Government knew seismic blasting would injure whales, dolphins
Years of international research clearly spells out risk of this noise to marine animals
Image: SUPPLIED
Scientists told the government in 2013 that up to 38 species of whales and dolphins off the Wild Coast could be injured or thrown into disorientating confusion by seismic “pules”. But it was downplayed and blasting and drilling was given the oily-red carpet.
I am submerged in 20 years of international research reports about the effects of intense human noise on marine animals. It’s bad for the heart.
“What did the whales do to humans, that we would treat them so badly?” asks my youngster. ’Zactly.
An excellent 2012 report “The potential impacts of anthropogenic noise on marine animals in South Africa”, published by the Endangered Wildlife Trust (EWT) and authored by scientists Renee Koper and Stephanie Plön belongs in your book club — in the horror section. In particular the chapter “Potential Impacts of Anthropogenic Noise”.
Koper and Plon write that the one of the worst physical impacts of high-intensity sound on marine animals include serious damage to body tissues or gas embolism (bubbles of air in the bloodstream), which often results in death. The authors report incident after incident of standings of marine animals around the world, which have been linked by scientists to various types of human high-intensity noise.
Like this one. In March 2000, 17 cetaceans — whales and dolphins -— including four different species, stranded themselves off the Bahamas. A large team of US scientists reported clear evidence of acoustic trauma, which was related to multiple military sonars which had been operating between 2.6 and 8.2kHz at 223dB to 235dB.
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The Endangered Wildlife Trust report reads: “All of these animals appeared to be in good body condition without any sign of disease... nevertheless, there was clear evidence of haemorrhaging around the brain, in the inner ears and in the acoustic fats located within the animals’ heads”. The 3D seismic survey will deliver sound of up to 250 dB in the 0-120Hz bandwidth.
A May 2021 paper by Australian researcher RD McCauley and his team cited 10 of their former papers which had shown that the combination of frequency, intensity and duration (up to months) of seismic survey operations could result in varying degrees of acute and chronic impact on a suite of marine animals.
They stated: “These are primary considerations for regulators and industry in the approval and environmental management of exploration permits using seismic surveys.” Hear here!
The 2013 Environmental Management Programme (EMPr) for the Algoa & Transkei Exploration Right (ER), lists 28-38 cetacean species possible in both ER areas. It recognises that the potential impacts of seismic pulses to whales and dolphins “could include physiological injury, behavioural avoidance of seismic survey areas, masking of environmental sounds and communication, and indirect impacts due to effects on prey”.
But the potential effects on whales are assessed as “medium" significance, which converts to "low" significance if these are adequately mitigated (reduced) by certain actions, as listed.
For our humpbacks these include that surveying must be avoided during December. But “if that is not avoidable”, which is appears it is not, then “all other mitigation measures must be stringently enforced”.
Ah, an escape clause. Imagine Mama humpback and her new calf swimming into that lot.
Our local whale gurus John Barry (Southern Cross Cruises) and Kevin Cole (Principal Scientist at EL Museum), are concerned. They say that in 2021 the humpback whales have not been observed coming inshore on their return journey southwards during October and into late November.
These guys are well connected to a community of observers and deep-sea fishermen, and in whale season Barry spends up to 20 hours a week at sea, observing and listening to marine mammals on his hydrophone.
Cole says: “This time last year we were seeing two or three go past every few days. This year — no playfulness and no youngsters frolicking around. Sunday was a dedicated day of observation at Kwelera and I saw nothing.”
Barry believes something may have driven the whales to deep sea or that they could be late. Readers, please forward any 2021 observations to kcole@elmuseum.za.org.
● Dr Mandy Uys of LaughingWaters is an Eastern Cape aquatic ecosystems specialist.