COTF4: Genetic Analysis of Bottlenose Dolphins

Research Vessel Celtic Explorer is a great platform to get information on offshore animals for which there are little studies. Bottlenose dolphins are well studied in inshore waters of Europe were there can be easily studied on day trips. There is a knowledge gap on the offshore dolphins, even though thousands of animals are thought to inhabit offshore areas in particular the shelf edge (according to previous ship and aerial surveys).

I am studying bottlenose dolphin population genetics in the North East Atlantic (from Scotland to the Azores) using biopsies and samples from stranded animals which I get from different organizations and institutes across Europe (including GMIT and IWDG) which I thank a lot for their collaboration.

Locations of samples used in the study (162 biopsies and 242 stranded animals)

The Cetaceans on the Frontier survey is an unique opportunity to get samples from offshore bottlenose dolphins. Last year I included the first biopsy sample of bottlenose dolphins from European offshore waters in my analyses. On this trip I realized how difficult it must have been to get this sample, because of the often high swell of the offshore waters, and the evasive behaviour of the offshore bottlenose who are powerful and fast moving.

My genetic analyses are still on-going, but preliminary results show that inshore bottlenose dolphins are genetically distinct from offshore bottlenose dolphins. Last year COTF biopsy sample fits in the same group as animals that were biopsied in the Azores and some of the stranded animals from Ireland to Spain, which we consider as the “offshore” group.

I hope that we will encounter more bottlenose dolphins in the following days, and fingers crossed that the weather will be good enough for RIB launches, to allow us collect more biopsies.

Marie Louis
(PhD student, University of la Rochelle, CEBC-CNRS, GECC)

COTF4: Microplastics in the Sea

While everyone else on the ship (apart from those on the graveyard shift) is primarily interested in the macrofauna found in Irish waters, I am using the opportunity to sample the water for microplastics.

Microplastics are small pieces of plastic generally up to 5 mm in size that are found in almost every habitat in the world, from populated urban areas to remote beaches. Sources of microplastics can be raw plastic pellets (called nurdles) used in the production of user plastics; grains and beads used as exfoliants in cosmetics, and powders used for air blasting. Microplastics also make their way into the sea as larger debris which breaks down into smaller fragments and fibres. There is a rapidly increasing concern about the input of synthetic fibres from washing machines into the sea.

So I guess that plastics don’t really fit under the banner of marine biology, however their presence, occurrence and interactions with organisms in the marine environment does.  Research into microplastics in the sea has gained more and more attention over the past 10 years. One effect of microplastic interaction is ingestion by wild fish, birds and invertebrates. It is likely that a number of other species interact with microplastics due to their distribution in the water column but further research is needed. Other effects of microplastic can include physical blockages, leaching of chemicals and accumulation of chemicals within organisms’ tissues. There could be an effect between trophic levels but this is still unknown.

Microplastic sample collected during the COTF4 cruise, as seen under the microscope (c) Amy Lusher

In regards to the Irish marine environment there are no specific studies focusing on microplastics in the sea.  To do this we first need to identify whether microplastics are in the water, and in what quantity. Microplastics are generally buoyant and found in the top few meters of water, if they are fouled by organisms they can sink to the sea floor, however the purpose of this work focuses on the surface water. We are sampling the water for microplastics along our transect, I change my filters every 1.30 hour and the plankton team help by taking samples overnight for me. This is providing a continuous dataset to look at.

Microplastic sample collected during the COTF4 cruise, as seen under the microscope (c) Amy Lusher

During the few days we have been back in Galway I have worked out some of the samples. EVERY sample collected appears to have microplastics. Fibres are the most common, and I have found some fragments and films. It is going to take a while to work up the sizes and number of particles over given areas, but I’m pretty confident that the method we have developed can be used on future cruises and we could compile a picture of microplastics in the marine environment.

Amy Lusher

(Postgraduate Student, Galway Mayo Institute of Technology)

COTF4: The Graveyard Shift

A well planned research expedition makes use of every available minute. The old adage ‘time is money’ definitely rings true for offshore scientific surveys. In order to make the most of this ship time we employ surveying and sampling techniques which don’t rely on daylight. These can include oceanographic mapping, video surveys for pelagic fauna and continuous sampling for plankton & microplastics.

My role onboard revolves around plankton sampling for which we make use of a CTD probe (which measures conductivity, temperature & depth, amongst other parameters). This probe is dropped vertically while the ship is stationary. It provides us with a good way of taking water samples, mounting plankton nets and other equipment such as a video camera system all at the same time. In addition to this it allows us to assess the different water masses from which we are sampling. The water below us is often stratified, with the strata having different salinities, temperatures and oxygen concentrations. The diversity of strata leads to diversity of organisms. We can measure photosynthesis (eg. phytoplankton) in each of these strata, as well as taking water samples at specific depths. This allows us to assess the origin of what we find in water samples, as each water mass, with its own distinct signature, comes from a different area (for example Mediterranean and Arctic waters can be distinguished from each other).

