Analysis underway...

Well I've been a bit silent since the end of the trip - our heads are down analysing the data collected during the survey. Two tasks underway at the moment (1) writing a paper from the analysis of the IMPRESS* North Sea data looking at changes in the feeding behaviour of sandeels (picture shown above) and kittiwakes (picture shown on right) over tidal and diurnal (i.e. changes over day-night) cycles**, and (2) analysing the fish data collected in July firstly to determine species composition, and then to look at changes in species schooling behaviour with time of day, tides (high/low tides as well as spring-neaps). We're hoping to have the paper submitted by Christmas, and the preliminary James Cook data processing done by January. At the end of January we have a James Cook workshop in the lake district where we will present all our findings to date and hopefully find out how all the different bits (turbulence, dye dispersion, plankton, benthos, fish, seabirds) link together & tell us a more complete story of what's going on down in the Celtic Sea.

* IMPRESS = Interactions between the Marine environment, PREdators and prey: implications for Sustainable Sandeel fisheries: a project Beth Scott was previously involved in & from which sandeel data was available to analyse

** This work was presented in September at the ICES (International Council for the Exploration of the Seas) conference in Halifax, Nova Scotia.

Figure 3 - Typical echogram of sendeel schools - so recall we're travelling from left to right, the bottom green line shows the seabed, and the top red line is the echo from the surface. The sound is bouncing back off these sandeel schools. The photo on the right shows a feeding aggregation of kittiwakes (and a few other seabird species) that occur when the sandeels are found at the surface.

So we're busy beavering away...

At the end of October we had a meeting with NERC and DEFRA to meet the other 5 projects funded under the sustainable marine bioresources program. It's a really interesting and diverse array of projects:

(i) modelling interactions between top predators and fishing vessels - looking at the overlap between seal foraging and fishermen using satellite tags both on the top of the heads of seals and on the fishing vessels.

(ii) new production in the North Sea deep chlorophyll maximum - similar to our study they have been analysing the sub-surface chlorophyll levels that exist at the thermocline but throughout the whole of the North Sea. They are then linking this to the rest of the North Sea ecosystem from zooplankton to fish.

(iii) a spatially resolved ecosystem model for the assessment of fisheries - by linking our understanding of how oceanography influences the growth and migrations of fish, these models are able to model the dispersion and age-structured distribution of fish stocks.

(iv) population structuring of cod around the UK - by taking DNA samples of lots of different cod from around the UK it is possible to determine how much genetic mixing there is between populations, by then comparing this to tag data on cod (they can tag fish!!!) they can see how this compares to the actual movement patterns of the cod (they make quite big migrations!).

(v) climate change and macroecological patterns in an exploited marine fish assemblage - a topical subject modelling benthic fish communities with environmental variables over time to see what effect climate change may be having on fish communities.

So, it's a really interesting group of projects & very exciting work! So I better get back to my paper writing & analysis... deadlines to make! Watch this space for progress...

Bonanza day(s)

Wowee! What a day! The shelf edge was as exciting as I was hoping, and it felt a bit like the last day of school, the way everyone was grinning all day.

I, Beth & the birders managed to force ourselves up for dawn (around 5:30am) – this was unusual for me, but not for Beth (with her dawn bongo nets), nor for the birders (who are up nearly every day at dawn looking for birds). Apart from getting up ridiculously early (yawn) it's a lovely time of day to be awake - we had a lovely sunrrise (see picture to right) - it dawned a glorious sunny day with calm blue seas… perfect for whale-spotting. As we approached the shelf edge, lines of surface slicks (one indication at the surface of internal waves beneath the sea surface) appeared on the horizon, and soon we were in amongst the slicks and on cue lots of storm petrels appeared, picking food from the surface (a couple are pictured below).

We stopped close to the shelf edge for a few CTD stations, bongo net deployments to see how different the shelf edge is from the area on and around Jones Bank, and some sediment grabs (Nick happily found lots of worms in the sandy substrate). Meanwhile, the birders threw over ‘chum’ made with the soggy remainder of the mackerel Inigo had left over as bait for his camera, mixed in with sunflower oil & cornflakes. They wanted to make sure that they got some interesting birdy sightings at the shelf edge. As I popped out onto the back deck, all three birders turned and beckoned, grins on their faces and gleams in their eyes like little schoolboys… ‘it’s a Wilson’s storm petrel!’ they exclaimed. I grabbed Andy’s soggy mackerel encrusted binoculars, but there were so many European storm petrels surrounding the ship, dip feeding on the chum, that I couldn’t pick it out. But I did spot some feeding common dolphins again! Everyone who wasn’t working was on the deck enjoying the sunshine, the dolphins and the storm petrels (see picture on right).

