Norfolk Shark eats Seal (its in the Sun) (1 Viewer)

StuartReeves said:

I think Ilya's suggestion is much more likely than the wild speculation about large sharks in the North Sea. Porbeagle is the only large shark that regualrly occurs in the North Sea. While Blues, Threshers and maybe even Mako maybe regular of the South-west of Britain, the North Sea is a very different environment oceanographically. A good analogy would be Wilson's Petrel or Great Shearwater, both of which occur in the Atlantic waters of the South-West but are very rare in the North Sea.

Click to expand...

Stuart,

Without wishing to be critical to a large degree, can I point out that this post would make any form of sea watching pointless? I have pulled this out separately to my other reply because had you reversed this and posted it on one of the birding threads, you may have been hung, drawn and quartered (LOL) I think what we have to recognise about marine creatures is that their barriers are barely greater than those of birds yet, are much less restricted than terrestrial creatures. In other words, if it is possible for a species to be in a given place it probably will be at some point in time. For example, it was thought that the leatherback turtle was an accidental visitor to UK (Welsh and Irish) coasts (certainly the case when I was a student at UCNW Bangor graduating in 1990). It is now thought that the turtles deliberately choose to be here even if numbers are low on an annual basis and given the global population of these animals. If we can have missed a large air-breathing reptile for so long, why should we dismiss the possibility of creatures that do not necessarily get to the surface and may for other reasons, not be recorded in catch returns?

Ian

Ian Peters said:

Stuart,

Without wishing to be critical to a large degree, can I point out that this post would make any form of sea watching pointless? I have pulled this out separately to my other reply because had you reversed this and posted it on one of the birding threads, you may have been hung, drawn and quartered (LOL) I think what we have to recognise about marine creatures is that their barriers are barely greater than those of birds yet, are much less restricted than terrestrial creatures. In other words, if it is possible for a species to be in a given place it probably will be at some point in time. For example, it was thought that the leatherback turtle was an accidental visitor to UK (Welsh and Irish) coasts (certainly the case when I was a student at UCNW Bangor graduating in 1990). It is now thought that the turtles deliberately choose to be here even if numbers are low on an annual basis and given the global population of these animals. If we can have missed a large air-breathing reptile for so long, why should we dismiss the possibility of creatures that do not necessarily get to the surface and may for other reasons, not be recorded in catch returns?

Ian

Click to expand...

Fair enough point, except that...if the Sun reported a "large shearwater spp" going past Cromar I wouldn't rule out the Mongolian Navy, let alone Fulmar or Manxie.

Start with the obvious and go from there. Anybody tell me why think it wasn't a boat propeller? Happy to concede if provided with a convincing argument, but waiting for something other than conjecture....

Well, looking at the pictures I'd say it is more like a bite mark rather than a propellor but like you said, if there isn't a proper examination of the body then the whole debate is rather futile because we're never going to know. What I really don't understand is that there are supposed to be procedures for investigating seal deaths along the coast. Aren't the Institute of Zoology supposed to be informed and a post mortem conducted if appropriate? Nothing seems to have been reported as to whether the body has been taken away for such an examination and if not, why not?!

Ilya Maclean said:

Fair enough point, except that...if the Sun reported a "large shearwater spp" going past Cromar I wouldn't rule out the Mongolian Navy, let alone Fulmar or Manxie.

Start with the obvious and go from there. Anybody tell me why think it wasn't a boat propeller? Happy to concede if provided with a convincing argument, but waiting for something other than conjecture....

Click to expand...

Hi Ilya,

I had a feeling that the 'wild speculation' comment was generated by the fact that the initial story was carried by The Sun and I was not offended by Stuart using this phrase. I have found this thread fascinating and far from speculation it has just been a discussion on possibilities. There have been quite a number of less sensationalist books on sharks over the years but it is usually necessary to plough through the rest to find them. However, some of the best ones have as much detail as we would expect from a good bird guide and this is where much of the information came from. Basically, the distribution maps show that there is a possibility of encountering more large sharks than are commonly known from British waters. Indeed, it is likely that some have been taken as by-catch during trawling operations but have not been recorded because they were never landed at a port

If you look carefully at the image, the edges are slightly scalloped and this would be consistent with a bite mark rather than propeller damage. In fact, the damage seems too regular compared to other propeller injuries I have seen photographed. It is rare for propeller damage to be comprised of a single injury too because there are often slash marks before the propeller digs in. The account says the injury had a slightly ventral bias too although this may be a bit misleading because the state of the flesh looks (unless someone else has a view) as though the injury could have been caused post mortem.

