Whales and dolphins inhabit some of the largest and seemingly most pristine environments on Earth, from tropical coastlines to Antarctic waters. Yet even they cannot escape PFAS – persistent “forever chemicals” that leak from our homes, factories and waterways into the sea.
Forever chemicals are the secret ingredients in our non-stick pans, waterproof jackets and stain-resistant carpets. These chemicals belong to a group of more than 1,400 compounds known as PFAS (per- and polyfluoroalkyl substances). They enter the environment through manufacturing waste, industrial runoff, wastewater treatment plants and firefighting foams. But once these chemicals escape our homes and factories, they become almost impossible to get rid of. Washed into waterways, they make their way to the sea.
Small organisms absorb them from the water, fish eat those organisms and larger predators eat the fish. At each step, the chemical load increases. As top predators, whales and dolphins can end up with very high levels in their bodies. Not even deep-diving species living and feeding far from humans are safe.
In our new research, we found PFAS concentrations in cetaceans have increased globally since 2000. Animals in the Pacific Ocean were the most contaminated, with humpback dolphins showing the highest PFAS concentrations.
These mammals are sentinels of ocean health. They sit high in the food web, live for many years and are exposed to pollution across large areas of the ocean. When whales and dolphins show signs of chemical exposure, it tells us something is wrong in the wider marine ecosystem.
Forever chemicals move through the food web and end up in the bodies of high-level predators such as dolphins.Dmitry Miroshnikov/Getty
Why are we worried about forever chemicals?
Many of these chemicals have been in use for decades. Their sheer durability and ability to resist heat, oil and water make them very useful.
Scientists have grown increasingly concerned about them because they persist for decades and build up over time in our own bodies, as well as in wildlife and the broader environment.
The key concern is what these chemicals may be doing to the animals that accumulate them.
Research in humans and laboratory animals links PFAS to immune suppression, hormonal changes, reproductive problems and developmental effects. But we don’t yet have enough research to understand how different PFAS compounds and levels of exposure affect health.
Understanding these impacts in whales and dolphins is harder still. Marine mammals are long-lived, highly mobile and exposed to many human-made problems at once, from climate change to noise pollution to other contaminants.
Even so, there are warning signs. Some dolphin studies have reported changes in immune-related markers associated with PFAS exposure.
How do you test a whale for forever chemicals?
For humans, testing PFAS levels is usually done with a blood test. It is not as simple for whales and dolphins.
It is extremely difficult to take blood samples from large marine mammals in the wild. Scientists often rely on tissue samples from dead animals, particularly from the liver and kidney where many PFAS compounds tend to accumulate. These samples are analysed in specialised laboratories capable of detecting tiny concentrations of individual PFAS compounds.
This way, scientists have been measuring PFAS in whales and dolphins for decades. Each study added another piece to the puzzle, showing these chemicals were present in different species, populations and oceans.
Our study took a step back and looked at the global picture.
We compiled PFAS data from cetaceans worldwide, focusing on liver samples because they are the most commonly available tissue type, allowing us to compare studies across species and regions.
What did we find?
We found PFAS contamination differed substantially across species, location, sex, age and time.
Infographic showing the main findings of the study.CC BY
The highest concentrations tended to be found in coastal dolphins and porpoises, suggesting animals living near urban and industrial areas face greater exposure.
Cetaceans in the Pacific had higher levels than other oceans. This is likely due to high industrial activity and the extent of historical PFAS production in coastal regions.
Female whales and dolphins can transfer forever chemicals during pregnancy and nursing. This means their calves can be exposed to concerning levels of PFAS at a very early age.
Males often end up with higher levels than females overall, as they cannot transfer these chemicals to their young.
There are some large gaps in the global dataset we collated, which means we don’t fully know the extent of PFAS contamination in cetaceans off India, Indonesia and parts of Africa.
Female whales and dolphins can transfer forever chemicals to their calves.Kerstin Meyer/Getty
What should we do?
While important questions remain about the effects of forever chemicals on whales and dolphins, the widespread contamination we observed is a real concern. We need to continue monitoring while strengthening regulations and working to reduce PFAS flows into the environment.
History shows global action on harmful chemicals works. After it became clear Earth’s protective ozone layer was being eaten away, nations agreed to phase out the chemicals responsible. The ozone layer is now recovering.
The European Union moved to ban some PFAS compounds 20 years ago. Our study found lower levels of some legacy PFAS compounds in the Mediterranean Sea, a pattern that may reflect the effects of regulation. This is positive, but not sufficient given overall PFAS levels in whales and dolphins have increased globally over time. The EU is now moving to better regulate this class of forever chemicals.
