Monday, 31 July 2017

Surveying Bassurelle Sandbank and Wight-Barfleur Reef cSACs/SCIs

Bassurelle Sandbank


Having arrived at Bassurelle Sandbank our scientists began work collecting grab samples to look at the creatures living within the sediment and using a towed camera sledge to record footage of what is living on the seabed.

Sea Potatoes on a 5mm sieving table. Image © JNCC/Cefas 2017.
Animals like sea potatoes (Echinocardium cordatum), a type of sea urchin, were collected in grab samples. Sea Potatoes use the spines which cover their bodies to burrow into the sand, where they feed on organic debris amongst the sediment.


Grab and camera sledge sampling stations at Bassurelle Sandbank (note that some grab stations were visited more than once).
In total at Bassurelle Sandbank, 140 grab samples were collected, along with 26 video transects. The information that these samples tell us about the communities of organisms that make this sandbank their home will help JNCC and Cefas to understand how to better protect this site and ensure its condition is maintained and improved.


Wight-Barfleur Reef


At Wight-Barfleur Reef the survey objective was to collect images of the rocky reefs that occur at the site, as well as the animals that inhabit them. As with Bassurelle Sandbank, this information will be used to monitor the condition of the site.


The first job was to collect acoustic data to enable our scientists to identify areas likely to have reef so that a camera could be lowered down to examine the habitat. As Wight-Barfleur Reef is so big, sampling took place within a few more manageable-sized boxes inside the site boundary.

Example map of one area of Wight-Barfleur Reef visited on this survey. This is to demonstrate how drop camera stations are planned by first collecting blocks of acoustic data.


The HD video and still images revealed a diverse community of sponges and bryozoans, as well as animals that use the reefs for shelter and as a feeding ground.

Images from Wight-Barfleur Reef: (a) Elephant hide sponge (Pachymatisma johnstonia) growing on a rocky ridge. (b) An edible crab (Cancer pagurus) shelters under a rock. (c) A bryozoan colony, known as a “Ross Coral” (Pentapora foliacea), forms in a cluster of rose petal-like sheets. (d) A brightly coloured male cuckoo wrasse (Labrus mixtus) swims amongst the cobbles. Images © JNCC/Cefas 2017.


In total 82 drop camera transects were completed and acoustic data was acquired from ~170.5 km2 of seabed.


Having attained all the samples needed, the survey came to an end. Work will now begin on analysing the samples that were collected, which will help us monitor the site over time. JNCC would like to thank all those involved who helped make this another successful JNCC/Cefas partnership survey.

Heading west towards the sunset and our final stop on this survey at Falmouth. Image © JNCC/Mike Nelson.


James Albrecht
JNCC Offshore Seabed Survey Ecologist

Friday, 16 June 2017

Fauna from the canyons


 Over the last week we’ve been exploring the deeper areas of the Canyons from around 1000m to ~1700m. It’s been a really varied landscape from rippled sand with gravel patches and the odd boulder, to areas of bedrock and cliff-like overhangs. Each tow has been a big surprise, not knowing what fauna we might see, or if the geology will surprise us with a rocky landscape.

The most spectacular tows have been those comprising the Feature of Conservation Importance habitat Coral Gardens. These have shown us a variety of coral species from bamboo corals Isididae, antipatharians (black corals) to scleractinians (hard corals). The scleractinians have mainly been Madrepora oculata, with some Lophelia pertusa. Bamboo corals are named for their stems which have a ‘joint-like’ appearance similar to bamboo. We’ve seen the bamboo coral Lepidisis sp., amongst others, and the antipatharian Stichopathes sp., an orange coral with a spring-like coil morphology. We’ve also seen beautiful fan-shaped gorgonian corals and the aptly-named bubblegum coral Paragorgia sp.. Although much rarer, there have been a few sponges, mainly encrusting on rocks and boulders, but also what we think may be Phakellia sp., and a Hexactinellid glass sponge. 
Glass sponge and gorgonians
Phakellia sp and Paragorgia sp
Madrepora oculata and Lepidisis sp
Some sandy areas have shown us small clumps of the bamboo coral Acanella sp. and the occasional cup coral, Caryphyllia sp. We also saw a beautiful ‘forest’ of stalked crinoids. Although they look like plants (known as ‘sea lilies’), crinoids are actually animals, and are attached to the seabed via their stalk, with a mouth on the top surface that is surrounded by feeding arms. Stalked crinoids were the trigger for deep-sea exploration back in the 19th Century – see this blog from the Australian Natural Environment Science Programme - https://www.nespmarine.edu.au/crinoids-were-trigger-deep-sea-exploration

Acanella sp

Stalked crinoids

Stichopathes sp

Tuesday, 13 June 2017

North West of Jones Bank and the Canyons Survey Update


On the 22nd of May 2017 a partnership JNCC and Cefas monitoring survey to North-West of Jones Bank (NWJB) MCZ and The Canyons MCZ departed from Lowestoft. Just under 48 hrs later RV Cefas Endeavour arrived on site at NWJB MCZ having replaced a Waverider buoy south-west of the Isles of Scilly. The buoy is now running, with the data viewable.

