COTF6 Day 6: It Ain't Over Until The Fat Turtle Sings

As we make our way into Galway Bay to dock tonight, it's time to look back on yet another superb days surveying on board the R.V. Celtic Explorer in the waters off West Ireland.

It was both a busy night and day for the acoustic monitoring teams with the hydrophone picking up plenty of common dolphin whistles as well as some lively vocalisations from long-finned pilot whales. 

Common Dolphin clicks and whistles (c) Enda McKeogh

Our starting point over the Hovland Mound SAC at the North end of the Porcupine Seabight remained quiet enough for the first hour or so before large numbers of common dolphins with several calves started making their way towards the bow. During all this commotion, a separate group of 30 or so very active dolphins some distance ahead of the ship caught our attention. With behaviour and a breaching style suggestive of striped dolphin we decided to break track and investigate. A mixed group of both common dolphins and at least three striped dolphins then appeared on our port bow, showing incredibly well, allowing for some excellent photo opportunities (closer examination of which reveals 'foetal folds' also known as 'birth rings' on one of the striped dolphins, indicating its young age). It was a real treat to get such good views of this infrequently encountered species in Irish waters after our brief run in with them earlier in the week.

Striped Dolphin. Just look at how it bursts out of the water! (c) Jason McGuirk

Striped Dolphins. Note the prominent, slightly bulging and steep forehead (c) Rossa Meade

Striped Dolphins. Always acrobatic! (c) William Hunt

Common Dolphin (c) Roisin Pinfield

Later in the afternoon, a large sized and active group of common dolphins had with it an entourage of milling seabirds, namely sooty shearwaters, gannets, European storm-petrels and a circling pomarine skua. All indications of a mixed species feeding association on the go, the birds perhaps availing of fish pushed to the surface by the dolphins? Whilst scanning through the flocks of seabirds, that unmistakable shape of a leatherback turtle, complete with its ridged carapace and prehistoric looking head, came looming out of the water among them not more than 100 metres from the ship. A stunning view of an ancient and gnarly animal. Magic!

Leatherback Turtle (c) Hannah Keogh

Aside from the aforementioned leatherback turtle, more marine ‘megafauna’ was recorded again today such as a large ocean sunfish with lesser black-backed gulls in attendance (perhaps picking parasites off it?) and half a dozen or so albacore tuna breaching close to the ship.

Ocean Sunfish (c) Jason McGuirk

Seabirds were generally low in number yet again but the patch of feeding activity associated with the common dolphins and leatherback turtle in the afternoon certainly bumped up some figures. A Wilson’s storm-petrel showed well first thing this morning as it passed by close to our port side. A total of four very fine adult pomarine skuas complete with ‘spoons’ (i.e. their uniquely shaped tail streamers) flew right over the observation deck. New species added to the trip list today included a puffin, a black-headed gull and numerous great black-backed gulls. Other tallies in the form of a great shearwater, 20 sooty shearwaters, 19 Manx shearwaters, 58 European storm-petrels and 7 great skuas were noteworthy. 

Pomarine Skua (c) Jason McGuirk

Marine litter surveys continue (c) Jason McGuirk

In the final minutes of survey time for the seabird team, a totally unexpected migrant songbird landed on the railings just 1 metre beside the observers... a nightingale! The bird took flight and made its way out to sea before coming back and landing in the rescue boat on the deck! It then flitted about from here to there for about 10 minutes or so, not looking very settled at all, before flying back out to sea, never to be seen again. This all occurred some 40 nautical miles West of Loop Head, Co. Clare. Nightingales are a very rare passage migrant to Ireland with just 30 or so documented records to date. An amazing send off at the end of the trip! Additional new migrant birds on the R.V. Celtic Explorer included a merlin, a blackcap and a lone swallow which was seen circling the crow’s nest.

Nightingale on the R.V. Celtic Explorer (c) Rossa Meade

Nightingale in flight (c) Rossa Meade

Nightingale in flight (c) Rossa Meade

Nightingale in flight (c) William Hunt

Merlin on the R.V. Celtic Explorer (c) William Hunt

News of our killer whale sighting from a few days ago seems to have been a popular story with the media, receiving coverage in the national papers, radio and TV. Here's an article on the subject on BreakingNews.ie for those interested.

COTF6 Day 2: Porcupine Bank Bonanza!

What a day! We awoke this morning with news from Enda and John (at the tail end of their hydrophone/acoustic monitoring night shift) that common dolphins were present around the R.V. Celtic Explorer throughout the night from about 02:30. The daytime observation teams were out on deck and in position, ready to go from 07:30 but were faced with a misty horizon, moderate sea state and some patches of rain for much of the day. Not ideal but we’ve been out in worse!

Steaming due West for the M6 weather buoy over the top end of the Porcupine Bank, crossing over a depth of 2,000m we came across a group of five Atlantic white-sided dolphins, a species limited to the deeper offshore waters within the Irish territory. In typical fashion for these dolphins, they didn’t approach the boat too close and headed off fairly quickly as we made our way along the transect line. Hopefully we’ll bump into more white-sides again over the coming days and secure some nice images as they are a species infrequently seen or photographed in Irish waters, at least in recent years.