For the next station we were going over the edge… into water 3000m deep – it dropped off so quickly – an odd feeling to know that you’re essentially going over the edge of an underwater cliff, and hovering up above. En route, many of us were busy with polystyrene cups writing messages & drawing silly pictures, and tying them onto the outside of the CTD. What on earth is this silly ritual? Well, the CTD was going to be sent into the abyss… to be lowered on the wire down to nearly 2000m to measure the temperature & salinity through the water column, and to collect water samples for ‘muf’ Clare to analyse. At such depths, anything with air in it is squished small by the huge pressure of the water sitting above it – so hey presto – our large polystyrene cups are turned into miniature souvenirs of the trip (see before and after pictures below).
But the main excitement of going over the edge was the whales… it wasn’t long before the first blow of a whale was spotted – this looks like a big tall plume of steam – which it is more-or-less, but it’s actually very smelly fishy watery breath of the whale that it spurts out of its blow hole on the top of its head when it comes up to breath after a long dive under the sea to feed. You can see these blows for miles – right up to the horizon. And if you’re lucky (we were), after the blow, you’ll see the long black back, and finally the dorsal fin (the sharp fin on its back) – this was a fin whale. And the first of many – for the whole 5 hours that we were over the abyss, we were surrounded by the blows of fin whales. Inigo and I stood up at the birders boxes for hours marvelling at the magnificence of these beasts. And as the sun began to set, the birders (Andy, Mark & Adam) & Beth also came up with some cans of beer, and we sat in the opera boxes and toasted a great day (see photos below)… and were rewarded with the green flash!!!

Adam, Andy, Mark, Beth & Inigo toasting the green flash over the abyss

The green flash, for any of you lucky enough to see it, occurs as the sun is just sinking over the horizon, and fills with a bright bursts of green colour as it disappears… this is the green flash – and it’s spectacular to see. The scientific explanation of the green flash can be found at the Wikipedia here.

...and I was going to end the blog today on that note, but just as I was going to press the birders spotted a pod of killer whales on the starboard bow!!!! Now, I've never seen a killer whale in the wild in my life, despite many hours at sea, so I was OVER THE MOON!!!! I was so absorbed watching the 3 female adults, 2 wee calves and nice hefty male with a nice tall dorsal fin, that I didn't take any photos - sorry! But I do have a nice sunset photo to end on:

the Aberdeen crowd celebrating the end of a magnificent day

So we're now steaming for Falmouth to offload - so the last blog of the cruise might be a bit delayed in all the kerfuffle... but so far it's been a fantastic finale to the trip :o)

Trawler safely delivered to the Scilleys

Another quick blog - just to let you know that the trawler was safely delivered into the hands of the Scilley Isle lifeboat's hands this morning (see photo above). There was also a mad dash to mobile phones as we came within telephone range, and a longing look at land (the Scilleys are a beautiful group of islands).

I have been asked by the birders to mention the great shearwater sighting we had yesterday as we rescued the Crystal Sea - and it was a magnificent sight - gliding aerobatically and smoothly over the waves - it had even me, a non-birder, captivated. It's apparently a rare sight in these waters :o)

Also while en route yesterday evening, since there was no science to be done, we had a Trivial Persuit tournament Liverpool (POL) v Oban (SAMS) v the 'East Coast Posse' (Aberdeen). Despite there only being 6 of us versus 12 SAMS and 7 POL, we, the East Coast Posse won all the cheeses (see photographic proof to right). Ok, SAMS won the 1987 version of the game, and we won the 1990's version of the game. See, we do get to have some relaxation on the ship from time to time!

So today, we spent most of the day steaming back to Jones Bank to retrieve the last of the moorings (all safe and sound on board, despite having problems yesterday with the one on the bank being stuck in the mud), and now we're heading off to the shelf edge to track the internal waves and nutrients from the shelf edge (where the shallow UK shelf drops off into the 4000m abyss) to Jones Bank. The birders & I have high hopes of lots of birds and marine mammal sightings at the shelf edge, so we'll be up at the crack of dawn for a bonanza of top predators ;o)

The Scillies lifeboat towing the Crystal Sea to safety against the backdrop of the island of St Agnes

More trawler in strife!

You would have thought that the Crystal Sea had had more than enough of it's share of bad luck! But those poor crew-members of the Crystal Sea had yet more bad luck in store for them: this morning they managed to snag something in the propeller while towing on the flat (MS4) site and were left helpless floating on the sea. We were in the midst of trying to retrieve the moorings (after 3 weeks of data collection), when we heard their bad luck. So we've come to the rescue (rescue number 2!) & are now towing the somewhat limping Crystal Sea back to the Scilley Isles. And true to form, the common dolphins appeared in the wake of the trawler (do they smell out trouble? Or are the dolphins like the seabirds and prefer feeding off the fish from the trawlers nets than finding their own food? Andy Webb put it nicely by calling it 'fast food').
So here we are slowly towing the Crystal Sea and their two crew & the MRAG observer (Jim) to the safety of the Scilley Isles...
Keep checking the blog for the latest installment of the James Cook Celtic Sea adventure!

Darren (one of the cooks on the ship) pointing out the Crystal Sea being towed behind us

All action day!

Two posts in one day??? Well, today deserved a blog all to itself! This morning I lethargically forced myself out of my bed and tramped heavily up the stairs to the mess to find some breakfast & was delighted to behold through the window a beautiful mirror-calm sea! (I have no porthole in my cabin - it's a bit tomb-like to be truthful). Such calm conditions are so rare, especially so far off shore, so I quickly grabbed some toast, and dashed up to the the birdy 'opera boxes' hoping for some marine mammal action (my particular favourite marine mammals are harbour porpoises - which are one of the smallest species of cetacean (the name given to all whales, dolphins & porpoises), and are very difficult to see except in very calm conditions. They're the most abundant species of cetacean in UK waters). We did indeed see a few porpoises resting on the surface (logging) and swimming past, as well as a lot of birds - mainly following the trawler.