CTD being lowered for sampling (c) Emilia Chorazyczewska

CTD read out (c) Emilia Chorazyczewska

Plankton are sampled continuously on these vertical tows, and give us an idea of the various groups living in a column of water. So far on Cetaceans on the Frontier 4, our deepest drop has been to a depth of around 4.5km. During Cetaceans on the Frontier 3 in 2012, these small samples went on to be involved in studies involving genetic analysis of plankton and understanding how cetaceans fit into food webs using stable isotope analyses (their trophic ecology). This time around, despite some limitations related to weather, we have managed to take plankton samples for trophic studies of fish, sampled water to look for microplastics, aided in a test of acoustic releases for sensor moorings and tested an experimental camera system for studying plankton.

 Purpose built, deep sea camera (c) Fergal Glynn

 Plankton sample; a Euphausiid krill & two copepods (c) Fergal Glynn

There’s no working around the weather at the moment unfortunately. Even after we changed methods to try to deal with the swell and wind, we had to temporarily suspend sampling when it reached a solid seven (rather more wet and windy than solid!). We look forward to getting out and dropping some more sampling stations when we make a break for sea.

Watch this space for more updates from the graveyard shift.

Fergal Glynn
(Queen’s University Belfast)

COTF4: Ring-billed Gull

A few of us went for a lunchtime stroll down to Nimmo's Pier today which produced some nice bird sightings. The pier is famous amongst birders across Europe for its track record of drawing in rare species of gull from the Arctic and North America.

One of the more frequently occurring North American specialties is ring-billed gull, one of which was present today and showed very well, down to a few meters at times (with a little help from two loaves of bread!).

Light-bellied brent goose, bar-tailed godwit, great northern diver, red-breasted merganser, little egret and rock pipit were some of the other highlights noted between the pier and Mutton Island causeway.

Great biodiversity out there along the outskirts of Galway. Check it out!

Adult Ring-billed Gull. The thick, neatly demarcated bill band, strong yellow colouration to bill and legs, stern expression and pale eye are all good features for ID'ing it from the similar looking Common Gull (c) Niall Keogh

COTF4 Day 5: Coming Inshore

With a particularly nasty weather system making its way east across the Atlantic, a wise decision was made to shelter inshore for a few days until the worst of it passes and Galway was the port of choice for our 'mid-cruise' break. We still managed 5 hours of good survey time this morning however and added a few new species to the trip list.

Although still 40 miles west of Loop Head at 9am, it was instantly apparent that we were nearing land by simply observing the change in cetacean & seabird species composition around us. A group of 3 harbour porpoise was a great find by Conor. A typically inshore species frequently seen along the Clare coast but certainly notable this far out. A couple of common dolphins began bow riding not long after which were a sight for sore eyes after their absence offshore in recent days.

Gannets, kittiwakes and fulmars were present as per usual but the sudden appearance of guillemots, razorbills (new for the trip), herring gulls and great black-backed gulls in numbers were a sure sign we were over shallower water. Once we entered the mouth of Galway Bay itself, wedged between Inis Oírr & Black Head, sightings of shag and cormorant completed the expected species list for the day. Whilst moored in the bay south of Silver Strand waiting for the pilot boat, a 1st-winter iceland gull made an appearance, nicely complementing its similar looking but larger relative, the glaucous gull, which we had encountered yesterday. Then to finish off, a couple of great northern divers near Mutton Island welcomed us into Galway docks.

With any luck things will calm down out over the shelf sooner than expected so we can get back to business but until then we'll get down to the task of collating and preparing our data collected so far.

Galway pilot alongside the R.V. Celtic Explorer (c) Conor Ryan

COTF4 Day 4: Return to Form

Expectations were high as we skirted along the edge of the Porcupine Seabight shelf, a habitat far more productive for feeding cetaceans & seabirds compared to the ‘abysmal’ plains we were over for the past few days.

Conditions this morning were a lot like yesterday with favourable swell, sea state & wind in comparison to recent days but with a hint of the dreaded sea fog lingering. This cleared up after an hour or so however and with that, the birds started tipping by nicely and by mid morning we had our first cetacean sighting.

Kittiwakes were the order of the day for the seabird team, with double figure flocks loafing around the R.V. Celtic Explorer for much of the morning, no doubt thinking she was a trawler. All this activity drew in some gannets (our first in days), small numbers of great skuas and plenty of fulmars. We then sailed into a feeding flock which produced added bonuses in the form of a puffin and a manx shearwaterwhich was a new species for the survey list.

