Now we're in the Irish Sea, welcome to Croker Carbonate Slabs Site of Community Importance!

On the 23rd October 2015, JNCC, in partnership with the Centre for Environment, Fisheries and Aquaculture Science (Cefas), began a 14 day survey of Croker Carbonate Slabs Site of Community Importance aboard the Research Vessel (RV) Cefas Endeavour. Croker Carbonate Slabs is one of the 20 offshore candidate Special Areas of Conservation (cSAC) in UK offshore waters. The area is located in the Irish Sea, approximately 30km west of Anglesey. 

Map showing the distribution of Annex I habitat “Submarine structures made by leaking gases” within the cSAC/SCI boundary. View and download spatial data for this MPA on the JNCC UK MPA interactive mapper © JNCC, 2015.

The site is designated for Submarine structures made by leaking gases, specifically methane-derived authigenic carbonate (MDAC). These carbonate blocks and slabs form when methane rising from deep below the seabed is consumed by microbes in the seabed sediment.  The microbes create the carbonate, which acts as a cement, gluing sediment particles together to form a type of rock. The seabed habitats created by these MDAC structures support a diverse range of marine species that are absent from the surrounding seabed, which is characterised by coarse sediment.  Large carbonate blocks support a diverse range of soft corals, erect filter feeders, sponges, tube worms and anemones, whereas the flatter, pavement-like MDAC structures are colonised with scour-resistant animals such as hydroids and bryozoans.

During the survey, we will focus on gathering evidence to contribute to the development of a monitoring time-series for Croker Carbonate Slabs SCI from which the rate and direction of change in the condition of ‘submarine structures made by leaking gases’ can be inferred in the long term.

The survey aims to improve our knowledge of the distribution and spatial extent of MDAC, map the finer spatial extent of MDAC and gather further information on biological communities, including characterising the wider sediment areas found within the site.

By Alice Cornthwaite

Farewell to the Field, parting with the Plain

Hello once more from the Scotia, where our survey has drawn to a close and we have begun our 12 hour steam back to Aberdeen from East of Gannet and Montrose Field and Norwegian Boundary Sediment Plain Nature Conservation Marine Protected Areas (NCMPAs).

As the sun sets on the last day of the survey, the MRV Scotia heads back to Aberdeen © JNCC, 2015. 

So, what have we achieved in our 2 weeks out here in the middle of the North Sea?

Despite losing some time to bad weather, we have collected all of the data we originally set out to collect, as well as some additional camera sledge transects. Thanks to the persistent hard work of the crew and scientists aboard w,e now have a comprehensive dataset describing the animals and seabed habitats at both sites that will be used to help inform the monitoring work described in earlier posts.

In total, we have collected 276 Hamon grab samples (156 and 120 grab samples from East of Gannet and Montrose Field and Norwegian Boundary Sediment Plain respectively) and completed 57 camera sledge transects at East of Gannet and Montrose Field. The maps below show where the samples and transects have been collected.

Completed Hamon grab and camera sledge stations at East of Gannet and Montrose Field NCMPA (top), and Hamon grab station at Norwegian Boundary Sediment Plain NCMPA (bottom) © JNCC, 2015. 

It is with many thanks to the captain and crew of the MRV Scotia and our Marine Scotland Science colleagues for their efforts on this survey that this account closes. Please check back with us soon for more survey action, this time from Croker Carbonate Slabs Site of Community Importance (SCI) in the mid-Irish Sea!

Goodbye from the day shift (top) and the night shift (bottom) © JNCC, 2015.  

By Joey O'Connor

All things small and wriggly

This time it's good morning from the day shift! Having collected and sieved 157 Hamon grab samples from East of Gannet and Montrose Field NCMPA and 50 from Norwegian boundary Sediment Plain NCMPA we are getting very familiar with a few of the animals in the mud.

The grab collects about 25 litres of seabed sediments and deposits it in a large tray. This sediment is then sieved with running water to remove the finer sediment leaving behind shells, stones and any animals.

