Weekend break for the ridge

After a rocky nights sleep we eventually made it to the Wyville Thomson Ridge at 01:00 hours on 27th October 2012. With relatively calm weather at dawn, calibration and testing of the on board kit began. This included lowering of the camera frame onto the ridge and testing the lasers and lights. A Sound Velocity Profiler was then lowered through the water column to find out the speed of sound at different water depths. This is very important to help us when calibrating the mutibeam system – a piece of kit that produces a depth image of the seabed and enables us to then pick out features of interest such as pinnacles and furrows.

Blowing a gale

With the forecast not looking particularly encouraging over the next few days, we have decided to focus on using multibeam to generate a picture of the seafloor bathymetry in the northern part of the Wyville Thomson Ridge study site on a relatively shallow part of the ridge at c350m. This is in the hope that there will also be time to get some video and camera tows included in the same area before the bad weather arrives.

The majority of Saturday and the early hours of Sunday morning were spent multibeaming the shallow part of the ridge feature. Despite the fairly rough sea conditions, the pictures on screen were of reasonable enough quality and resolution to help guide the decision on which areas might be of interest to collect data using towed video and camera transects.

Initial multibeam outputs

Using multibeam outputs to select areas for towed video transects



At 08:00 hours on 28th October we deployed our first towed video transect. Attached to the frame was a HD camera, supplied and run by Plymouth University PhD student Rebecca Ross. This was the camera’s first outing and is already starting to produce results.

In five hours we had three transect lines worth of data, but the bad weather came creeping back halting any further progress today. Fingers crossed for another weather break soon!

Deployment of towed video camera

High definition camera frame image from Plymouth university with size calibration lasers   

Munida rugosa (Squat lobster) on stony reef at Wyville Thompson Ridge

Cidaris cidaris (Pencil urchin) on stony reef at Wyville Thompson Ridge

All hands on deck and bon voyage

Progress so far has been slow, with the acoustic equipment requiring some final checks before departure. Once we finally left the harbour at 14:30 hours on 25th October 2012 it was a frantic wave to our colleagues in the JNCC Aberdeen office before steaming on to our first destination – The Southern Trench. The intention was to test and calibrate some of our on board kit, but unfortunately due to the Force 8 winds and big sea swell, we haven’t managed to do any calibration yet.

MRV Scotia

Then weather conditions took a turn for the worse and it wasn’t long before many of the staff on board were turning a little green. A tour of the ships facilities and getting to know the ins and outs of the sampling equipment has kept us all busy so far. We are due to arrive at the first of our study sites the Wyville-Thomson Ridge at 10pm on 26th October 2012. Fingers crossed for good weather!

Trying on an immersion suit

MRV Scotia to survey Wyville Thomson Ridge SCI

Four members of JNCC staff have joined the Marine Scotland research vessel ‘MRV Scotia’ for the next two weeks to undertake a detailed survey of the Wyville Thomson Ridge candidate Special Area of Conservation. The Wyville Thomson Ridge is a rock ridge situated in the Atlantic Ocean at the northern end of the Rockall Trough approximately 150km north-west of Cape Wrath, Scotland. The site was submitted to the European Commission in 2010 for its reef features and has since been made a Site of Community Importance (SCI).

Wyville Thomson Ridge  © Crown Copyright

Wyville Thomson Ridge rises from 1000m at its deepest point to 400m at the summit. Along the ridge there are large areas of stony reef, thought to have been formed by the ploughing movement of icebergs through the seabed at the end of the last ice age. Bedrock reef is present on the flanks of the ridge and, due to the differences in water masses, there are different species compositions on either side.These reef communities comprise sea urchins, sea spiders, sea cucumbers, dense beds of featherstars and brittlestars, a range of colourful sponges and both cup and soft corals.

The main aim of this survey is to obtain evidence to facilitate fisheries management discussions in relation to Wyville Thomson Ridge SCI.  In addition, the survey provides an opportunity to improve our understanding of habitat distribution and community composition within the site and develop methods for future site monitoring.

After surveying Wyville Thomson Ridge, the vessel will transit to an area near the Faroe-Shetland Channel to investigate the extent of deep-sea sponge aggregations for the Scottish Marine Protected Area Project.

Diverse marine habitats

After a busy weekend of multibeam, a low pressure weather system moved in and
the Pole Star was forced to head back to Oban to shelter. This gave us time to
back-up and examine the data we had collected during the previous week.

Based on multibeam data that Gill and Kirsten (BGS) processed on board, we
were able to select locations for sampling. Groundtruthing is an important part of
the survey as it allows us to assign particular habitats to corresponding areas of
multibeam. The two pieces of equipment we are utilising for this purpose are a
drop-camera and Day grab. The drop camera allows us to take videos and
high-resolution stills of organisms living on the reef or projecting from the
sediment, whilst grab samples of sediment allow us to extract organisms from
within. Cefas are providing technical support and expertise in the form of Simon
and Jo to assist with the groundtruthing.

