CSHAS 2016: Megafauna madness over the Celtic Deep

Day 15: Friday 21st October

Skipping ahead a bit here since the last blog update but doing so in order to share some notes and pics from an absolutely superb day spent watching an impressive abundance of 'marine megafauna' over the Celtic Deep, well to the south of Co. Wexford.

As the first rays of dawn broke, a peek out the cabin porthole revealed a flat calm sea and visibility clear to the horizon line. After a quick breakfast we were on deck and ready for action. Within minutes the seabird team picked up a small group of harbour porpoise off our port side which when radioed in to the marine mammal team was met with a reply of "we're watching more off to our starboard!". After trying (and failing) to spot some porpoises during the inshore legs of our transect lines off Cork, Waterford and Wexford over the past two weeks, we were surprised to finally encounter them this far offshore and what's more, we weren't expecting to see so many! Every time we scanned we seemed to find more and more porpoises and at one stage a single scan across the view-shed revealed no less than 58 animals! Final tallies for the day almost reached 200 animals!

Consulting with the Marine Institute fisheries scientists in the lab who were monitoring the underwater acoustic images being recorded by the ship, it was clear that there was a lot of activity going on below us with masses of plankton, krill, forage fish (herring) and even a plethora of bluefin tuna showing up! This abundance below water was certainly mirrored at the surface and in addition to the harbour porpoises we noted lots of common dolphins, racked up no less than fifteen sightings of Minke whales, two fin whales (one of which crossed right in front of the bow at close range), a single humpback whale, an Atlantic grey seal, several breaching bluefin tuna and even some blue sharks swimming at the surface (being able to see the latter is a testament to how calm the conditions were).

No doubt there was some duplication in sightings at play due to the close proximity of the parallel survey transect lines, yet the marine mammal observers in the crow's nest still amassed an impressive total of 78 sightings involving up to 500 animals!

After a ten hour day out on deck we are all a little tired and more red in the face than usual so I'll finish up and let the following selection of pics tell the rest of the story...

Ideal conditions over the Celtic Deep (c) Niall T. Keogh

Harbour porpoise (c) Niall T. Keogh

Blue shark 'knifing' at the surface (c) Niall T. Keogh

Blue shark clearly visible underwater! (c) Stephanie Levesque

Bluefin tuna (c) Niall T. Keogh

This common dolphin showed exceptionally well, actively surfacing just metres away from the ship. Closer examination of the pics suggest it may be unwell. The protruding rib-cage and sunken appearance behind the skull (known as a 'post-nuchal depression') indicate that it is in poor body condition (c) Niall T. Keogh

A couple of perfectly healthy looking common dolphins (c) Meadhbh Quinn

Minke whale showing the typical, falcate (sickle shaped) dorsal fin (c) Gary Kett

Minke whale showing a straighter, more erect shape to the dorsal fin (c) Meadhbh Quinn

This humpback whale spent quite some time logging (resting) at the surface (c) Meadhbh Quinn

But after a while the humpback eventually treated us to a nice tail-fluke! (c) Meadhbh Quinn

Fin whale surfacing sequence (c) Meadhbh Quinn / Niall T. Keogh

Irish Whale and Dolphin Group marine mammal observers: Meadhbh Quinn and Gary Kett

Marine and Freshwater Research Centre GMIT seabird observers: Stephanie Levesque and Niall Keogh

Celtic Sea sunset (c) Gary Kett

Celtic Sea Herring Acoustic Survey 2016

Introduction 

Every year since 2004, an acoustic survey of the winter spawning herring stock which can be found in the Celtic Sea off southern Ireland has been conducted by the Marine Institute from the state research vessel, RV Celtic Explorer. The Celtic Sea Herring Acoustic Survey (CSHAS) will be carried out once again this year across three weeks during October. Working alongside the fisheries survey, a team of seabird and marine mammal observers will be on board, documenting the distribution and abundance of top marine predators often associated with herring and sprat in the Celtic Sea region.

