Epilogue

All good stories must come to an end. So on Saturday morning, 6.30am, we picked up the pilot in the Solent, and slowly sailed along Southampton Water until we docked outside the National Oceanography Centre. By 08:30 the ship was tied up alongside, and the expedition was officially over.

The Itchen Bridge, seen from Southampton Water
The Itchen Bridge, seen from Southampton Water

Demobilisation started immediately, and in no time boxes, sampling equipment, containers and deep-sea vehicles were lifted onto the quayside. Suddenly our home for 5 weeks changed beyond recognition, and we realised the expedition was now really finished. Time to go home!

We all said our goodbyes, already making arrangements to see each other again in the near future. Looking forward to exchanging science results, catching up on new projects, and bringing back happy memories from our 5 weeks at sea.

The end of the expedition does not mean the end of this blog or Twitter feed, though. As we develop the research and the first results start coming in, we plan to keep you updated with what we’ve learnt about Whittard Canyon, about mapping complex deep-sea environments and about submarine canyons in general. So keep watching this space, we’ll be back soon!

On sea pens that look like trees and black corals that are … orange!

This post was written by Raissa Hogan from the National University of Ireland, Galway

With the last ROV dive we closed the very successful biological sampling of JC125. These samples are invaluable for our better understanding of the biology and evolution of marine species, as well as their role in the largest habitat on the planet -the deep sea. These can also help us to understand better which kind of protection this ecosystem requires.

Overall, deep-sea research is known for being very difficult and expensive, mainly because of the extreme environmental conditions, such as darkness, high pressure and low temperatures, requiring advanced technologies as the ROVs and AUVs to be able to cope with such conditions and still bring us high quality data.

Despite my research on the deep-sea coral species Pennatulacea (sea pens) and Antipatharia (black corals) collected from the Whittard Canyon between 2010 to 2014, I haven’t actually been here before, making this a very special expedition. Also, it was the first time my project collected samples in depths deeper than 3000 m. These samples are an important component to assess the phylogeography ( the patterns of present-day geographic distributions of species as a result of genetic selection processes) and to understand how these species evolved in the oceans over different spatial scales and bathymetric ranges. Nevertheless, one of the challenges is that the taxonomy and identification of deep-sea species are still unclear, with new species frequently being described. Because of this, the first step of my project is to assess the diversity of species from the Whittard Canyon with a combination of molecular work (DNA analysis) and traditional morphological investigations, needing also to develop further markers to obtain a greater molecular signal.

In fact, when I was first organising my working plan for this cruise, I was really focused on which species I was going to find and would be able to collect, and how they would help me to assess the phylogeography of these groups. However, even though these were the main objectives, the interaction with the other researchers, engineers, ROV pilots, vessel crew and chefs opened a new and great perception of the cruise in the Whittard Canyon. Definitively, I will be taking with me a lot more than just the amazing coral specimens collected. Yeah! I need to admit that my “geologist” side has developed considerable. I will recognise a “turbidite” (basically, it is a bit of sand in the middle of mud 😉 ) in any core in the world… Thanks Russ!

This orange, tree-looking specimen is actually a species of 'black coral' (called like this because their skeleton is black)
This orange, tree-like specimen is actually a species of ‘black coral’ (called like this because its skeleton is black)

 

But I also think my colleagues became quite good in identifying some of the species of sea pens and black corals. First they got a bit disappointed to know that the black corals actually have strong warm colours like orange and red, but when I showed them the samples with their black skeleton they became a bit more convinced. According to some of them, sea pens look like trees, which reminded me some of the first descriptions of these animals back in the 16th century: They look like a small tree, but if we touch them they can bury themselves, and they also have light (bioluminescence), and then, when they die, they become a rock!!!” Indeed, sea pens are quite intriguing animals, being the most advanced of octocorals in terms of their colonial complexity and functional specialisation. They are adapted exclusively to soft sediments, having a part of their organism, the peduncle (that looks like a roots), that stays buried and keeps them anchored in the mud.

During this cruise, the sea pen that became the most popular was the genus Umbellula. They are the ultimate in adapting to the deep-sea conditions, with large polyps to enhance the food capture. In the ROV control van everybody, from the ROV pilots to the geologists, enjoyed to see the deep-sea “flower” Umbellula!!! In fact, the deepest sample collected (at 4173m), was an Umbellula! That was a good reason to celebrate!

