Are blasting airguns jeopardizing Atlantic Ocean’s ecosystem?
by Robert Devet
Halifax Media Co-op
November 21, 2013
K’JIPUKTUK, HALIFAX – Nova Scotia’s offshore oil and gas production is on the upswing. Natural gas is flowing from the Deep Panuke natural gas field on the Scotian Shelf.
And now there are two new kids on the block. This time it’s oil they are after.
Shell Canada spent the summer mapping the geology of a large area in the Shelburne Basin about 300 kilometers south east of Halifax. Next summer BP Exploration (Canada) will follow suit.
Shell for one is happy with the results of its discovery effort. “The initial indication is that the data we’re seeing looks really good,” Shell spokesperson Larry Lalonde told the Chronicle Herald in early September of this year. “We’re quite excited about what we are seeing.”
But local environmental activists are worried. And the concern is not just about spills like the one we saw in the Gulf of Mexico in 2010. Concerns emerge even in this early discovery stage when geologists are determining how much oil there really is, and where exactly that oil can be found.
Problem is, that discovery process is a very noisy affair.
Seismic testing involves the use of airguns fired from moving ships. The airguns generate loudblasts below the ocean’s surface approximately every 20 seconds. The nature of the resulting seismic waves allow geologists to map the geological strata below the ocean floor.
Many environmentalists believe that the noise generated by airguns, almost as loud as dynamite explosions, has a profoundly negative effect on fish, sea turtles and whales in the seismic testing area.
Lindy Weilgart, a Dalhousie University research associate in Biology, has studied the effects of seismic testing on marine wildlife since she was a postdoctoral fellow at Cornell University.
“When the airgun is fired you actually see a bubble coming to the surface, air is released under incredibly high pressure, and with a very sharp onset,” says Weilgart. “One shot, and if you don’t have ear protectors on you can go deaf.”
Weilgart is not just worried that sea creatures find themselves too close to the airguns and suffer permanent hearing damage. There are other reasons why seismic testing is particularly hard on ocean dwellers, says Weilgart.
Although under water sound drops off faster, it carries much further than it does on land. The sound of the airguns can be heard as far as 4,000 kilometers away. Combine that with how crucial sound is for fish and sea mammals, and you have a big problem.
“Often it is the quiet signals that are important,” says Weilgart. “For instance, fin whales have to listen for the sounds of potential mates, to meet up. For them it could mean the difference between a mating opportunity or not.”
And not just whales. Weilgart mentions studies that show that fish make very poor decisions about handling their prey when in a noisy environment. Even squid are affected.
The impact of seismic testing on ocean wildlife is complex. Weilgart gives example after example to drive home this point.
“We have to look at it in the way the animal experiences it, we have to be animal-centric,” says Weilgart. And behaviour isn’t always a good indicator of what is really going on.
“Sometimes the most vulnerable and most desperate of the individuals will stay, not because they aren’t bothered by the seismic testing, but because they can’t afford to leave, they don’t have the luxury,” says Weilgart.
Sea creatures are not just facing this one seismic survey, they are dealing with other noise sources as well, says Weilgart. Ships, the bow thrusters of oil platforms, the seismic ships themselves make noise.
Then there is stress caused by overfishing and loss of prey, climate change and warming of the oceans, acidification, the list goes on.
Environmental approval for this summer’s seismic testing by Shell was granted by the Canada-Nova Scotia Offshore Petroleum Board, an independent joint federal-provincial agency that regulates all offshore oil and gas activities.
It’s written approval of this summer’s seismic testing effort states that it is not likely to result in significant adverse environmental effects, especially given the precautionary measures to which Shell has committed.
Those precautionary measures consist of independent monitors who travel on board of the ships and watch for whales and turtles, and sensors that pick up sounds made by whales below the ocean surface. Work stops immediately when there is any sign that such ocean wildlife is present.
Mark Butler, Policy Director at the Ecology Action Centre in Halifax, does not think that is good enough.
What monitors are able to observe is just the tip of the iceberg, Butler says. Thick fog and big waves can make it very difficult to see a tail flick somewhere in that vast expanse of ocean.
Butler is also not happy that the exploration by Shell was taking place during the summer. He believes that it is better to stop seismic testing during sensitive periods.
“People don’t realize how much life comes into our waters in the spring and summer to feed, it’s like a highway out there,” says Butler.
This is why Butler asked that Shell postpone the seismic testing until later in the year, but Shell refused, arguing that the project was already approved and that bad weather in winter was too much of a risk to the crew.
“If you are striving, as some would perhaps suggest, for no environmental impact than there would be no man-made activities on land or on sea,” says Stuart Pinks, CEO of the Offshore Petroleum Board.
“But the purpose of the environmental assessment is to make sure that there is no significant adverse impact and to minimize any impact that has been identified to the lowest extent possible,” Pinks says.
Minimizing impact may be a matter of degree, but for Weilgart we’re not cautious enough.
“You can’t keep asking the animal to adapt, there is not enough luxury and play in the system,” says Weilgart. “The oceans are not doing well, and now you are throwing this at them.”
“At the very minimum you have to be precautionary.”
Follow Robert Devet on Twitter @DevetRobert