The target monitoring features at NWJB MCZ are subtidal mud (
http://jncc.defra.gov.uk/page-5802) and seapens and burrowing megafaunal communities (http://jncc.defra.gov.uk/page-6028). These mud habitats tend to form in low energy environments where sediments can settle out and become fairly compacted.

At NWJB MCZ two day grabs and a 200m video sledge transect were collected at 71 stations. The day grabs at NWJB have been sampled for macrofauna, particle size analysis (PSA, aka sediment size) and organic, carbons and nitrogen. When sieving out the mud, the fauna has been mainly polychaetes (aka worms) of all shapes and sizes, which we need to pluck out of the sieve to make sure we don’t miss any of the important diversity in the final analysis. We have also found the occasional Nephrops, a small crustacean you may know as scampi. These bury in muddy sediments, forming semi-permanent burrows that create part of the Feature of Conservation Importance ‘Sea-pens and burrowing megafauna’. We’ve also found a few amphipods, crabs and sea-pens in the grabs.



In addition to the grab and video data, 14 NIOZ cores and 4 day grabs were acquired to support wider work on shelf biogeochemistry being carried out by Cefas.













After a 10 hours transit to the south-west the RV Cefas Endeavour arrived at The Canyons MCZ. Work has been completed on interfluves, the shallower area (200-500m) between the canyons themselves which reach down to ~2200m. The canyons themselves are named Explorer and Dangeard, with Explorer being the northern one of the two. The habitat on the interfluves is mainly muds with a veneer of sand, but the site is also comprised of ‘mini mound’ features, where coral may have been present in the past.


Drop camera transects and NIOZ cores are being carried out on the interfluves. In total 113 stations have been sampled across the two interfluves. Some interesting species have been seen at the interfluves. This included a large number of the anemone Actinauge richardi. This anemone doesn’t usually live attached to a hard surface or burrow into soft sediments like other anemones. Instead its base forms an almost enclosed cup which encloses mud and sand acting as an anchor onto the soft sediments. 


Different species of sea-pen have also been seen, including the tall sea-pen Funiculina quadrangularis, the phosphorescent sea-pen Pennatula phosphorea and what we think may be the deep-sea species Kophobelemnon sp., though this is not a confirmed identification. 


Numerous sea cucumbers have been dotted around, mainly the species Parastichopus tremulus, and a few pencil urchins Cidaris cidaris



Some examples of a soft coral, which we struggled to identify, were found in the early hours of Sunday morning (4th June), with its polyps retracted. Luckily later in the day we captured a lovely example of it with its polyps out (and a sneaky squat lobster hanging out). On discussion with some of our deep-sea colleagues, we think it is a soft coral of the Alcyoniidae family, likely to be a Drifa species. These can be identified fairly well by their shape as they look rather like cauliflower.



During our drop-camera transects on the interfluves, we have identified five species of Elasmobranchs, including some deep-water species. One of these species is the velvet belly lanternshark (Etmopterus spinax), which is one of the smaller shark species with a maximum total length of 60cm. The individuals we have seen have been ~30cm in length. This species occurs in depths between 200-500m and uses hormones to control small pigment-lined structures called photophores (seen as dark blotches on the belly) to emit light for camouflage (to predators below), and possibly to communicate with other lanternsharks.




Wednesday, 19 April 2017

Offshore Survey commencing in the English Channel



Today (19th April 2017), JNCC and Cefas have embarked on a survey of Wight-Barfleur Reef cSAC/SCI (Annex I Reef) and Bassurelle Sandbank cSAC/SCI (Annex I ‘Sandbanks which are slightly covered by seawater all the time’) aboard the RV Cefas Endeavour (CEND0617). A map of these sites is attached below.

Wight-Barfleur Reef cSAC/SCI is characterised by a series of well-defined exposed ridges of bedrock up to 4m high and stony reefs. These habitats support a diverse range of wildlife including sponges, tube worms, anemones and sea squirts. More information about Wight-Barfleur reef cSAC/SCI can be found here; http://jncc.defra.gov.uk/page-6544.

Bassurelle Sandbank cSAC/SCI is characterised by its thickness of the sediment (up to 25m thick) and elevation above the surrounding area. These sandbanks support communities of a large variety of infaunal species most notably polychaete worms. More information about Bassurelle Sandbank cSAC/SCI can be found here; http://jncc.defra.gov.uk/page-6528.

Photo from the team this morning en route to site © JNCC.