Proposed tracklines for the October 2016 Celtic Sea Herring Acoustic Survey

The seabird team hails from the Marine and Freshwater Research Centre, GMIT and is led by PhD student Niall Keogh. This year marks the fifth in which seabird surveys will be carried out during CSHAS. Building data time series such as this forms the basis for Niall's research on seabird ecology in Irish offshore waters as well as feeding into the Celtic Sea Ecosystem Tipping Points project.

Gary Kett has joined the seabird team this year after spending the summer as a research assistant at the Shannon Dolphin and Wildlife Foundation in Kilrush, Co. Clare.

Meadhbh Quinn will carry out marine megafauna surveys for Irish Whale and Dolphin Group (IWDG) from the crow's nest, continuing long term monitoring of whales, dolphins, seals, turtles etc. during CSHAS over the past twelve years by the group. In addition to acting as coordinator for the Shannon Dolphin and Wildlife Foundation centre in Kilrush, Meadhbh is also the current Membership Officer for IWDG.

Blog readers can stay updated with our progress over the course of the next three weeks by checking in every few days here or on our Facebook page to view the latest pics and sightings. We hope you enjoy!...

From left to right: Niall Keogh, Gary Kett and Meadhbh Quinn (c) Usna Keating

Day 1: Friday 7th October

Mobilisation for CSHAS 2016 on board RV Celtic Explorer took place on Friday afternoon at Galway docks. After a safety tour and scientific staff meeting, we set sail at 8:30pm in order to make our way towards Dunmanus Bay in West Cork for Saturday afternoon where the fisheries acoustic equipment will be calibrated before beginning the survey transect lines.

RV Celtic Explorer docked in Galway and the pilot boat seeing us out safely that evening (c) Niall T. Keogh

Day 2: Saturday 3rd October

Dawn on our first day at sea saw us steaming south past the Blasket islands, Co. Kerry. After a hearty breakfast, the seabird and marine mammal observers headed out on deck for a few hours to 'get the eye in' before reaching the survey transect lines. 

From the off it was a busy morning, as is always the case in this area during autumn. Flocks of sooty shearwaters wheeled about to and fro as if in search of something hidden from our eyes, only later to consolidate themselves under groups of diving gannets which gave away the presence of lunge feeding baleen whales. All this foraging activity was due of the bounty of sprat in the area, as observed by the fisheries team monitoring what is present in the  water column underneath the ship as we go.

In total we observed four minke whales amongst feeding flocks of seabirds and had an all too brief encounter with a single humpback whale, blowing and surfacing several times as it made a beeline for a feeding group of seabirds and whales just a few kilometres to the southwest of the Skelligs.

Common dolphins followed the ship throughout, as expected. Our third cetacean species of the day will no doubt be our most abundant species for the rest of the trip. Rounding off the list of 'marine megafauna' was a single ocean sunfish, being tended to at the surface by a lesser black-backed gull (presumably checking it out for parasites to pick off and eat?).

The seabird tally for the day ended up at a respectable 16 species: gannet, fulmar, sooty shearwater, Manx shearwater, Balearic shearwater, European storm-petrel, great skua, Arctic skua, Herring gull, lesser black-backed gull, great black-backed gull, kittiwake, common gull, guillemot, razorbill and puffin. 

 Minke whale lunge feeding on sprat among flocks of gannets and shearwaters (c) Niall T. Keogh

Close up of the lunge feeding Minke whale (c) Niall T. Keogh

Skelligs (c) Niall T. Keogh

Common dolphin (c) Niall T. Keogh

Sooty shearwater (left) and a Balearic shearwater (right). Note the differences in size, structure and colour (c) Niall T. Keogh

1st calendar-year lesser black-backed gull (c) Niall T. Keogh

WESPAS Days 10 to 12: west coast shelf waters

Days 10 to 12 sightings: 13th, 14th and 15th July 2016

After finishing up our survey tracklines over the Porcupine Bank, we spent a few days checking out the shallow shelf waters to the west of Galway Bay. Seabird and cetacean species encountered here were those more typically associated with inshore areas, Manx shearwaters and common dolphins dominating the totals in each category. 

