Offshore survey of Fladen Grounds due to commence in the New Year

On Friday 4th January a two week survey will kick off a new round of planned JNCC offshore surveys for 2013. The first survey of the year will be heading out to a large muddy basin off Scotland called the Fladen Grounds. Two members of JNCC staff have joined the Cefas Endeavour research vessel, to undertake detailed surveys of three national Nature Conservation MPA proposals within the Fladen Grounds area. These MPA proposals could contribute to the protection and conservation of Scotland’s spectacular and diverse marine environment.

The three areas to be surveyed are Central Fladen MPA proposal, Western Fladen MPA proposal and South-east Fladen MPA proposal. These areas have been identified to protect components of the feature ‘Burrowed mud’. The Central Fladen MPA proposal includes  Seapens and burrowing megafauna and the tall sea pen Funiculina quadrangularis, with Western and South-east Fladen identified as science-based alternatives to the representation of the seapens and burrowing megafauna contained within the Central Fladen MPA proposal. Burrowed mud habitats can contain a range of creatures like seapens, fireworks anemones, amphipods and burrowing megafauna such as the Dublin Bay Prawn Nephrops norvegicus, more commonly known as scampi.

The main aim of this survey is to gather additional evidence to support these Nature Conservation MPA proposals for the Scottish Marine Protected Area Project.

Land ahoy!

Well folks....we've just arrived back in Lowestoft after fourteen days at sea. In light of the appalling weather we've had on the trip, we're certainly happy with the amount of data we've managed to gather at the three areas of interest; both from a quality and quantity perspective.  It is important not to forget though that the work doesn't stop here, and the data will need to be analysed and interpreted following the survey. 

You may have noticed a few hairy upper lips on some of the male scientists throughout the blog posts.  In a show of solidarity, scientists from Cefas and JNCC donned their Mo's and joined their hairy compatriots to show support for Movember.  Check out the picture below....



Cefas and JNCC scientists commemorating the last day of Movember.


All that's left to say now is a big thanks to the Cefas scientists (and a special mention to Sue the Scientist in Charge plus Julia and Joanna, the shift leads) as well as the Master and crew of the RV Cefas Endeavour.  We hope you've enjoyed reading the survey blog.  Until next time.....



The sun sets on another survey.



Nearly finished surveying Turbot Bank…

Over the last two days we’ve focused on finishing the grab samples and drop camera transects.  On Wednesday, faced with winds from the north and a northerly swell, we were limited to running multibeam lines across the Turbot Bank area for the first part of the day. Due to the size of the site and the fact that we could only run lines in one direction, it took the first seven hours of the day to complete just three! The screengrab below shows some of the raw multibeam bathymetry data. The data show a depth range across the survey area of 80 metres (in the north) to roughly 60 metres (in the central area).

Screen grab of multibeam data. Note: To increase data coverage, further survey lines will be completed in due course.

Throughout the rest of Wednesday and some of Thursday, the day and night shifts shared the effort of grab sampling and sieving.  There was a collective sigh of relief when the final grabs were processed. We were able to use the remaining contingency time to complete some extra drop video tows. In order to facilitate the interpretation of the multibeam backscatter data, the video tow stations were positioned to intersect with the multibeam survey lines. The backscatter data show the sound energy reflected back from the seabed and this can be linked to the physical properties that make up the sediment (see image below; energy values are shown using a grey scale). On the screen grab below, the darker areas indicate higher reflectance.  The video tows confirmed our predictions that the darker regions were indicative of gravel dominated substrates while the lighter areas were indicative of sandier substrates. 

Screen grab of multibeam backscatter data. The darker areas indicate relatively high sound energy reflectance.

With our survey time at Turbot Bank coming to an end, we’re getting ready for our final transit home in the early hours of tomorrow morning.

A shot of the day shift team in the plot lab…

The boat that rocked

Today has involved a mixture of survey methods, with the early hours involving finishing the remainder of the priority grab sites. The next task of the day was to focus on getting video footage from a subset of those areas from which we had already taken grab samples. The visibility at this survey location is really good and we could get a clear picture of the seabed. The sediment here ranges from coarse sand with the odd pebble or cobble to much coarser gravelly sediment with boulders. There is a lot of Hornwrack (the bryozoan Flustra foliacea)  growing on cobbles and pebbles in the sediment as well as cushion stars (abundant Porania pulvillus but also Hippasteria phrygiana which apparently is rather rare in British waters) urchins, anemones and plenty of squat lobsters and crabs. The squat lobsters and crabs were especially prevalent in the areas containing cobbles and boulders.

 Dahlia anemone Urticina felina 

 Edible crab Cancer pagurus and Flustra spp.

Plumose Anemone Metridium senile

 Red Gurnard Aspitrigla cuculus

Seven armed starfish Luidia spp.

Starfish Henricia spp.

Starfish Hippasteria phrygiana

Sunstar Crossaster papposus

The day shift continued with the camera tows. We also planned some supplementary multibeam lines, in case we got some rougher weather which was forecast to arrive towards the end of the day. The four ‘corridors’ of additional survey lines ran in a north-south direction and supplemented the east to west survey lines, providing a grid of acoustic data. The new lines were placed across many of the planned drop-down camera tows and Hamon grab stations within the area. Due to the sheer size of the site, it won’t be possible to get full acoustic coverage….that would take many days of intensive multibeam survey. The intersecting lines that we have planned should nevertheless provide a set of acoustic data which are representative of the area. Towards the latter part of the day, the wind picked up and the sea became a little too rough to use the Hamon grab, so we switched to the planned multibeam lines to finish off the day. 