I have been reluctant to suggest this because it was dismissed so early in the thread but I am not entirely convinced that orca can be ruled out. I am not sure how they do it but I have seen photographs of damage to the flanks of whales known to have been caused by orcas that is every bit as clean as this mark. Of course, the size of the mark would rule out an adult but orcas sometimes let the youngsters practise their skills when the conditions are rightn and this would make sense if the seal was already dead.

Ian

There was an interview with the lifeboat man who found it on Stephen Nolan's programme on Radio Five Live last night. If anyone can be bothered you can hear it on the 'Audio on demand' section on this page. The interview starts 2 hours 46 mins in:
http://www.bbc.co.uk/fivelive/listen/

Stephen Nolan is a bit of an oaf but it's quite an interesting interview.

Ron

NoSpringChicken said:

There was an interview with the lifeboat man who found it on Stephen Nolan's programme on Radio Five Live last night. If anyone can be bothered you can hear it on the 'Audio on demand' section on this page. The interview starts 2 hours 46 mins in:
http://www.bbc.co.uk/fivelive/listen/

Stephen Nolan is a bit of an oaf but it's quite an interesting interview.

Ron

Click to expand...

Thanks Ron,

I found it in the end. Interesting that one of the experts has stated this could have been caused by the original attack bite. I am pretty sure that contemporary ideas have moved away from this idea and explain why GWS attacks on humans do not always involve a catastrophic bite of this kind but usually a slashing wound. Bites on humans are not always a good comparison anyway because we have limbs that can be easily bitten through or removed. However, seals are normally hit from below with the lower jaw of the shark opening a massive haemorraging wound. There is no need to bite down during the initial attack because the victim will be disabled by shock and blood loss and will be dead within minutes. I still say this case is of a feeding bite and this does not necessarily rule out any particular species except on the grounds of size.

Ian

At this stage, I would like to thank everyone for a great discussion given that this was promoted from sensationalist souces and could easily have got out of hand. Hats off to BF-ers.

Whatever the cause of the injury, I think the seal should have been left in situ, It would have made superb bait for any passing Ivory Gulls following the recent cold easterly winds.

This thread should not be in the" Live Bird News from around the World" section it should be moved to "Mammals & Sea Life" it's not as if there wasn't a category to put it into.

Twite.

In that case may I present an alternative theory that the seal was dropped by a south-bound gannet?

Ian Peters said:

Stuart,

Without wishing to be critical to a large degree, can I point out that this post would make any form of sea watching pointless? I have pulled this out separately to my other reply because had you reversed this and posted it on one of the birding threads, you may have been hung, drawn and quartered (LOL) I think what we have to recognise about marine creatures is that their barriers are barely greater than those of birds yet, are much less restricted than terrestrial creatures. In other words, if it is possible for a species to be in a given place it probably will be at some point in time. For example, it was thought that the leatherback turtle was an accidental visitor to UK (Welsh and Irish) coasts (certainly the case when I was a student at UCNW Bangor graduating in 1990). It is now thought that the turtles deliberately choose to be here even if numbers are low on an annual basis and given the global population of these animals. If we can have missed a large air-breathing reptile for so long, why should we dismiss the possibility of creatures that do not necessarily get to the surface and may for other reasons, not be recorded in catch returns?

Ian

Click to expand...

This reply misses my basic point that there is a substantial habitat difference between the oceanic waters off the South West and the shallow shelf sea of the North Sea. This is the basis of my original analogy with Wilson's Petrel; birds at the shelf edge off the SW are in their normal habitat whereas birds in the North Sea are a long way off course. Most sharks (and Leatherback Turtles for that matter) are similarly linked with specific hydrographic conditions. The waters of the North Sea are better studied and more intensively fished than those of the SW but Porbeagle is still the only large shark to be found with any regularity. In contrast a much wider range of species occur off of the SW. If the seal corpse had been found on the coast of Cornwall then shark attack might have been a plausible hypothesis. I really don't think that that holds for the southern North Sea.

Stuart