Seabed sediments straight from the grab (left) and the animals, stones and shells that remain after sieving © JNCC, 2015. 

The sieves so far have contained an assortment of worms, clams, urchins, hermit crabs, brittlestars and sea pens. Among the empty shells present in the sediments, we are finding lots of tusk shells (Scaphopods), which are molluscs commonly found in the offshore muddy sediments but rarely seen along a beach.  Large numbers of the empty bivalve shells have a small perfectly round hole through the shell.  It is likely these have been eaten by predatory snails which bore through the shell to reach the animal inside.

 Bivalves, hermit crabs and tusk shells have all been sighted in grab samples © JNCC, 2015.

Many of the grabs contain small brittle stars (see image below). These have five arms which, as their name suggests, are fragile and easily break off.  This helps the brittle star escape from predators, and the brittle star is able to regrow the lost arm. They also use these arms for feeding, where they hold their arms up off the seabed in the water to collect passing food particles.

Brittle star collected in a grab sample © JNCC, 2012.

The Norwegian Boundary Sediment Plain NCMPA grab samples have been muddy sand and we have regularly found heart urchins, or sea potatoes as they are more commonly called. These bury into the sediment using their spines and feed on particles that fall to the seafloor.  Today, one grab contained a large, fist-sized, purple heart urchin (Spatangus purpureus).

Purple heart urchin (Spatangus purpureus) © JNCC, 2015. 

We are currently taking advantage of some good weather to do some video work, but are looking forward to getting back to the sieving soon.

By Karen and Beckie

Sea pens and quahogs – the mysterious world of offshore mud

Good morning from the night shift! We’re now about half way through our survey and have settled into life onboard the good ship Scotia, where disadvantages include getting up at midnight and advantages include having a full English breakfast for lunch!

On this survey we are investigating the habitat ‘features’ for which the two nature Conservation Marine Protected Areas (NCMPAs) we are visiting have been designated: the ocean quahog and ‘offshore deep sea muds’. We are gathering an initial dataset on these features which will inform future monitoring and assessment. The goal is to determine whether there are any changes to these features over time.

Arctica islandica captured using high resolution photography © Becky Hitchin, 2015

You’ve already heard a little about the amazingly long-lived Ocean Quahog, or Arctica islandica for latin speakers (see previous blog post). This clam is typically found buried in sandy and muddy sediment with two feeding tubes called siphons peaking out above the seabed surface.  These siphons are pretty tiny and, although they can be captured using high resolution photography (see picture above), they are very difficult to spot using the underwater camera sledge. It is, therefore, far more effective to record the quahogs using a seabed sediment sampler. Encouragingly, we have already found evidence of quahogs, and have collected both live specimens and many shells in our grab samples.

The living ocean quahog shells are brown in colour whereas the dead ones tend to be mostly white. Any live specimens found within the grabs are measured and photographed by the scientists onboard before being returned to the sea. The shells recorded so far have ranged in size from very small juveniles of less than 1 cm in diameter to adults of up to about 8 cm.

The ‘offshore deep sea mud’ habitat is associated with communities of sea pen (a type of soft coral that grows in the shape of a quill) and large burrowing crustaceans such as Nephrops norvevicus, also known as scampi or the Norway lobster. We have three common species of sea pen in the UK – Pennatula phosphorea which is a very distinctive red feather, Virgularia mirabilis which is straight and upright with white polyps, and Funiculina quadrangularis which is very tall, bowed at the top, and found in deeper waters.

                                                                               

                                                       

Sea pen images captured using a camera sledge: Pennatula phosphorea (top picture) and Virgularia mirabilis (left in bottom picture) next to another Pennatula. © JNCC/MSS, 2015

As the camera sledge descended for our first tow, we were happy to see a large number of Pennatula sea pens spread across the seafloor, interspersed with a few Virgularia. All our video transects so far have shown evidence of sea pens, and at some stations we have also found high numbers of burrows with the occasional Norway lobster sticking its head out. It is likely that burrows are found in the areas with a higher proportion of mud rather than sand, but we will have to wait for the results of the particle size analysis of the sediment samples to confirm.

