These are the plastic items that most kill whales, dolphins, turtles and seabirds



Shutterstock

Lauren Roman, CSIRO; Britta Denise Hardesty, CSIRO; Chris Wilcox, CSIRO, and Qamar Schuyler, CSIRO

How do we save whales and other marine animals from plastic in the ocean? Our new review shows reducing plastic pollution can prevent the deaths of beloved marine species. Over 700 marine species, including half of the world’s cetaceans (such as whales and dolphins), all of its sea turtles and a third of its seabirds, are known to ingest plastic.

When animals eat plastic, it can block their digestive system, causing a long, slow death from starvation. Sharp pieces of plastic can also pierce the gut wall, causing infection and sometimes death. As little as one piece of ingested plastic can kill an animal.

About eight million tonnes of plastic enters the ocean each year, so solving the problem may seem overwhelming. How do we reduce harm to whales and other marine animals from that much plastic?

Like a hospital overwhelmed with patients, we triage. By identifying the items that are deadly to the most vulnerable species, we can apply solutions that target these most deadly items.

Some plastics are deadlier than others

In 2016, experts identified four main items they considered to be most deadly to wildlife: fishing debris, plastic bags, balloons and plastic utensils.

We tested these expert predictions by assessing data from 76 published research papers incorporating 1,328 marine animals (132 cetaceans, 20 seals and sea lions, 515 sea turtles and 658 seabirds) from 80 species.

We examined which items caused the greatest number of deaths in each group, and also the “lethality” of each item (how many deaths per interaction). We found the experts got it right for three of four items.

Plastic bag floats in the ocean.
Film plastics cause the most deaths in cetaceans and sea turtles.
Shutterstock

Flexible plastics, such as plastic sheets, bags and packaging, can cause gut blockage and were responsible for the greatest number of deaths over all animal groups. These film plastics caused the most deaths in cetaceans and sea turtles. Fishing debris, such as nets, lines and tackle, caused fatalities in larger animals, particularly seals and sea lions.

Turtles and whales that eat debris can have difficulty swimming, which may increase the risk of being struck by ships or boats. In contrast, seals and sea lions don’t eat much plastic, but can die from eating fishing debris.

Balloons, ropes and rubber, meanwhile, were deadly for smaller fauna. And hard plastics caused the most deaths among seabirds. Rubber, fishing debris, metal and latex (including balloons) were the most lethal for birds, with the highest chance of causing death per recorded ingestion.




Read more:
We estimate up to 14 million tonnes of microplastics lie on the seafloor. It’s worse than we thought


What’s the solution?

The most cost-efficient way to reduce marine megafauna deaths from plastic ingestion is to target the most lethal items and prioritise their reduction in the environment.

Targeting big plastic items is also smart, as they can break down into smaller pieces. Small debris fragments such as microplastics and fibres are a lower management priority, as they cause significantly fewer deaths to megafauna and are more difficult to manage.

Image of dead bird and gloved hand containing small plastics.
Plastic found in the stomach of a fairy prion.
Photo supplied by Lauren Roman

Flexible film-like plastics, including plastic bags and packaging, rank among the ten most common items in marine debris surveys globally. Plastic bag bans and fees for bags have already been shown to reduce bags littered into the environment. Improving local disposal and engineering solutions to enable recycling and improve the life span of plastics may also help reduce littering.

Lost fishing gear is particularly lethal. Fisheries have high gear loss rates: 5.7% of all nets and 29% of all lines are lost annually in commercial fisheries. The introduction of minimum standards of loss-resistant or higher quality gear can reduce loss.




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How to get abandoned, lost and discarded ‘ghost’ fishing gear out of the ocean


Other steps can help, too, including

  • incentivising gear repairs and port disposal of damaged nets

  • penalising or prohibiting high-risk fishing activities where snags or gear loss are likely

  • and enforcing penalties associated with dumping.

Outreach and education to recreational fishers to highlight the harmful effects of fishing gear could also have benefit.

Balloons, latex and rubber are rare in the marine environment, but are disproportionately lethal, particularly to sea turtles and seabirds. Preventing intentional balloon releases and accidental release during events and celebrations would require legislation and a shift in public will.

The combination of policy change with behaviour change campaigns are known to be the most effective at reducing coastal litter across Australia.

Reducing film-like plastics, fishing debris and latex/balloons entering the environment would likely have the best outcome in directly reducing mortality of marine megafauna.




