A study has found that the number of marine mammals washing ashore in Scotland has increased significantly over the past 30 years. Between 1992 and 2022, 5,147 cetaceans were stranded on Scottish coasts. A new paper reveals that stranding rates for some species have surged by as much as 800%, with the trend continuing to grow each year.
The research, conducted by the University of Glasgow’s Scottish Marine Animal Stranding Scheme (Smass), comes after an unusual series of strandings this summer involving rarely seen deep-diving whales along northern European shores. Over just over two weeks, 36 beaked whales and pilot whales were found stranded from western and southern Ireland to Orkney, Norfolk, the Netherlands, and southern Sweden. These animals appeared to have entered shallow waters where they couldn’t find their usual prey, such as deep-sea squid.
The widespread nature of these events is causing serious concern, especially among volunteer groups trying to rescue stranded whales—though none of the recent cases were successful.
“Clusters of beaked whales should raise suspicions,” said Dr. Andrew Brownlow, director of Smass.
Sonic disturbances are believed to cause deep-diving whales to strand. Rachel Lennon, lead author of the paper published in Scientific Reports, noted that in Scotland, “sources of human-made noise are abundant, including seismic survey air guns and drilling from industrial construction.”
The paper does not address concerns that military sonar exercises in the open ocean are a known factor in such events. Brownlow pointed out that in 2018, a “globally unprecedented” group of 118 stranded beaked whales off Ireland and western Scotland was traced to a single sound source beyond the continental shelf.
The paper was released just weeks after Smass scientists responded to the strandings of four northern bottlenose whales—another beaked whale species—and a pod of 23 pilot whales in the Orkney Islands. The pilot whale stranding occurred almost exactly a year after a record 77 of the same species stranded on the same Orkney beach. So far this year, 150 animals have mass-stranded off Scotland.
Smass scientists are also worried about the sharp rise in stranded baleen whales, such as fin, minke, and humpback whales, over the study period. This could be due to more animals moving north as waters warm from climate change. It might also be a delayed effect of the end of whaling—Lennon observed that “as populations begin to recover from historic whaling, reports of entanglement have increased.”
As surface feeders, baleen whales are more likely to get caught in fishing gear, leading to slow deaths from starvation or infection. The paper also shows an increase in stranded common dolphins and harbour porpoises, which are vulnerable to collisions with leisure boats.
The 30-year report indicates that stranded whales and dolphins act as “sentinels”—visible warnings of how human activity is impacting the marine environment.
“Clearly the oceans are changing,” Brownlow said. “Scotland is on the edge of this shift. We now see sperm whales calving off our shores, whereas we never saw females in these northern waters before. Beaked whales used to be recorded only in small numbers in the autumn. Temperature, salinity, prey distribution, oceanic heatwaves—the patterns are shifting, and we need to be aware.”We are getting better at locating these animals and determining when they are present. “This is the new normal, and we must proceed with the utmost care.”
Frequently Asked Questions
Of course Here is a list of FAQs about the increase in whale and dolphin strandings in Scotland designed to be clear and helpful for a range of audiences
General Beginner Questions
Q What does stranding mean
A A stranding is when a whale dolphin or porpoise gets stuck on land either alive or dead and is unable to get back to the water on its own
Q Has there really been an increase in strandings in Scotland
A Yes Organizations like the Scottish Marine Animal Stranding Scheme have recorded a significant and concerning rise in the number of reported strandings in recent years
Q What kinds of animals are most commonly stranding
A In Scotland its often deepdiving species like sperm whales and northern bottlenose whales as well as dolphins like the common dolphin and harbour porpoises
Q What should I do if I find a stranded whale or dolphin
A 1 Do not approach or try to push it back 2 Call the experts immediately at the British Divers Marine Life Rescue hotline 01825 765546 They will give you instructions
Causes Reasons
Q Why are more whales and dolphins stranding Whats causing it
A There isnt one single cause Its usually a combination of factors like human activity disease injury from fishing gear and natural toxins from algal blooms
Q Ive heard about sonar How does that cause strandings
A Powerful military sonar or seismic surveys for oilgas can disorient deepdiving whales They may surface too quickly to escape the noise which gives them decompression sickness leading to injury and stranding
Q Can pollution cause strandings
A Indirectly yes Chemical pollution can weaken an animals immune system making it more susceptible to disease Ingesting plastic debris can also cause internal blockages malnutrition and death leading to a stranding
Q Are these strandings a sign of a bigger problem in our oceans
A Absolutely Strandings are often a vital indicator of ocean health A spike in numbers can signal wider environmental issues such as changes