Forever chemicals are one of the defining pollution challenges of our time. The more we understand how these chemicals accumulate in whales and dolphins, the better equipped we will be to reduce future contamination and protect marine ecosystems.
What ends up in the ocean does not simply disappear. And neither do PFAS.
This article is based on collaborative research that also included Lavinia Stokes (University of Wollongong), Jesuina de Araujo (National Measurement Institute) and Gavin Stevenson (National Measurement Institute).
Frédérik Saltré receives funding from the Australian Research Council.
Karen Stockin and Katharina J. Peters do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.
The Northern Territory government’s newly released climate resilience plan has listed the acceleration of gas extraction at the Beetaloo Basin as a top priority. Environment groups have fiercely criticised the plan, saying it will “make climate change worse”.
The spectacle of the One Nation leader having a blue with journalists — or indeed anyone even vaguely associated with Canberra incumbency — is catnip for the Hanson algorithm. And the lady is not stupid.
After months of anticipation, the Bureau of Meteorology officially declared an El Niño on June 16.
El Niño is a naturally occurring variation in temperature and winds across the Pacific Ocean that can influence weather around the globe.
During El Niño, sea surface temperatures in the central and eastern Pacific warm up and trade winds – which typically blow from east to west along the equator – weaken. As a result, a region of strong storm activity known as the Walker Circulation shifts east over the Pacific Ocean, drawing moisture and clouds away from Australia.
Past El Niño events have coincided with some of the driest and hottest weather in Australian history.
Making El Niño official
El Niño events occur about every three to seven years, and can last anywhere from six months to two years. They typically ramp up in winter and spring, before easing in autumn.
The likelihood of El Niño has been in the news for months, but the Bureau of Meteorology only just officially declared it active. That’s because there is a specific set of criteria that must be met.
Scientists must observe at least three of the following:
Sea surface temperatures in the central Pacific Ocean must be greater than 0.8°C above average
The trade winds that blow east to west across the Pacific have to be weaker than average for the past four months
The Southern Oscillation Index, which measures the difference in atmospheric pressure between Tahiti and Darwin, must be lower than -7. This tells us whether the region of strong storm activity is closer to Darwin or Tahiti
The majority of global seasonal forecasting models must predict that ocean temperatures in the Pacific will stay warm for at least three months.
Importantly, an El Niño declaration is not a forecast. Rather, it’s a statement on the current conditions in the Pacific Ocean.
On average, past El Niño events were associated with warmer than normal maximum temperatures across Australia, particularly in winter and spring. They were also linked to drier than average winter and spring conditions, especially in eastern Australia.
Western Australia is not as affected by El Niño because, particularly compared to eastern states, it’s only indirectly influenced by Pacific Ocean conditions. The north of the country, however, tends to experience fewer tropical cyclones on average and a delayed start to the monsoon season during El Niño.
It may seem counterintuitive, but El Niño can lead to colder minimum temperatures and therefore more frost. This is because we tend to see less cloud cover during El Niño, and nighttime clouds act like a blanket that stops heat from escaping to space.
However, global average temperatures tend to be hotter during El Niño. And we often see record breaking years coinciding with El Niño.
It’s worth noting, human-made greenhouse gas emissions are the main driver of rising global average temperatures. However, El Niño can tip these temperatures to record breaking levels.
You may have seen reports of a potential “Super El Niño”. A “super” or “strong” El Niño refers to events where the sea surface temperatures in the Central Pacific Ocean are about 2°C warmer than normal.
As of June 14, the sea surface temperatures in this region were 0.92°C above average. However, forecasting models suggest temperatures could exceed the 2°C threshold by late winter.
However, a “super El Niño” will not necessarily lead to “super droughts” or “super bushfires”. That’s because, in Australia, the strength of an El Niño event is not related to the severity of its impacts.
The 2002 El Niño event was weak, but was still associated with widespread drought and severe bushfires in some parts of Australia. In contrast, the strong El Niño of 2015 affected rainfall patterns differently across the country.
El Niño is just one ingredient in the recipe of Australian weather.
Our weather is influenced by El Niño in the Pacific Ocean as well as the Indian Ocean Dipole, sometimes known as El Niño’s cousin to the west. Australia’s weather is also shaped by shifts in the jet stream to the south – which impacts how many cold fronts reach Australia – and tropical storms in the north.
Now that El Niño has been declared, scientists will keep a close eye on what happens in the Indian Ocean. If waters off Australia’s northwest cool over winter, the rest of the year may be quite dry. But if the waters off northwest Australia get warmer, it’s less likely a drought will develop.
