JNCC and Cefas Offshore Survey to Haig Fras

January-February 2011

 

JNCC and Cefas undertook a marine survey that integrated biodiversity and other environmental monitoring on the same cruise. This was to trial novel techniques for survey planning and sample stratification as well as to collect data for specific monitoring requirements. The purpose of integrating the work in this way was to make best use of available resources and to collect data in the most time and cost-effective way.

 

The survey was conducted on the Cefas Research Vessel Endeavour from 20th January - 3rd February 2011 at, and in the vicinity of, the Haig Fras Site of Community Importance (SCI). Remote sensing was used in conjunction with ground truthing techniques to compile evidence of the extent of the SCI as well as to investigate the sensitivity of indicators to fishing pressure to the north-east of the site. Prior investigation of existing pressures and activity data in the area has allowed a suitable gradient to be determined and so form the basis for the indicators testing. Data collected will be used to deliver on the wide ranging assessments of both agencies (for example to allow assessment of Good Environmental Status under the Marine Strategy Framework Directive) and provide high quiality science based advice going into the future.

 

 

Day 14 – Wednesday 2nd February 2011 – Thursday 3rd February 2011

Team photo at Lowestoff © Cefas, Matt Curtis

Wednesday started with the day and night shifts being reunited as the night team tried to get their body clocks back to normal. The day was spent backing up the remainder of the data and ensuring the labs and plot room were clean and tidy. The weather became a little overcast, so unfortunately the visibility wasn’t too good for marine mammal spotting as the boat made its way through the English Channel.

 

Cefas and JNCC staff also got together to discuss the results of the survey and how the last two weeks had gone. Everyone felt the survey had been a success and were pleased with how much data had been collected, giving us positive results for both of the survey projects’ aims. The sidescan sonar proved to be a successful method of detecting trawl marks; the results of the grab sample taxonomic analysis will tell us whether infaunal communities on the seabed change with different levels of pressure.  We also gained good multibeam coverage of Haig Fras reef, which will enable JNCC to more accurately map the reef area with greater confidence than previous data allowed. The video and stills gathered have also given us a greater understanding of the communities living on the reef which will assist us in developing a management strategy for the SCI. Everyone was pleased with how the integrated approach to the survey went. The two teams from JNCC and Cefas worked well together, with both team’s providing different sets of skills to the survey.

 

In the afternoon Chris and Neil gave a quick presentation to the boat’s crew to give them an idea of what the survey was all about and how much their hard work was appreciated. Then once everyone was satisfied that the labs and plot rooms were tidy, we were all able to enjoy a well-earned break as the boat made its way back to port.

 

On Thursday morning the team awoke to find land in sight and we docked at Lowestoft at 9am. There was time for a final team photo before the goodbyes were said and everyone headed off to see how their sea legs fared on land!

 

Day 13 - 1st February 2011

Day 13 started with more multibeam data collection and the night shift completing their analysis of the previously analysed video tow. For quality control reasons, it is good practice to reanalyse at least 10% of the video by different people to ensure they are getting consistent results.  The abundance of species is defined semi-quantitatively using the SACFOR scale; Superabundant; Abundant; Common; Frequent; Occasional; or Rare. This enables us to identify the characterising species of each habitat type in the section of reef captured by the video tow.

 

Julia and Bill finishing off the sidescan sonar processing © JNCC, Laura RobsonSunset at the Isles of Scilly © JNCC, Laura Robson

 

Neil and his birthday cake! © JNCC, Laura RobsonAs today was the last day of data acquisition, and with a departure time from the survey area around lunch time, the clean up began in preparation for returning home.  This involved a general tidy up of the labs and plotting room, organisation of the samples and equipment to be taken back onshore and the slow process of copying and backing up all the data gathered. At 12 noon the final multibeam line was completed and the boat started the long transit back to Lowestoft. There’s always work to do though, so the day shift worked on completing the data processing, data entry and creation of maps and figures for the cruise report. At sunset a misty view of the Isles of Scilly could be seen from the bridge – our first sight of land for 2 weeks!

                                                                                                           

It was also celebration time for Neil’s birthday. Unfortunately not the most exciting of birthdays having to work 10 hours, however there was time for a present and a fantastic cake made by the boat’s chef!

