Whales & dolphins of Dingle Bay, West Kerry, s.w. Ireland
Our 2012 whale and dolphin watching season has now closed and below is a brief summary of our encounters with some of Irelands most interesting megafauna in 2012.
Early in the season [April, May , June] our most interesting megafauna are the huge basking shark [second largest fish in the world after the whale shark] swimming near the surface of the water with their snouts, large dorsal fin and tail fin visible as they twist and turn in their never ending pursuit of the minuscule plankton on which they feast, especially when the water is around 11 to 12 degrees. Although they were plentiful again this year - on some days we could truthfully describe the waters around the Blaskets and Dingle Bay as shark infested- they did not quite attain the numbers present in 2011, and then one day they just disappeared like they had never been there. We are always surprised by this phenomenon as they appear gradually at the start of the season to feast on their favourite plankton but their disappearance is always sudden and unexpected and more or less complete apart from an odd straggler.
Harbour porpoises our smallest cetacean, are the most numerous of our cetaceans but not necessarily the most commonly sighted as because of their small size [max. 6 ft] they can only properly be observed in calm sea conditions , sea state of 3 or less, and also because of their shy disposition they do not approach the boat in the same way as dolphins. On a flat calm morning with a nice glassy sea we can more or less guarantee to show you a family of them below the 2,500 year old promontory Dunbeg fort on our way out to the Blasket Islands. If we stop the boat for a while and switch off the engines you can watch them gamboling through the water and hear their "blows" as they hunt for prey. No doubt 2,500 years ago the people who built and lived in this prehistoric fort on top of the cliffs in turn hunted them for prey and in Irish their name is "muc mara" - "sea pigs". Maybe this is one of the reasons for their reticence around humans.
We are lucky that around the Blasket Islands and Dingle Bay we have 3 species of dolphins commonly seen and another 3 species occasionally seen further offshore.The species most encountered on our eco marine tours is the common dolphin and we are liable to come across a school of them anywhere on any of our boat tours. They always give the maximum enjoyment to our passengers as they race alongside and bow ride the boat. They are our fastest dolphin and we always keep a steady course and speed and leave it up to them to accompany us or not.
Blasket Islands Eco Marine Tours observed more bottlenose dolphins this year than in any previous year [apart from Fungie the Dingle dolphin we rarely encountered any bottlenose last year] and most of the sightings were in Ventry Habour which we use as our home port and departure base for our boat trips. A lot of the photo id shots taken from our boat were within a couple of hundred yards of the pier, our moorings and the beach.
The start of the season up to about mid July seems to be the best time to see the Risso's dolphins which we see usually on our afternoon guided eco marine tour around the further out Blasket islands and Tiaracht lighthouse. There appears to be a summer resident family of eight and they are always a pleasure to see as their coloration is lighter than our other species of dolphins, occasionally almost white and they always have distinctive marks on their sides from their encounters with each other as they have very sharp teeth [all the better to hold their slippery prey with] and possibly also gained from rough amorous encounters with each other.
Minke whales are plentiful in the bay all summer and apart from common dolphins are our most observed species [but not our most plentiful as above]. We had some quite spectacular sessions with them this year as they jumped and leaped at bait balls and although they are a relatively small whale [max. length 30ft] when there are a few of them together lunge feeding and accompanied by a frenzy of common dolphins and recklessly diving gannets it is a fantastic wildlife spectacle to behold.
This year fin whales were the least viewed of our resident or migrating cetaceans and our sightings were confined to two, and some sightings of some unidentified "blows" in the distance. Fin whales are the greyhounds of the sea and unless they are actively engaged in feeding it is very hard to keep up with them while they are on passage as they regularly cruise along at speed of up to 20 knots.
We had a very nice encounter with two killer whales [orca] just a few miles off Slea Head on one of our evening tours and it was all the more special in that we had a vey quiet morning tour and afternoon tour and also our compliment of passengers for the evening tour was mainly children and their parents who enjoyed the orca staying near the boat for over half an hour by which time we decided it was time to leave them, We later identified them from photo id shots taken by some of the children by mobile phone as being part of the West Coast Community of killer whales associated with the west coast of Scotland. This particular male killer whale was first photo identified off the west coast of Scotland in 1992 [twenty years ago] and was given the name "John Coe". We also established from our photo id that it was his mother that was accompanying him on his trip to the Blaskets. "Mrs. Coe" I presume
The big news of the year for Blasket Islands Eco Marine Tours was the presence of four humpback whales n.w. of the Blaskets for over four months [as viewed by Nick Masset from his observation station above Clogher Head]. Typically the weather was rarely suitable to bring passengers to the area where they were feeding as it was usually just beyond the limits [time wise and passenger endurance wise] of our 4 hr. afternoon or 3 hr evening trips and swell and tidal conditions were often not suitable. On the occasions when we did get out to see them or they came a little further inshore our passengers got the opportunity to watch them bubble netting and tail fluking beside the boat.
CLIMATE CHANGE IN IRELAND AND THE DISTRIBUTION OF MARINE SPECIES
We have tried to guess at a reason why these four humpbacks spent four months off the West Kerry coast before going on to West Cork and then West Waterford for the sprat and herring season there and the only reason we can think of is that because of the exceptionally wet and unsettled summer, which of course brings a lot of nutrient enriched rainwater down the Shannon river [the biggest river in the British Isles] and as this nutrient rich fresh water [specific gravity 1.000 approx.] stays on the surface of the more dense and heavier sea water [specific gravity 1.025 approx.] and is carried along by the strong tidal streams as far as the Blaskets and there it meets the strong tidal streams flowing from the south it is tossed to and fro, up and down, north and south in a relatively small area of turbulence and attracts huge blooms of phytoplankton which in turn attracts huge swarms of zoo plankton including krill and this all in turn attracts small fish, fry and sprat which in turn attracts the humpback whales with their huge expandable mouths to sieve all this live squirming food biomass from the water and stuff it in their large insatiable holds. It definitely appears that they spent at least four months of this summer feeding in the same approx. area and around the 100 metre depth contour while waiting for the herring and sprat shoals to appear in September. This theory can not be proved outright without taking samples of the available food biomass; the specific gravity; temperature and salinity of the surface water in this area as opposed to the readings in other parts of Dingle Bay which could be used as a baseline. We hope to do some of this research next year from "Blasket Princess" as part of the educational and survey element of our eco tours.
It is also worth noting that a straight line from the centre point of the narrowest part of the mouth of the Shannon between Kilcredaun Head and Beal Point drawn through the centre point of the widest part of the mouth of the Shannon between Loop Head and Brandon Point and continued on past the Blaskets exactly overlays the 100 metre line depth contour where these four humpbacks spent the summer feeding which gives some credence to this theory of fresh water instigated biofood chain as this line is the direction of the main flow of nutrient rich fresh water from the whole of the Shannon catchment area into the North Atlantic. If this is the case then basically the presence of these four humpbacks for four months off the West Kerry coast is directly related to the wet summer of 2012 which in turn is probably a result of climate change.
There is no doubt that climate change in Ireland is greatly affecting the distribution of species in all sorts of unexpected ways including the terrestrial ecosystem [wet drainoff from water logged land] affecting the marine ecosystem.
Thats the best thing about whales and whale watching - they make you wonder !
To find out more about the whales and dolphins of Dingle Bay, West Kerry, s.w. Ireland press the "Book a Tour" button on the homepage of www.marinetours.ie to book a trip aboard our dolphn and whale watching boat M. V. "Blasket Princess".
Captain Whales Galore