Posted by: orcaweb | May 31, 2017

The finbacks are coming!

After last week’s enormous numbers of dolphins and a fascinating experience with a mother and juvenile Cuvier’s beaked whale, where the mother appeared particularly malnourished, it’s been a pretty quiet week in Biscay.  Heather and I did have common and striped dolphins there early in the week but the numbers had dropped significantly and we didn’t even get a sniff of a blow from a large rorqual whale.

You might have read my last blog, Musings on Migration, where, amongst other things, I discussed fin whale movements and asked where all the large whales had gone.  I can now say, with my tongue firmly in my cheek, that the answer to that is currently Ireland!  For five consecutive weeks now we have picked up many basking sharks on our Saturday approach to Cork so we know that the plankton is there and where there is plankton there should be fish.  And we also know that fin whales feed on both zooplankton and small shoaling fish.  So we waited and we waited.  We’ve heard reports in recent weeks of fin whales off Fastnet and humpback whales off County Cork, but still we waited…

This week on a grey early Saturday morning in the Celtic Sea we reached the area where the basking sharks had previously been sighted and readied ourselves for shark fins in the waters below.  And there it was – not the second largest shark on earth (the basking shark) but the blow of the second largest whale on earth – the fin whale!  Off the starboard side, relatively close to the ship, the leviathan surfaced giving us good views of the rostrum and splash guard around the blowhole.

FW, Cork, 27052017, 4

Fin whale surfacing beside the Pont Aven

To say that we were excited would be an understatement.  Here were the finbacks we had waited for that we were sure would turn up eventually.  Perhaps even more excited than Heather and I were the German couple standing next to us.  After a moment of awe they realised that they were actually face to face with a huge whale and the gentleman clearly struggled to contain his joy as he slammed the palm of his hand onto the wooden deck rails three times and simultaneously let loose three expletives which are unprintable here but understandable in any language.  We laughed at him, we laughed at the whales, and inside I smiled for Heather who has had so many distant tantalising whale blows this season and finally experienced the majesty of this animal up close.  But we had no time to muse as we realised another fin whale was close by and a little way off three more signalled their presence with their blows and then rolled through the water as they shallow dived to feed.

FW, Cork, crop, 27052017

fin whale roll

We were elated to find a number of other passengers rush up to us to ask what it was that they had just witnessed and we cruised into Cork alert for any others and very satisfied with our early morning.

Heather, Cork Harbour

Heather eagerly searching for more fin whales as we enter Cork harbour

The Roscoff-Cork route is particularly important to ORCA due to the increasingly reported prevalence of fin whales off Ireland.  We see fins regularly on our flagship routes through Biscay and are interested in documenting their movements in the North Atlantic which are still relatively unknown and we would like to know if there is a northwards shift to their feeding habits.

To be fair, fin whales have historically been recorded off Ireland.  Between 1920 and 1980 nearly 700 fin whales were taken by whalers off the north west coastal shelf of Ireland (we know that worldwide their numbers probably declined by 70% during modern commercial whaling and the IUCN still classes them as endangered), suggesting that Western Ireland is historically part of their migration route.  Fin whales have been recorded off the coast of Ireland during eleven months of the year with the season believed to start in May and peak in the autumn-early winter.  What is interesting about these fin whales off the east coast of Ireland is that this is not the deep water at the edge of the continental shelf – what is assumed to be typical fin whale habitat.  These are sightings which occur each year on the shelf in shallow water (under 100 metres).

FW, close to Cork coast

Fin whale close to the coast of Ireland

This suggests that the Celtic Sea’s plankton productivity may have ranged further north, above the continental shelf’s upwelling, than it has in the Bay of Biscay.  Although it is interesting to note that last year, later on in the season, ORCA surveys and Sea Safaris were surprised to report fins on the northern shelf of the Bay, an area that we have not previously recorded them in any numbers.

Yet that is what is so fascinating about these whales, they range widely and seem to occur right the way across their Atlantic territories at all times of the year and we have so much left to learn about them, especially where they breed.

They are called many things: from finback in the States, to rorqual commun in France, and they have been dubbed the Herring Whale in Scandinavia – perhaps homage to their generalist feeding habits which are the complete opposite of their larger rorqual cousins the blue whale.  The most recent abundance estimates for our part of the world – an area which consists of the waters around Ireland and the UK, Spain and Portugal (including The Bay of Biscay) were produced by CODA in 2007 and sit at 9,000 whales.

Needless to say we were keen to get out on deck as soon as we could when we departed Cork later that day.  Not far from land I was shocked to spot an immense splash at the stern of the ship and turned to see a large patch of white water a few hundred meters from the stern and then the distinctive roll of a big fin whale racing away from the ship.  I suspected a warning breach had taken place and I had just missed it.  When a mother came up to me later to say that her young son claimed he had seen a whale jump at the back of the ship it confirmed my suspicions.  Unfortunately, this particular whale had been far too close to the ship for comfort.  We know that fin whales in particular are susceptible to ship strike when feeding, more so than any other whale.  It has been claimed that in some areas as much as a third of stranded fin whales show signs of collision with ships.  So it is always very worrying when we witness them in close proximity with shipping.  That is why ORCA is involved in programs to attempt to mitigate ship strike and are currently conducting a research project on board the Pont Aven to understand how these large whales react when approached by a large ship so we can find ways to help the shipping world avoid such collisions.

Soon after that Heather shouted “blow” from the other side and we had almost an hour where we recorded another 7 fins including one juvenile all within sight of land.  It was a beautiful sunny evening and dozens of French and Irish passengers enjoyed the experience with us.  A short while later a solitary minke whale was also recorded

FW back, Cork, 27052017

fin back!

The Biscay trip that followed, despite the added advantage of having a full ORCA survey team on the bridge, still didn’t yield any large rorquals.  Although we did have many striped and common dolphins, a couple of Cuvier’s beaked whales, and a good sized pod of pelagic bottlenose dolphins.  So still we wait for the ecology of Biscay and the plankton biomass to work enough to attract the great whales in big numbers.  In the meantime we shall enjoy their presence in the Celtic Sea.  They will come, and when they do it will, as always, be spectacular.  Of one thing you can be sure, and that is that you will hear about it from ORCA when they do.  Keep an eye on our webpage and future blogs to find out when.

CD, May 17, 3

common dolphin leaping in the Bay of Biscay

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