Wellington, Oct 12
The sinking of a New Zealand navy ship near the southern coast of Upolu in Samoa has caused concerns over reef damage and oil leaks' threat to the ecosystem.
The multipurpose maritime support ship HMNZS Manawanui, with a displacement of 5,741 tons, struck a reef and was grounded off Samoa last Saturday while conducting a hydrographic survey one nautical mile from shore. All 75 people aboard were successfully rescued, news agency reported.
Samoa has confirmed that the capsized Manawanui is leaking residual oil from three locations. Assessments show the area of physical destruction to the reef from the shipwreck and anchor chain, is roughly half the size of a large rugby pitch, according to Samoa's Marine Pollution Advisory Committee.
The effects of a catastrophic oil spill can persist over a long period as the chemical components of oil are absorbed by marine organisms and deposited in marine sediments. This can continue to have lasting effects on the fitness of populations of exposed animals, Bridie Allan, a lecturer of the Department of Marine Science, University of Otago, said on Saturday.
As oil is agitated at the surface due to wave and wind energy, the chemical components, including highly toxic heavy metals and polyaromatic hydrocarbons (PAHs), in the oil are weathered out, which results in the release of these chemicals into the water column where marine organisms may encounter them, Allan said.