Most Americans associate fall with football and raking leaves, but in the Arctic this season is about ice. Every year, floating sea ice in the Arctic thins and melts in spring and summer, then thickens and expands in fall and winter.
As climate change warms the Arctic, its sea ice cover is declining. This year scientists estimate that the Arctic sea ice minimum in late September covered 1.77 million square miles (4.59 million square kilometers), tying the sixth lowest summertime minimum on record.
With less sea ice, there is burgeoning interest in shipping and other commercial activity throughout the Northwest Passage – the fabled route that links the Atlantic and Pacific oceans, via Canada’s convoluted Arctic archipelago – as well as the Northern Sea Route, which cuts across Russia’s northern seas. This trend has serious potential impacts for Arctic sea life.
In a recent study, we assessed the vulnerability of 80 populations of Arctic marine mammals during the “open-water” period of September, when sea ice is at its minimum extent. We wanted to understand the relative risks of vessel traffic across Arctic marine mammal species, populations and regions. We found that more than half (53 percent) of these populations – including walruses and several types of whales – would be exposed to vessels in Arctic sea routes. This could lead to collisions, noise disturbance or changes in the animals’ behavior.
Less ice, more ships
More than a century ago, Norwegian explorer Roald Amundsen became the first European to navigate the entire Northwest Passage. Due to the short Arctic summer, it took Amundsen’s 70-foot wooden sailing ship three years to make the journey, wintering in protected harbors.
Fast-forward to summer 2016, when a cruise ship carrying more than 1,000 passengers negotiated the Northwest Passage in 32 days. The summer “open-water” period in the Arctic has now increased by more than two months in some regions. Summer sea ice cover has shrunk by over 30 percent since satellites started regular monitoring in 1979.
Arctic seas are home to a specialized group of marine mammals found nowhere else on Earth, including beluga and bowhead whales, narwhals, walruses, ringed and bearded seals and polar bears. These species are critical members of Arctic marine ecosystems, and provide traditional resources to Indigenous communities across the Arctic.
According to ecologists, all of these animals are susceptible to sea ice loss. Research at lower latitudes has also shown that marine mammals can be affected by noise from vessels because of their reliance on sound, as well as by ship strikes. These findings raise concerns about increasing vessel traffic in the Arctic.
Sensitivity times exposure equals vulnerability
To determine which species could be at risk, we estimated two key factors: Exposure – how much a population’s distribution overlaps with the Northwest Passage or Northern Sea Route during September – and sensitivity, a combination of biological, ecological and vessel factors that may put a population at a higher risk.
As an illustration, imagine calculating vulnerability to air pollution. People generally are more exposed to air pollution in cities than in rural areas. Some groups, such as children and the elderly, are also more sensitive because their lungs are not as strong as those of average adults.
We found that many whale and walrus populations were both highly exposed and sensitive to vessels during the open-water period. Narwhals – medium-sized toothed whales with a large spiral tusk – scored as most vulnerable overall. These animals are endemic to the Arctic, and spend much of their time in winter and spring in areas with heavy concentrations of sea ice. In our study, they ranked as both highly exposed and highly sensitive to vessel effects in September.
Narwhals have a relatively restricted range. Each summer they migrate to the same areas in the Canadian high Arctic and around Greenland. In fall they migrate south in pods to offshore areas in Baffin Bay and Davis Strait, where they spend the winter making deep dives under the dense ice to feed on Greenland halibut. Many narwhal populations’ core summer and fall habitat is right in the middle of the Northwest Passage.
Vulnerable Arctic regions, species and key uncertainties
The western end of the Northwest Passage and the eastern end of the Northern Sea Route converge at the Bering Strait, a 50-mile-wide waterway separating Russia and Alaska. This area is also a key migratory corridor for thousands of beluga and bowhead whales, Pacific walruses and ringed and bearded seals. In this geographic bottleneck and other narrow channels, marine mammals are particularly vulnerable to vessel traffic.
Among the species we assessed, polar bears were least vulnerable to September vessel traffic because they generally spend the ice-free season on land. Of course, longer ice-free seasons are also bad for polar bears, which need sea ice as a platform for hunting seals. They may also be vulnerable to oil spills year-round.
