Earth & Sky

First-ever map of human impacts on oceans

Humans have left no spot on Earth’s oceans untouched, according to research biologist Ben Halpern of U.C. Santa Barbara.

In early 2008, he and his colleagues released the first-ever global map of the total human impact on the seas.

Ben Halpern: It’s probably worse than people realize. There’s no space left on the planet that’s untouched by human activities. And there’s large areas, over 40 percent that are being heavily impacted. Scientists mapped seventeen different human activities in categories like fishing, pollution, and climate change.

Halpern said his research confirmed that, for example, the world’s coral reefs and mangroves aren’t doing so well.

Ben Halpern: There are other ecosystems that are actually in worse condition. And these are ones that people probably don’t pay much attention to, like rocky reefs, which are shallow, rocky areas that have huge diversity in them, and the continental shelves, which are where you get a lot of productivity of fish.

But Halpern said there’s hope. His research also found large, pristine waters near Earth’s poles, guarded today by nearly inaccessible ice.

Ben Halpern: We really need to be doing something now about this. Because of there being places left in the ocean that are untouched, and because we now have a better sense of where and how we’re affecting the oceans, we’re armed with the information we need in order to start moving forward to implement better ocean management.

Halpern said that, on land, humans degrade ocean ecosystems through fertilizer run-off, pollution, and damage to habitat. On the sea, Halpern cited extraction of resources such as fish, invasions non-native species from ship ballasts, and pollution.

Our thanks today to NOAA, the National Oceanic and Atmospheric Administration.