Sea conditions were variable and on the evening of 14th July, heavy mist and rain dampened our hopes of seeing much. Then at about 8pm while some 20km NW of Loop Head, we started noting a lot of common dolphins following the ship and foraging in association with rafting flocks of Manx shearwaters.

Scanning through these mixed groups later revealed a large minke whale which parted a flock of shearwaters in two as it surfaced and then all of a sudden, the unmistakable 'gnarly' profile of a humpback whale surfaced closer again! Those of us on watch at the time put a call out on the walkie-talkies and after gathering all observers together we were able to confirm the presence of three humpbacks around the ship! One of them even did us the honour of tail-fluking right off the stern of RV Celtic Explorer!

It was a real treat to see this group of large baleen whales not far from the Clare coastline. It wasn't all that long ago that humpbacks were considered a rarity in Irish waters, and now they are well known between Kerry and Wexford but their move into Clare waters seems to be a more recent development. How times have changed! (and what further changes await?)

Humpback whale tail fluking (c) John Power

Humpback whale (c) Niall T. Keogh

Humpback whale tail fluking off the stern of RV Celtic Explorer (c) Niall T. Keogh

Common dolphins are the 'bread and butter' cetacean species for any survey in Irish waters. While they are widely distributed and abundant, they are always a delight to watch, especially when following the ship on clear, sunny days. We've noticed at least three melanistic individuals among the various groups so far through the survey. These darker colour variants are infrequently encountered and can cause momentary confusion, almost looking like a different species. Check out Dan Brown's blog post about them on the Birding Frontiers website.

Common dolphins (c) Sean O'Callaghan

Melanistic common dolphin (c) Niall T. Keogh

Also included in our tallies for the past few days in this area was the first basking shark of the trip well west of the Aran Islands and a decent sized ocean sunfish, perhaps up to 2m in length, west of Kerry Head. 

Basking shark (c) Mick Marrinan

Ocean sunfish (c) Niall T. Keogh

A general increase in the abundance and diversity of seabirds was noted, as expected for inshore areas closer to the breeding colonies. It was nice to get good views of great skua, puffin, Arctic tern etc. as well as recording yet more Wilson's storm-petrels, this time two birds among a flock of 15 European storm-petrels some 40km southwest of Slyne Head on 13th July.

Great skua (c) Niall T. Keogh

Puffin (c) Niall T. Keogh

Two Wilson's storm-petrels and a gannet (c) Niall T. Keogh

Arctic tern (c) Niall T. Keogh

Fulmar (c) Sean O'Callaghan

So that brings us up to Friday just gone... next up a blog post about the seabird and cetacean feeding frenzy we encountered off the Blaskets on Saturday! (and what a spectacle it was) ...stay tuned

The Humpback Whales of Cape Verde - documentary tour

A packed audience attended the launch of the new Canola Film Productions/Irish Whale & Dolphin Group (IWDG) documentary on The Humpback Whales of Cape Verde at the LexIcon in Dun Laoghaire on Tuesday 12th January 2016. 

This film documents the most recent IWDG expedition to Cape Verde in search of humpbacks in September 2014. IWDG have been visiting the island archipelago in an attempt to discover the breeding grounds of humpback whales visiting Ireland in the summer and winter periods.

The next showing of the film will be in Killarney Library, Co. Kerry on 23rd January 2016 with Sean O'Callaghan at 2:30pm.

Other confirmed dates are:

Clonakilty Library, West Cork on 27th January 2016 @ 7:30pm with Padraig Whooley (booking essential by email: padraig.whooley@iwdg.ie or moblie: 086-3850568)

Kilkee Library, Co. Clare on 10th February 2016 with Simon Berrow

Youghal Library, Co. Cork on 25th February 2016 with Andrew Malcolm

Further information is available from Isabelle Courtney of Canola Pictures

mobile: 087-2366878

e-mail: isabelle@canolapictures.com

A trailer for the documentary can be viewed by clicking on the image below