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Newly hatched Florida sea turtles are consuming dangerous quantities of floating plastic


The Conversation


Lauren Roman, Postdoctoral Researcher, Oceans and Atmosphere, CSIRO; Britta Denise Hardesty, Principal Research Scientist, Oceans and Atmosphere Flagship, CSIRO; Chris Wilcox, Senior Principal Research Scientist, CSIRO, and Qamar Schuyler, Research Scientist, Oceans and Atmospheres, CSIRO

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Photos from the field: these magnificent whales are adapting to warming water, but how much can they take?



Olaf Meynecke, Author provided

Olaf Meynecke, Griffith University

Environmental scientists see flora, fauna and phenomena the rest of us rarely do. In this new series, we’ve invited them to share their unique photos from the field.


The start of November marks the end of the whale season in the Southern Hemisphere. As summer approaches, whales that were breeding along the east and west coasts of Australia, Africa and South America will now swim further south to feed around Antarctica.

This annual cycle of whales coming and going has taken place for at least 10,000 years. But rising ocean temperatures from climate change are challenging this process, and my colleagues and I have already seen signs that humpback whales are changing their feeding, migration and breeding patterns to adapt.




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As krill stocks decline and ocean circulation is set to change more drastically, climate change remains an unprecedented threat to whales. The challenge now is to forecast what will happen next to better protect them.

Losing krill is the biggest threat

I’m part of an international team of researchers trying to learn what the next 100 years might look like for humpback whales in the Southern Hemisphere, and how they’ll adapt to changing ocean conditions.

Whales depend on recurring environmental conditions and oceanographic features, such as temperature, circulation, changing seasons and biogeochemical (nutrient) cycles. In particular, these features influence the availability of krill in the Southern Ocean, their biggest food source.

Whales are particularly sensitive to this because they need enormous amounts of food to develop sufficient fat reserves to migrate, give birth and nurse a calf, as they don’t eat during this time.

In fact, models predict declines in krill from climate change could lead to local extinctions of whales by 2100. This includes Pacific populations of blue, fin and southern right whales, as well as fin and humpback whales in the Atlantic and Indian oceans.




Read more:
Climate change threatens Antarctic krill and the sea life that depends on it


Still, when it comes to their migration and breeding cycles, recent studies have shown humpback whales can adapt with changes in ocean temperature and circulation at a remarkable level.

Whales can adapt to warming water, but at what cost?

In a long term study from the Northern Hemisphere, scientists found the arrival of humpback whales in some feeding grounds shifted by one day per year over a 27-year period in response to small fluctuations in ocean temperatures.

This led to a one-month shift in arrival time, but a big concern is whether they can continue to time their arrival with their prey in the future when the water gets warmer still.

Likewise, in breeding grounds near Hawaii, the number of mother and calf humpback whale sightings dropped by more than 75% between 2013 and 2018. This coincided with persistent warming in the Alaskan feeding grounds these whales had migrated from.

Collecting humpback whale exhale (“whale snot”)

But humpback whales shifting their distribution and behaviour can cause unexpected human encounters, and cause new challenges that weren’t an issue previously.

Research from earlier this year found humpback whales switched to fish as their main prey when the sea surface temperature in the California current system increased in a heatwave. This has been leading to record numbers of entanglements with gear from coastal fisheries.




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And between 2013 and 2016, we documented hundreds of newborn humpback whales in subtropical and temperate shallow bays on the east coast of Australia, 1,000 kilometres further south from their traditional breeding areas off the Great Barrier Reef.

However, since these aren’t designated calving areas, the newborns aren’t well protected from getting tangled in shark nets or colliding with jet skis or cruise ships.

Protecting whales

The Whales and Climate Program is the largest project of its kind, combining hundreds of thousands of humpback whale sightings and advanced modelling techniques. Our aim is to advance whale conservation in response to climate change, and learn how it threatens their recovery after decades of over-exploitation by the whaling industry.

Each whale season between June and October, I sail out to the open ocean. This means I have unique opportunities to see and engage with whales, especially during the breeding season. The following photos show some of our breathtaking encounters, and can remind us of our marine ecosystem’s fragile beauty.

A humpback whale fin

Olaf Meynecke, Author provided
Breaching humpback whale in front of buildings

Olaf Meynecke, Author provided

During one of our boat-based surveys on the Gold Coast, we encountered this acrobatic humpback whale calf, shown in the photos above. We counted 254 breaches in two hours, making it the record holder of most breaches in our 10 years of observation.

