Google says it is joining the effort to stop illegal fishing that is threatening fish populations around the globe.

The Internet giant says it is partnering with two environmental groups, SkyTruth and Oceana, in a project dubbed Global Fishing Watch to combat illegal "overfishing" wherever it occurs in the world's oceans.

Google announced that for its part in the partnership it would be providing mapping software and servers, engineering services and financial support.

The effort comes as the Food and Agricultural Organization of the U.N. warns that a third of the world's fisheries have been overharvested, and around three-quarters of the remaining stocks are being pushed to sustainable limits, with catches going unreported or unregulated.

Global Fishing Watch has used Google's mapping technology to display the tracks of some 25,000 ships either registered as large commercial fishers or seen moving in a manner that suggested they were engaged in fishing activity.

While that data is from 2012-2013, the plan is to create a publicly available service to track large fishing vessels in near real-time to give authorities the ability to quickly identify illegal fishing activities, conservationists say.

"Then you'll actually be able to see someone out there fishing within hours to days," said Oceana vice president for U.S. oceans Jackie Savitz.

That would be quick enough for authorities to act on the information if the fishing is happening illegally, such as in a marine protected area, she said.

With large fishing fleets turning to technology like sonar and GPS mapping and navigation to trawl the worlds oceans, identifying illegal fishing is also going to have to go high-tech, conservation groups say.

"So much of what happens out on the high seas is invisible, and that has been a huge barrier to understanding and showing the world what's at stake for the ocean," SkyTruth President John said in a statement. "But now, satellite data is allowing us to make human interaction with the ocean more transparent than ever before."

An Oceana report has estimated illegal fishing results in $10 billion to $23 billion in global losses annually.

While the Global Fishing Watch system can't pinpoint boats that aren't registered with the global automatic identification system (AIS) or those that choose to "go dark" before entering restricted waters, the hope is the watch system can be an important tool to encourage fishing fleets to operate within international law, Google said.

"We think this could be a tool for positive reinforcement to reward good fishing behavior," says Brian Sullivan of Google's Ocean and Earth Outreach program.