Celtic Explorer 2009 – Week 1

For 3 weeks in May & June 2009, the R/V Celtic Explorer went into the Bay of Biscay and out into the Atlantic to study cold water corals with the help of the new Irish ROV (Remotely Operated Vehicle) the Holland 1. Two of the students aboard posted this blog.Welcome aboard the Research Vessel Celtic Explorer! We, Paula and Marie, will tell you the story of our 14 days aboard the 2nd leg of the CoralFISH cruise.

Day 1 – Tuesday 5th May
We joined the R.V. Celtic Explorer in Brest, France at 10.00 a.m for the 2nd leg of the CoralFISH CE0908 survey. The crew and some of the scientific staff had already boarded the ship in Galway some 5 days earlier. The equipment – ROV (Remotely Operated Vehicle) – necessary for this survey was already onboard and operational.

After leaving our luggage in our respective cabins, we went on a tour aboard the French R.V. Pourquoi pas? (IFREMER vessel) which was docked close to the R.V. Celtic Explorer. She is a very big ship with 7 decks, a lift, 5 wet labs and the most impressive of all were the equipment onboard: the submersible Nautile, the Remotely Operated Vehicle ROV Victor 6000 and an autonomous underwater vehicle (AUV). It was amazing!

French research vessel Pourquoi pas? (photo by Marie Le Guitton)

Back aboard the R.V. Celtic Explorer, we had our first lunch before the safety tour and talk. The safety tour consisted of informing the new staff of the locations of the safety gear (life jacket, survivor suits), lifeboats and the safety procedure in the event of a fire for example. We set sail at 4.00 p.m. towards our first station. We went to bed quickly because of the motion of the ship and to prevent the seasickness.

Harbour and castle of Brest (photo by Marie Le Guitton)

Day 2 – Wednesday 6th May
We arrived on station at 4.00 a.m. The location of the first dive was Le Guilvinec Canyon (cf. map on section: Where is the ship?) in the Bay of Biscay. The ROV entered the water at 7.45 a.m. and reached the bottom of the seafloor approx. 1 hour 30 minutes after. The transect thus began in at a depth of 1,300 meters. The ROV continued along a predefined transect, recording images of the seafloor. Our work involved watching 2 TV screens all day long in the dry lab and to record the important events we saw on the seafloor, for example, changes in sediment type/structure or presence/absence of fish, corals etc. We also noted any plastic bags which where caught on the coral mounds in order to have some data for a future study about the human impact on the deep-sea. The same work was done by Anthony, Anna, Brigitte and Pascal in the container where the ROV was controlled. All the camera feeds were recorded on tape on board the ship. The dive continued up the canyon wall to approx. 800 meters. At the end of dive, we came across the coral reef we were hoping to find. The ROV exited the water at 8.00 p.m.

Remotely Operated Vehicle (ROV) before and after its launch. (photo by Marie Le Guitton)

During the night, and every night from then on, some brave students Damien, Bill and Catherine carried out a total of 55 Conductivity Temperature Depth (CTD) profiles to obtain oceanographic information (temperature, salinity, density, dissolved oxygen and pH) from both the dive sites and other transects. A total of 5 SAPS (Self-Automated Pumping System) deployments were also carried out during the night shift to provide samples for the assessment of organic compounds in the water column.

Day 3 – Thursday 7th May
Before launching the ROV, we saw a fishing boat fishing on our intended transect line. We contacted it for a location of their gear to avoid entanglement of the ROV.. With this information, the ROV was launched at 7.55 a.m. and reached the bottom one hour later at a depth of 900 m. We worked a further 400 meters of the same transect line as yesterday before moving to a new location on the Guilvinec Canyon. It took less than one hour to move to the new location. The ROV entered the water at 1.39 p.m. for dive 3 and reached the bottom at 2.12 p.m. at a depth of 1176 m. During dive 3 we discovered lots of dead and live corals and some of the species we saw included Lophelia pertusa and Madrepora sp., which are the main species of reef building deep-sea corals. The area was very diverse both in habitat and species. The ROV was taken out of the water at 5.51 p.m. at 689 m depth.

TV screen on which we followed the progression of the ROV in the dry lab. (photo by Paula Harrison)

During the afternoon, a guest came on board, surprising us. It was a lovely owl.

Owl (photo by Marie Le Guitton)

Day 4 – Friday 8th May
During the night we travelled to Le Croisic Canyon in the Bay of Biscay. CTD casts were done in the early morning. The ROV entered the water for dive 4 at approx. 9.00 a.m. The depth reached by the ROV was 1,466 meters. This was a very interesting dive straight from the start as there was a 60 meters wall, which was abundant in coral, yellow corals, sponges and Brachiopoda. After this wall, the terrain was terrace like with sandy sediment between these terraces. A number of fish species were present during this dive such as scorpion fish, monkfish, orange roughy, Nephrops, sharks and an octopus. The dive was terminated at 5.00 p.m. due to very strong bottom currents.

A deep-sea fish imaged during ROV dive 4

Day 5 – Saturday 9th May
During the night we began our transit towards the southwest of Ireland. Was it a sign? The weather, which was sunny, began to change. The Celtic Explorer was on its way to our next station: the Arc Mounds on the margin of the Porcupine Bank. The work of the day consisted of saving all the data we had collected during the last four days and trying to solve the problems we met, but also to relax.
After dinner, some lucky people (Pascal, Anna and Catherine) had the chance to see some dolphins.

Common dolphins (photo by Dave Wall)

Day 6 – Sunday 10th May
Sunday was a day of rest for a lot of people. The crew stopped painting the ship, but scientists continued to prepare for the next days. We were still on our way to the next station: the Arc Mounds, on the Porcupine Seabight.

Discussion on the bridge (Left to right: Paddy, Paul, Pat and Anthony) (photo by Marie Le Guitton)

Day 7 – Monday 11th May
We arrived on station in the morning. The ROV was launched at 10.00 a.m. for dive 5 in a canyon called Canyon T1 located on the SW margin of the Porcupine Bank. After 2 and a half hours of diving, we lost the G.A.P.S. (Global Acoustic Positioning System) signal, i.e. we didn’t know the exact position of the ROV on the bottom. The ROV pilots decided to retrieve the ROV rather than risk potential damage flying blind, so dive 5 was terminated at 1.30 p.m. To finish the day four grab samples were taken recovering dead coral, although new colonies were visible on the reef . These samples were quite rich in animals especially ophuiroids.

Paddy and Frank waiting for the grab, here it is (photo by Marie Le Guitton)

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