 

Day 12 - 31st January 2011

 

A large spiny starfish, Marthasterias glacialis, and two cup sponges, Axinella infundibuliformis, on Haig Fras reef © Cefas/JNCCReteporella beaniana identified from Sunday evening’s camera tow © Cefas/JNCCCommon sunstar, Crossaster papposus, identified from Sunday evening’s camera tow © Cefas/JNCC

 

Monday started with a bleary eyed night team (following the muster drill on Sunday), carrying on the data entry and multibeam lines.  They were rewarded though with a sea surface that was as flat as mill pond and an amazing sunrise.  The Marine Mammal Observers spotted a pod of common dolphins and also a pod thought to be white-beaked dolphins – unfortunately the cetaceans were too far away to get a good picture.  Further species identification was undertaken from the two video tows carried out on Sunday with a number of species (previously unrecorded on the survey) being identified including the pretty and delicate bryozoan, Reteporella beaniana and a common sunstar, Crossaster papposus.   Video analysis for the first tow was completed by the day shift and the team carried on with further multibeam collection and processing.

 

Day 11 - 30th January 2011

After collecting data on the shallower end of Haig Fras reef, it was decided another camera tow would be a good opportunity to determine whether the marine life varied on the shallow reef highs compared with the deeper areas we recorded on Tuesday. The tow proved exciting as the team saw an array of colourful jewel anemones, Corynactis viridis, encrusting and massive sponges and coralline algae on the bedrock surfaces as well as plumose anemones, Metridium senile, and a couple of large crawfish hiding under boulders. The deeper areas of reef had similar communities to those on the previous tows, largely dominated by Devonshire cup corals, Caryophyllia smithii, and encrusting bryozoans.

 

Yellow encrusting sponge, small jewel anemones and pink coralline algae growing over the shallow bedrock reef © Cefas/JNCCThe crew undertaking the lifeboat safety drill © JNCC, Fionnuala McBreenTwo sleepy members of the night team carrying their smoke masks during the muster drill © JNCC, Neil Golding

 

Later in the day the team got back to work completing multibeam lines on the reef, before work was paused so that the crew could undertake a man-overboard drill. The night team watched as the crew got into lifeboats and motored out to sea to save a buoy! This was followed by a second drill at 4pm for the whole boat where the unlucky night shift were woken from their sleep and had to find alternative means of escape from their cabins, as their normal route was blocked by the ‘simulated fire’.  Everyone arrived at the muster point ‘safely’ with Chris and Fionnuala carrying smoke masks which would provide an emergency air supply if needing to escape from smoke-filled areas.

 

The afternoon was then spent continuing multibeam followed by a final camera tow of the reef. The communities were similar to those seen previously, with a large spiny starfish, Marthasterias glacialis, (around 40cm diameter) stealing the limelight for the tow!

 

Day 10 - 29th January 2011

How multibeam (on the left attached to vessel) and sidescan sonar (on the right towed behind the vessel) work © NOAA.gov.us

Day 10 started for the night shift with an easy handover into multibeam, and little changing for either shift over the following 24 hours. Data collection is a continuous process of running up and down the survey area in a ‘mowing the lawn’ fashion. Multibeam works as a fan shaped beam of sound that is sent into the water as a wave, painting a stripe crossways to the ship on the seabed (known as a swathe). As the ship moves through the water this wave reflects off the seabed, building up successive stripes into a swathe of information which is analysed to inform on substrate properties and seabed depth.

 

Video analysis of the previous camera tows continued, with large amounts of time dedicated to defining habitat changes and faunal identification. Weather conditions continued to improve and we hope to get good multibeam coverage of the majority of Haig Fras reef before the return journey back to Lowestoft on Tuesday afternoon. The improved weather has given the Marine Mammal Observers a chance to watch out for more marine mammals and seabirds.

 

Diagram showing how multibeam and sidescan sonar work is copyright National Ocean and Atmospheric Administration.

 

A representation of the bathymetry of the south west corner of Haig Fras reef with the different seabed types draped over the top (blues are thought to represent sandy sediment, the rusty brown to represent gravels and the uprising bedrock can also be seen) © Cefas/JNCC

 

Day 9 - 28th January 2011

Kittiwakes © Neil Golding, JNCCWith sea conditions improving all the time and a favourable forecast, data collection recommenced in earnest.  The night crew continued infilling gaps in the multibeam data in Block D before transiting down to the south-western corner of Block C to commence data gathering there. The multibeam lines were taking longer, roughly an hour and twenty minutes per line. This gave the team an opportunity to look in more detail at the photos collected on Tuesday and Wednesday. A handy powerpoint guide of the more obvious species from the still photos was created. This will be used to assist in identifying species from the video footage.

 

The team started to get excited after lunch as it was time to bring the pots in. We all watched from the bridge as the crew braved the cold weather to grab the rope with a grappling hook and drag the pots up. As they came up one by one there was a little disappointment as not much appeared to be in them. However on further investigation we found two conger eels, a long-clawed squat lobster, an edible crab and many isopods riddling the bait (sea creatures that resemble woodlice in appearance and act as scavengers on the seafloor).  After recording our finds, the creatures were released back into the sea.