To check on whales’ health, we collect and study the air they exhale through their blow hole (“whale snot”), and measure their size at different times of the year. The photo above shows me tagging a whale with CATs suction cup tags, to collect data on short term changes in their movement patterns.

Close up of a humpback whale's mouth

Olaf Meynecke, Author provided

In regions where the whales adapt to ocean changes and, as such, move closer to shore for feeding and shift their breeding grounds, there’s a higher risk of entanglements and other human encounters. This is particularly concerning when they travel outside protected areas.

A newborn humpback whale resting on its mum's head

Olaf Meynecke, Author provided

Look closely and you can see a newborn humpback, just one to three days old, resting on its mother’s head.

In the first days of life, baby humpback whales sink easily and aren’t able to stay on the water surface for long. They need their mothers’ support to stay on the surface to breathe.

Once they’ve gained enough fat from the mothers milk they become positively buoyant (meaning they can float), making it easier for them to breathe.

Photo of a whale underwater

Olaf Meynecke, Author provided

A final note — during one of our land-based whale surveys this year, a keen whale watcher approached us, and we helped him find the whales with our binoculars. I will never forget the joy in his face when he spotted them.

It’s a joy I hope many future generations can experience. To ensure this, we need to understand how we can best protect whales in a changing climate.




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Photos from the field: capturing the grandeur and heartbreak of Tasmania’s giant trees


The Conversation


Olaf Meynecke, Research Fellow in Marine Science, Griffith University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Swimming with whales: you must know the risks and when it’s best to keep your distance



Shutterstock/anna sanfeliu gozalvez

Chantal Denise Pagel, Auckland University of Technology; Mark Orams, Auckland University of Technology, and Michael Lueck, Auckland University of Technology

Three people were injured last month in separate humpback whale encounters off the Western Australia coast.

The incidents happened during snorkelling tours on Ningaloo Reef when swimmers came too close to a mother and her calf.

Swim encounters with humpback whales are relatively new in the Australian wildlife tourism portfolio. The WA tours are part of a trial that ends in 2023. A few tour options have also been available in Queensland since 2014.

But last month’s injuries have raised concerns about the safety of swimming with such giant creatures in the wild.

Close encounters

Until recently, you had to travel to Tonga, Niue or French Polynesia for similar humpback whale encounters in Oceania. Or you could swim with other species, such as dwarf minke whales on the Great Barrier Reef.




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Whale of a problem: why do humpback whales protect other species from attack?


But when we interact with wild animals there is always a risk to safety, especially in challenging environments such as open water.

Whales, like other wildlife, may behave unpredictably. Active surface behaviours such as breaching, tail and fin slaps present a significant risk for swimmers and whale watchers.

Four drawings of a humpback whale.
A humpback whale (1) breaching, (2) head lunge, (3) tail slap and (4) pectoral fin slap can all be a danger to people close by.
Chantal Denise Pagel, Author provided

In one of the WA encounters, the nursing female was reported to display pectoral fin and tail slaps. These are potentially threatening due to the size (up to 16 metres long) and power of humpback whales.

These behaviours are frequently observed in social interactions between humpback whales and can present a severe risk of injury to anyone close by, with potentially life-threatening results.

A recent study of the impacts of swimmer presence on humpback whales off Réunion Island (on Madagascar’s east coast in the Indian Ocean) confirmed a high occurrence of aggressive and/or defensive whale behaviour.

The researchers observed flipper and tail fluke swipes and thrashes – sudden movements of a whale’s extremities – especially in mother-and-calf pairs.

A humpback whale slaps its pectoral flipper and splashes the water
Active whale behaviour is exciting to observe, but that flipper can pack a powerful punch.
Flickr/Michael Dawes, CC BY-NC

Keep your distance

While the reasons for the Australian incidents are still unclear, a possible explanation could be that the swimming groups approached the whales too closely and ignored the signs the whales did not welcome visitors.

Maintaining a safe distance should be required of any tourists interested in seeing or getting close to unpredictable wildlife, especially in unfamiliar environments.

We cannot expect tourists, who are often first-time whale swim participants, to be able to read and interpret whale behaviour. So it is vital that crew members are skilled and experienced and can end an encounter if it needs to be.

Knowledgeable in-water guides are indispensable in commercial swim-with-whales programs. Yet this is often not a requirement by organisations issuing licenses for such activities.

For example, permits in New Zealand require “knowledgeable operators and staff”, but there is no requirement to have guides in the water during the encounter. People interested in swim-with-whale encounters should choose tour companies that provide in-water guides who join them in their adventure.