Testing a new ROV-based vibrocorer

Virbrocorer mounted on the ROV

This blog post was written by Jenny Gales, a postdoctoral researcher at NOC.

An important event towards the end of the cruise was testing a new ROV-based vibrocorer, a coring system that works by vibrating aluminium core barrels into the seafloor. The benefits of a vibrocoring system over traditional coring methods, such as piston and gravity coring, is the ability to core into sandy substrate: pure sand is notoriously difficult to core as the sand grains interlock under the weight of the core barrel. By vibrating the barrel this problem can be avoided. As the vibrocorer is mounted on the ROV, it also allows coring sites to be precisely targeted on the two ROV cameras and on the forward facing sonar. We tested this new system in shallow water (~200m water depth) and successfully recovered five sandy cores, making the shallow water trials a success. In the long run, we aim to use the system at full ocean depth, i.e. up to 6000m deep, where nobody has vibrocored before!

Sandwaves seen in the forward facing sonar
Sandwaves seen in the forward facing sonar

On one of the dives, we targeted a small area of sandwaves at the head of the canyon. During the dive we could locate ourselves using the forward facing sonar and vibrocore in precisely the correct location. This was a huge advantage over traditional coring methods, where it is often difficult to target specific areas of the seafloor due to currents causing drift on the coring rig as it is lowered to the seafloor. A second dive took us right into the middle of a sandy chute at the edge of the canyon. We could see steep walls surrounding the ROV on the forward facing sonar so knew that we were in the middle of the chute- exactly where we wanted to be. We look forward to using this system again in the future!

Corals, corals, corals and other animals!

This blog post was written by Inge van den Beld, a PhD student at Ifremer

Last Friday night (4 Aug), ROV Isis was sent to the seabed one more time to take images of the seafloor of Whittard Canyon. The steep topography seen on the multibeam bathymetry maps, and video footage taken at nearby locations, suggested we would again encounter deep-sea corals during this dive. Deep-sea or cold-water corals are different from tropical corals as they live much deeper (below 200 metres water depth), can cope with colder temperatures (usually between 2-10°C) and do not need sunlight for their energy, because they lack symbiotic algae.

Earlier on the cruise, we investigated a wall on the opposite flank of this branch of the canyon using Isis. This wall was dominated by large colonies of colonial stony corals (mainly Lophelia), together with Ascesta bivalves, some gorgonian (seawhip or fan) species and a brown sponge. Therefore a similar community was expected on the (near-) vertical feature investigated on Friday night. However, although we saw many corals, the species assemblage was not really what we expected.

Large colonies of gorgonians, seen on the other flank, were dominating this flank of the canyon, while colonies of stony corals (perhaps not even the same species) were less abundant and smaller in size. The brown sponge was replaced by a white, cup-like sponge, and the Ascesta bivalves disappeared (except for one small patch). At the base of the vertical feature, large colonies of another stony coral, Enallopsammia sp., were encountered, and at the top, we saw large stylasterid hydrocorals.

The observed differences in community between flanks of the same canyon branch may be a result of the steep canyon walls being oriented at different angles to the current (which brings food and (coral) larvae), and possibly also due to differences in substrate. Initial analysis of Isis video suggest the rock type on this latest dive was igneous or metamorphic in origin, and very different to the sedimentary rock seen in the previous dive on the opposite side of the canyon.

Bamboo coral and sponge
Bamboo coral (left) and a cup-like sponge that may be dead (right)

During my PhD, I am studying the distribution of cold-water coral habitats and their faunal composition within the submarine canyons of the French part of the Bay of Biscay, including all canyons south of Whittard Canyon until Capbreton. During this JC125 cruise, we have seen many habitats formed by cold-water corals, ranging from gardens of gorgonians, fields of seapens comprising different species, and reefs formed by the colonial stony corals Lophelia pertusa and Madrepora oculata. Whittard Canyon is therefore very rich in terms of species, whether they are habitat-forming or not.

This is the first time that I have ‘visited’ Whittard Canyon, even though it is only a few nautical miles away from the northern part of ‘my’ study area. It is nice to see that the habitats I encountered in the French canyons are both similar and different from those in Whittard Canyon. Stony coral reefs on non-vertical terrain, some of the seapen aggregations, and a vertical wall dominated by Solenosmilia are habitats that are similar. However, some habitats in Whittard Canyon were new for me, for example the above described gorgonian and sponge community. On the other hand, fields of Funiculina seapens is an example of a habitat seen in French canyons but not in Whittard Canyon during this cruise. Some of the fish species swimming around in Whittard Canyon were also not known to me or only on paper, for example a fish probably belonging to the Halosauridae family.