But this trawler was there because we'd asked it to come along to fish for us, and find out what fish are found in the areas we've been surveying (on the bank and off the bank). This is what Beth had been busy organising most of this trip - working out where we'd like them to fish and when, liasing both with the CFPO (Cornish Fishermen Producers Organisation) who were the ones who pursuaded the fishermen to go and fish for us (proven to be invaluable), and with the observers supplied by MRAG (Marine Resource Assessment Group). The observers are recording the species caught by the trawlers, and measuring the size of the fish for us. We've got two trawlers coming out: the Crystal Sea - who is trawling the seabed to see what fish are on the bottom to see if they match the photos on Inigo's seabed camera; and the Imogen - who is carrying out mid-water (pelagic) trawls to find out what fish we're seeing on the echosounder. Unfortunately, the Imogen has been delayed due to engine problems, but the Crystal Sea was out today trawling for us, with Jim the MRAG observer onboard. The first haul brought up 2 large conger eels (no surprise there!), some haddock, John Dory, boarfish...

The second trawl started as I was sitting in the opera boxes watching for birds and marine mammals, the Crystal Sea disappearing into the distance, trawling its nets. But soon there was a commotion - word had come in from the Crystal Sea that a french trawler had been hassling them - circling menacingly, and in the process, the french trawler had trawled up one of our moorings & cut it loose from the buoy that marked it's location. Thankfully the mooring also had an acoustic release (this is a device that we can communicate with via sound - in fact it sounds very much like a dolphin whistle - it can tell us how far away we are from the mooring, and on an acoustic command it releases the lander with the current profiler & my CPOD from the anchor so it can float to the surface). So we managed to retrieve the mooring complete with 3 weeks of current profiler data, to which the oceanographers collectively sighed with relief!

Meanwhile, the Crystal Sea tried to continue fishing while still being hassled by the french trawlermen - who were obviously trying to look threatening by shaking baguettes at the crew of the Crystal Sea - Beth & Inigo laughingly discovered whole baguettes floating in the french fisherman's wake. Eventually the Crystal Sea were left in peace to trawl, but unfortunately one of their crew had an accident and sliced off the tips of a few of his fingers (ouch). We got ready to go to their aid with Malcolm, our medic (see picture of the rescue boat ready to go), but instead we just had to wait for 20-25 minutes before the coastguard sent out the rescue helicopter from HMS Culdrose (pictured with the Crystal Sea below), and the crewman was winched up and flown off to hospital (quite a sight). The whole process was pretty quick & impressive!

HMS Culdrose to the rescue of the crewman of the Crystal Sea (photo by Mark Lewis)

We were all up on the deck or bridge watching the rescue - meanwhile, a small shark swam past (& incidentally a blue shark was seen off the stern of the ship last night) - you can tell I'm a biologist to get distracted by a small shark! And... just to top it off, as the rescue was coming to an end, a large school (or pod) of common dolphins appeared - surrounding the ship, and before long the dolphins were swimming and leaping alongside the ship - which put a big smile on everyone's face after quite a stressful day.

Common dolphin caught post-leap by Mark Lewis

Since then, the Crystal Sea has continued to trawl for us, happily finding lots of nephrops (more of the shrimp like the one shown in the previous blog in the sediment core), and a surprisingly wide variety of fish, and different fish on the bank than on the slope to off the bank - which is fascinating, and interesting. So far it looks as though we have the nephrops (shrimp) off the bank, flat fish on top of the bank (lemon sole, plaice, etc.), and John Dory, along with a number of other species on the bank slope.

So all in all, today felt a bit surreal!
...sending best wishes for the injured crewman of the Crystal Sea from us on the James Cook :o) Hope you're ok out there too Jim!

Catch-up blog: Ships = foraging hotspot

It’s been a lethargic few days, the birders frustrated by lack of birds (see the form for MS5 in the photo above from a few days ago), and when they did appear it was in the wake of the fishing trawlers crossing our bows leaving a stream of stuffed gannets and fulmars sitting on the surface burping (ok, maybe I embellish a little…). Even everyone on the ship has had a sleepy look about them, as if walking in a trance. But the weather has been improving day on day, and with the good weather, more sunfish (check out the two photos on the left), and a large school of mackerel tucked in around the back of the ship, clustered around the turbulence profiler. We watched them glinting in the sun for a few hours before the fishing rod came out, and before long Viv (pictured on the right below with some mackerel), Beth, Inigo, Susan & Romaine had caught 40 mackerel. The chef cooked them up for tea today… yummy :o)

As for the science, it’s been quite interesting to go and explore our new control site (MS5) – which was indeed much like we expected – no feeding birds and not a huge amount of fish. We’ve also done grab sampling of the sediment at the bottom of the sea to see how it changes from MS5, over the bank to MS4. Nick (our benthic animal expert from the University of Dublin) had a lot of fun sifting through the sand or mud digging out the creatures – there were some cool looking worms, and a lovely shrimp with a green head and bright pink body. Even Morten captured a nephrops (type of shrimp) in his core sample, which proceeded to dig a tunnel out of the sand in the core (see photo on the left). You could see the shrimp through the Perspex tube, shovelling sand along the tunnel and out onto the surface – nature in action :o) After taking sediment samples, it was back to the slope part of the bank (MS2) to carry out a 2nd 25 hour turbulence profile station – and with that, and the echosounder we were able to see the classic set-up of the internal waves: the deepening of the thermocline as the current speeds up off the bank, and then as the tidal current relaxes, the thermocline releases with a 30m change in the depth of the thermocline creating internal waves. It wasn’t as dramatic as the last springs (this is a much smaller spring tide than at the beginning of the survey), but it was still nice to watch.