We should also question whether interactions with female whales caring for newborn calves should be allowed. Best-practice guidelines advise against interactions where calves are present.

A mother humpback whale underwater with her calf.
We need to be extra careful when near a mother humpback whale with her calf.
Shutterstock/Lewis Burnett

Recent research in the popular whale-swim destination Tonga showed mother-and-calf pairs avoid about one-third of tour vessel approaches by diving for longer periods.

Yet surface resting times are critical for calves. Any decrease in time spent resting for mother-and-calf pairs can affect a calf’s growth rate, overall fitness and chances of survival.

Similar observations were made in Réunion. Three out of four (74%) mother-calf-pairs changed their behaviour to avoid swimmers.

Safety first: for whales and swimmers

The Pacific Whale Foundation is undertaking a study to assess the impact of swimming with humpback whales in Hervey Bay, Queensland, Australia.

This research is to monitor the behaviour of humpback whales, providing critical insights into whether tourism activities add stress to this recovering population.




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But research into the suitability of wildlife species used for commercial tourism operations and their health and safety provisions still lacks fundamental depth.

In highly interactive tourism activities such as swim-with-wildlife programmes, tourists should receive education about the risks involved in these “bucket list” experiences. This should include information on animal behaviour and the potential consequences for swimmers.

Furthermore, training tour operators to identify behaviours that may indicate disturbance or have the potential to be harmful to clients is an important additional step towards safer interactions.The Conversation

Two images of a humpback whale breaching the water and one of a whale tail raised above the water.
Humpback whale breaching and tail slap.
Flickr/Grant Matthews, CC BY-NC-ND

Chantal Denise Pagel, Doctoral student | Marine Wildlife Tourism Professional, Auckland University of Technology; Mark Orams, Acting Dean, Health and Environmental Sciences, Auckland University of Technology, and Michael Lueck, Professor of Tourism, Auckland University of Technology

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Whales and dolphins found in the Great Pacific Garbage Patch for the first time



Adult and infant sperm whales have been spotted in the Great Pacific Garbage Patch.
Inf-Lite Teacher/Flickr, CC BY-SA

Chandra Salgado Kent, Edith Cowan University

Scientific research doesn’t usually mean being strapped in a harness by the open paratroop doors of a Vietnam-war-era Hercules plane. But that’s the situation I found myself in several years ago, the result of which has just been published in the journal Marine Biodiversity.

As part of the Ocean Cleanup’s Aerial Expedition, I was coordinating a visual survey team assessing the largest accumulation of ocean plastic in the world: the Great Pacific Garbage Patch.




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When the aircraft’s doors opened in front of me over the Pacific Ocean for the first time, my heart jumped into my throat. Not because I was looking 400m straight down to the wild sea below as it passed at 260km per hour, but because of what I saw.

This was one of the most remote regions of the Pacific Ocean, and the amount of floating plastic nets, ropes, containers and who-knows-what below was mind-boggling.

However, it wasn’t just debris down there. For the first time, we found proof of whales and dolphins in the Great Pacific Garbage Patch, which means it’s highly likely they are eating or getting tangled in the huge amount of plastic in the area.

The Great Pacific Garbage Patch

The Great Pacific Garbage Patch is said to be the largest accumulation of ocean plastic in the world. It is located between Hawaii and California, where huge ocean currents meet to form the North Pacific subtropical gyre. An estimated 80,000 tonnes of plastic are floating in the Great Pacific Garbage Patch.




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Our overall project was overseen and led by The Ocean Cleanup’s founder Boyan Slat and then-chief scientist Julia Reisser. We conducted two visual survey flights, each taking an entire day to travel from San Francisco’s Moffett Airfield, survey for around two hours, and travel home. Along with our visual observations, the aircraft was fitted with a range of sensors, including a short-wave infrared imager, a Lidar system (which uses the pulse from lasers to map objects on land or at sea), and a high-resolution camera.

Both visual and technical surveys found whales and dolphins, including sperm and beaked whales and their young calves. This is the first direct evidence of whales and dolphins in the heart of the Great Pacific Garbage Patch.

Mating green turtles in a sea of plastics.
photo by Chandra P. Salgado Kent, Author provided

Plastics in the ocean are a growing problem for marine life. Many species can mistake plastics for food, consume them accidentally along with their prey or simply eat fish that have themselves eaten plastic.

