The technology, known as Global Fishing Watch, was officially released to the public during the Our Oceans Conference hosted by US Secretary of State John Kerry in Washington today and tomorrow.

"Today, this unprecedented technology is available to everyone in the world. I encourage everyone to go check it out," DiCaprio told the conference.

"This platform will empower citizens across the globe to become powerful advocates for our oceans." Available at GlobaFishingWatch.org, the technology aims to offer a crowd sourced solution to the problem of illegal fishing, which accounts for up to 35 per cent of the global wild marine catch and causes yearly losses of USD 23.5 billion, according to the UN Food and Agriculture Organization.

Overfishing is also a growing problem worldwide, with about two thirds of fish stocks in the high seas either over exploited or depleted, said the FAO.

Some of the planet's largest fish, including tuna and swordfish, are below 10 percent of their historical level.

Using satellite technology combined with radar aboard boats, the platform allows people to zero in on areas of interest around the world and trace the paths of 35,000 commercial fishing vessels.

"It gives the public an opportunity to see what is happening, even out in the middle of the ocean," said John Amos, president and founder of SkyTruth, one of three partners in the project along with Google and Oceana.

"We need the public to be engaged to convince governments and convince the seafood industry that they need to solve the problems of overfishing," Amos told AFP.

"If you can't see it and can't measure it, you are not going to care about it and it is not going to get solved." The project has cost USD 10.3 million over the past three years to build, with USD 6 million of those funds contributed by the Leonardo DiCaprio Foundation in January.

In order the make the data available for free, Oceana and its partners negotiated a deal with the satellite company Orbcomm to use its three-day old data, which is described as "near real-time," along with historical records.

Although the delay means that any criminals won't be nabbed instantaneously, advocates say the technology will open the world's waters to public watchdogs in a way that has never been done before.