Large whales moving inshore in increasing numbers

16th Sep 2013

At this time of year it probably comes as little surprise to IWDG members and whale enthusiasts alike that in recent weeks there has been a significant increase in sightings of large whales, most of whom can be confirmed as fin whales Balaenoptera physalus. The slow trickle of sightings in July from West Kerry, built to 8 records in August, most of which were from along the Cork coast.  Now into September there is the feeling that fin whale numbers are building as they forage along familiar West Cork waters.

A report however on 4th Sept from colleagues in the Irish Air Corp, Maritime Unit serves to remind us that our predominantly inshore records are likely to be the tip of a much larger iceberg.  Once again the CASA team have secured great images of these giants, the planet's second largest animal, feeding in offshore waters along the Porcupine Seabight in waters deeper than 1,000 Mts, and the group estimate of 9 animals is certainly the largest aggregation to date in the 2013/14 "large whale" season.  It is not uncommon to see large feeding aggregations of fin whales in inshore waters of upwards of a dozen animals.  But if this year pans out like previous years, the best has still yet to come, as historically the months November to January are the peak period for the "herring hog" inshore along the Irish South coast. Two of 9 fin whales recorded feeding offshore 04/09/13 © Irish Air Corps, "Charlie 253"

This weekend's IWDG whale watching course on Cape Clear may afford new members a chance to either glimpse fin whales from Cape's south facing cliffs, or to view them at closer quarters during the weekend's pelagic whale watch trip.  But recommended land-based sites for viewing them would be Cape Clear, Baltimore Beacon, Toe Head, Galley Head, Seven Heads, Old Head of Kinsale or Roche's Point.  We exlude Slea Head in Co. Kerry on this as there is no evidence that there are currently fin whales from this hotspot....but don't feel too sorry for them, as they've enjoyed record humpback whale action in recent weeks.  Nick Massett was still recording two humpbacks off Clogher Head as recently as 10th Sept. We also note with interest that Co. Waterford has yet to confirm any fin whale activity which is at odds with recent years, where our man Andrew Malcolm has often recorded the first significant fin whale activity of the season as early as late May.  Ram Head, Ardmore is a classic whale watch site, and a really good spot to view fin whales later in the season.

So, what should we be looking out for?  Well, they are big, and to give you an idea of just how big, at 60-75ft, they'd be 2-3 times larger than a minke whale. Their blow can be seen for many miles, even in windy conditions and can reach 7-8 Mts, appearing as an inverted cone. The less wind there is however  the more visible the blow is, as it hangs suspended in the atmosphere for longer.   They are generally gregarious, recorded in groups of 2-3+ individuals, but as above, larger feeding aggregations of up to a dozen fin whales are not uncommon in the Celtic Sea area. They have a very obvious dorsal fin, situated 2/3 along their back, which is "backswept " in profile. The most diagnostic feature is the assymetric head colouration, with the jawline on the right side showing as white in colour, but dark on the left side (image above).They are often found in the company of large numbers of common dolphins, and may even travel loosely with humpback whales, or be seen targetting the same bait balls as the much smaller minke.  

Fin whale pair on Porcupine Seabight 04/09/13 © Irish Air Corps, "Charlie 252"

If you think you've seen something matching this description then you are probably in the company of fin whales. We are very fortunate that over the coming months these feeding machines are likely to move closer inshore to within relatively easy binocular range of headlands, cliff tops and bays, as they hunt sprat and herring shoals in an east direction along the Irish south coast.  Enjoy them. 

You can also help IWDG protect them by reporting any observations online on www.iwdg.ie for validation.  Please note IWDG can not validate sighting records posted on facebook or twitter.

Pádraig Whooley
IWDG Sightings Coordinator