Beaked whales live deep in the ocean, far from cities, harbors and other populated areas. The animal rarely meets people. And yet it affects us in fourteen different ways, new research shows.
This can be read in the magazine Royal Society Open Science. For the study, the researchers analyzed previously published studies that focused on beaked whales (see box). These studies revealed a number of threats to beaked whales, and researchers have now collected them and assessed the extent to which they are actually affecting the beaked whales.
Fourteen threats
The review leads to a less-than-encouraging study in which researchers must conclude that humans (or human activities) threaten beaked whales—also considered the least human-contact species—in fourteen different ways. “The situation of beaked whales can serve as a warning because it suggests that no species – no matter how remote or rare – is immune to anthropogenic impacts,” says researcher Laura Feyrer.
Beak whale
Beaked whales are a family belonging to the suborder of toothed whales. This family is home to 24 species, including Cuvier’s dolphin, Blainville’s beaked whale, and black dolphin. The latter species is – as far as we know – the largest beaked whale; females – which grow larger than males – can be up to 10 meters long. Most of the beaked whales live in remote areas, at great depths and are rarely found on the coast. We know very little about most species. Actually; Beaked whales are known as the least studied mammals on earth. Some species have never even been seen alive and are only described from captured fish or washed-up carcasses. And it doesn’t seem impossible that we haven’t even discovered all species of beaked whales yet.
We may rarely see beaked whales and not know them; According to a new study, they really do bother us. And in fourteen different ways. The biggest man-made threats are climate change and plastic pollution, as can be read in the research article by Feyrer and colleagues.
Climate change
For example, climate change changes the habitat of beaked whales and the ecosystem of which it is a part. For example, climate change leads to a decrease in sea ice, acidification of sea water and an increase in sea heat waves. “These changes have significant implications for the migration, growth, reproduction, and survival of marine organisms, including cetaceans (such as beaked whales, ed.),” the researchers write.
Plastic
Plastic pollution is also a big problem for beaked whales. The few beaked whales studied by scientists have been found to have plastic in their stomachs with considerable frequency. And it often turned out that beaked whales actually suffered from this or even died from it. And we’re not even talking about microplastics, which beaked whales are likely to ingest directly – or indirectly through microplastic-filled prey. These have also been observed in several beaked whales and can accumulate in their bodies and lead to health problems, the researchers warn.
Sonar
What is also of great concern to researchers is the use of military sonar. The use of this can be linked to the stranding of at least eight beaked whales, all of which eventually died. There are also studies showing that at least eleven beaked whales deviate from the probe; they stop hunting, change their diving behavior – giving them symptoms similar to diving sickness – flee their habitat and likely become so exhausted that their health suffers and they may even die. This may happen more often than expected; the deportations mentioned by the researchers took place near populated areas. But military exercises further out at sea can sometimes result in invisible beaked whales suffering health problems or even dying.
Oil
Other threats that the researchers identify in their research are ship noise and collisions between beaked whales and ships. Mammals are also at risk of entanglement in fishing nets. Drilling for oil and oil spills during oil spills is also likely to pose a threat to beaked whales.
To hunt
But it’s not just modern human activity that’s leaving its mark on lampreys. Scientists suspect that whaling continues to have a negative impact on beaked whales, as it led to population declines and changed ecosystems forever. For the black dolphin, whaling is not completely gone; in some places these animals are still hunted. We don’t know what the consequences of this are for the population.
Unknown threats: inbreeding or deep sea mining
And beaked whales may also face threats that are not yet on our radar – in part because we know so little about beaked whales. Researchers are thinking about health problems caused by population decline, inbreeding or infectious diseases, for example. But since we don’t know exactly how beaked whales are doing, there isn’t much that makes sense to say. Another threat that we cannot yet fully understand is deep-sea mining, which is expected to have adverse consequences for beaked whales, but it remains unclear what exactly these consequences will look like.
Cumulative effect
And so beaked whales have a lot to digest. And that is also a cause for concern. Because a beaked whale can survive a single threat, but an accumulation of threats and challenges can eventually destroy it. At the same time, it remains somewhat unclear which species in which areas face which challenges and whether they really have a cumulative effect. A follow-up study should reveal this. “However, our assessment highlights that despite their remote habitat, beaked whales are exposed to many anthropogenic stressors, which may make them more vulnerable,” the researchers concluded.
To what extent this really is a problem – and may even lead to species extinction – is unclear. Because we simply don’t know enough about the beaked whale for that. Therefore, it is not surprising that scientists recommend more research on these rather mysterious animal species. First, it is important to find out how large their populations are. After that, it is necessary to study what challenges individual beaked whales face and to what extent this affects the population size. The researchers also call for more research aimed at finding out the current and future effects of climate change on beaked whales. “A better understanding of beaked whale population size, health and behavior is critical to developing effective conservation strategies,” concludes Feyrer. “This study highlights the importance of monitoring and regulating human activities that affect beaked whales (…) worldwide.”