Tuesday, 6 April 2010

Not neccessarily happy slapping?

Hi Cliff,
very few porpoise around in the sound, a couple on Friday, non on Saturday, a couple on Sunday, Alison was still out there when I left, maybe she had better luck.

Those that did arrive down the sound on Sunday had to run the gauntlet of NT Boats.
Funny how some of these boats enter the porpoise sensative area, decide after a few minutes there are non to see then leave as if there is no porpoise sensative zone!

I had a incident of a porpoise tail slapping last week, this one individual, apparently an adult, on its own, tail slapped repeatedly, diving for a few seconds then reappearing and tail slapping again, my last thought was, was it just trying to get a bit more power into a quick shallow dive?

cheers
Malcolm


Interesting thought Malcolm.
I have seen and filmed Common Dolphins suffering from a spinal deformity (Scoliosis) doing just that and there are instances of similar behaviour in the case of a female bottlenose dolphin in the Moray Firth. Presumably some injury to the spine might cause the same effect in porpoises, although this, and how animals might sustain such an injury or indeed an injury as sustained by Splitfin are open to conjecture.

Yes as you say, again the season for Nature Trip (NT?) boats is on us and again the skippers are under pressure to get in and out quickly to fulfil the number of trips that will increase bums on seats and profitability. The operators seem to feel this is reasonable and has no effect on porpoise numbers using the sound. Who knows sightings may even increase?

None the less it does seem that from your work and Alison's observations there is some pretty obvious decline in sightings since the end of the last nature trip season. Whatever the reason it is a cause for concern and highlights the fact that were it not for yours and Alisons efforts along with Ernst and Anieks work and photo's, these facts collected would not be documented.

Splitfin photo : Ernst Schrijver