Thursday, 21 February 2013

Stena Irish Sea Survey, are our porp's on the move? nothing is certain!

Steve Rosser, Hannah Harries, Elfyn Pugh, Dave Cunnife and the Walrus headed off to Rosslare on Tuesday afternoon, a veritable "A" team ,all of whom responded at a couple of hours notice to my call! 
Conditions were pretty good on the way out and Dave was on fire, spotting porpoises way before the rest of us! It really does illustrate the fact that on any given day no two observers will neccessarily be switched on to the same degree. On another day it might be me or Steve, we are not robots!
Hannah was also pretty alert and clocked a couple more porp's  for us, but Dave scored again with two animals that were most probably Risso's but we just did not manage to get them clearly enough as they silhouetted against the low sun and dissapeared into the glare on our port side.

Aerchive Image: Steve Rosser.

They will go down as "unidentified dolphins"  because although all of us were pretty sure, they were Risso's, none of us were 100% and thats an other good illustration of how with some of the best observers I know, you still cant expect to nail everything that is sighted. None the less we were pretty sure we had  not missed much even if we could not positively identify every single animal.
The following morning the wind had got up and our team were faced with a choppy sea with a low winter sun and plenty of glare! It does not matter how good you are are how hard you try,  There is no way you can really work efficiently in those conditions on effort so any sightings are then demoted to casual. Not surprisingly the only animals seen were a couple of Strumble porpoises.
The interesting thing is that we saw several animals strung out right across the transect (the ferry route) . Steve recalled another similar crossing at the same time last year with similar porpoise sightings spread across the Irish Sea.

 Archive Image: Ernst Schriver
  We will have to have a look into our records and try and see if this is a trend because although we do see porpoises at different places across the transect, most are seen within the inshore areas. We have also had plenty of surveys in good conditions where none were seen offshore. It may well be that we are beginning to identify movements between the irish and welsh coast, perhaps seasonal. Porpoises are generally small and inobtrusive and boat shy. Most often when we see them,  they either just dive or swim away from the boat so its not really possible  to tell which way they are swimming because they are probably just reacting to the close and oncoming presence og a 30,000 ton ferry. Of course as yet we cant be certain but we can speculate . perhaps more detailed examination of our records will be more revealing!