This survey is aiming to gather evidence to monitor and inform assessment of the designated features of both sites.

At Bassurelle Sandbank cSAC/SCI, our scientists will be collecting a range of data including sediment, epifaunal and infaunal samples. At Wight-Barfleur Reef cSAC/SCI, multibeam echosounder (MBES) and sidescan sonar will be used along with video and still imagery to gather data on the seabed species and habitats that are present at the site. Environmental data, such as temperature and salinity, will also be collected to provide additional important contextual information.

Stay tuned to our blog and JNCC Twitter feed for further updates throughout the survey!



Thursday, 6 April 2017

2017 Offshore Seabed Surveys

JNCC has just published a new page on our website with details of our upcoming offshore seabed surveys that are currently planned for 2017. Take a look at the webpage to find our which Marine Protected Areas the surveys will be visiting, who we are collaborating with, the survey dates and the data we hope to collect. The webpage will be updated with new details as the planning progresses.

Link to webpage:
http://jncc.defra.gov.uk/page-7405



Monday, 7 November 2016

Too many fish in the sea?

I think it is fair to say that no, there are not too many fish in the sea. However, when you are trying to survey the seabed, you really can have too many fish! In order to groundtruth our acoustic work, we have been taking video transects throughout the three sites of Pisces Reef Complex cSAC. This means that we can check exactly what the data from the acoustic methods are showing, and monitor the species and habitats that are present. The day shift duly carried out pre-defined line transects, recording video footage of what was on the seabed. One particular line, however, proved a little more tricky than the rest. 
Seabed image from Pisces Reef ©JNCC/Cefas, 2016
Holy Mackerel! A school of fish had taken up residence and were attracted by the lights and lasers from the drop camera frame, which are used to light up the pitch black seabed and provide a measure of scale.  The fish were dancing around in front of the cameras, kicking up the top layer of sediment and making our lives rather difficult. Getting a good view of the seabed, the point of the exercise, was close to impossible. Eventually we had to give up and move on to the next line, leaving the night shift to return later on to see if the fish had dispersed. Luckily, the return attempt was successful, although still with the presence of some rather over excited mackerel dancing around under the lights.  The mackerel appeared bright blue on the video, but you could clearly see the tiger-like stripes in the still images. Hopefully these young mackerel will grow on to become productive adults and help maintain stocks of one of the nation’s favourite fish.

Mackerel stirring up sediment! ©JNCC/Cefas, 2016
By Nikki Taylor
JNCC Marine Mammal Advisor

Friday, 4 November 2016

What does a dolphin look like?


JNCC and Cefas are currently on site at Pisces Reef Complex cSAC on the RV Cefas Endeavour to gather evidence for monitoring and to improve our ability to map the extent of the habitats found at each of the three reef areas in the site. In order to differentiate between exposed reef areas and those covered by a layer of mud, we’ve been using a sub-bottom profiler system known as a chirper, which uses sound to penetrate the seabed surface to identify the substrate layers within.
The chirper deployed through the ship’s ‘moon pool’. ©JNCC/Cefas, 2016


The chirper produces sounds that can interfere with cetacean species (whales, dolphins and porpoises), which rely on sound for foraging, navigation and communication. To mitigate this impact, we have on board a Passive Acoustic Monitor (PAM) and a Marine Mammal Observer (MMO). Gareth, our PAM from Gardline, takes the night shift, detecting the sounds these animals produce by using submerged underwater microphones (or ‘hydrophones’) to identify if they are in our 500m mitigation zone. During daylight hours, James, our MMO, takes the reins from the bridge to visually monitor for animals in advance of any acoustic operations. If a detection is made during the specified time prior to operations, work is paused until the animals have moved to a safe distance. If the all clear is given, the sub-bottom profiler is initiated with a ‘soft start’, using low power and slowly ramping up until the desired operating power is achieved, giving any remaining animals within earshot a chance to move away.

The first two shifts were clear, with no cetaceans gracing our presence despite the perfect conditions for spotting on the surface.  Our first detection occurred during the second PAM shift before the acoustic gear was switched on. The normally steady green sound waves on the display started dancing with shapes and colours, as dolphin whistles came through the headphones (see picture below).

So what does a dolphin look like in the world of PAM?

Screen grab from PAM software; the coloured lines and shapes shown above are produced by the whistles made by the dolphins, and in this recording, there were clearly at least two animals whistling, given the proximity of the sound profiles. ©JNCC/Cefas, 2016
 
Fortunately, the dolphins only stayed long enough to provide some excitement for the staff on board, but not so long that the work was significantly delayed. A great example of how acoustic mitigation can be applied to ensure a balance between getting the job done, but not to the detriment of our magnificent megafauna.
 
By Nikki Taylor 
JNCC Marine Mammal Adviser