Surging populations threaten coastal ecosystems


    “We’ve pushed the seas perilously close — and in some cases — past their natural limits. Ingrained wasteful behavior must be overcome if the wealth of the seas is to serve our children.” — Troubled Waters — A Call to Action

    Too much population is putting a lot of stress on “the seam between land and water” — as what coastlines are described — that they have a hard time recovering from the onslaught.

    Some estimates suggest that over half of the planet’s population now lives and works within 200 kilometers of a coast; other calculate that over a third of the world’s people live within 100 kilometers of the sea.

    “While there may be debate over the exact figures, there is no disagreement that the coastal zone is consistently the most populous part of the world and that there is a continuing tendency for people to migrate to it from the interior of the continents,” wrote Dr. Edgardo D. Gomez in an article which appeared in Our Planet.

    “The tremendous flux of people is increasing the pressure on an already stressed area, and increasing contamination from sewage and industrial pollution, as well as agriculture,” said Dr. Gomez, who once served as director of the Marine Science Institute of the University of the Philippines (UP).

    According to the former UP professor, fisheries and other living resources of the sea are concentrated in the narrow coastal zone. Some 90% of the world’s fisheries production comes this zone, though it makes up only about 10% of the world’s oceans.

    “The productivity is generally explained by the shallowness of the sea allowing adequate light penetration to drive photosynthesis, the recycling of nutrients and the subsidies of nutrient or energy received from the land,” Dr. Gomez pointed out.

    “The proximity of large human populations to the most productive parts of the marine realm is, alas, no accident; a natural affinity brings them together,” he added. “But it causes critical problems.”

    Overfishing, for instance, is tied to population and poverty in many developing countries. “The growth of population in coastal areas is remarkable,” said Dr. Gomez. And these people are putting a lot of strain to the ecologically fragile coral reefs.

    “More and more people are depending on the same number of reefs — or even fewer as they become degraded,” Dr. Gomez deplored. “It is difficult to reduce the number of people fishing the reefs, because they have no other way to earn their living,” the UP professor lamented.

    “The pervasive poverty of many coastal dwellers in developing countries aggravates the situation.” What makes it even harder is how to address the overexploitation that results from greater prosperity.

    “As some developing countries progress, more and more people increase their buying power, and this raises demand for many commodities, not least marine living resources,” Dr. Gomez said. “Just increasing the demand for traditional food products strains marine production.”

    Mangroves –the communities of trees in the tidal flats in coastal waters, extending inland along rivers where the water is tidal, saline, or brackish — are not spared from destruction. Half of the 500,000 hectares of mangroves that existed in the country at the beginning of this century have already been converted to fish and shrimp ponds.

    “The ponds destroy traditional fishing grounds, removing a source of income from local communities,” Dr. Gomez said. “The displaced fishermen are not provided with alternative sources of income, apart perhaps for a handful employed as pond laborers.”

    Although a World Bank report released in 2005 stated that mangrove cover in the country was “now relatively stable” – particularly those around Bohol and Siquijor islands – Dr. Rafael D. Guerrero III said that mangroves are still in peril.

    “Notwithstanding, our mangroves are disappearing due to unabated deforestation,” informed Dr. Guerrero, former director of the Philippine Council for Aquatic and Marine Research and Development. The current rate of mangrove deforestation ranges from 2,000 to 3,000 hectares per year.

    It’s hard not to include seagrasses when coastal ecosystems are mentioned. “The seagrass beds have only been recognized for being just as productive as the other two, if not more so,” Dr. Gomez said.

    “If seagrass beds continue to disappear, there will be serious economic and ecological consequences,” warns the regional office of the Bureau of Fisheries and Aquatic Resources (BFAR) in Davao City. Seagrass beds are rated the third most valuable ecosystem globally (on a per hectare basis), only preceded by estuaries and wetlands. Yet, they are completely ignored and not given importance.

    “Despite their high biodiversity and abundance, seagrass habitats are still poorly understood in our country,” says Dr. Miguel D. Fortes, the country’s foremost expert on seagrasses. “Hence, it appears only marginally useful when, in fact, the ecosystem plays significant economic and ecological roles.”

    Pollution has also taking a toll on the coastal areas. Take the case of Manila Bay. The State of the World Report of the Washington-based Worldwatch Institute once reported: “Seen from an airplane, the surface waters of Manila Bay resemble a green soup.”

    If coastal zones have to be become more productive, they have to be well protected. “Many papers on the marine environment have focused on the physical aspects of environmental degradation — but more and more people are now realizing that the solutions to environmental problems are often not technological, but political and sociological,” Dr. Gomez pointed out.


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