Pilot Whale Mass Stranding (1 Viewer)

[Mono]

On Isle of Lewis today 55 animals.

Entire pod of 55 whales dies after mass stranding on Lewis

Just 15 were alive after the stranding and vets had to euthanise the survivors on welfare grounds.

www.bbc.co.uk

As with a lot of these Pilot Whale strandings it seems to be a case of a single injured or diseased individual straying into shallow water and rest of the pod following them.

It makes me curious as to the evolutionary benefit of such a behaviour. The gain of staying with a debilitated pod-mate must be huge to counteract to counteract the losses of such standings.

Any thoughts?

 

[Phil Andrews]

My thoughts are that this number is just 7% of those killed annually on the Faroes in the grind 🤬

 

[Farnboro John]

I think we need much more research and analysis to understand the mechanism let alone the cost/benefit aspects.

Why do Pilot Whales do this and not other podding species (or do they?) Is it always Long-finned Pilot Whales or do Short-finned do the same thing? What about Orcas, or super-pods of Common Dolphins, or Sperm Whales?

Is the killer leader always the senior member of the group or can it be any individual? If it is always the leader, why doesn't it happen every time a leader gets ill or sinks towards senescence and death?

Why hasn't the behaviour been evolved out given its fatality?

Are there common factors in the beach profiles? If not, how do we explain the phenomenon?

And one for the would-be rescuers: if you identify and actively kill the sick individual do the remainder stop the suicidal behaviour?

John

 

[angusmcoatup]

Are there historical records of regular mass strandings before technology introduced lots of unnatural factors into Cetacean environments?

 

[Farnboro John]

Are there historical records of regular mass strandings before technology introduced lots of unnatural factors into Cetacean environments?

Yes. Right back into the fossil record. It's not a human produced problem and if it had been then WWI and WWII with their huge convoy battles and consequent torpedo and depth charge explosions all over the Atlantic would have seen incidents rocket. Not only that but every ship from trawler to huge super-tanker uses active sonar to look at the seabed and for other obstructions - and dolphins still bow-ride.

On top of that, as I've said before, although naval vessels including submarines carry large and powerful active sonars the effect of using them is to say "here I am, come and kill me" and those are used only as a desperate last resort to get a hard target fix in time to shoot first: otherwise they stick exclusively to using passive sonar (i.e. listening elements only, no active pinging) to avoid detection while still hearing what is around them.

The biggest effect sonar has ever had on oceanic wildlife is its use by fishing boats to find and catch big shoals of fish, and you don't hear people campaigning for the removal of fish-finding sonar from trawlers worldwide.

The whole activist anti-sonar campaign is rubbish. Humans are not responsible for every wildlife problem in the world.

John

 

[Mono]

I seem to recall an incident in Scotland where a group of Pilot Whales were trying to get into a narrow inlet they were driven back out to sea by boats. They tried several times. Some did strand and then the rest just swam back out to sea. Amongst the stranded ones was an old and obviously very ill individual.

 

[dantheman]

Apparently at the time the west coast of America was 'discovered' a couple centuries ago the population of Californian Condor extended all the way up to Washington State or something like that. Feeding on washed carcasses as a major food source. Whaling put an end to all that (iirc and not misrecalled details or it was just someone's pet theory).

 

[dantheman]

The whole activist anti-sonar campaign is rubbish. Humans are not responsible for every wildlife problem in the world.

John

Don't get between John and his beloved sonar too early in the morning ...

;-)


As it is hard to always know what is going on in environments we can't see too well, I reckon a line of it being a possible influence.

Military exercises occurring do sometimes coincide with mass stranding events - don't know what statistical analysis has been done and with what results/rigour. An issue is that underwater sonar events/testing/explosions won't have always been reported by the militaries involved.

Temporary deafness or disorientation nearer shore could have greater effects when then coupled with other factors such as the local seabed topography and become a causal factor ...


First googling -

Does Military Sonar Kill Marine Wildlife?

The frequency used in military testing could be harmful to some animals

www.scientificamerican.com

The jury may be out, but I think healthier to remain cynical of government instruments to some degree ... ;-)

 

[Farnboro John]

Don't get between John and his beloved sonar too early in the morning ...

;-)


As it is hard to always know what is going on in environments we can't see too well, I reckon a line of it being a possible influence.

Military exercises occurring do sometimes coincide with mass stranding events - don't know what statistical analysis has been done and with what results/rigour. An issue is that underwater sonar events/testing/explosions won't have always been reported by the militaries involved.