So that’s the catch up blog – and I’ll stop there, because today’s adventures are another blog entirely… and will follow in only an hour or two…

Chasing pink dye

The last couple of days have been monotonous for the birders (very few birds & those seen are nearly exclusively gannets – check out Andy’s blog to get an idea of how they’re enjoying sitting looking at a blank sea). But elsewhere on the ship there is more excitement. We got a really nice clear porpoise click train on the last CPOD deployment (at MS3 – the bottom of the bank), meanwhile Inigo’s camera came up with two uneaten fish (these had gone down frozen), one fish skeleton, and a good sample of the amphipods (sea lice) that are devouring them (see picture above). These were only 6mm long, but some of the ones he’s seen on the camera look more like 5cm long (what with those & the massive conger eels, I think I’ll stay above water thank you!). Others took more simple pleasures – like working outside in the sun (see Matthew Palmer from POL (turbulence man) in the picture to the right).

But the most excitement was in the ‘pink dye team’: Mark Inall (SAMS), Claire Neil (University of Strathclyde) and John Beaton (SAMS). Like earlier in the cruise (see previous blog & picture above of Mark & Claire tracking the dye), the pink dye was injected with a long tube with a weight on the end, into the thermocline (the layer that forms between the warmer surface water and the colder bottom water). They then track its dispersion using the fluorometer (measures the amount of colour in the water column) on the scanfish (the CTD that goes up and down the water column towed behind the ship) – so they can track the dye both vertically and horizontally through space. They tracked the dye after 4 hours, 12 hours, 24 hours and 36 hours, grabbing snatches of sleep in-between. It actually moves with the tidal & wind currents quite a lot even before the dispersal occurs, which means it’s quite challenging to find, even with the drogue with a satellite transmitter on it so you can track the currents (it only gives a position once an hour – so it’s a bit of a guessing game between position updates!). Between Mark, Claire & John and the Captain, they seemed to have a lot of fun trying to calculate the exact position of the dye, and then getting the ship to travel through where they thought the dye would be. Captain Peter Sargeant (pictured right) seemed to enjoy this task immensely, probably a bit like solving the cryptic crosswords he has stashed on the bridge ;o) Anyway, between their combined efforts in predicting tidal & wind drift they were successful and managed to find & track its dispersal over the bank. I’m not sure what they discovered since they finished at 1am and are now tucked up in their cabins catching up on sleep (well except the Captain). Incidentally - you can't get a better captain in my book - Peter is calm, spry and nearly always smiling :o) We have a great crew on the ship.

Meanwhile there have been more CTDs, more ‘giants tights’ bongo samples of zooplankton (there looks like a lot less biomass of zooplankton at the new control site MS5 from early conversations with Beth this morning), more sediment cores… and a very interesting talk about the phytoplankton & bacterial communities that Keith Davidson’s team are investigating. I’ll try and talk about their work a bit more in the next blog. As to me – I’ve been working up some of the fish data to see if we can solve part of the mystery behind few benthic fish on Inigo’s lander, and few feeding birds. As far as I can see there are a lot of fish down there – but then I mainly look at mid-water fish on the echosounder – so I can’t say very much about the fish in the top 10m or on the bottom. So maybe the fish aren’t close enough to the surface for the birds (and not enough marine mammals to bring the fish to the surface in bait balls), and they are mainly mid-water fish rather than bottom fish. It will be interesting to see what the fishermen catch when they come along after us – whether they find benthic fish (like plaice, sole… which Inigo isn't seeing on his lander but we were expecting), and what fish species come up in the mid-water (pelagic) trawls. That starts on Monday, with Beth co-ordinating their fishing efforts having pored for many hours over the fish echograms to work out where they should fish so we can find out what we’re seeing on the fish echosounder.

Still a lot of fun activities ahead… but let’s hope for more birds & marine mammals to break up the birder monotony. And on that note, I will end with an apt picture of gannets flying into the sunset…

gannets flying into the sunset... (& I'm sure the birders would be happy if they didn't come back!)

'A whiff of a porpoise'

Every time the camera lander is deposited on the seabed to take photos, a C-POD is attached to listen for and record the clicks of porpoises and dolphins. So I’ve had a few deployments of the CPOD and each time I have sent the files we collected to Nick Tregenza who built the C-PODs (Chelonia Ltd.), and within hours he’d reply… ‘no animals’. Until yesterday! When Nick reported a ‘whiff of a porpoise’: three minutes of porpoise clicks – wooohooo! Meanwhile, Inigo found few fish in his photographs and wondered whether the porpoise had scared all the fish away.

So that was yesterday’s excitement (thanks Nick!)… that and a ‘muster drill’ – every so often we have to practice the emergency drill – what happens when the emergency alarm goes off. We all gather on the deck complete with warm clothes, woolly hats, and lifejackets. If we have to abandon ship we have assigned life rafts complete with immersion suits – like big waterproof duvets – that we have to don. Yesterday Claire & Chris had to demonstrate the donning of the immersion suits – see the photo to the left! More like a space suit than a sea outfit!!!

Meanwhile, the box circuit over the bank was repeated this time at neap tides – so round and round we go around the oval looking for birds and fish while the scanfish zig-zags up and down the water column measuring temperature and salinity. It looks like more fish, more widely distributed feeding gannets, but fewer feeding storm petrels from a first glance at the data. And certainly much smaller undulations of internal waves – nothing so dramatic as the spring tide internal waves. Not sure what all this means yet, but looking forward to finding out as we do the analysis.

