luke Denniss of Australia gestures as he dives in the air from the Kuala Lumpur Tower during the KL Tower International Jump in Kuala Lumpur, Malaysia, Saturday, September 27, 2014. BASE stands for the places such jumpers usually jump from: buildings, antennas, spans (bridges) and earth (cliffs). (Photo by Lai Seng Sin/AP Photo)

Dr. Marius Kruger (C) and memeber of the Kruger National Park keeps the head of a rhino up during a white rhino relocation capture on October 17, 2014. The Kruger National Park relocated four rhinoceros from a high risk poaching area to a safer area as part of ongoing strategic rhinoceros management plan. (Photo by Stefan Heunis/AFP Photo)