Research in the harsh and remote Arctic seas is notoriously difficult, and there are many gaps in our knowledge. Certain areas, such as the Russian Arctic, are less studied. Data are sparse on many marine mammals, especially ringed and bearded seals. These factors increased the uncertainty in our vessel vulnerability scores.
We concentrated on late summer, when vessel traffic is expected to be greatest due to reduced ice cover. However, ice-strengthened vessels can also operate during spring, with potential impacts on seals and polar bears that are less vulnerable in September. The window of opportunity for navigation is growing as sea ice break-up happens earlier in the year and freeze-up occurs later. These changes also shift the times and places where marine mammals could be exposed to vessels.
Planning for a navigable Arctic
Recent initiatives in the lower 48 states offer some models for anticipating and managing vessel-marine mammal interactions. One recent study showed that modeling could be used to predict blue whale locations off the California coast to help ships avoid key habitats. And since 2008, federal regulations have imposed seasonal and speed restrictions on ships in the North Atlantic to minimize threats to critically endangered right whales. These practical examples, along with our vulnerability ranking, could provide a foundation for similar steps to protect marine mammals in the Arctic.
The International Maritime Organization has already adopted a Polar Code, which was developed to promote safe ship travel in polar waters. It recommends identifying areas of ecological importance, but does not currently include direct strategies to designate important habitats or reduce vessel effects on marine mammals, although the organization has taken steps to protect marine habitat in the Bering Sea.
Even if nations take rigorous action to mitigate climate change, models predict that September Arctic sea ice will continue to decrease over the next 30 years. There is an opportunity now to plan for an increasingly accessible and rapidly changing Arctic, and to minimize risks to creatures that are found nowhere else on Earth.
Donna Hauser, Research Assistant Professor, International Arctic Research Center, University of Alaska Fairbanks; Harry Stern, Principal Mathematician, Polar Science Center, University of Washington, and Kristin Laidre, Associate Professor of Aquatic and Fishery Sciences, University of Washington
This is an article from Curious Kids, a series for children. The Conversation is asking kids to send in questions they’d like an expert to answer. All questions are welcome – serious, weird or wacky! You might also like the podcast Imagine This, a co-production between ABC KIDS listen and The Conversation, based on Curious Kids.
What sea creature can attack and win over a blue whale? – Drake, age 7, Sydney.
Hi Drake. That is an interesting question.
As you probably know, blue whales are the largest creatures to have ever lived on Earth – bigger than any dinosaur. They can grow up to 30 metres in length and weigh over 150 tonnes. This is very, very BIG. To give you an idea of how big a blue whale is, it’s the size of a Boeing 737 plane! Because of their size, power and speed, adult blue whales have virtually no natural ocean predators.
The only sea creature known to attack blue whales is the orca whale (scientific name: Orcinus orca) also known as the “killer whale”. They have been known to work in groups to attack blue whales.
However, there are very few reports of orcas actually killing blue whales. We know that orca whales interact with them because many blue whales carry scars from the teeth of orcas. But blue whales probably see orcas as more of a pest than a predator.
Curious Kids: Why do sea otters clap?
The human threat
A much more serious problem for blue whales is humans. Humans have caused a lot of trouble for blue whales over the years.
One big problem is what we call “ship strikes”. This is when large ships collide with blue whales causing dreadful wounds and, in many cases, death.
Blue whales migrate freely across all the great oceans of the world to breed. They travel each year to the Antarctic in search of food. Global warming is a major future threat to their way of life. This is because rising sea temperatures and ocean acidification (which are caused by climate change) are likely to cause severe disruption to the production of their main food source, the very small crustacean we call “krill”.
Blue whales were the target of commercial whalers, mainly in Antarctica, between 1900 and the 1970s. During that time, over 330,000 blue whales were killed.
Fortunately – and only just in time – the International Whaling Commission banned commercial whaling in 1966. Blue whales are now a protected species and are recovering from the brink of extinction. People on whale watching trips at various locations around the world can see them, if they are lucky. The risk of whaling still exists in several countries, including Japan, Iceland and Norway. Many people in these countries are seeking to return to commercial whaling. Recently, whalers in Iceland killed a hybrid blue whale.