We’ve just finished the neap box circuit, and taking more zooplankton samples, more measurements of the water column with the CTD, and more sediment cores. Talking of which, it’s very clay-like here at the bottom of the bank (we’re at MS3 at the moment), unlike the top which is loose sand. Morten (pictured on the right with his sediment cores) & Susan are collecting these samples – Morten is using the samples to look at the nitrogen cycle within the sediment. What is the nitrogen cycle? Well, nitrogen is an essential element in life – amongst others it is found in DNA and proteins, and luckily there is a lot of nitrogen around since the air we breathe is 78% nitrogen. However the nitrogen in the air is not in a readily usable form, so organisms (especially bacteria – they do have their uses!) have to process it (‘fix’) the nitrogen into a form that can be used by other living organisms. Some bacteria (especially in the ocean) reconvert the nitrogen compounds back into nitrogen gas & so complete the cycle. It’s a bit more complicated than that – I’d recommend reading the Wikipedia guide if you’re interested.

So, anyway, Morten is measuring the nitrogen cycle within the sediment by taking chunks of sediment and ‘incubating’ them (keeping the sediment with all its bacteria in a nice cold room at a similar temperature at which it would have been on the bottom of the sea, and measuring the nitrogen & nitrogen compounds released). He’s also measuring the oxygen in the sediment – since many bacteria need oxygen to live. Apparently here in this offshore turbulent water the oxygen layer depth is only 1cm (so only 1cm has significant levels of oxygen), whereas productive coastal areas have a much deeper oxygen layer – especially undisturbed areas. I think this means there isn’t much activity going on in the sediments here – the sediment bacteria process all the dead animals that should fall to the bottom - so maybe the dead organisms are being swept off elsewhere to settle & feed bacteria elsewhere… science is full of many mysteries… (which is what makes it fun!).

So, is it all work and no play on the ship? Not at all! There’s a library, a video room, a bar (which is well frequented), a gym and a sauna! Now I’ve not tried out the sauna yet, but yesterday I did finally venture to the gym, which isn’t badly equipped for a ship (see photo below)! But for now, I’m off to the bar ;o)

Inigo & Linda 'relaxing' in the gym

Fish madness

Half way point. Two weeks gone since we set food on the RRS James Cook, and two weeks until we get off the ship. This was celebrated last night with a long and fun game of trivial persuit (version 1987!!), along with a good dose of laughter.

So where are we in the plan? Yesterday we did our ‘box’ surveys (more like an oval) of the flat site. So towing the ‘scanfish’ temperature profiler through the water column while recording the fish acoustics & watching for seabirds. We had expected this site to be pretty dull, predicting few fish and little feeding activity (expecting more productivity on the bank than off it). However, it was a fish hotspot (we saw sandeels at the surface at night from the back of the ship) and the day was filled with diving feeding gannets – which is a sight to behold… the gannets hover high up in the sky looking down at the sea, spot a fish, tuck up their wings and plunge beak first into the sea (looks painful).

Despite having more fish & feeding activity than we hypothesised… ahah, a new theory reveals itself… Mark Inall’s drogue (‘underwater parachute used to track currents’) showed that the combination of southerly winds & tidal flow resulted in a net flow from the Jones Bank off to the southeast – directly into the waters where we had stationed our ‘control’ flat site ‘MS4’. This means that the intense mixing that occurs over the edges of the bank is swept over this area, thus increasing productivity in the vicinity… well that’s our current theory. So slight change of plan… we’re going to do another station at the other side of the bank, and this time we theorise there won’t be many fish or feeding birds (the new ‘MS5’). Fun stuff! New discoveries daily :o) Well until this theory is dashed by new data (that’s science for you – it’s more fun when the sea reveals surprises!).

Talking of new discoveries… check out the 1.6m (5’ 3’’ to those imperial – basically my height!) conger eel captured on Inigo’s camera at MS4!!!! Whoa! One massive eel! In fact the majority of the bait had been devoured within a few hours by what look like very small amphipods (think of them as sea fleas) – which was very different from the other deployments on the bank (see previous blog). The conger eel came along to mop up the remains.

Check out this conger eel - the scale shown in the sand is a metre long - so this is a BIG eel!

Yesterday, one highlight of the day was the passing of the Queen Mary II cruise liner – which drew quite a crowd, including ‘muf’ Claire (‘enzyme queen’ who is looking at nutrient limitation for plankton. Plankton take up phosophorous, an essential element, differently dependent on whether there is a lot around or not much around – thus by using enzymes Claire can tell whether the plankton on/off the bank have received enough nutrients or not… why is this important? Well it tells us a bit about nutrient uptake where there is more or less turbulence. You’d expect them to be less nutrient-limited where there is more turbulent mixing. Hopefully I’ve got that right!). Anyway ‘muf’ Claire is pictured here with the Queen Mary in the palm of her hand (muf is the name of the chemicals she uses for her enzyme experiments just in case you were wondering).

Today we’ve been sitting in one spot carrying out turbulence profiling (the chimney brush or toilet brush as many of us call it) – back at the bank slope (MS2) measuring the turbulence through the water column but this time during the neap tides. And as we’d expect there is no internal wave activity at all with the tidal cycle (nothing visible on the fish echosounder anyway). Nice and predictable. Meanwhile we had some great sightings of a couple of sunfish who cruised around the ship flapping their fins & giving us great views (the photo doesn’t do it justice!). And we’re still here, with the profiler going up and down the water column every 5 minutes (operated manually by 3 or 4 people – painstaking!), and I sit here and watch the fish behaviour change as we go from day (more fish towards the bottom) to night (migrate to the surface).

