From 23 to 27 January 2012, the world sets its eyes on the seas and coasts. Two international conferences in Manila led by the United Nations Environmental Programme (UNEP) will review how well governments translated into action a global plan to protect the seas and coasts from land pollution and degradation, and how to do better in the future.

The review will focus on the quality of the water and ecosystems in the oceans and coasts resulting from land-based contaminants such as sewage, heavy metals from mine tailings and electronic waste, persistent organic pollutants (POPs) or synthetic pesticides, nutrients, oil and other hydrocarbons, silt and other sediments, litter (solid waste), and physical destruction or alteration of habitats, all originating from the land. In particular, participants are expected to measure their actions from the viewpoint of environmental, economic, and cultural values.

Indeed, the problems concerning the seas are as complex, multidimensional, and vast as the oceans and seas themselves, which cover 70% of the globe. Some 80% of the pollution of oceans and seas originates in the land.

Global condition

Although the coastal zone occupies only 4% of the world's total land area, it is home to about a third of the earth's human population. Currently, eutrophication and toxic algal blooms, resulting from so-called nutrients, principally synthetic nitrogen (nitrate and ammonium) and phosphorus, impact more than 500 coastal areas worldwide. Much of these pollutants come from run-off of synthetic fertilizers used in farming. Some are from wastewater, 90% of which in developing countries is flushed into the seas untreated. Some 120 million tons of synthetic and reactive nitrogen are produced each year, two-thirds of which "ends up polluting air, water, soil, marine and coastal areas," according to UNEP. Southeast Asia, 600,000 tons of nitrogen are discharged each year into rivers, then finally into seas. Still, other such pollutants flow down from phosphorus mines, which produce 20 million tons each year, roughly half of which is washed out into the oceans at a rate eight times than of nature.

The coral triangle, Christian Science Monitor.

Eutrophication saps the oxygen content in seas and other water bodies. By choking the oxygen supply, it saps the biodiversity, productivity and food security of fisheries, 90% of which worldwide rely on estuarine (bays, lagoons, harbors, inlets and sounds) and near-shore habitats. Synthetic fertilizer use is principally behind what is now known as the "dead zone" phenomenon. In dead zones, synthetic nutrients sink to the bottom waters, where algae at nighttime depletes the oxygen while feeding on the nutrients. Bacteria then further deplete the oxygen while feeding on the dead algae. The expansion of dead zones kills or stunts fish it encompasses, and further shrinks the healthy habitats of marine life.

Since the 1970s, the number of dead zones increased to over 400, with the largest such as those in the Gulf of Mexico spanning over two million hectares each and fed by fertilizer run-offs from the Mississippi River. But, even where there are no dead zones, such contamination results in massive fishkills, driving down food supplies and income of fishers.

Coral reefs thrive and grow in water very low in nitrogen and phosphorus, but are smothered and eventually destroyed by fields of algae thriving in nitrogen and phosphorus-laden water.

Eutrophication harms seagrasses largely by reducing light, making the water more acidic, raising ammonium levels toxic to them, and allowing algae to swamp them.

Eutrophication degrades mangroves by increasing foliage, branch, leaf and top-heavy canopy growth without proportionally growing their roots, making them vulnerable to drying out, and battering by wind and wave. Mangrove forests are extremely vulnerable to synthetic herbicides, which kill trees by desiccating or drying leaves, plugging vessel elements, and destroying root cortexes.

Coral reefs and mangrove forests are under attack not only from unsustainable fishing but also from sediment pollution in the form of soil erosion and run-off from logging and mining, according to the UNEP. Heavy coating with silt kills mangroves by clogging their pneumatophores (aerial roots) and lenticels, the cells in roots and trunks that serve as byways between gases in the atmosphere and their internal tissues.

By making the ocean waters more acidic, climate change driven by fossil fuel use and deforestation is bleaching and killing coral reefs and degrading others. Already, 30% of the world's corals are estimated to be undergoing degradation from global warming, a figure projected to rise further to 60% by 2030.

Each year, 6.4 million tons of litter or solid waste are discharged into the seas and oceans worldwide that decompose slowly and accumulate in the sea floor and coasts.

The UNEP reports that during the past four decades, the world's wetlands and mangrove forests are declining rapidly, typically by 50-90% in most regions.

A study in 2002 showed that more than 70% of the world's tropical and temperate coasts have been already impacted heavily by the building of resorts, hotels, settlements and other human infrastructure, a figure estimated also to rise to 90% by 2032. This trend is expected to exacerbate the planet's already severe marine pollution and degradation.

The Philippine situation

As an archipelago with one of the longest coastlines in the world at 36,000 kilometers, 64% of Filipinos live in coastal areas. Moreover, the Philippines lies at the apex of the Coral Triangle, the global center of marine biodiversity which includes all or part of Indonesia, Malaysia, Brunei, Timor Leste, Papua New Guinea, and the Solomon Islands. Studying the distribution of 2,983 species in 2004, scientists Kent Carpenter and Victor Springer found central Philippines to have the highest number of marine species per unit area in the world, thus calling it "the center of the center of marine shore fish diversity" globally. A re-analysis of data in 2008 also revealed central Philippines to have the world's richest concentration of coral species. Moreover, the country is second only to Australia in seagrass diversity.

And yet, a study by Callum Roberts and other scientists in 2002 also identified the Philippines as the region with the highest threat level to coral reefs or any center of marine endemism. It ranks second in the Coral Triangle in terms of pressure from the aquarium trade.

Of the estimated 2.7 million hectares of coral reefs in the Philippines, only 5% or 135,000 hectares are in excellent condition according to recent studies. Researches also found seagrass beds to have either been lost or degraded by half since 1950. The rate of degradation of the remaining 2.7 million hectares is increasing due to land reclamation and marine pollution. Nearly all beach forests are converted to coconut plantations and settlements. From 1918, mangrove forest cover shrank from 450,000 hectares to 138,000 hectares in 2005 largely due to conversion to fishponds, but is reported to be slightly increasing.

Fishing productivity in terms of catch per unit effort for many poor small fishers plunged, worsening their poverty and resulting in 80% of municipal fishers living below the poverty line. As unsustainable commercial fishing proliferates, depleted fish stocks are being harvested at rates 30-50% below what they can naturally produce.

The Philippine government reported in its 2005 environment monitor that "logging and unsustainable farming practices in recent decades have led to increasing soil erosion and frequent flooding" - a reality that appears to persist to this day. In addition, scientists have already begun to observe coral bleaching in Philippine waters due to global warming.

The complex and multidimensional problems of land-based marine pollution and degradation require holistic, multi-pronged and integrated approaches. The strategy of designating and managing marine protected areas (MPAs) and sanctuaries, including 1,169 in the Philippines as of 2007, are helping conserve or restore marine ecosystems and provide ecological services and better incomes to communities. With the designation of "no take areas," fish biomass and yields increased in their immediate vicinity. But many of these MPAs are too small, with only 3% of Philippine coral reefs covered as of 2005. Moreover, only 20-30% are evaluated as effective, with poaching live aquarium fish and corals still rampant.

In the face of these challenges, research on land-based marine degradation and pollution in the Philippines remains far too scant and inadequate. While the responses required appear to be monumental and daunting, the two conferences raises new hopes that the world can yet look forward to healthy and productive coasts and seas.