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Tuesday, September 12, 2006
Tankers' group explains fate of marine oil spills
THE International Tanker Owners Pollution Federation (ITOPF) Limited bares the fate of oil spills at sea.
The ITOPF is a non-profit organization with 90 percent of its income coming from subscription paid by P&I insurers on behalf of the ship owner members.
It has a membership of over 4,800 tanker owners and bareboat charterers that operate about 8,650 tankers, barges, and combination carriers with a total gross tonnage of about 240 million GT.
This volume represents all the world's tonnage of bulk oil, chemical and gas carrier.
ITOPF was established in 1968 and had evolved into a primary source of technical advice, expertise and information on effective response to ship-source pollution including oil spills at sea.
It had also specialization on oil clean-up operations, and assessment of technical merits of claims for compensation at the time of a spill.
Their services are free for all members of the organization. They were able to publish a Handbook that spells out the consequence of oil spill at sea, oil spill clean-up technique and assessment of cost for damages due to clean-up.
The Guimaras oil spill had caught the attention of the ITOPF and had offered its services in the clean-up and evaluation activities. Thus it immediately responded and provided orientation training to all key players in the clean-up including the Department of Environment and Natural Resources (DENR).
In a handbook published by the ITOPF it mentioned that when oil is spilled at sea it spreads and moves on the surface while undergoing a number of chemical and physical changes, collectively called weathering.
According to the handbook, the weathering processes known as evaporation, dispersion, dissolution and sedimentation lead to the disappearance of oil from the surface of the sea, whereas others, particularly the formation of water-in-oil emulsions (mousse) and the accompanying increase in viscosity (oil's resistance to flow) may promote its persistence.
The speed and relative importance of the processes depend on the factors such as the quantity and type of oil, the prevailing weather and sea conditions and whether the oil remains at sea or washed ashore. Ultimately, the marine environment assimilates spilled oil through a long-term process of biodegradation.
There are two kinds of spilled oil. One is known as the non-persistent oil, which tends to disappear rapidly from the sea surface, and persistent oils, which dissipate more slowly and usually require a clean-up response.
There are properties of oil that may affect the behavior of spilled oil at sea. We have the specific gravity (its density relative to pure water); volatility (distillation characteristics); viscosity (resistance to flow); and pour point (the temperature below which it will not flow).
In the case of Guimaras, it may appear that the bunker oil belongs to the persistent oil group since it did not dissipate but flowed toward the shore thus, it needs a clean-up process.
The handbook also explained three oil spill clean-up techniques. One is the use of Booms and Skimmers. Booms are used to contain and concentrate the floating oil in a certain area avoiding wide spread and use oil-absorbent materials.
It is often seen as an ideal solution, and if effective, would remove the oil from the marine environment. Specialized skimmers either recover concentrated oil or oil debris is removed from the area to a special storage areas.
Another clean-up method is what we call the "In-situ burning". This is an alternative method when the oil spill is in the middle of the ocean and gathering it towards the land is difficult. Special fireproof booms surround the area covered by the spill where oil is burned right there in the middle of the sea. Residues from burning however may sink with potential long-term effects on seabed ecology and fisheries. Sometimes it is also hard to concentrate the spill in a small area due to the current of water and the movement of the winds at sea.
Another method is the use of dispersant chemicals that work by enhancing the natural dispersion of the oil into the sea. The oil is broken into tiny droplets, which are dispersed into the water column, where they are diluted by water currents and eventually break down naturally. These chemicals can be sprayed from boats, planes or helicopters. This can cover a wide area effectively and quickly. Dispersants should be applied to oil before it has become viscous through evaporation or had formed an emulsion.
Oil spill clean-up method should be appropriate to the level of contamination and the shoreline type. This type may range from mud flats, sandy and cobble beaches, rocky shores and high cliffs, as well as man-made structures such as breakwaters ad protective walls. Through experience, ITOPF noted that sensitive areas such as marshes and mangroves often recover more quickly and completely if invasive clean-up techniques and physical disturbance are avoided like in the case of some mangroves in Semirara. Natural cleaning can also be effective in rocky shores that are exposed to strong wave action like some parts of Panobolon Islands in Guimaras.
Another clean-up process is the application of oil-degrading bacteria and nutrients to contaminated shorelines to enhance the process of natural degradation of oil. In Guimaras, it was found out that there are some endemic oil-degrading bacteria. Perhaps if growth of these bacteria could be enhanced by feeding them, we may not need a massive clean up in the mangroves. This can be a good area for research because according to the ITOPF this kind of technology has not yet been demonstrated to be technologically feasible or beneficial for large-scale restoration projects.
These data taken from the Handbook of ITOPF is very educational. It can help people understand better the clean-up activity being done in Guimaras. "Information such as these should be given to the media so that they could give the general public a better view of how the characteristics of oil spill, how it should be contained and cleaned," says RED Amador
More help
Offers to help in the coastal clean-up of the oil spill in the island province of Guimaras still continue to pour in. The latest to offer assistance was Coral Cay, a British environment conservation group, which has done extensive research on the country's vast coral reefs.
According to the Ambassador Victoria Bataclan, Philippine Ambassador to Sweden and the rest of the Nordic countries, President Gloria Macapagal-Arroyo was open to discussing Coral Cay's offer.
Coral Cay is a partner of the Philippine Reef and Rainforest project at Danjungan Island focusing mainly on preserving the marine part of the project. It also sent volunteers for a conservation project in Taytay Bay in Palawan.
Ambassador Bataclan said the President might meet with Coral Cay's representatives when she visits London as part of her five-nation trip. In the face of the larger ecological threat posed by the Guimaras oil spill, the President has decided to pursue the adoption of the Ocean Initiative at the Sixth Asian-European Meeting (Asem).
The President first proposed the Asem Ocean Initiative at the Senior Officials Meeting held in Hanoi two years ago to promote Asia-Europe cooperation and dialog in marine environmental protection and marine scientific research. Indonesia and Portugal have backed this initiative of the Philippines at the Asem.
The Arroyo government is keen on sustainable development to keep the country's land and territorial waters "not just inhabitable for life but also as providers for the needs of the present and future generations," according to Bataclan.
This is also the guiding principle of all remediation chemicals, technologies and procedures used in dealing with the effects of the Solar I oil spill.
According to DENR 6 Executive Director Julian Amador any object or method utilized in the clean up should not be harmful to marine and terrestrial life and should have no ill-effects in the environment in the near and distant future. (RAC/PIA)
(September 12, 2006 issue)
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