 

Multibeam data collection continued as well as continuation of the video and stills analysis.

 

Laura examining the contents of the pots © Neil Golding, JNCCA gannet passing by the vessel in the hope of a free meal © Neil Golding, JNCC

 

Day 8 - 27th January 2011

A 3D view of the seabed, highlighting an area of reef on Haig Fras © Cefas/JNCCAs Day 8 dawned, the weather showed no sign of improving. The rough seas continued to pitch and rock the boat. Some multibeam data collection was attempted, trying to minimise disturbance by mapping in one direction only. A small section of Block C was mapped at night, and in the morning the boat moved north to fill in gaps in the multibeam data in Block D. When the weather got particularly bad the logging had to be halted due to the poor quality of the data coming back. We were surprised to see a small fishing vessel out fighting the waves though - let’s hope the fishermen have stronger stomachs than we do!

 

After lunch, multibeam infill logging carried on. In the meantime we started to analyse some of the video collected on Tuesday, splitting the video into sections based on habitat type and reviewing the species present to give us a better idea of the communities living on Haig Fras reef.

 

The rough seas – a port hole view © JNCC, Laura RobsonA fishing vessel attempts to sail the high seas © JNCC, Neil Golding

 

Day 7 - 26th January 2011

Camera work continued after midnight with the tows recording some colourful and interesting species including black brittlestars (Ophiocomina nigra), vivid green jewel anemones (Corynactis viridis) and purple urchins (Echinus esculentus). The final tow also revealed some good examples of ross coral (Pentapora foliacea). Once the third tow was complete, the night team got back to the multibeam data collection and processing.

 

Stills taken from the camera tow: Ross Coral, Pentapora foliacea © Cefas/JNCCA stagshorn bryozoan, Omalosecosa ramulosa surrounded by Devonshire cup corals, Caryophyllia smithii © Cefas/JNCCCushion star, Porania pulvillus, with encrusting bryozoans and Devonshire cup corals, Caryophyllia smithii © Cefas/JNCC

 

Acoustic data gathering continued throughout the day. However the calm seas we’d been treated to for the past six days decided to end and the wind and swell picked up. A few of the day team started to flag as bouts of sea sickness hit! A game of ‘grab the stuff being thrown around the plotting room’ began! This also had implications for the quality of the multibeam data, which wasn’t detecting the seabed with all the pitching and rolling.  With multibeam data quality issues, it was agreed to hold station for a time on ‘weather downtime’ and re-start data gathering once the swell had calmed.  All equipment was lashed down and secured to prevent expensive scientific equipment falling over in the heavy seas.  We ‘battened down the hatches’ and prepared to sit out the bad weather.

 

Day 6 - 25th January 2011

The night shift took over at midnight and finished up the last of the prospect lines. This gave us an indication of the reef’s extent and a more detailed survey line plan was worked up from there. The site was broken up into manageable blocks with data collection beginning on Block A in the early hours of the morning. Meanwhile, the ship’s crew were hard at work stringing pots for a unique investigation into the epifauna of the Haig Fras reef. Deployment of the baited pots, which are used to target some of the more cryptic species on the reef, was completed on the day shift. 

 

I Ken, I saw, I camera'ed….the drop camera © JNCC, Neil Golding

The baited pots ready for deployment © JNCC, Laura Robson1mm and standard size pots being deployed by the boat’s crew © JNCC, Neil Golding

 

In order to ground truth an interesting area of habitat transition from reef to sediment, acoustic data was processed immediately, giving us picture of the dramatic topography of the seabed below.  From this, locations for the underwater camera deployment were identified.  Deployment of the camera was achieved late in the evening and highlighted the range of marine life associated with the Haig Fras reef. Video analysis will identify and characterise the habitat further.

 

Day 5 - 24th January 2011

The night shift took over the grabbing work at midnight and continued to collect samples and sieve the sediment until 6am. The sediment was all a mixture of sandy muds and muddy sands but a few recognisable fauna (even to the untrained eye) were found including the sea urchin, Brissopsis lyrifera, and small burrowing brittlestars, Amphiura sp. Once the final grab was taken, the team went back to the plotting room to finish off some sidescan sonar lines along the low pressure site.  These cross-lines were about 90° to the previous lines to test whether a comparable number of trawl scars were counted from a different direction. The RV Cefas Endeavour was then ready to transit to the next site, Haig Fras reef.

