Lindy Welgart, a Californian living on Canada’s east coast, has spent her life chasing sperm whales, the species of whale immortalized in the novel Moby Dick. But Weilgart doesn’t have harpoons or weapons, but only tools to add logic to preserve seabirds and measure the effects of underwater noise pollution on marine species. Once, she even spent a year at sea with her young, following the migration of whales from America to New Zealand.
One of the world’s great experts in underwater noise, Weilgart spent a few days invited by Ocean Care in Barcelona to discuss how to achieve calmer waters for whales and dolphins, reduce the risk of ship collisions with cetaceans, and reduce emissions. are invited to present their findings on reducing of greenhouse gases and polluting gases in the ocean and atmosphere. and to shore up the scientific basis of the Mediterranean Cetacean Migration Corridor, the already approved Zepim (Specially Protected Area for the Mediterranean) for which the management plan is being drawn up.
If there was no noise, what would we hear in the sea?
We will still hear sounds but they will be natural… waves, fish, whales… they will be organic sounds. Noise generated by human activities is more harmful as animals adapt to natural sounds. And not everyone can adapt to the noise of now. Fish that live for three years cannot live. Instead, whales, whose lives are as long as 200 or 250 years, may have adapted.
If they lived that long, there would be whales that prowled the water before the industrial revolution and propellers
Well, yes, we know that bowhead whales live so long because ivory harpoon tips were found stuck in their skin and this was later verified by other means. So suddenly one day industrial noise appeared in the sea they were swimming in.
Why is it important to reduce underwater noise in the oceans?
In a report I wrote there are about 150 marine species that are affected by noise in various ways, some even severe enough to threaten the health of the species. I’m not only talking about cetaceans, but also fish and invertebrates, including plankton.
Could they be deaf too?
This is one of the serious consequences, but not the only one. For example, it can kill plankton. It also causes high mortality in scallops. And this affects the ability to communicate, because fish communicate with sounds. Reproductive rates drop: Fish reproduce less and are unable to care for their eggs. We know that noise from boats increases stress. And, very important, the masking effect, noise drowns out the sound that cetaceans and other species need to communicate with other members of their group, or to hear their prey, or their predators, or the sound of waves , they need to orient themselves. They are very important for the survival of the animals and the noise of the boats cancels them out.
What is the most important thing that you have explained these days at the Oceannoise2023 conference in Vilanova i la Geltru?
I have submitted the report that I have prepared for the United Nations Convention on Migratory Species, entitled Best Available Technologies (BAT, Best Available Technology) and Best Environmental Practices (BET, Best Environmental Practices) for reducing noise sources. There is a series of technical recommendations. , These sources are basically marine navigation, seismic surveys and the construction of offshore wind farms, but what worries Spain most is the noise generated by marine traffic, and fortunately this is the easiest cause of noise, as it is circumstantial. Everyone wins with cool boats.
Natural sounds are very important for the survival of marine species and the noise of ships cancels them out”
Lindy Welgart Biologist
Is noise a problem common to all seas and oceans on the planet? Or is it particularly worse in the Mediterranean?
The situation is much worse in the Mediterranean Sea. Also in the North Sea, in Gibraltar, in the English Channel, around all lines of maritime traffic. in the northern hemisphere it is much worse than in the south
Is it a matter of boat traffic volume?
Yes, with around 200,000 ships passing through the Mediterranean every year, it is one of the most heavily trafficked regions. On the other hand, there is no seismic activity associated with oil and gas exploration in Spain, although the noise travels very far, it can reach hundreds of kilometers. Noise originating in Libya or North Africa can also be heard in this part of the Mediterranean.
If ships move 10% slower, the area affected by noise is already reduced by 40%.
Lindy Welgart Biologist
What is the most worrying thing about noise?
In this case, the whistle of ships, which is produced by the ship’s propellers, especially at high speeds. The faster the boat moves, the more cavitation occurs, ie bubbling and wake. Most boats start caving at twelve knots, so we know that one of the easiest ways to reduce noise is to reduce the speed of the boat. We know that 95% of the noise of ships comes from cavitation.
Does slowing down the boats fix the problem?
Measures can be taken in the design of the hull and propeller which can also reduce cavitation, but what we recommend is to go slow, a measure that can be implemented now without the need to design from I can list eight advantages of so-called low stemming: more efficiency and therefore less money to spend, less greenhouse gas emissions, less nitrates, less toxic emissions, less suspended particles, less soot particles, and fewer conflicts with cetaceans. Only a 10% reduction in speed reduces the area affected by noise by 40% and this is already a huge advantage. It makes a lot of sense to a whale or a fish.
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Is this one of the great threats to whales?
I cannot categorize the threats, as whales suffer from hunting, collisions, noise and other factors like pollution, overfishing… but it is one of the most invisible threats to whales. Noise is sometimes a silent killer. Because it is difficult for us to prove when noise is the cause of some misfortune. For example, there have been several cases of whales stranded on the beaches of the Canary Islands that have been able to be correlated with the sonar of ships. The stress caused by noise is invisible.
Are the big shipping companies aware and will they agree to reduce the speed of their ships?
I think so, really. The World Maritime Organization (WMO) considers this a major problem and has already published a guide on reducing marine noise and the European Union is preparing new Maritime Strategy Directive. In fact, one study says that noise in all European waters doubled between 2014 and 2019. And there are a series of binding objectives, such as that no more than 20% of the affected habitat can be lost, which shipping companies have to respect. They will have no choice but to join. But, other than that, it is that shipping companies will save money if their ships move more slowly.
In the port of Vancouver they have decided to protect their killer whales and have reduced rates for slow boats by 75%.
Lindy Welgart Biologist
Does this already happen in any country?
I know that agreements have been made with MSC and other companies in Spain and they have agreed to change their routes to avoid collisions and reduce speed to reduce noise at sea. Many measures are voluntary now but will be mandatory in the future. It’s always better to move on. Like in Canada.
Does Canada serve as an example?
He is the leader in this matter. And the killer whales of the Pacific Northwest around Seattle and Vancouver are very illustrative. There, cetaceans are greatly affected by noise, pollution and the scarcity of fish such as salmon. Orcas do not have enough food, they starve and draw on their internal stores of fat, but this releases toxins into their blood and also makes it difficult for them to use their biological sonar and this makes them more vulnerable to their prey. prevents hearing the echoes of It’s like a big domino effect.
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And have the authorities intervened?
The Port of Vancouver has decided to protect killer whales and has decreed that the quietest boats pay 75% less port fees. As there are stations for weighing goods, so they have established stations for measuring the noise of ships. So shipping companies save cost. We would like to see this on many other sites. France prepares slow steaming map. Spain is also to begin drawing up a ‘decarbonisation’ map of maritime traffic and a management plan for the Mediterranean cetacean migration corridor. A number of technical measures are available to reduce the speed of ships.
Reports of sightings in Catalonia have skyrocketed recently
April and May are good months for sightings in this Mediterranean corridor area, but the ocean is not a laboratory that you control, but it’s so hard to follow the trail to find out why things happen in cetacean communities. What it is better to know for sure, and that is to pay attention to noise reduction. Quieter is always better.