In short, many factors must coincide to cause severe droughts and bushfires in Australia. Currently, this is not happening. So the Bureau’s long-range forecast – which considers all these factors as well as El Niño – offers the most accurate information about Australia’s ever-changing weather.
Kimberley Reid receives funding from the Australian Research Council.
US President Donald Trump hailed the deal ending the US-Israel war with Iran with a triumphant message: “Ships of the World, start your engines. Let the oil flow!” he wrote on his online social media platform.
But how realistic is a swift resumption of ship movement through the Strait of Hormuz?
Oil traders are hopeful. The benchmark price for Brent crude oil has fallen below US$80 a barrel to US$78.96 (A$111.82) for the first time since early March. This signals a belief that Trump’s Iran deal is going to stick, despite the president claiming a peace deal about 40 times.
The US Navy has said its blockade will remain in place until the agreement is signed on June 19.
Even so, it could take at least six months before oil flows out of the Strait of Hormuz are back to pre-conflict levels, and much longer for liquefied natural gas (LNG), due to Iran’s extensive damage to Qatar’s LNG facilities.
Shippers are cautious
A quarter of the world’s seaborne oil trade and 19% of refined petroleum products are carried through the Strait of Hormuz. It also carries about one-fifth of the world’s LNG and a significant share of the global seaborne chemical trade, particularly fertilisers.
The conditions of the reopening are ambiguous. There is no published text of the draft agreement, but Iran’s Mehr state news reported there would be a reopening of the strait within 30 days under “Iranian arrangements”.
However, there should be some near-term supply boost. About 60 tankers loaded with crude oil that have been trapped in the Persian Gulf since the conflict began in February may be able to start moving oil to markets.
Some of these ships are large enough to carry 2 million barrels of oil (roughly two days of Australian oil consumption.
But it will take longer for the significant number of ships waiting outside the Strait of Hormuz to enter the Gulf and be loaded, based on maritime traffic tracking data.
Is the strait safe?
Since Sunday’s announcement, there has been little change to traffic through the strait. And shippers have given a cautious reaction to the draft agreement. Little wonder – 38 vessels have been hit during the conflict: 24 by Iran, four by the US and the rest unconfirmed.
According to reports, it could take also months to clear the strait of mines laid by Iran.
There are mixed messages coming from Iran and the US, with Tehran saying it will charge a fee for services, while Trump said the strait will be toll-free. This apparent difference has yet to be explained.
Much damage is yet to be fixed
The war caused significant damage to energy infrastructure in the region. More than 80 facilities were attacked during the conflict.
The recovery will be gradual as damage has affected oil fields, refineries and pipelines across the Persian Gulf, IEA executive chairman Fatih Birol said. This damage includes:
United Arab Emirates
Last month, the United Arab Emirates (UAE) said it would take until 2027 before full oil flows will resume, even with an immediate end to the conflict. The UAE is the third-largest oil exporter shipping through the strait behind Saudi Arabia and Iraq.
Iran
Iranian oil producers should welcome the agreement, which is expected to include a US waiver on oil sanctions that will allow Tehran to sell oil to more customers. However, some of Iran’s energy infrastructure was damaged when Israel struck the South Pars gas field and infrastructure at the nearby Asaluyeh processing hub. Iran said it has restarted production at three offshore platforms in the South Pars gas field, but did not indicate how long it would take to repair the damaged infrastructure.
Qatar
A full recovery of the region’s LNG exports could take up to five years following an Iranian attack on the largest LNG processing facility, Qatar’s Ras Laffan gas complex. Before the war, this facility was producing 77 million tonnes of LNG – almost 19% of global output last year. QatarEnergy said repairs will see 12.8 million tonnes offline for between three and five years.
Australia has weathered the storm
In the early weeks of the war, the IEA warned the Iran conflict was the largest supply disruption in the history of the global oil market. But despite this, Australia has weathered the storm in reasonable shape.
The country has been importing record volumes of diesel, boosting stocks of the fuel vital to trucking mining and farming. Diesel accounts for more than half of Australia’s daily oil consumption. As a result, Australia has managed to remain at level 2 of the National Fuel Security Plan, meaning there were no mandatory fuel restrictions.
If it eventuates, a permanent peace deal will no doubt be welcomed by all energy users. However, if the deal does not hold and the strait is once again forced to close, prices could rebound higher and drivers will be once again be concerned about future shortages.
Kevin Morrison is affiliated with the Institute of Energy Economics and Financial Analysis (IEEFA).
