The gift allows the "Entourage" star to search for "the loneliest whale," whose calls are too high to be heard. 
 
 Adrian Grenier, the first big-screen Aquaman (albeit on a small screen in HBO's Entourage), wants to locate a rare and elusive sea creature – and Leonardo DiCaprio is helping him do it. 
 
 Through his environmental non-profit Leonardo DiCaprio Foundation, the Titanic star has made a $50,000 donation to Grenier's Kickstarter project, 52: The Search for the Loneliest Whale. 
 
 The five-figure gift, made in the last 24 hours of the crowdfunding campaign, pushed total donations to a goal of $300,000, meaning Grenier and his team can now access all pledges made by over 3,300 backers. (With DiCaprio's gift, the total amount raised stands at $330,124.) 
 
 The documentary film, to be directed by Josh Zeman and executive produced by Grenier, will follow the pair's search for a storied whale of unidentified species, dubbed "52 Hertz" for the extremely rare 52-hertz frequency at which he or she emits calls. 
 
 The sound, slightly higher than the lowest note a tuba can play, is well out of hearing range for other whales, who typically emit calls in the frequency of 0 to 39 hertz. The result is that 52 Hertz travels alone — and has taken on the melancholic descriptor, "the loneliest whale in the world." 
 
 The whale was first discovered by sonar equipment in 1989, and in the years since has been detected in parts of the Pacific Ocean, as far north Kodiak Islands and as far south as the California coast. But 52 Hertz has only ever been heard, but never seen. Grenier is seeking to change that. 
 
 “Thank you to the 3,300 backers and the Leonardo DiCaprio Foundation for making this science based creative project come to life. These donations validate our ongoing efforts and to get their vote of confidence is a huge moral boost for myself and team Lonely Whale,” Grenier said in a statement. 
 
 All of the funds raised by Grenier's Kickstarter campaign will go towards paying for an expedition to locate 52 Hertz, "from our boat to the gas, the food, the permits, and our scientists," Zeman adds in a promotional video. 
 
 In recent years, DiCaprio has made multiple big-dollar donations to various environmental organizations. In 2012, he gave $1 million to the Elephant Crisis Fund, and in 2014, he pledged $2 million to Oceans 5, an oceanic conservancy aiming to quell overfishing. 
 
 Grenier has produced several documentary film projects since finding fame as Vinnie Chase, the laid-back movie star at the center of HBO's Hollywood send-up, which debuted in 2005 and aired for eight seasons. 
 
 He'll return to that world when Entourage – the motion picture – hits screens on June 5. ||||| Country music legend Neil Young debuted his high-fidelity music player, PonoMusic, at SXSW 2014, and the Kickstarter campaign raised over $2 million in less than 48 hours. It clearly helps if your crowd-funded project has a big celebrity behind it. But it's a little contradictory, no? Famous, wealthy stars asking for financial help from their fans? 
 
 Scroll down to see some successful — and not so successful — celeb attempts at raising dinero for their side projects.
– Another case of stars crowdfunding cash from other stars: Entourage star Adrian Grenier has launched a Kickstarter campaign to find a mysterious whale, and it just received $50,000 from Leonardo DiCaprio's environmental nonprofit. The campaign just ended today, and the Hollywood Reporter says the Leonardo DiCaprio Foundation's donation came in during the last 24 hours and was the one that pushed the campaign over its goal of $300,000. (It ended at $405,937.) With the money, Grenier will produce a documentary following his search, alongside director Josh Zeman, for "52 Hertz," a "storied" whale that emits calls at the rare, extraordinarily low 52-hertz frequency. It's not even clear what species the whale is. Since the whale's calls are too low to be heard by fellow whales, he or she travels alone and has thus been dubbed "the loneliest whale in the world." The whale has actually never been seen, but has been caught by sonar a number of times since 1989. (Read up on other celebs who have turned to Kickstarter.)