Temporary deafness or disorientation nearer shore could have greater effects when then coupled with other factors such as the local seabed topography and become a causal factor ...


First googling -

Does Military Sonar Kill Marine Wildlife?

The frequency used in military testing could be harmful to some animals

www.scientificamerican.com

The jury may be out, but I think healthier to remain cynical of government instruments to some degree ... ;-)

But since many (most?) mass stranding events occur in the waters of e.g. New Zealand which is famous for not operating anything effective and banning transit by any nuclear vessels e.g. submarines - which are the ones with the big sonars - it is evident that Pilot Whales will mass strand without intervention by humans. In any case it is already been demonstrated (hence mention in the OP's post) that the whales follow an injured or diseased animal onto the beach and if a whole herd/school/pod had been hit by sonar in the way activists would like to believe then all of them would be injured (and if all were deafened one wonders if they could keep contact with each other let alone find the coast and the beach). It's just nonsense and I really wonder if it's actually Russian propaganda intended to reduce Western navies' effectiveness through political action by the terminally gullible.

John

 

[dantheman]

But since many (most?) mass stranding events occur in the waters of e.g. New Zealand which is famous for not operating anything effective and banning transit by any nuclear vessels e.g. submarines - which are the ones with the big sonars - it is evident that Pilot Whales will mass strand without intervention by humans. In any case it is already been demonstrated (hence mention in the OP's post) that the whales follow an injured or diseased animal onto the beach and if a whole herd/school/pod had been hit by sonar in the way activists would like to believe then all of them would be injured (and if all were deafened one wonders if they could keep contact with each other let alone find the coast and the beach). It's just nonsense and I really wonder if it's actually Russian propaganda intended to reduce Western navies' effectiveness through political action by the terminally gullible.

John

Random article -

What Caused the Largest Known Mass Stranding of Stejneger’s Beaked Whales?

New scientific article is the first comprehensive paper on this elusive, deep-diving species, Stejneger’s beaked whale.

www.fisheries.noaa.gov

From the article -

Globally, strandings and mass stranding of deep-diving whale species, such as beaked whales, have been causally linked to mid-frequency active sonar (MFAS) use by military operations. Previous research looked at the tissues in stranded beaked whales whose deaths were causally-linked to military sonar operations near the Canary Islands. They found hemorrhaged and congested tissues around the acoustic jaw fat, ears, brain, and kidney. There were also gas bubble-associated lesions and fat embolism in the vessels and tissues of vital organs. The result of this tissue damage is something akin to decompression sickness, caused by nitrogen supersaturation beyond levels that tissues can withstand.


As I say, it's part of the story. No-one saying the only part.

 

[Mono]

With the most recent Pilot Whale stranding one of the older females in the pod, the pods are thought to be matriarchal, was suffering from a vaginal prolapse. This may be linked to another stranding on Lewis a few weeks ago of a single, near-term, neonatal Pilot Whale.

 

[Farnboro John]

Random article -

What Caused the Largest Known Mass Stranding of Stejneger’s Beaked Whales?

New scientific article is the first comprehensive paper on this elusive, deep-diving species, Stejneger’s beaked whale.

www.fisheries.noaa.gov

From the article -

Globally, strandings and mass stranding of deep-diving whale species, such as beaked whales, have been causally linked to mid-frequency active sonar (MFAS) use by military operations. Previous research looked at the tissues in stranded beaked whales whose deaths were causally-linked to military sonar operations near the Canary Islands. They found hemorrhaged and congested tissues around the acoustic jaw fat, ears, brain, and kidney. There were also gas bubble-associated lesions and fat embolism in the vessels and tissues of vital organs. The result of this tissue damage is something akin to decompression sickness, caused by nitrogen supersaturation beyond levels that tissues can withstand.


As I say, it's part of the story. No-one saying the only part.

Since kidneys are not part of the acoustic organs and it would be challenging to establish cause and effect, plus there are findings of gas bubble associated lesions in other tissues, it sounds like whales are capable of exceeding their own capacities. Also the sentence I have highlighted does not say why these things have been linked to MFAS and I think you will find it is the unsupported accusations of the activists I have already mentioned rather than scientific investigation. Causal linking is not the same as establishing fact.

Part of the article you didn't quote said:

"NOAA Fisheries marine mammal experts contacted the U.S. Navy shortly after the 2018 mass stranding. It confirmed that they had not conducted training or testing activities using sonar or explosives anywhere in Alaskan waters since May 2017.