About half an hour away from the M6 buoy, a whale blow appeared dead ahead up to 800m away. The frequent nature of the short, bushy blows coming from the same spot lead us to believe a sperm whale was the culprit and a view of the body during a break in the swell confirmed this. While concentrating on the sperm whale we were coming up on, a group of energetic and acrobatic, small sized dolphins suddenly started moving through our field of view with tremendous speed. Leaping clear out of the water like sleek, silver bullets it was instantly apparent that these were not your run of the mill common dolphins. A sub group breached not more than 100m from the bow and a solid view of the flanks complete with a thin, black, wavy line, confirmed that these were, as suspected, striped dolphins! In all three groups of 10-15 animals each barrelled North in front of us, clearing the water in an impressive, organised phalanx before re-entering with a forceful smack of the tail, sending a sizeable splash of water into the air. Striped dolphins are a real sub-tropical, oceanic species with sightings in Irish waters a relatively recent phenomenon, typically confined to late summer and autumn when surface water temperatures are at their highest. As such the window of opportunity for seeing them appears to be quite short and not surprisingly, these animals constituted a new species or only a second/third sighting for many present on deck at the time. Truly exciting stuff!

Striped Dolphins (c) Jason McGuirk

Striped Dolphins (c) Simon Berrow

Striped Dolphins (c) Hannah Keogh

Once maintenance works on the M6 buoy were completed in ever efficient fashion by the ship’s crew, we changed track and headed South East along the shelf edge, crossing over a changing water depth as we went over the slope, from 3,000m to 500m. Soon after a shout of ‘blow!’ went out and the on deck cetacean observation teams were treated to some nice, prolonged views of a feeding fin whale, the second largest animal on Earth. We came upon more fin whales later in the afternoon, this time a group of three animals actively feeding in close proximity with plenty of blows, side rolling and some shallow lunge feeding on offer at close range! Absolutely fantastic!

Fin Whale (c) Simon Berrow

Fin Whales (c) Simon Berrow

Fin Whale (c) Joanne O'Brien

Fin Whales (c) Hannah Keogh

Fin Whale lunge feeding/side rolling (c) Simon Berrow

Fin Whale lunge feeding/side rolling (c) Joanne O'Brien

The evening then drew to a close for the cetacean team with multiple sightings of common dolphins (some groups size of 40 animals) coming in to bow ride as we came over a water depth of 500m. The nocturnal acoustic team took over at 20:00 and soon after several detections of sperm whales were made really close to the ship, their position calculated as near as 200m! We were all able to gather in the dry lab and listen to their rhythmic clicks through the speakers, sounding almost like an electric fence pulse. Also best not forget to mention the sightings of two different ocean sunfish which we passed by at close range during the day! Bizarre fish altogether and always great to see.

Common Dolphin (c) William Hunt

Ocean Sunfish (c) Hannah Keogh

Sperm Whale clicks (c) Enda McKeogh

The seabird team had a day of quality over quantity, with just a trickle of fulmars, a handful of gannets and a small entourage of lesser black-backed gulls in attendance. Saying that a couple of excellent sightings early on made all the effort worthwhile (cetaceans aside!). A great shearwater came in for a look at us first thing before carrying on its way to the South. Not long after we approached a group of fulmars on the water with a Wilson’s storm-petrel bouncing around them which showed well at close range before travelling on to the West. Both of these species have undertaken a mammoth journey from their breeding grounds on sub-Antarctic islands to Irish waters in order to avail of rich feeding here in the late summer and autumn. Amazing to think the distance they have covered. Intrepid birds! A pomarine skua spotted by Simon, trundling by the ship late evening was the last addition to the seabird list for the day.

Great Shearwater (c) Niall Keogh

Wilson's Storm-petrel (c) Niall Keogh

Wilson's Storm-petrel (c) Niall Keogh

Wilson's Storm-petrel (c) Niall Keogh

The murky visibility, rain and moderate North East wind dropped some more migrating passerines (songbirds) onto the ship overnight with 10+ meadow pipits, 3 wheatears and a white wagtail doing the rounds of each deck throughout the day, some even ending up inside the dry lab! The inclement weather must have disorientated them whilst on migration to Iberia/West Africa and the R.V. Celtic Explorer looked like a good place to rest. A few individuals became very tame as they searched around the ship for scraps of food, but ignored all of the tasty morsels we left out for them! Hopefully clearer conditions in the morning will allow them to get their bearings and head off again on their merry way.

Wheatear (c) Jason McGuirk

White Wagtail (c) Niall Keogh

Meadow Pipit (c) Niall Keogh

Now we make our towards the Porcupine Bank SAC where we will retrieve a static acoustic monitoring device positioned there in May and will continue East across the Porcupine Seabight.