Underwater ship noise won’t harm marine life: Baffinland
“If they need to be in that area, they’ll come back to that area”
Of the 204 trips a year that vessels hired by Baffinland Iron Mines Corp. would make to carry 18 million tonnes a year of iron ore from Steensby Inlet to Europe, none of the underwater noise would adversely affect marine mammals, Bevin Ledrew, who works for the company on marine issues, said July 16 during final hearings for the project in Iqaluit.
He said Baffinland studied how far sound travels underwater, and the hearing capacities of different species, including seals, walrus, and beluga.
Belugas are able to hear very high frequencies, while ring seals and walruses hear at lower levels. Baffinland plotted these frequencies on a graph and showed them as evidence at the hearing.
“Most of the noise from the vessel is very low-frequency,” Ledrew said.
The biggest noise contributor is the ship’s propeller, but the breaking of ice does not produce as much noise underwater, he said.
The studies looked at how noise would travel from the vessel and it was found in the marine assessments that high frequency noise dissipates faster than low frequency noise.
Baffinland said when there are disruptions in animal habitat, the animals will eventually come back to that same habitat.
“If they need to be in that area, they’ll come back to that area,” Ledrew said, adding that this is not a prediction of transboundary effects.
“However, these predictions will be monitored,” he said.
But Baffinland, NIRB and other agencies have been working for several years to address key areas of concern, said Oliver Curran, Baffinland’s director of sustainability.
The company’s marine assessments consider adverse effects on sea ice, water and sediment, and take “marine knowledge” into account.
Recommendations for follow up would be implemented if the proposed project occurs, Curran said.
He said monitoring how ship noise affects wildlife is a priority for the company, given that the project calls for shipping ore from Steensby Inlet at least every two days.
The hulls of the vessels would extend 20 metres below the surface of the water, travelling at a speed of between three and seven knots while observing other vessels and marine mammals, Curran said.
Ore-carrier designs continue to be evaluated, and would be polar class four vessels.
Double-lined fuel tanks to reduce the potential of a rupture would be a major feature of ship design.
Furthermore, Baffinland would work with shipyards to reduce their fuel consumption by 20 per cent, Curran said, and also to reduce ship noise.
“It is important to understand that ship builders know how to minimize the sound of propellers,” Curran said.
That will be an inherent design requirement, Curran said.
Another concern, the threat of invasive species, was deemed by the company to be of low risk when compared with Churchill, Manitoba, he said.
This method was peer-reviewed and overseen by the Department of Fisheries and Ocean’s Centre of Expertise for Aquatic Risk Assessment.
One community concern was how the shipping route would affect walrus harvesting areas.
The proposed shipping route was moved from west of Rowley Island further east, to avoid the harvesting grounds between Hall Beach and Igloolik.
And another survey was completed for the Steensby approaches.
Aerial surveys were also done from 2006 to 2008 for seals near Steensby Inlet as well as at Foxe Basin.
“It is clear that careful design does lead to environmental benefits,” said Erik Madsen, the company’s vice president of sustainable development.
Baffinland has been collecting baseline data for the past several years, he said, adding that scientific studies compliment traditional knowledge.
The corporation set up formal working groups to address environmental issues affecting terrestrial and marine wildlife.
“Together we can make this a success story for all,” he said.