To finish - here is a closer shot of the Queen Mary - for you Mom! (I know it's QMII not QMI but thought it might bring back some memories).

Escape to freedom

Saturday… though on the ship all the days blend together, and it feels like we’ve been on here forever! Yesterday, amongst many activities, Inigo 'Jones' Martinez (FRS) retrieved his lander from the top of the bank. The lander (shown with Inigo in the picture to the left) has a camera & flash attached, and is positioned so it floats a few metres over a large weight with mackerel bait attached to it (see second photo - some of the mackerel bait is wrapped in plastic bags that disolve over time, so that there is bait available to the fish over a longer period of time). The camera is programmed to take photos every minute. This way we can see what fish & other critters are on the sea bed, and how this changes with tidal speed (well, ideally). The photo below shows a photo of a whiting (which in the next photo swims off with a whole mackerel bait! Thief!), and lots of hermit crabs, and a very sandy bottom. In other photos Inigo identified a gurnard, haddock, little shoals of small fish, starfish & brittle stars, and snails. It’s fun to see what’s down there!

Picture above shows a whiting & lots of hermit crabs heading for the mackerel bait taken at MS2 around 70m depth

Meanwhile, science life continued (I realise I still haven’t talked about the activities of over half the scientists – so much going on!) – the main activity yesterday was the tracking of the dye released into the thermocline two days ago. So a large chunk of yesterday was spent towing the scanfish (that moves up and down the water column measuring temperature & salinity with depth – and on this one a fluorometer that was able to measure the amount of dye in the water) around the area where the dye had been released to track its progress. This is essentially to determine how turbulent mixing at the thermocline disperses material (whether plankton, nutrients, etc.). The dye had spread in a plume of around 8km long – which was interesting :o) Mark Inall, Claire Neil & John Beaton (SAMS) sat poring over the computer as the scanfish sent live dye readings to their computer (nifty programming on Claire’s part), and displayed a spatial map of the dye spread.

As to today, I escaped to freedom! We launched the rescue boat to go out and try my vertical hydrophone array. This has underwater microphones positioned at 4 different depths through the water column & is hung over the side of the small boat to record the sounds of … well… hopefully feeding dolphins. What I’d like to do is to work out how deep the dolphins are diving when they’re feeding, to see if they’re feeding at the same depth at which the fish are found on the echosounder, or to the depth of the thermocline. Today we were just testing the hydrophone, and certainly it was all peaceful down there in the deep sea (I can get down to 65m depth)… all I recorded was the distant ping of the ship echosounder. After around 30 minutes drifting on the swell, we all turned a bit green – Peter (1st Mate & boat driver), Steve & I. So since it was all working & nothing to be heard apart from the gentle ping of the ship, we returned to our home. I, for one, was glad to be back on the more stable RRS James Cook… home for now.

Our escape to freedom on the rescue boat...

Sunshine & dolphin madness

Gosh… sunshine AND feeding common dolphins! Yay! The mixture of sunshine and dolphins plus a large dosage of cabin fever resulted in a wee bit of madness…

A relatively quiet day on the RRS James Cook (equipment broke last night, and was being fixed today)… everyone busy sitting processing data at computers quietly, and blinking wide-eyed after discovering the sunshine outside. So we did long slow transects towing the temperature chain through the water (this is a long cable with temperature loggers at regular intervals from the surface to around 60m). I was processing some of the fish data, manually counting all the fish schools so that I can plot them, and see how they match with the bird data (see Andy Webb’s blog for a nice plot of the feeding gannets – nicely clustered over the bank where we’d measured lots of internal wave activity).

Meanwhile the birders were busy spotting… um… virtually no birds… though Andy did get pooped on while on watch :o) I went out for a spell of birding, and in 2 hours saw all of one or two fulmars, the odd gannet, one very distant bonksy… and then… Adam spotted, out of the corner of his eye a group of gannets hovering and swooping in the distance, and as we got closer we found a group of around 10 common dolphins feeding underneath the gannets (the gannets taking advantage of the fish brought the surface by the common dolphins). This activity resulted in much mad behaviour by the scientists (see photos to the right & below) & certainly I was grinning :o)

Right: Andy estimating the angle to the dolphins
Below: there are the dolphins! Silly tomfoolery after the event...

So that’s today’s blog… short and sweet… and compliments to the chef on a very excellent banoffee pie today!

Dolphins!

News hot off the press (it's nearly 1am BST)... Susan spotted a few dolphins alongside the boat in the dark :o) No species id... but first dolphins of the trip! Yay!
Thanks Susan :o)

The plan

I had a request today – to explain what the survey plan was. Hmmm, good question, the plan changes daily, hourly even – all dependent on the weather. However there is a general plan… the survey had been planned so that we’d hit one big spring tide (5th July) and one very low neap tide (13th July). A spring tide occurs when there is a new or full moon (moon lined up with the sun), which makes for bigger tidal currents, and a neap tide occurs half way between the new & full moons with smaller tidal currents. This results in more mixing (& more internal waves) at spring tides than at neaps tides. So the theory is that the spring tides mix the water up and bring nutrients to the surface, but the neap tides let things settle a bit and allow the phytoplankton to stay close to the surface & grow with the sun & make the most of the nutrients. This regular alternating between vigorous mixing and more settled tidal conditions makes our tidal seas as productive as they are… and this is what we’re here to investigate.