Both beaked and sperm whales have been recently found with heavy plastic loads in their stomachs. In the Philippines, a dying beaked whale was found with 40kg of plastic in its stomach, and in Indonesia, a dead sperm whale washed ashore with 115 drinking cups, 25 plastic bags, plastic bottles, two flip-flops, and more than 1,000 pieces of string in its stomach.

The danger of ghost nets

The most common debris we were able to identify by eye was discarded or lost fishing nets, often called “ghost nets”. Ghost nets can drift in the ocean for years, trapping animals and causing injuries, starvation and death.

Crew sorts plastic debris collected from the Great Pacific Garbage Patch on a voyage in July 2019.
EPA/THE OCEAN CLEANUP

Whales and dolphins are often found snared in debris. Earlier this year, a young sperm whale almost died after spending three years tangled in a rope from a fishing net.

During our observation we saw young calves with their mothers. Calves are especially vulnerable to becoming trapped. With the wide range of ocean plastics in the garbage patch, it is highly likely animals in the area ingest and become tangled in it.

It’s believed the amount of plastics in the ocean could triple over the next decade. It is clear the problem of plastic pollution has no political or geographic boundaries.




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While plastics enter the sea from populated areas, global currents transport them across oceans. Plastics can kill animals, promote disease, and harm the environment, our food sources and people.

The most devastating effects fall on communities in poverty. New research shows the Great Pacific Garbage Patch is rapidly growing, posing a greater threat to wildlife. It reinforces the global movement to reduce, recycle and remove plastics from the environment.

But to really tackle this problem we need creative solutions at every level of society, from communities to industries to governments and international organisations.

To take one possibility, what if we invested in fast-growing, sustainably cultivated bamboo to replace millions of single-use plastics? It could be produced by the very countries most affected by this crisis: poorer and developing nations.




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Designing new ways to make use of ocean plastic


It is only one of many opportunities to dramatically reduce plastic waste, improve the health of our environments and people, and to help communities most susceptible to plastic pollution.The Conversation

Chandra Salgado Kent, Associate Professor, School of Science, Edith Cowan University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Why Iceland is set to resume whaling despite international opposition


Julia Jabour, University of Tasmania and Rachael Lorna Johnstone, University of Akureyri

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.




Read more:
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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.

Iceland later re-adhered to the convention, but with a reservation to the temporary ban. Iceland’s reservation included the statement that:

Under no circumstances will whaling for commercial purposes be authorised without a sound scientific basis and an effective management and enforcement scheme.




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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”.




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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.

The ConversationWhaling 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.

Julia Jabour, Senior Lecturer, Ocean and Antarctic Governance Research Program, University of Tasmania and Rachael Lorna Johnstone, Professor of Law, University of Greenland, University of Akureyri

This article was originally published on The Conversation. Read the original article.

Your drive to the shops makes life pretty noisy for whales



File 20180221 161926 7puvco.jpg?ixlib=rb 1.1
Living alongside humans gets noisier all the time.
Katrina Burgers/Shutterstock.com

Andrew J. Wright, Fisheries and Oceans Canada

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.




Read more:
Noise from offshore oil and gas surveys can affect whales up to 3km away


The fuel

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.

Rex Virtual Drilling.
Chooywa/wikimedia, CC BY-SA

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.

The car

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 relative density of commercial shipping routes in our oceans.
B.S. Halpern/Wikimedia Commons, CC BY-SA

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.

Parts of the ocean are filling up with man-made noise, and that presents many dangers to marine life.
B. Southall/NMFS and NOAA

The groceries

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.




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The solutions

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.

Time for a rethink?
Joe Goldberg/flickr, CC BY-SA

You can also buy locally produced items and support the local economy too. That way everyone wins.

The ConversationNo 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.

Andrew J. Wright, Marine Mammal Researcher, Fisheries and Oceans Canada

This article was originally published on The Conversation. Read the original article.

What whales and dolphins can tell us about the health of our oceans



File 20170921 8179 260m8r.jpg?ixlib=rb 1.1
Dolphins contribute important knowledge about ocean health.
Shutterstock

Stephanie Plön, Nelson Mandela University

From the poles to the equator, marine mammals such as seals, dolphins and whales, play an important role in global ecosystems as apex predators, ecosystem engineers and even organic ocean fertilisers. The ocean off the coast of South Africa is home to a high diversity of these mammals and is recognised as a global marine biodiversity hotspot.

