World’s coastal areas “face a grim future”

In the first comprehensive analysis of the world’s coastal ecosystems, researchers warn that if the planet’s coastal zone continues to be extensively modified or destroyed, its capacity to provide fish, protect homes and businesses, reduce pollution and erosion, and sustain biological diversity will be gravely endangered.

The analysis, Pilot Analysis of Global Ecosystems (PAGE): Coastal Ecosystems, released on 17 April by the research-based international NGO, the World Resources Institute (WRI), warns that “unless things change very quickly, the world’s coastal areas face a grim future” with many the rapid disappearance of lagoons, wetlands, mangroves, and coral reefs.

Nearly 30% of the land area in the world’s coastal ecosystems has already been extensively altered or destroyed by growing demands for housing, industry and recreation, the report says, with an estimated four out of every ten people living within 100 kilometres (62.5 miles) of a coast. This proportion is continually increasing placing further pressures on coastal ecosystems.

Nearly two-thirds of all the fish harvested in the world depend on coastal wetlands, mangroves, seagrass beds, and coral reefs, with about 95% of the world’s marine fish harvest coming from coastal waters. More low-value fish are being caught today as stocks of valuable fish like cod, hake, and tuna are declining, with an overall 75% of fish stocks depleted or being fished at their biological limit, the report says.

Beach erosion is also a growing problem and affects tourism revenue, especially in island nations, such as in the Caribbean, where as much as 70% of beaches studied over a ten-year period were eroded. Here more than almost anywhere else, the long-term success of tourism in the region, the principal money-earner, is dependent on the presence of abundant, beautiful beaches and a pristine marine environment. In addition, studies by the world’s climate scientists indicate that an increase in ocean temperatures could result in rising sea levels by as much as 95 centimetres at the end of this century intensifying erosion, habitat loss, increased salinity of freshwater aquifers, and extreme coastal flooding.

The protection of shorelines, especially in small countries and countries with limited fertile land, has become particularly important. In Japan, the government estimates that 46% of its shorelines need protection and has spent more than $40 billion on this effort.

The report also warns that the outright destruction of coral reefs by destructive fishing practices and mining is a serious problem. Coral bleaching, resulting from rising ocean temperatures caused by climate change, is also increasing and further threatens the resource. In addition, scientists at a recent international symposium on coral reefs warned that the Pacific Ocean faces losing the majority of its coral reefs by the end of the century and that the economies of its islands would be crippled (see related story).

Among the most worrying findings contained in the report are:

  • in the last 50 years, as much as 85% of mangroves have been lost in Thailand, the Philippines, Pakistan, Panama and Mexico, while globally, about 50% of mangrove forests have been lost;
  • in recent decades, the increase in pollution from inland sources and the loss of coastal habitats that filter pollution have led to the expansion of dead or hypoxic zones, such as those in the Gulf of Mexico (see related story);
  • the incidence of harmful algal blooms along the United States coastlines increased from 200 in the 1970s to 700 in the 1990s, which since 1991, have caused nearly $300 million in terms of fish kills, public health problems, and lost revenue from tourism;
  • more invasive or alien species are being found in coastal areas, often disrupting the food chain and eliminating native species. Scientists estimate that on any given day, as many as 3,000 different species are carried in the ballasts of the world’s ocean fleet (see related story). Scientists have identified 480 invasive species in the Mediterranean, 89 in the Baltic Sea, and 124 in Australian waters.

“These indicators show that the world’s coastal ecosystems are going down the drain fast,” commented Jonathan Lash, WRI president. “The challenge before us is to find ways to meet the needs of human development while protecting the ecosystems that are the foundation of all life.”

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