Commercial fishing covers more than 55 percent of the ocean's surface, a new study has revealed in a potentially worrying sign about the depletion of marine resources.
Fish from the wild do not currently contribute a significant portion of human caloric consumption, but "the footprint of industrial fishing in the ocean is over four times larger than the land area occupied by agriculture," researchers said in a paper published by the journal Science on Thursday.
Graphic courtesy SkyTruth.
And the bulk of activity is dominated by just five countries: China, Spain, Taiwan, Japan and South Korea.
Publishing a comprehensive map of global fisheries for the first time using satellite technology and big data, researchers discovered that fishing patterns were strongly influenced by cultural and political events rather than weather: "The Christmas holiday and fishing moratorium in China have a bigger effect on the global temporal footprint of fishing than any seasonal weather changes."
Every year, the world's second-largest economy imposes a nation-wide fishing ban that usually lasts for three months. Beijing will institute the rule in the Yellow River from April 1 to June 30 this year, Xinhua reported this week. Other water bodies, such as the Yangtze River and Pearl River, could also see annual bans.
Even amid massive consumption of marine resources, biodiversity isn't entirely at risk.
"Significant regions of the ocean are not heavily fished, and these areas may offer opportunities for low-cost marine conservation, creating 'buffer-zones' which conservationists say help marine species to regenerate," the study said.
Well-enforced policy can play a significant role in curbing over-exploitation, the authors found, adding that they hoped the study's high-resolution information on global fishing will pave the way for improved ocean management.