(Photo: Wikimedia Commons)

More than a fifth of humanity lives close to a tropical coastline, and those stretches of the world are rapidly unraveling and already descending into environmental calamity. Fisheries are crashing, ocean acidity levels are rising, development is proceeding seemingly unchecked, and pollution from the land is washing into the seas, killing coral reefs and fueling algae outbreaks.

In a paper published today in Marine Pollution Bulletin, two dozen researchers, including social scientists, fisheries authorities, and marine law experts, argue that current approaches to managing these coastal areas are broken. "Current management of coastal marine environments suffers from a piecemeal approach, failure to recognize connectivity among local habitat units including critical links with inland systems, weak governance, corruption, and persistence of deeply embedded belief systems that view the ocean as unlimited and open to all," they write.

The 1.95 billion people living within 100 kilometers of a tropical coastline, up from 1.36 billion today, will be hungry, impoverished, and dangerously frustrated.

They suggest a new, alternative approach. Instead of creating ad-hoc marine protected areas, fisheries restrictions, and restoration projects, the experts urge the widespread adoption of "marine spatial planning." That means planning that's based on the type of land-use planning already common around the world. That means zoning some areas for fishing, some areas for marine protections, and some areas for aquaculture.

"We looked at current trends in climate and human population, both of which indicate that the stress on coastal water is only going to increase—it's not going to decrease," says marine ecologist Peter Sale, a professor at the United Nations University in Ontario and the lead author of the new paper. "Current management approaches are simply not working."

The group combined the results of climate modeling, population forecasting, and data on the loss of coral reefs to paint a worrying picture of a swollen coastal populace in 2050. The 1.95 billion people living within 100 kilometers of a tropical coastline, up from 1.36 billion today, will be hungry, impoverished, and dangerously frustrated—unless approaches to managing tropical oceans are overhauled. Without such reforms, the researchers say they are "confident" of forecasting the following for 2050:

(1) Most coastal fisheries will be chronically overfished or collapsed. (2) Loss of reef habitat will further reduce fisheries production and strain food security. (3) Land-based pollution will increase to the extent that hypoxia and harmful algal blooms are routinely present. (4) Pressures of coastal development will combine with sea level rise and more intense storms to further intrude on and erode natural coastlines, severely reducing mangrove, salt marsh and sea grass habitats. (5) The cost of dealing with these impacts will further strain coastal economies, and the future for people on tropical coasts in 2050 will be substantially more bleak than at present.

The really "irritating" thing about it all, according to Sale, is that we have the technology to fix the problems. But it's useless so long as non-governmental organizations and other funders support projects that run for only several years and national governments shy away from radical actions. "This is possible to tackle," he says.