Stanton Banks SCI is proposed for designation because of its Annex I rocky and
stony reef habitat. Through use of the drop camera, we now have information on
the types of species that live on and around the reef. From images collected so
far, we have seen various types of crab, starfish, featherstar, sea urchin and sponge.



Brittlestars (Ophiocomina nigra)





Edible crab (Cancer pagurus)

Featherstars (Leptometra celtica) and squat lobster (Munida rugosa)

We have also found muddy sediments around the reef features. Though there are
 fewer conspicuous species on the surface compared to the rocky areas, we have
seen a number of sea pens and nephrops.



Sea pens (Funiculina quadrangularis) and langoustine (Nephrops norvegicus)

We are currently heading for a crew change before transiting back out to Stanton
Banks to try and finish the survey in a good weather window between gales.

A lesson in multibeam acoustics

Last time I mentioned that we were anticipating some bad weather. When it finally hit
we had to batten down the hatches and take shelter moored on the beautiful Isle of
Barra overnight. We managed to go ashore whilst the vessel took on fresh water,
stock up at the local shop, and make a visit to the local pub.

We are now back collecting multibeam data over the southern section of Stanton
Banks SCI (Site of Community Importance). Our BGS colleagues have written a
paragraph to explain a bit more about their work:

Hydrographic surveyors “look” into the ocean to see what the sea floor looks
like. A multibeam echosounder is a device typically used by hydrographic
surveyors to determine depth of water and the nature of the seabed. On the
Polestar, we use a Simrad EM3002D shallow water (0.5-160m) high resolution
multibeam system. This  system collects a swath of bathymetry data that is up to
10 times the water depth wide. By running survey lines correctly spaced apart,
very accurate 100% coverage of the water depth can be collected. Data is
processed onboard using Caris, taking into account position, ship motion etc.
The final product is displayed using 3D viewers to fly through the data as if
the water were not there. The images BGS produce can then be used to aid
JNCC and CEFAS scientists in determining the best locations for camera tows
and grab sampling.

Kirstin & Gillian

On a closing note, this morning we saw dozens of common dolphins jumping in the
wake of the ship and spied a pod of about 150 out in the distance. I also saw my first
ever minke whale this afternoon as well!

Becca Lowe

Playing with Mud

After a couple of days of multibeam to the north of the Stanton Banks site, we got to do some biological sampling. We conducted five video tows and two grab samples from areas of interest detected in the multibeam images. On one camera tow over rocky reef, we observed hundreds of small prawn cracker sponges, Axinella infundibuliformis (see image), encrusting the rocks. On other tows, we saw areas of burrowed mud, with seafans and evidence of Nephrops norvegicus. The two grab samples we collected were both of muddy sediment, which have now been sieved and preserved ready for analysis. It was my first time doing grab sampling, hence the cheesy photo with the Day grab! We use a Day grab to sample finer sediment as it tends to disturb the sediment less during collection.

We are now back to using multibeam for the next couple of days over the larger south-eastern portion of the Stanton Banks site.

There is a large area of low pressure heading towards us over the next couple of days with some murmurs of swells reaching up to 2.5m so there is some trepidation about that!

Becca Lowe

A Rough Start

Stanton Banks are a series of granite rises which outcrop from the seafloor south of the Outer Hebrides (approx. 124km west of UK mainland). Stanton Banks was designated as an SAC in 2008 and has now been accepted as a Site of Community Importance. Five surveys have been conducted on Stanton Banks, which confirm the presence of Annex I reef. The aim of this survey is to acquire further information on the presence and extent of Annex I reef and additional data to help develop a baseline for future monitoring of the site.

After a couple of small teething problems (including electrical failure onboard the vessel) leading to a minor delay to the survey departure, we have finally set sail bound for Stanton Banks. We departed Oban at 1300hrs on Friday 17th August and sailed through calm seas to arrive at Stanton Banks at 2200hrs. The Pole Star is proving herself to be an incredibly rocky ship even with very little swell of just 1m. Acclimatising to this is proving to be a challenge in itself but all in all, we are all in ship shape.

I should mention who 'we' all are: Gareth Johnson and myself (Becca Lowe) from JNCC, Simon Pearson and Jo Murray from CEFAS and Kirsten Crombie and Gillian Horner from BGS. BGS are currently hard at work using acoustic techniques to measure bathymetry of the seabed so that we can decide where best to take video and biological samples.

On a less technical note, the food is top notch (if you can manage to keep it down!) and I also spotted a pod of common dolphins yesterday evening and this morning jumping beside the vessel. I didn't have my camera with me at the time but hopefully some wildlife pictures to come....

Becca Lowe