A fish that probably belongs to the Halosauridae family
A fish that probably belongs to the Halosauridae family

Differences in benthic communities and dominant species between canyons may be caused by e.g. food supply, current directions, (investigated) depth range and/or substrate type. However, we haven’t investigated each centimetre of the 100 or more canyons that are present in the Bay of Biscay. So there is much more to explore and discover!

Becoming a marine biologist for a day (or two)!

A selection of biology sampled on the seafloor by ROV Isis

This blog post was written by Tahmeena Aslam, a PhD student in physical oceanography at the University of East Anglia

Sometimes we have so many biological samples to process that even those of us (like myself) who work in a non-biological field are roped in to help. I study physical oceanography and until now I’ve never appreciated how “clean” data collection has been for me! Here are some of my thoughts from my few days as a biologist helping Laura to process the Acesta clams that she has written about previously:

  • It’s a bit disconcerting when your colleagues, who seemed fairly normal, suddenly whip out their dissection kits and gain a morbid fascination with slicing up flesh and muscle. And you’re trapped on a ship with them in the middle of the ocean with no chance of escape.
Laura, my patient biology teacher
  • Processing samples involves getting very cold. Dissecting occurs in a cold room (4ºC), so as to preserve specimens. Cue wooly hats, multiple layers of clothing and jumping up and down to keep warm … in the middle of August.
  • Processing takes time. Record keeping is key and we don’t want to waste any material that we’ve gone all the way to the bottom of the ocean to collect. Samples will be sent to multiple scientists to ensure that each life lost on the sea floor is not in vain.
P1000330
Acesta clam samples
  • No anthropomorphising of specimens allowed. Do you really want to name that shrimp “Dave” and then “preserve” him? No.
  • It’s weirdly satisfying! Doing something practical, when usually a lot of my work on a cruise is done sat behind a computer while my robot or instrument collects data, is really refreshing.
  • It makes you really think about the connections between the biology we see and the differing oceanographic and geological settings that they are found in. Why is this clam found here and not in that other part of the canyon? What influence does the water column or the geology have on their distribution? On an interdisciplinary cruise like this, it’s great to work with scientists from different disciplines and to start to figure out the reasons why amazing habitats, such as the ones found here in Whittard Canyon, occur where they do.

The seafloor at higher and higher resolution!

This blog post was written by Katleen Robert, a postdoctoral researcher at NOC

One of the main aims of the CODEMAP cruise is to use innovative methods to map the seabed.  For many of the deeper areas, we still only have coarse maps for which many of the finer details, such as vertical walls, small gullies or coral mounds, are absent. However, these are important features, that play a big role in the local biodiversity in the canyon. To do the mapping, multi beam echosounders are usually used.   These sonars create a swath of sound across the path of the ship and measure the time for the sound to leave the ship, bounce off the seabed and return.  This gives estimates of the depths below the ship.  But to get more details, we need to get closer to the seabed.  This is where autonomous underwater vehicles (AUVs) like Autosub6000 or remotely operated vehicles (ROVs) like ISIS are useful; they can fly much closer to the seafloor (less than 100m).  Of course there tends to be a trade-off, as we get more and more resolution, we tend to be unable to cover very large areas.  This is why we still very much rely on ship-board multibeam to find target areas to further investigate using the AUV, and then use the maps resulting from the AUV surveys to decide on ROV video transects.

For one location in the eastern branch of the canyon, where a vertical wall covered in cold-water corals had been discovered during a previous cruise in 2009, here is an example of the different levels of detail that can be achieved using all the vehicles.

Blog_LowRes

The first layer is part of a larger ship-board survey of the entire canyon branch (resolution ~50m), the second layer is from a ~25km2 AUV survey (resolution ~5m) (upper panel), and the third layer shows the previously mapped vertical wall (middle panel), a survey carried out using a multibeam mounted on the front of the ROV (~0.5m resolution).  The white track shows an ROV dive carried out during the CODEMAP cruise imaging overhanging cliffs covered in both hard and soft corals, clams and anemones (lower panel).

But in the end, why do we do this?  The information we get from the bathymetry allows us to derive other environmental characteristics such as slope (steepness and direction) or rugosity of the terrain.  As animals tend to select habitats with specific characteristics we can try to link these to where specific species occur, based on the collected videos and pictures.  Since we still lack information about the distribution of many species in our oceans, these links between species and their physical habitat can provide us with some information for areas we have not yet explored.