So I diverge a little. We cover a big spring tide and a small neap tide, so we should be able to see the contrast between the tides in the physics (we expect stronger & bigger internal waves at springs & lower at neaps), and in the biology (I’d probably expect there to be more surface feeding by seabirds during springs because the internal waves push the food to the surface – but I could be proven wrong). So, we chose a nice productive bank – Jones Bank (see map in previous blog) to look at these internal waves, and the associated physics & biology in three locations: on top of the bank (MS1), on the middle of the slope of the bank (MS2) and on the bottom of the bank (MS3). We also have a control site south of the bank by a few miles in a flat area (MS4) where we don’t expect the abrupt dramatic internal waves we’ve already seen on the bank edge (just some slow gentle internal waves).

So as part of this we do 25 hour stationary monitoring both on the bank and at the flat control site, taking regular measurements of turbulence through the water column (we expect more turbulence in internal waves, at thermocline boundaries etc.), plus a range of other variables through the water column: temperature, salinity, nutrients, dissolved oxygen, bacteria, phytoplankton, zooplankton (see previous blog), and probably other stuff that I haven’t found out about yet! In these sites we also take samples of the sediment, so that we can look at interchange of nutrients between the sediment & the water column & see if the internal waves have any effect on the productivity of the bottom, and therefore of course what critters are living in the sediment (so far it’s been sand or muddy sand at the bottom). We also have a camera that takes photos of the fish at the seabed (more of that later), and we also collect fisheries acoustics data & carry out visual watches for birds & cetaceans. These stations are carried out on the bank at spring & neap tides, and at the control site.

Then we have the ‘boxes’ (described yesterday) – surveying an oval 12 times over a 25 hour period, measuring oceanography (the temperature & salinity through the water column), fish & seabirds/marine mammals (if we ever see any of the latter). We’ll do these boxes on the bank both at spring & neaps, and at the control site.

One final activity is the dye release – but that’s in progress now, and quite cool… so I’ll concentrate on that in tomorrows blog :o)

...since there are no photos for todays blog I thought I'd put in a photo of the sunset I took yesterday...

Oooo check out those waves!

Today we’ve been going around in circles… well an oval really – an oval over the edge of the bank and back up again, one circuit every 6th of the tidal cycle for 25 hours – so we get two repeats of the tidal cycle over one day-night cycle. During these circuits we’ve been towing an ‘MVP’ – a Moving Vessel Profiler – which basically goes up and down the water column (hopefully not hitting the bottom on its way down!) measuring temperature and salinity through the water column. Also, we’ve been collected fish data using the echosounder & the birders have been busy with their binoculars… in a bit of sunshine! (well briefly – enough to make Mark get a wee bit sunburnt).

The physicists got very excited seeing some of the internal waves visible on the fish acoustics (I got excited too… check out the waves dude! Those fish are surfing the internal wave!).

What is an internal wave?… hmmm, well instead of a wave at the surface, it’s a wave at the thermocline – so where the warm light water sits on top of the cold heavy water (different densities – think of oil sitting on water) – at the boundary waves can travel (try it out – half fill a beaker with water & with oil, then jilt it a little and see if you can make a wave travel across the boundary layer between the oil and the water… I’ve not tried it – just thought it up so it might not work… but fun to try!). Anyway, these waves are basically caused by water flowing across bumps on the sea bottom and creating waves at the thermocline that travel, and cause mixing where they occur (turbulence), and so allow the nutrients from the cold deep layer to mix with the warmer surface layer, which is great for the phytoplankton (mini sea plants) & hence for the other critters in the sea. So well… that’s why we got all excited to see them on the fish echosounder… along with lots of fish (still trying to work out what species they are – but we’ll have fishermen coming along after us to fish & see what’s out here).

After all this excitement with the internal waves, I spent an afternoon with the birders to see if all this sub-surface activity was resulting in lots of birds and marine mammals. Alas not (still no dolphins, sorry)! We had a fun afternoon eating icecream and talking about sharks in supermarkets and dogs eating hotdogs (I guess you had to be there!), and were occasionally interrupted by the flitting storm petrels (look like bats darting across the surface – they’re tiny!), a few gannets & fulmars, a big fat bonksy harassing a young gannet, and some lovely Cory’s shearwaters (not seen them before – they come up from the Azores… goodness knows why in this July weather!) – but very elegant twisting and turning over the waves. The birders take this business all very seriously (check out Andy & Adam in the photo). And I enjoyed my relaxing birding afternoon, very peaceful (though I came in before the heavy rain!).

More fun tomorrow – more horrible weather on the way…

Been too knackered to blog...