Blue whales can talk
One of the most interesting things about blue whales is that they use very low frequency sounds to communicate. Through this they can talk to each other over great distances. The low frequency sounds can pass through the earth, so it’s possible to record their songs and sounds from anywhere in the world.
In the 1960s, an American scientist called Chris Clark got permission to use the USA’s submarine listening system across the Atlantic Ocean to listen to blue whales. One day, he heard a blue whale calling from the far northeast Atlantic Ocean and realised another whale many thousands of miles away in the southwest Atlantic Ocean was answering it. Through their calls, he tracked them over the next few weeks moving towards each other. The two blue whales met and spent time together in the middle of the Atlantic. Then they separated and went on their way!
It is important for all who are interested in the conservation and protection of these amazing creatures to remain vigilant and involved in making sure that they remain safe. Whales are part of the international heritage of all people of the Earth.
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After a two-year pause in the fin whale (Balaenoptera physalus) hunt, Icelandic whaling company Hvalur hf. will resume whaling this summer, with a government-issued quota.
Two factors help explain why Iceland and other countries are determined to hunt whales in defiance of international disapproval. The first is demand for the product; the second is Iceland’s interpretation of international law on whaling.
Whale meat and its buyers
Demand for whale meat appears to be stable in Iceland. Many reports suggest that Icelanders no longer eat whale meat in great numbers. Yet minke whale (Balaenoptera acutorostrata) meat is readily available in supermarkets and sells for the equivalent of A$29.80 per kilogram.
Much of this is imported from Norway, indicating that there remains a strong domestic demand that is not being met by Icelandic whaling, and suggesting that it is not just Iceland’s growing number of tourists who want to eat whale meat. The fin whale hunt, in contrast, is intended primarily for export to Japan.
Fundamentally different rationales
The second, and far more complex, factor to understand why pro- and anti-whaling nations differ is that they have different interpretations of the basic purpose of the international regime to protect whales.
The International Convention for the Regulation of Whaling has banned commercial whaling. In line with the norms of international law, only parties to the whaling convention are obliged to observe this ban.
Iceland was an original member of the International Whaling Commission (IWC) and accepted the temporary halt on commercial whaling, which came into effect in the mid-1980s.
However, Iceland left in 1992 after the IWC refused to authorise quotas, even when scientific evidence indicated that controlled commercial whaling would not threaten the survival of the targeted species. The zero quota on all whale species, irrespective of their conservation status, has been criticised by several other countries, including Norway and Japan, as non-scientific.
Under no circumstances will whaling for commercial purposes be authorised without a sound scientific basis and an effective management and enforcement scheme.
Iceland argued that the ban had become a permanent one and that this was contrary to the object and purpose of the convention, which was initially about regulating whaling rather than prohibiting it.
Essentially, Iceland and other pro-whaling countries reject arguments that the object and purpose of the convention has evolved into the preservation of whales rather than their conservation for sustainable use.
Iceland also objects to the ongoing situation whereby a scientific procedure adopted by the IWC to assess stocks and the potential for sustainable whaling was not followed up by the promised adoption of a non-scientific (political) scheme that would allocate actual quotas. Because of majority voting in the IWC, this standoff has created a persistent stalemate between pro- and anti-whaling countries.
Iceland’s current position
After a couple of years of heated discussions among members, Iceland was readmitted to the IWC. However, other countries (including Australia) still object to its reservation, meaning there is no universal acceptance of Iceland’s position.
If Iceland were cast out of the IWC, then it would not be bound by the convention at all. However, it would not be able to export to other IWC members, including Japan.
The whaling firm Hvalur hf. intends to resume its commercial hunt for fin whales in June. Quotas have been awarded consistently since 2006, but in 2016 and 2017 the company did not use them, citing doubts about profitability because of difficulties reaching target markets (especially Japan). A couple of shipments of whale meat were made recently (one in 2015 and one in 2016), using the Northern Sea Route to avoid customs delays and, potentially, protesters at Dutch harbours. The pause merely reflected the commercial reality of the time.
For 2018, Fiskistofa (the Directorate of Fisheries) has set a quota of 161 fin whales, with an additional 30 carried over from the unused 2017 quota. Although the IUCN listed the fin whale as endangered in 2008, there are no concerns about sustainability since the Icelandic quota represents 0.9% of the lowest estimate of fin whale numbers off the Icelandic coast.