Spectacular marine life seen during CODEMAP expedition!

This blog post was written by Russel Wynn, a Senior Research Scientist at NOC

In addition to studying the deep-sea fauna of Whittard Canyon with our robotic vehicles, we have been recording marine life at the sea surface with more traditional equipment – binoculars! One of the scientific team, Russell Wynn, has been undertaking daily marine mammal and seabird observations, to better understand the range of species using the Whittard Canyon area and their habitat preferences.

The most spectacular sighting so far has been a Blue Whale, the largest animal on the planet, and probably first ever to be photographed in English waters! The huge mammal, twice as long as a double-decker bus, was seen on 24 Aug over a deep part of the canyon within the English portion of the UK EEZ. I had been watching up to seven Fin Whales around the ship when the Blue Whale suddenly surfaced about a kilometre away. It lingered just long enough to allow conclusive photos to be secured (and several people to see it from the bridge), before it disappeared in a band of rain and fog.

This sighting follows the first photographic record of Blue Whale off SW Ireland in Sept 2008. The species was hunted to near-extinction in the NE Atlantic region in the early 20th century, but these recent sightings, and others from observers on ferries crossing the Bay of Biscay further south, may indicate that the population is slowly starting to recover and move into new areas.

Blue_Whale1(24-08-15)

Blue_Whale3(24-08-15)
In these two photos the Blue Whale is surfacing and moving left; the dissipating blow is visible to the right in the upper image, with the mouth and splashguard (which protects the blowhole) on the left. In the lower photo the Blue Whale is preparing to dive; the mottled bluish-grey back and tiny dorsal fin are clearly visible.

In addition to the Blue Whale, over 20 Fin Whales (the second largest animal on Earth) have also been seen using the deep waters of the canyon, in aggregations of up to six animals. Other marine mammals recorded so far include Pilot Whales, hundreds of Common Dolphins and two groups of offshore Bottlenose Dolphins.

One of the most remarkable cetacean sightings was of a lone juvenile Pilot Whale, seen continually surfacing alongside the ship for most of the day on 18 June. This apparently orphaned animal was evidently in some distress, which became even more apparent when it reappeared alongside the vessel two days later some 50km to the southwest!
One of the most remarkable cetacean sightings was of a lone juvenile Pilot Whale, seen continually surfacing alongside the ship for most of the day on 18 June. This apparently orphaned animal was evidently in some distress, which became even more apparent when it reappeared alongside the vessel two days later some 50km to the southwest!

On the same day that the Blue Whale was seen, the survey team also recorded a Broad-billed Swordfish several hundred metres below the surface using ROV Isis. Swordfish are very rarely encountered in UK waters, and the footage obtained may also be the first of this species in the wild in English waters. Equally spectacular, up to 12 Blue Sharks have regularly been seen around the ship, and have also been captured on ROV video.

This image of a Broad-billed Swordfish was taken from video obtained using ROV Isis. The robotic arm of the vehicle is visible in the right of the image.
This image of a Broad-billed Swordfish was taken from video obtained using ROV Isis. The robotic arm of the vehicle is visible in the right of the image.
This image shows two Blue Sharks, photographed by ROV Isis during its journey to and from the seabed.
This image shows two Blue Sharks, photographed by ROV Isis during its journey to and from the seabed.

Seabirds have included rare Wilson’s Storm Petrels and lots of true oceanic wanderers such as the Great Shearwater, Grey Phalarope and Long-tailed Skua.

Great_Shearwaters_230b(26-08-15)

Up to 270 Great Shearwaters have regularly been seen aggregating around the ship in the daytime, and hunting fish attracted to the ship’s lights at night.
Up to 270 Great Shearwaters have regularly been seen aggregating around the ship in the daytime, and hunting fish attracted to the ship’s lights at night.

Finally, we have also seen a few land bird migrants taking refuge on the ship, including species such as Wheatear, Redstart and Reed Warbler that migrate south to winter in sub-Saharan Africa.

Redstart(18-08-15)

Reed_Warbler(17-08-15)
Redstart (upper image) and Reed Warbler (lower image); these birds were seen resting on the ship before continuing their migration to Africa.

With just under two weeks to go until the end of the cruise there will certainly be more interesting marine life sightings to come, so keep an eye on our Twitter feed for further news!