 

Ken starts the multibeam processing © Neil Golding, JNCCAmber, one of our Marine Mammal Observers, watches out for marine life © Neil Golding, JNCCNeil radios to Bridge to start the next multibeam line © Neil Golding, JNCC

 

The day team took over work at midday and began completing prospecting multibeam lines across Haig Fras SCI. These will give us a quick assessment of the extent of the reef at the site, and will allow us to plan more detailed survey lines. During the daylight hours we encountered marker buoys for fishing gear, showing that even 85 nautical miles out fishing lines are still set. Each multibeam survey line takes approximately one hour to complete, so in between lines the team got on with processing the acoustic data gathered previously and entering data into spreadsheets, a time consuming but necessary process, helped along by many cups of tea!

 

Day 4 - 23rd January 2011

Day 4 began with the completion of the last few acoustic sidescan lines on the low pressure site. Statistical advice prior to the survey suggested that 32 samples at each of the low and high sites would be adequate for a confident assessment of variation at and between the locations. Armed with this knowledge the team went about the task of randomising 32 sampling locations. ‘Redundant’ stations were also generated, even though only 32 stations were required, to provide a set of back up locations. These back up stations were used to replace stations that fell foul of certain sampling criteria. For example, samples that were proposed within 50m of the site’s edge were rejected and the next location in the sequence was used instead. Day grabbing began at 3:00am and continued all day and night!

Crew member Michael gets on the fire suit during the safety drill © Neil Golding, JNCC

Beginning the sediment sieving process © Neil Golding, JNCCHard at work sieving the grab samples © Neil Golding, JNCC

 

With health and safety always being a priority onboard ship, the scientists and ship’s crew both participated in the week’s muster and safety drill. The scenario was the reporting of an imaginary fire in the net room, leading to an ‘explosion’ and two casualties. The scenario played out with casualties being airlifted to safety (unfortunately there was no real helicopter). After the post exercise debrief the surveying continued.

 

Day 3 - 22nd January 2011

Acoustic work continued on the two prioritised high and low pressure sites, with 18 sidescan lines taken at each site, running at a bearing of approximately 30o. Each line took approximately 45 minutes to complete.

 

The boat’s crew deploy the Day Grab © Neil Golding, JNCC

Getting the sidescan towfish ready for deployment © Neil Golding, JNCCSediment grab equipment on the boat deck; The Day Grab is in the forefront with a Hamon Grab in the background © Neil Golding, JNCC

 

The ‘acoustic return’ from the sidescan sonar showed both sites to be predominantly soft sand and mud and early indications suggested that it would be soft enough to use the more user friendly Day Grab when sampling commenced. The Day Grab is a comparatively compact sampler that is capable of capturing sediment between its two jaws (see photo above right) and allows scientists to easily study the sample’s undisturbed surface before processing (analysing the sediment grain size and identifying the animals living in the sediment).

 

Day 2 - 21st January 2011

Having survived their first 12 hour shifts at sea, the day and night crew have settled into a rhythm and work has commenced in earnest. Soon after arriving at the proposed sediment location, several initial acoustic lines were run to get an idea of the sediment type and begin investigating sidescan sonar as a suitable exploratory tool for the identification of pressure on the benthic environment. These lines were cross referenced with sediment and pressure information collected prior to survey and allowed two 25km2 survey boxes to be selected; the boxes correspond to areas of high and low pressure.  We hope to complete the acoustic coverage of the high pressure box by Saturday morning.

 

Screen grab showing sidescan data with fishing trawl marks on the seabed © JNCC, 2011

 

Marine Mammal Observers (MMOs) onboard have been spotting wildlife at the sea surface and sharing their finds with us all. Both day and night shifts have been treated to sightings of pods of common dolphins and bow riding white beak dolphins.

 

Common dolphin spotted playing off the bow by the Marine Mammal Observers © Neil Golding, JNCCThe day team hard at work gathering data © Laura Robson, JNCC

 

Day 1 - 20th January 2011

We joined the vessel while she was still undergoing repairs to the becker rudder in Falmouth dry dock.  Once the “all clear” was given on the repairs in the afternoon, the dry dock was flooded and we were able to head out into the Fal Estuary and begin the transit to the survey site to the north-east of Haig Fras SCI.  We hoped to arrive early in the morning on the 21st January to start gathering sidescan data and grab samples to investigate the fishing pressure and any effect on the seabed communities present.

 

The JNCC survey team ready for action …..just add water © Neil Golding, JNCCRV Cefas Endeavour, our home for the next 14 days © Neil Golding, JNCCThe night shift, enjoying the last of the daylight before they become nocturnal © Laura Robson, JNCC

 

Map of the survey's course to midnight 1st February 2011

To see where the vessel currently is visit Marine Traffic and search for Cefas Endeavour.

Map of JNCC and Cefas Offshore Survey to Haig Fras