The harvest is primarily destined for the Japanese market, which had been difficult to access for a number of reasons, including the effects of the 2011 tsunami, which disrupted processing facilities.
Minke whales are hunted by the company IP-Útgerð ehf., mostly for Icelandic consumption. In 2017, only 17 were taken. This was well within the quota of 269, although numbers were higher in previous years. The IUCN assesses the status of minke whales as “least concern”.
Iceland is making no efforts to stop whaling and never has. Unlike Japan, Iceland does not claim that its whaling is for scientific research, which is authorised under Article VIII of the whaling convention. It agreed to the temporary ban in order to gather scientific evidence that was supposed to protect the whaling industry in the medium to long term.
Iceland has never had sentimental ideas that whales should not be hunted. Nevertheless, the country has two whale sanctuaries, in Faxaflói (the bay around Reykjavík) and in the north, to support the tourism and whale-watching industry.
Whaling might not be popular in some countries – and indeed some Icelanders would like to see it end – but foreign interference is viewed with suspicion and is more likely to make the traditionalists who support the whale hunt dig in their heels (and harpoons) still further.
As unlikely as it may seem, your drive to the supermarket is responsible for a lot of noise pollution in our oceans – and a lot of stress to marine life as a result.
Of course, it’s not the specific sound of your car trundling along the street that the fish and whales hear. But many of the products that feature in your weekly shop – from the goods you buy, to the petrol you burn, to your car’s component parts – contribute to marine noise pollution.
Let’s start with the oil. Before we can drill the oil or turn it into fuel to drive our cars, oil companies have to discover it.
Companies look for oil using high-pressure airguns. These machines are towed across the surface of the ocean, firing off sounds to determine the make-up of sediment layers in the seafloor. These are some of the loudest human-created sounds – researchers working in the middle of the Atlantic Ocean have been able to record the sounds produced from coastal oil surveys.
These sounds are problematic for marine life. Whales and other animals that rely heavily on sound for communicating and finding food are most affected. Hearing is to these animals much the same as vision is to humans. Unusually loud sounds can disturb whales’ behaviour and, if they are close enough, can damage their hearing. There is even some suggestion that the airguns can cause whale strandings, although this is not yet completely certain.
Currently, one-third of all oil comes from offshore sources and this proportion is expected to increase. This can only mean more bad news for our marine life.
What about the metal box that consumes all the oil? Parts for the car are sourced from all over the world and have to be shipped across our oceans. In turn, the raw materials needed to make these parts are usually shipped in from yet more places. The commercial shipping needed for all this represents another problematic source of ocean noise.
The contributions of individual ships may seem trivial in comparison to the loud noise from airguns. However, the world merchant fleet includes around 52,000 ships. Collectively, these increase the ambient noise levels in our oceans. In fact, the amount of low-frequency sound in some parts of our oceans has doubled each decade over the past 60 years.
Humans perceive only some of this sound, because of the very low pitches involved. But these sounds are well within the frequency range used by baleen whales. Recent work suggests that this constrains the communication ranges in whales, causing chronic stress and potentially interrupting mating behaviour.
Oh, and most of your groceries are shipped around the world at some point too, as are many other consumer items – including the battery in your hybrid car, if you have one. Around 90% of world trade is carried by commercial ships at some stage. Not all of this ends up in your shopping bag, but a large proportion enters the consumer market at some point.
Certain grocery items, such as fish, originate from the oceans themselves. Like cargo ships, fishing vessels produce noise from their engines and propellers, but they also have noisy fish-finding sonars and winches as well.
The good news is that noise pollution, unlike chemical pollution, dissipates quickly. This means that the future for underwater noise remains bright. If you want to give the whales a break, just drive a little less, or support higher efficiency standards for vehicles. This will not only reduce oil consumption, but also the wear and tear on your car, meaning that fewer replacement parts will need to be shipped in.
You can also buy locally produced items and support the local economy too. That way everyone wins.
No matter how connected we think everything is, the situation is generally even more complicated than we can imagine. So next time you walk to the shops and buy an apple grown in your state, you should allow yourself a moment to feel good about yourself, safe in the knowledge that you have helped to make the oceans a tiny bit quieter.