Human Errors are Behind Most Oil-tanker Spills

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An oil spill is disastrous and is ecologically, economically and socially disturbing. Researchers need to refocus discussions about tanker safety on to the human behaviours that cause accidents and also on improving safety protocols.

Also they must re-evaluate the risk-prediction models that are used to judge how often to inspect ships, besides focus on upgrading Clean-up technologies before being commercialized.

The two trends from the past decade that threatens those improvements are,

  • first, the accident rate for major tankers (those that carry more than 15,000 tonnes, with and without spills) almost tripled between 2008 and 2017: from 1 accident for every 40 tankers to 1 in every 15.
  • second, to cut costs, substandard ships with poor maintenance records and unqualified personnel are increasingly registered in countries that have lax regulation. The chance of a major spill occurring in a region that is unable to cope could rise, putting fragile coasts at risk.

Impact of Sanchi spill

The Sanchi spill, where a tanker carrying 136,000 tonnes of condensate oil, a volatile and toxic hydrocarbon compound had much of the unburnt cargo spilt, together with 2,000 tonnes of the ship’s own fuel. THis had caused much Ecological damage which is inevitable.

The area is a spawning ground for fish such as bluefin leatherjacket (Thamnaconus septentrionalis) and largehead hairtail (Trichiurus japonicus), and invertebrates such as swordtip squid (Uroteuthis edulis). It lies on a migratory route for at least three species of whale.

But no nation is duty-bound to issue an ecological assessment, because the accident happened in the high seas, beyond local jurisdictions. Neighbouring nations such as Japan and South Korea are keeping an eye on the situation. The tanker was Iranian-owned and registered in Panama. The cargo ship was based in Hong Kong.

Inappropriate investigation

Shipping records often list consequences — collisions, groundings and explosions — rather than reasons, such as poor navigation, lack of maintenance, miscommunication and other human errors. Researchers studying these databases thus reach the wrong conclusions and propose inappropriate policies. Tighter regulations on how ships are built do nothing if they go unenforced.

Clean-up technologies also need to improve to minimize damages from spills. The oil and shipping industries still use decades-old techniques, such as mixing chemical dispersants with oil-contaminated seawater. The dispersants break up the slicks into droplets that should, in theory, be easier for microorganisms to break down. But reactions can make the combination toxic to species such as rotifers (zooplankton at the base of the marine food web). There have been few long-term environmental studies of the ecological impacts of dispersants.

No single factor

The blame stretches beyond just the shipping operators. Half of oil tankers are registered in nations that do little to oversee vessel safety and crew training.

A dozen countries, notably Panama, Liberia, the Marshall Islands, the Bahamas and Malta, allow almost any ship to fly their ‘flags of convenience’. Panama and Liberia — the nations with the biggest fleets — control 18% and 12% of the world’s shipping tonnage (8,000 and 3,000 ships, respectively).

Tighter regulations are set out in the 1986 United Nations Convention on Conditions for Registration of Ships. It has yet to enter into force owing to industry lobbying. At least 40 states with more than 25% of the world’s shipping tonnage must sign on; only 14 have done so.

In the meantime, coastal nations inspect foreign-registered vessels that enter their ports to ensure they comply with international maritime conventions.

Port authorities use predictive models of risks to decide which vessels to inspect and how often. But parameters such as ship age or historical safety records are unreliable indicators of risk. Older vessels are often safer — they have survived owing to better-quality or well-maintained equipment. And historical safety records can be subjective and misleading. The results are shaped by who inspected the ship and how.

There are few civil or criminal penalties for flouting rules. Ships can travel thousands of kilometres between checks.

Human factors ignored

Human errors are behind at least 80% of tanker accidents. Such errors include fatigue caused by overwork, inadequate expertise on a specific operation, poor communication or the use of outdated navigational charts. Yet these are rarely listed as causes in databases of shipping accidents. Such confusion thwarts research and risk management.

Researchers often misinterpret the statistical results generated by oversimplified and improper classification data sets. Collisions, groundings and explosions, for example, are described as primary causes for tanker incidents even though they are consequences.

There is little or no information about the crew and their employer. Also, weak policy prescriptions follow, such as mandating that ships are resistant to grounding.

Policies would be more effective if they acknowledged the role of human error. For example, crew fatigue caused by long working hours and isolation is a significant contributor. Raising the minimum number of qualified crew can reduce average workload and help to prevent mistakes.

Three priorities

Research on the following would limit risk and damage.

Improve port inspections

Researchers should re-evaluate the algorithms that are used to decide which ships are inspected and when. The local maritime authorities should conduct randomized and controlled trials to optimize inspection strategies. They can borrow experiences from predictive policing schemes that use machine learning in some cities to fight crime11. Developed nations should provide aid for developing nations to ensure uniform standards.

Inspectors should look beyond records and, for example, conduct random interviews with crew members to judge whether they understand the safety protocols. We recommend they include surprise questions to test how tanker crew members will react in a crisis.

Study human errors

The International Maritime Organization (IMO) should collaborate with the research community to better understand how human error contributes to shipping accidents. Accurate data sets that document the objective causes of the incidents are key. Researchers need to revisit previous oil-spill incidents and reclassify the causes. Types of human error can be identified through the investigation reports on the IMO’s website.

The tanker industry must use these data to design better strategies for reducing human errors. For example, language is a barrier for many multicultural crews and could be improved through training.

Develop sustainable clean-up technologies

New physical and mechanical clean-up methods should be developed. Promising methods are emerging, such as soak-up sponges, bioremediation and devices for separating oil and water. They still need to be commercialized. Chemists and toxicologists should evaluate chemical dispersants for efficacy and toxicity. Government agencies and the oil industry should prioritize the funding of such interdisciplinary research.

As our understanding improves, regulatory instruments must also evolve. States need to take responsibility for their fleets.

The IMO should mandate the tanker industry to sign up to this reformed registration system first. As global energy demand grows, tanker safety must remain a priority.

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Source: Nature