We’d better get back to work!

By Megan and Yessica

Of (Sea) Mice and Mud

Greetings all from the deck of the Marine Research Vessel (MRV) Scotia, where we are currently surveying in the East of Gannet and Montrose Field (EGM) and Norwegian Boundary Sediment Plain (NSP) Nature Conservation Marine Protected Areas (NCMPAs) with our Marine Scotland Science colleagues.

Sunrise on the MRV Scotia © JNCC, 2015.

  

This first week has gone by quite quickly and has been spent adapting to ship life, where we work in 12 hour shifts to ensure the ship is able to collect scientific data around the clock. As we have spent a good deal of time this year planning this survey, I have really enjoyed this week and the opportunity to get out into the field to test the preparation work completed back in the office!

We have been very lucky with weather so far on this trip, with only 8 hours of ‘downtime’ experienced so far. This, in combination with our hard working crew and scientists, has allowed us to successfully complete almost 200 stations, using the large Hamon grab (pictured below). We hope to complete another 80 or so large Hamon grab stations and 60 camera sledge transects to help our colleagues monitor these sites, providing the good weather continues.

Morning breaks over the Hamon Grab (left) with sieves at the ready (right). © JNCC, 2015.

If you are new to our survey blog you will find earlier posts which detail what the Hamon grab and camera sledge are and how we deploy and operate these.

We have encountered mostly fine-grained, muddy material in our samples, which have contained a plethora of seabed dwelling animals including marine worms, brittlestars, sea potatoes (Echinocardium cordatum), sea pens (Pennatulacea sp.), a sea mouse (Aphrodita aculeata) and some crustaceans. Once aboard, the Hamon grab samples are sieved to remove material smaller than 1mm, and preserved for further analysis back in the laboratory.

 Just a few preserved seabed samples! © JNCC, 2015.

Unfortunately, we have had to dispose of three samples to date and redeploy the grab a second time as the hagfish present in these three samples would not have allowed us to ‘process’ the remainder of the sample. The threat posed by the all-consuming slime of the sampled hagfish is generally sufficiently convincing for marine scientists to redeploy sampling equipment in the hope of obtaining a more accommodating sample!

We have also managed to find specimens of Arctica islandica (also known as the ocean quahog), which is the protected feature common to both sites we will visit on this survey, in our samples. More about that later; now it is time to get back to those sieves... 

By Joey O'Connor 

JNCC are back at Sea!

Teams from JNCC and Marine Scotland Science are aboard the RV Scotia, in the seas to the east of Scotland, embarking on a cruise to conduct the first monitoring surveys within two offshore Nature Conservation Marine Protected Areas (NCMPAs). Our enthusiastic scientists will spend two weeks collecting seabed samples and photographic data from East of Gannet and Montrose Fields NCMPA and Norwegian Boundary Sediment Plain NCMPA.  These sites have been designated for two features; ocean quahog aggregations (including sands and gravels as their supporting habitat), and offshore deep sea muds.

East of Gannet and Montrose Fields NCMPA and Norwegian Boundary Sediment Plain NCMPA location

The ocean quahog (Arctica islandica) is a large and extremely long-lived species of clam which is typically found beneath the surface of sandy sediments. Ocean quahog are an important food source for several species of fish, including cod, and can live buried deep in the sand for long periods of time without food or oxygen to escape predators. Arctica islandica hit the headlines in recent years for being the world’s oldest animal ever recorded. An individual was collected from the seabed off the coast of Iceland in 2006 that was eventually aged by scientists as 507 years old (link to article). The scientists that collected the clam named it ‘Ming’, after the Chinese Ming dynasty that ruled over China when the animal was born. This means that Ming was four years old when Leonardo da Vinci painted the Mona Lisa and born only 7 years after Columbus first sailed to the Americas!

