Scientists reveal first-ever global map of total human effects on oceans

A global map of the overall impact that 17 different human activities are having on marine ecosystems. Insets show three of the most heavily impacted areas in the world [left],... Click here for more information.

(Santa Barbara, CA) – More than 40% of the world’s oceans are heavily affected by human activities, and few if any areas remain untouched, according to the first global-scale study of human influence on marine ecosystems. By overlaying maps of 17 different activities such as fishing, climate change, and pollution, the researchers have produced a composite map of the toll that humans have exacted on the seas.

The work, published in the Feb. 15 issue of Science and presented at a press conference Thursday February 14 at 1 pm EST at the American Association for the Advancement of Science (AAAS) meeting in Boston, MA, was conducted at the National Center for Ecological Analysis and Synthesis (NCEAS) at UC Santa Barbara and involved 19 scientists from a broad range of universities, NGOs, and government agencies.

The study synthesized global data on human impacts to marine ecosystems such as coral reefs, seagrass beds, continental shelves, and the deep ocean. Past studies have focused largely on single activities or single ecosystems in isolation, and rarely at the global scale. In this study the scientists were able to look at the summed influence of human activities across the entire ocean.

“This project allows us to finally start to see the big picture of how humans are affecting the oceans.” said lead author Ben Halpern, Assistant Research Scientist at NCEAS. “Our results show that when these and other individual impacts are summed up, the big picture looks much worse than I imagine most people expected. It was certainly a surprise to me.”

"This research is a critically needed synthesis of the impact of human activity on ocean ecosystems," said David Garrison, biological oceanography program director at NSF. "The effort is likely to be a model for assessing these impacts at local and regional scales."

“Clearly we can no longer just focus on fishing or coastal wetland loss or pollution as if they are separate effects,” said Andrew Rosenberg, a Professor of Natural Resources at the University of New Hampshire who was not involved with the study. “These human impacts overlap in space and time, and in far too many cases the magnitude is frighteningly high. The message for policymakers seems clear to me: conservation action that cuts across the whole set of human impacts is needed now in many places around the globe.”