Sieved to see another day…

When the night shift took over at midnight, the weather was still a little too rough for anything other than multibeam and so we continued to run some acoustic lines from East to West. The Turbot Bank survey site is large in comparison to the cSAC sites (nearly 30 times bigger than the Braemar and Scanner cSAC sites combined). Good quality data could only be gathered when the vessel travelled in one direction, with each line taking nearly two  hours. Just before sunrise we deployed the drop camera and found a number of interesting species. Some of the highlights have included squat lobsters, sandeels, sea urchins, occasionally some scallops and plenty of brittlestars and starfish.  It was evident when watching the footage of the seabed that this was a high energy site, with significant currents sweeping across the seafloor.

Squat lobster

Porania pulvillus

Echinus esculentus

A key sampling method at the Turbot Bank site will be using the Hamon grab to take samples of the seabed. We plan to deploy the grab at over 70 stations spaced evenly across the survey site. Particle Size Analysis (PSA) and macrofauna analysis will be undertaken on these samples in order to better characterise the substrate and the organisms that it supports. Sampling the sands and gravels at Turbot Bank presents some challenges compared with the soft muds at the Braemar and Scanner Pockmark sites. Occasionally grab samples have to be discarded if insufficient volume of sample material is collected and this is most likely to occur if the grab strikes cobbles or boulders. It will take some time to complete the sampling and so it’ll be important to prioritise the good weather windows for using the Hamon grab.

The first few grabs of the day brought up coarse sandy sediment, with some cobbles. This sediment had fewer worms than seemed to be present in the mud that we sieved at the cSAC survey sites, instead containing sand eels, burrowing urchins and brittlestars that live in the sediment. As the sediment was coarse it collected more readily in the 1mm sieves, extending the sieving time per sample. By lunch time a number of grabs had been taken but there was plenty left to go!

Some images of the species we found in the grab samples. Top left: spider crab, disguised with marine life growing on its shell. Top right: Purple heart urchin (Spatangus purpureus). Bottom: Sandeel, a key food source for seabirds in the North Sea.

Going cyclonic on the transit to Turbot Bank

The day commenced with continuation of video tows, a mixture of lines crossing those already carried out within the four main pockmarks and some additional video tows over some smaller pockmarks within the south of the Scanner Pockmark cSAC.  The multibeam bathymetry/ backscatter showed that these smaller pockmarks had some interesting ‘scour pit’ features trailing off their south end. After the last tow was completed we changed gear type to the Day grab to take some final sediment samples from within the four main pockmark features in the site. By the end of the third grab station the swell and wind had really picked up and it was no longer safe to deploy the Day grab from the ship.

A glimpse of the gale force weather



Soon after this, having collected sufficient acoustic and groundtruthing data for the Scanner pockmark cSAC, we began to transit to our third and final site Turbot Bank. As explained in yesterday's post, the decision was made to survey the site of a potential Nature Conservation MPA called Turbot Bank instead of one further north in the Fladen Grounds. This journey was especially eventful, with by far the largest swell we have experienced and with the weather on the beam, the ship was lurching all over the place with people and belongings sliding everywhere. At one point whilst sat in the lounge, people were sliding across the room whilst sat in their chairs!

At 2pm the ships general alarm sounded for our weekly emergency muster drill. We all donned our PPE (Personal Protective Equipment) - steel toe-capped boots, wet weather gear and hard hats, to brave the inclement weather to muster up on deck for a safety briefing.

Can you spot the stowaway?

We arrived at Turbot Bank just after dinner, and started running multibeam lines across the bank.  There is existing MCA Civil Hydrography Programme data for the western part of survey area, so we were careful to avoid duplication.  The weather was still too rough to deploy the Hamon grab or camera gear.  The forecast is looking slightly better over the next few days ....no gale warnings at least.

A grabbing and video marathon

A week into our survey and despite the ‘weather gods’ doing their best to hinder us, we’re still not far off schedule. We had a spell of calm weather at the start of the weekend and we made good progress with the Scanner cSAC survey. The first eleven hours of the day were spent using the day grab to get samples of the mud sediment for particle size analysis (PSA) and sieving for macrofauna  A subset of meiofauna and ‘organics’ were also taken.  In today’s samples we found the burrowing urchins, brittlestars, the sea pen Pennatula phosphorea and many different types of worms! A warm cuppa offered occasional respite from the cold work out on deck. 

Some of the creatures brought up in the grab samples

As the swell calmed down, the next task was to deploy the camera and take video and still images within the cSAC boundary. The first video tow showed a slightly different picture to that at Braemar with mud sediment rather than sandy mud and consequently many more Nephrops (scampi) and Nephrops burrows. We also saw lots of seapens and burrowing anemones. We planned single drop down camera tows across some of the smaller pockmarks and more intensive camera transects (four tow lines) intersecting with the Scanner pockmark.

Nephrops norvegicus

 

Burrowing cerianthid anemones

The sea pen Virgularia mirabilis and prawn

There has been a change of plan for the rest of the survey and assuming we complete the work on schedule, we’ll be leaving Scanner for Turbot Bank ( rather than the Fladen Grounds) tomorrow morning.   Similar to the Fladen Grounds, Turbot Bank is also a proposed area for a national Nature Conservation MPA but is located further south and closer inshore, 25 miles due east off Peterhead.