Capgrossos de Mataro team members fall during the 25th Castells' contest at the Tarraco Arena in Tarragona, Catalonia, northeastern Spain, 02 October 2016. The “Castells” is a popular event in which people create human towers up to a height of between six and ten levels. (Photo by Jaume Sellart/EPA)

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)

A woman holds a champagne bottle during New Year's celebrations in Bucharest, Romania, Wednesday, January 1, 2014. Tens of thousands of Romanians took to the streets of the Romanian capital to join parties and watch fireworks. (Photo by Vadim Ghirda/AP Photo)

This picture taken on March 21, 2015 shows a couple kissing in front of blooming cherry blossoms in Wuhan in central China's Hubei province. The cherry blossoms, now in full bloom, attracted tens of thousands of visitors, local media reported. (Photo by AFP Photo/Stringer)

A novice monk holds a book during an inauguration ceremony at Jogye temple in Seoul, May 11, 2015. Ten children on Monday were given the opportunity to experience life as Buddhist monks by staying at the temple until Buddha's birthday in two weeks. The writing on the book reads, “Novice Monk Prayer”. (Photo by Thomas Peter/Reuters)

A ten days old South American sea lion pup sits next to its mother Lunita at the “Tiergarten Schoenbrunn” Zoo in Vienna, Austria, July 28, 2015. The pup was born in the zoo and weighs about 14 kilograms (30 pounds). (Photo by Leonhard Foeger/Reuters)

A young child reaches out to a Gentoo penguin as it swims in its enclosure at Pairi Daiza Park in Cambron-Casteau, Belgium, Monday, July 5, 2021. Pairi Daiza, one of the biggest zoos in Europe, has recently added ten Gentoo penguins to their animal population. (Photo by Virginia Mayo/AP Photo)