Arctica islandica and Leonardo da Vinci's Mona Lisa © Creative Commons

Offshore deep sea muds are relatively stable environments which typically support communities of burrowing megafaunal species, such as the commercially important Norway lobster (Nephrops norvegicus), and populations of fragile sea pens.

Large amounts of data are needed to accurately sample the sediment communities at these sites. Weather permitting, the team hope to collect at least 270 seabed samples across the two sites for ocean quahog, with extra camera work where deep sea muds are found. This data will form the first point in a monitoring time-series, which will allow JNCC to monitor the rate and direction of long-term change in ocean quahog aggregations and offshore deep sea mud communities. 

Onwards to East of Haig Fras

The Cefas Endeavour arrived at East of Haig Fras Marine Conservation Zone (MCZ) at 1am on the 16th May. In contrast to the large bedrock reefs of Haig Fras SCI/cSAC (see blog post), previous surveys of this site have shown that it contains a complex matrix of different sediment types including: rock, sand and mud, as well as coarse and mixed sediments. We planned to carry out 10 minute High Definition (HD) camera tows with still images captured at 30 second intervals and take grab samples using the Hamon grab. At stations that were predicted to be potentially rocky or containing coarse sediments (therefore not suitable for grab deployment) we used the drop camera first to make a visual assessment of the seabed type. It then fell to the scientists to make the final decision as to whether it was a suitable area to deploy the Hamon grab.

                  a)                                                      b)

a) Example of the occasional ‘No Sample’ where not enough sediment was retained to produce an adequate grab sample and b) deploying the Hamon grab on the Cefas Endeavour.   

Despite all of our best efforts in predicting grab-able habitats, sometimes up to three attempts were required to obtain a sample that was adequate for both particle size analysis (a procedure used to determine the size of sediment particles) and infaunal taxonomic analysis (the identification of species living in the seabed).

After long days spent monitoring the video feed from the camera frame, the survey team were happy to get their hands dirty by sieving some sediment!

Day shift lead Simon Pearson checking the sieve for any small marine specimens.

Sieving seemingly endless grab samples requires something of an obsession with marine life; fortunately being on survey is one of the best parts of being a marine scientist! Here are just a few of the species we managed to collect in our samples.

                  a)                                                      b)

                                               c)

a) Nut crab Ebalia spp. b) Red starfish Echinaster sepositus c) Hermit crab Pagurus bernhardus

 Moving away from the obsessions of the slightly eccentric JNCC marine scientists to what this survey hopes to achieve in the broader context. East of Haig Fras was designated as an MCZ in 2013 under the Marine and Coastal Access Act (2009) for three protected features for which the conservation objective is ‘to remain in, or be bought into, favourable condition’. This survey forms part of a longer term monitoring strategy that will assess the change over time of seabed communities in the area, to ensure that the UK continues to work towards conserving these important habitats. Although it seems hard to appreciate (especially when you’re struggling with the Hamon grab at 4am!) each sediment sample collected will be processed, analysed and help to form high quality evidence used to inform environmental decision making at both local and national levels.

A stack of sediment samples prepared for infaunal analysis and an example of the infaunal analysis spreadsheet we will receive when the samples are processed.

It took the survey team a further 10 days to collect the 308 sediment samples and 138 camera tows at East of Haig Fras MCZ but we successfully carried out all of our planned activities within schedule. We even had time left over from contingency planning to return to our first sampling site, Haig Fras SCI/cSAC and re-do some of the camera tows that were initially undertaken in bad weather. Just enough time to sign off with a cheesy day-shift team photograph taken in front of the bridge!

Team photo of day shift. From left in orange overalls (crew): Mike, Mark, Tom and Pete. From left scientists: Charli, Mike (JNCC) Jo, Roi, Jess and Simon (Cefas).