Environmental groups have developed a sprawling new surveillance system to help track illegal fishing across the globe. A prototype of the Global Fishing Watch system was announced today at the IUCN World Parks Congress in Sydney, and was spearheaded by Oceana, a conservationist group, with financial and engineering support from Google.

Using satellite data from SpaceQuest and software developed by SkyTruth, the system maps and displays the activity of more than 25,000 fishing ships from 2012 to 2013. Some ships were registered as commercial fishing boats, others behaved in ways that suggested fishing activity. This activity is highlighted on the map by orange and yellow dots.

"this could be a tool for positive reinforcement."

The idea is to use advanced technology to monitor fishing activity at a time when global stocks are under increased pressure, posing serious environmental and economic threats. A 2013 report from Oceana estimated that illegal fishing costs between $10 billion and $23 billion in global losses every year. For now, Global Fishing Watch only displays ship activity from the previous two years, but Oceana aims to eventually incorporate more recent data that will allow authorities to act quickly.

"[T]he plan is that we will build out a public release version that will have near-real-time data,” Jackie Savitz, Oceana’s VP for US oceans, tells Wired. “Then you’ll actually be able to see someone out there fishing within hours to days."

Oceana has already used the system to monitor boats that have already been tagged for illegal fishing, though it still doesn't pick up boats that haven't registered with the automatic identification system (AIS), as well as vessels that go dark before reaching restricted waters. But the hope is that over time, Global Fishing Watch will serve as an important check to encourage fishers to stay within the law.

"We think this could be a tool for positive reinforcement to reward good fishing behavior," Brian Sullivan, of Google’s Ocean and Earth Outreach program, tells Wired. “If people can pay a premium for responsibly harvested fish with confidence in the supply chain, that aligns the economic incentives in a powerful way."