 Perfect 'as you see in the field' flight pic of a winter plumaged puffin (c) Alex Borawska

A young kittiwake with fulmars behind (c) Alex Borawska

Soon to follow was a sighting of at least two bottlenose dolphins off the starboard side. At last! Our target species for the trip. They moved on quickly however, but not before engaging in some belly rolls & tail fluking/slapping.

Not long after, the PAM team picked up some strange clicks on the hydrophone which could possibly have been a species of beaked whale. A little understood group which have been seen and heard on previous Cetaceans on the Frontier surveys. Tantalising! So to was a distant blow from a large whale species. 

Things really kicked off in the afternoon as we travelled right over the shelf from a water depth of 1000m to 200m. By this stage the wind was also blowing a good force 7 north west. Kittiwake numbers started to fluctuate dramatically, with flocks of up to 185 trailing us at times, again interspersed with more gannets, fulmars, great skuas, another puffin and most surprisingly a 1^st-winter glaucous gull (scarce winter visitor from the Arctic). We then came upon an active trawler and between its own entourage and those tagging along with the R.V. Celtic Explorer, a vast cloud of seabirds formed, comprising of 600+ kittiwakes, 100+ fulmars and 50+ gannets. Up to 4 ‘blue’ fulmars and a single great black-backed gull added some variety to the frenzy, all the while our friendly neighbourhood glaucous gull was still drifting alongside.

 1st-winter glaucous gull (c) Alex Borawska

A gnarly old great skua (c) Alex Borawska

A 'blue' fulmar, the darker, Arctic breeding counterpart (c) Niall Keogh

                              Kittiwakes en masse! (c) Alex Borawska

The best was most certainly saved for last. The cetacean team picked up an active group of breaching dolphins dead ahead of the bow which were quickly identified as more bottlenose! About 50 were present in total, leaping right out of the water and travelling at great speed past our port side. Some quick manoeuvring by the ships crew allowed for photo-ID but the dolphins obviously had other things on their mind and after several minutes, they slipped away with little effort.

An excellent sighting of an enigmatic group of animals.

Our Chief Scientist, Conor Ryan explains…

”We encountered about 50 bottlenose dolphins 58 miles west of Slea Head this afternoon, about an hour before darkness and in the teeth of a gale. It was in this same area, just on the edge of the continental shelf, that I witnessed my first 'offshore' bottlenose dolphins, in summer 2008. It seems that as we have come to expect, they did not approach the ship and we found it difficult to approach or track them. This strong avoidance of vessels appears to be a behavioural trait of offshores, unlike their inshore counterparts who cannot resist a good bow wave! Although we have yet to carry out a detailed analysis, the offshore bottlenose dolphins appear to be darker in colour and may be slightly smaller than the 'inshores'. We hope that with more genetic, morphometric and behavioural data, we can start to understand just how different these dolphins are to the coastal bottlenose dolphins.”

Offshore bottlenose dolphins (c) Simon Berrow

Offshore bottlenose dolphin...nicks along the dorsal fin useful for photo ID (c) Alex Borawska

Offshore bottlenose dolphin...Some individuals are strikingly dark with a well defined pale belly (c) Emilia Chorazyczewska

COTF4 Day 3: Pilot Whales & Puffins

After deploying a new PAP buoy out over the Porcupine Abyssal Plain this morning, we steamed north by north east for the rest of the day as we make our way inshore to take shelter from the pending storm (Donegal Bay seems a likely spot for a lovely weekend break!). We hope to continue our surveys along the northern half of our proposed track once it passes.

Swell & sea state were more conducive to surveying today but a thick sea fog reduced visibility to 300m at times. Saying that, we got our long-finned pilot whales! Two groups, of 8+ and c.5, were seen in the morning and afternoon respectively. As is typical for this species, the first group took a great interest in our presence and spent some time surfacing not far from the bow, allowing for photo-ID opportunities. Rarely seen from land so a great chance to catch up with this offshore speciality.

 Long-finned Pilot whales (c) Simon Berrow

Long-finned pilot whales (c) Alex Borawska

 Long-finned pilot whales (c) Alex Borawska

Pilot whale admirers (c) Niall Keogh

Two puffins were the highlight of the day for the seabird team. These charismatic auks spend the winter far out in the Atlantic before coming in to breed on our sea cliffs and islands from April onwards. Otherwise, a smattering of kittiwakes per hour and a handful of fulmars were the best we could filter out of the fog. Yet another gannet-less day!

 A nice, atmospheric pic of a kittiwake (c) Alex Borawska

  Not much of a view from the bridge (c) Niall Keogh