Human footprints in the ocean

The ocean covers about 70 percent of the earth. So one would think that maybe, just maybe, there was a part of it that we hadn’t gotten our grubby hands on, yet. Nope.

There’s no part of the ocean that isn’t feeling the effects of fishing, pollution or “human caused” global warming, according to a new study and map by UC Santa Barbara researchers and published in the journal Science.

The researchers looked at 17 human impacts and assigned scores for them for every region of the ocean. The result is a color-coded ocean map showing the areas where there was “very low impact” to those with “very high impact” and those in between.

The study showed that more than 40 percent of the world’s marine ecosystems are heavily affected. Of all human impacts, global warming and certain fishing practices were the most damaging. Global warming is heating up the ocean and making it more acidic, while trawl-fishing is especially harmful because it destroys sea floor habitat in its search for groundfish and shrimp.

The least affected areas were Antarctica and the Arctic, but, the study notes, global warming is affecting those places and will continue to worsen.

The most affected areas were continental shelves, the northeastern United States, the North Sea and Chinese coasts.

As the ocean knows no political boundaries, some scientists hope the map will be a call for international cooperation to protect these ecosystems.

See the map at http://news.nationalgeographic.com/news/bigphotos/76077234.html