Well, I’ve not updated for a few days, so I’m a bit overdue… been up to my eyes in fixing problems!!! So the last few days have been non-stop working, interrupted by meals (great food!) and sleep…

So what have we been up to? It all blurs together… let me check my activity log…
Ok, the weather calmed enough for us to finish deploying the moorings (4 in all), and yesterday (Sunday) started with a dawn CTD cast (measures salinity and temperature through the water column, and collects water samples through the water sample for all sorts of experiments by the other scientists (will find out more about their work & see if I can explain it in the blog later)). There were also bottom cores (takes a chunk of the bottom up for the benthic scientists to pore over), zooplankton collection…

…zooplankton… more of that now – it’s part of our project looking at everything from zooplankton – fish – marine mammals & seabirds. Beth’s in charge of zooplankton collection, and it involves towing something called bongo nets through the water (or the rest of us call them ‘giant’s tights’… because that’s what they look like (see photo on left)). These very fine nets are lowered through the water column to the bottom & then dragged back up & collects all the very small little creatures out of the water column – the tiny little animals that feed on plankton and other micro-animals… there are Calanus species (bugs that swim around very rapidly & vitally important animals in the food chain… species from sandeels up to 20-30m long whales eat these microscopic animals (I’m talking only the size of a millimetre or less)). Then there are the larvae of lots of other animals – so your baby crabs, baby fish, baby wormy things (which are cool – they look like translucent feathers that wiggle), and of course baby & small jellyfish… and lots more including cheatognaths… ever seen ‘Alien’ the movie? These translucent innocent looking creatures are actually voracious carnivores, and have a proboscis with a mouth on the end of it that comes out of their mouth to snatch up prey (thank goodness I’m not a zooplankton!) That’s just a few of the many creatures Beth found when she brought up her ‘tights’ out of the water. And it really is zooplankton soup out there … so much plankton (see picture on right of the inside of the end net – the cod-end... all that brown stuff is zooplankton)! Nice to see some life down there! COOL STUFF!

Why bother trying to find out about zooplankton? Well above the phytoplankton (micro plants), they’re the base of the food chain, so they’ll be the critters that attract fish that eat them, and the predatory fish that eat those fish, and the marine mammals & seabirds that feed on them all. So hopefully, where there are lots of dense aggregations of zooplankton we’ll find lots of fish, marine mammals & feeding seabirds (ok… I admit we haven’t seen any marine mammals and not much bird feeding activity yet… but well… that’s the idea anyway… and the weather has been a bit naff…).

Left: Beth & her zooplankton 'tights'

Lots more has been going on – we had a 25 hour stationary monitoring point during which Beth & I watched the fish echosounder and got overly excited by all the nice big fish schools, others got excited (or terribly bored) lowering and raising the turbulence profiler (aka the chimney sweep) through the water every 5 minutes, and the birders sat patiently watching the birds fly past. So lots of activities going on continuously – a real hive of activity. I’ll try and explain the different aspects as we go through the survey.

But now, after a beer in the bar, it’s time for bed… and tomorrow for more adventures.
:o) Clare

...bumpy seas...

Hello from the bumpy seas! Friday was a very bumpy voyage from Weymouth where we did the calibration to Jones Bank (see the map on left for our route – in black). So there were a lot of green faces (including me & I don’t usually get seasick!). However, there was still a hive of activity getting the moorings ready to deploy. The moorings sit on the seabed with instruments also spread through the water column, and then a big buoy at the surface. The moorings are placed along the edge of the Jones Bank (see map)… this is an area which is a fisherman’s hotspot – so there are lots of fish here, and it’s interesting to the oceanographers because of interesting tidal features which I’ll try and explain later in the cruise (in simple speak because I’m not an oceanographer!).
The moorings will be monitoring over the whole 3 weeks of the cruise lots of interesting things (well we think they’re interesting – that’s why we’re here!):

* ADCP = Acoustic Doppler Current Profiler (see picture on right)
A what? Well this sits on the sea bed and points towards the surface, transmitting a very high frequency sound pulse through the water which bounces off small particles in the water column (like zooplankton – your microscopic animals of the sea), and the reflection is picked up again by the ADCP. This allows the clever oceanographers here to work out how fast the currents are moving & in what direction throughout the water column. So it should show ebb and flood of the tides, as well as currents caused by the layering of the water column (where warmer water sits on top of cold water: the depth at which this occurs is called the ‘thermocline’)… and interestingly the currents travel in opposite directions on either side of the thermocline. This is great because it creates turbulence & mixing between the nice nutrient rich cold water, and the nice warm & sunny (????!!!) top layer – this means it’s good for phytoplankton – the little microscopic plants that allow our seas to be so full of life. Phytoplankton need both light & nutrients, so the thermocline is a good place for them in tidal places like here around the UK.

* Temperature loggers – these are placed at 5 or 10m intervals from the surface all the way to the bottom, and allow us to see where the thermocline is (where warm water changes to colder bottom water), and how it varies over the tidal cycle – both between the high and low tides, and between spring and neap tides.

* CPOD – a porpoise & dolphin click detector (Chelonia Ltd) is attached to each mooring (it’s the creamy tubular device attached to the moorings with lots of cable ties, jubilee clips and lots of gaffer tape curtesy of Em in the picture). These will detect any dolphin or porpoises within 1km of the mooring if they are producing echolocation clicks. Both dolphins and porpoises produce ‘echolocation’ high frequency clicks (higher frequency than we’re able to hear), which are believed to be used for locating prey & probably for navigation. A bit like the ADCP and the echosounder I’ve described: the porpoise/dolphin sends out click sound pulses into the water, and can acoustically ‘see’ fish, the bottom or even our ship from the echoes it hears. The CPOD will listen for & record these clicks so that we can see if there are any porpoises or dolphins around our moorings, and hopefully relate their presence to the oceanography we’re collecting at the same time… i.e. how does porpoise & dolphin presence change with the tidal cycle?

Gosh what a spiel! You can tell I have time on my hands! Well, two of the moorings went in last night before we were beset with 40 mph winds and an even bumpier sea… so that’s why I have time on my hands… we can’t do anything while the seas so rough! So now it’s a waiting game… waiting for the ‘unseasonal July weather’ to pass…