However, the U.S. Geological Survey’s Alaska Volcano Observatory’s monitors had detected human-caused seismic survey activity at regular intervals for hours at a time along the Aleutian Islands between July 5 and 20, 2018. Based on triangulation of data from multiple seismometers, the observatory determined the source of the noise likely centered about 40 miles northwest of Adak. Scientists still do not know the source of the seismic activity. Fourteen days passed between the last detection of the seismic activity and the discovery of the first whale that was part of the 2018 Adak mass stranding event. However, a link between the Stejneger’s beaked whale mass stranding and the seismic activity cannot be ruled out."

So MFAS is ruled out but human activity is not (though with proper scientific practice the article also acknowledges there is not established causal link between the seismic survey and the mass stranding, just circumstantial inference). Partisan selectivity in data revealing is part of misrepresentation of the story to support a campaign aim rather than truth telling.

Cheers

John

 

[dantheman]

Since kidneys are not part of the acoustic organs and it would be challenging to establish cause and effect, plus there are findings of gas bubble associated lesions in other tissues, it sounds like whales are capable of exceeding their own capacities. Also the sentence I have highlighted does not say why these things have been linked to MFAS and I think you will find it is the unsupported accusations of the activists I have already mentioned rather than scientific investigation. Causal linking is not the same as establishing fact.

Part of the article you didn't quote said:

"NOAA Fisheries marine mammal experts contacted the U.S. Navy shortly after the 2018 mass stranding. It confirmed that they had not conducted training or testing activities using sonar or explosives anywhere in Alaskan waters since May 2017.

However, the U.S. Geological Survey’s Alaska Volcano Observatory’s monitors had detected human-caused seismic survey activity at regular intervals for hours at a time along the Aleutian Islands between July 5 and 20, 2018. Based on triangulation of data from multiple seismometers, the observatory determined the source of the noise likely centered about 40 miles northwest of Adak. Scientists still do not know the source of the seismic activity. Fourteen days passed between the last detection of the seismic activity and the discovery of the first whale that was part of the 2018 Adak mass stranding event. However, a link between the Stejneger’s beaked whale mass stranding and the seismic activity cannot be ruled out."

So MFAS is ruled out but human activity is not (though with proper scientific practice the article also acknowledges there is not established causal link between the seismic survey and the mass stranding, just circumstantial inference). Partisan selectivity in data revealing is part of misrepresentation of the story to support a campaign aim rather than truth telling.

Cheers

John

Yes, and I agree with your very first point in post#3

"I think we need much more research and analysis to understand the mechanism let alone the cost/benefit aspects."


I'm also not selectively choosing data for misrepresentation - the bit I highlighted was really there for the highlighted bit in the key sentence- "Previous research looked at the tissues in stranded beaked whales whose deaths were causally-linked to military sonar operations near the Canary Islands" (I haven't looked at or opened any other articles or papers - it was the first I clicked on).

(The beaked whale cases different to the pilot whales of course). There have been a lot of strandings over the years - some of which some people have linked to military events. It would be interesting to look at some papers with an overview or analysis of the situation - I have no clue where to start.


If it were to be proven that no human-caused events had impacted cetaceans in this manner ever that would be fine be me. I would be surprised though ... things usually have consequences. (I do find it hard to get my head around the concept that the Russians have invented the whole idea tho!)

 

[Farnboro John]

Yes, and I agree with your very first point in post#3

"I think we need much more research and analysis to understand the mechanism let alone the cost/benefit aspects."


I'm also not selectively choosing data for misrepresentation - the bit I highlighted was really there for the highlighted bit in the key sentence- "Previous research looked at the tissues in stranded beaked whales whose deaths were causally-linked to military sonar operations near the Canary Islands" (I haven't looked at or opened any other articles or papers - it was the first I clicked on).

(The beaked whale cases different to the pilot whales of course). There have been a lot of strandings over the years - some of which some people have linked to military events. It would be interesting to look at some papers with an overview or analysis of the situation - I have no clue where to start.


If it were to be proven that no human-caused events had impacted cetaceans in this manner ever that would be fine be me. I would be surprised though ... things usually have consequences. (I do find it hard to get my head around the concept that the Russians have invented the whole idea tho!)

I wasn't suggesting the Russians invented it, but it's not unthinkable that they would exploit an opportunity to cause trouble.

John

 

[edenwatcher]

I think the beaked whale scenario is very different from pilot whales. I went to talk recently which presented the evidence around beaked whale behaviour - including tracking - which showed some fairly dramatic responses and changes in dive patterns. Basically it stops them from echolocating.

Rob