Marine mammals are often referred to as “sentinels” of ocean health. Numerous studies have explored the effects of both noise and chemical pollution, habitat degradation, changes in climate and food webs on these marine apex predators. Yet the interplay of these factors isn’t well understood.

Our research on the unfortunate dolphins incidentally caught in shark nets off South Africa’s KwaZulu-Natal coast has helped fill in some of the gaps. By assessing the health of these dolphins we have provided valuable baseline information on conditions affecting coastal dolphin populations in South Africa. This is the first systematic health assessment in incidentally caught dolphins in the Southern Hemisphere.

But to gain a fuller picture of the health of marine mammals in these waters I am now combining this contemporary field research with historical data, like the collection at the Port Elizabeth Museum Bayworld.

The combination of data on diet, reproduction, population structure and health helps us gain a better understanding of the pressures and changes these apex predator populations face. And it helps us understand it in relation to global change, including both climate change and pressures brought about by human behaviour.

My research sheds light on multiple factors: pollutant levels, parasites, and availability of prey, all have an impact on individuals as well as populations.

Understanding the health of these animals also gives us insight into the state of the world’s oceans. This is relevant because oceans affect the entire ecosystem including food security, climate and people’s health. This degree of connectedness is highlighted by recent discoveries about how whales act as ecosystem engineers.

The accumulation of this knowledge is important because the planet’s oceans aren’t being protected. Recent popular documentaries such as “Sonic Sea” and “Plastic Ocean” have highlighted their exploitation and pollution.

What’s missing

Without baseline knowledge it’s challenging to establish the potential effects that new anthropogenic developments (those caused by human behaviour) have on local whale and dolphin populations.

For example, we know that whales are sensitive to shipping noise, so what potential impact could a new deep water port have on mothers and their calves? Could it drive them away from these nursery areas, or could it lead to an increased risk of whales and ships colliding? To answer this and monitor the change that a new port brings with it, we are investigating the soundscape of two bays in the Eastern Cape (one with a new port, one without) in parallel with baleen whale mother-calf behaviour.

Another example is understanding how changes in the Sardine run over the past 15 years have affected the diets of these mammals. The Sardine run is an annual phenomenon when large shoals of Sardine migrate northwards along the coast into KwaZulu-Natal waters to spawn. Using long-term data and samples from the Port Elizabeth Museum research collection, we have been able to establish that over the the past 20 or so years the main predator in the Sardine run – the long-beaked common dolphin – has shifted its diet to mackerel. Although such changes in diet can have potential impacts on the health of the dolphins, parallel investigations on the trophic level these animals feed at (using isotope data from teeth) and the body condition of the dolphins (using long-term data on blubber thickness), indicated no adverse effects to the dolphins.

Our analysis highlights how marine mammals may be used as indicators of environmental change and why research is important.

Finding answers to intricate questions on environmental change is not always easy. But a better understanding and knowledge of the environment these animals live in has to be incorporated into studies contributing to their conservation and management. Such studies are becoming increasingly relevant as they highlight the fast degradation of the marine environment.

For example, a recent study identified antibiotic resistant bacteria in both sea water samples and exhaled breath samples from killer whales. This suggests that the marine environment has been contaminated with human waste which in turn has significant medical implications for humans.

Gaining such information is particularly important given the rapid changes taking place in the oceans, such as those on South Africa’s southern and eastern coastline. This includes increasing coastal development, new deep water ports being built or expanded, and parts of the deep sea being explored for oil and gas.

To assess these changes and what they mean for the environment, baseline studies need to be carried out so that potential effects can be assessed. Whales and dolphins are increasingly being recognised as indicators of ocean health in this endeavour.

And a continuation of the research we did on dolphins caught in nets will help document the cyclic changes that can be seen as normal variation in a population. This could prove important for assessing future catastrophic events, such as the Deep Horizon oil spill.

What next

The oceans absorb over 25% of the world’s carbon pollution as well as heat generated by global warming. They also produce at least 50% of the planet’s oxygen, and are home to 80% of all life on earth. Yet only 5% of this vital component of our planet has been explored.

The ConversationResearch on whales and dolphins contributes important knowledge about ocean health. Historical data increasingly provides a guideline to teasing out natural variations in populations and assessing the contribution that multiple factors have on these animals. In time, this will ensure that policy makers are being given sound scientific information. It will also provide us with a good barometer of the overall health of our oceans.

Stephanie Plön, Researcher, Earth Stewardship Science Research Institute, Nelson Mandela University

This article was originally published on The Conversation. Read the original article.