Thinking like phytoplankton: Professor Keith Davidson and the harmful algal blooms

SAMS BSc student Laken-Louise Hives interviews one of her lecturers

 



Around the world, harmful algal blooms are thought to be on the increase. About 4000 known marine species of phytoplankton –also known as microalgae– live in our oceans, harvesting sunlight for energy through photosynthesis. Though delicate under a microscope, phytoplankton form the foundations of the food chain in our world’s oceans.
Some species of microalgae have sporadic explosions of dense growth or “blooms”, and a number of those species are harmful.
Harmful algal blooms (HABs) are a natural part of marine ecosystem processes, and at SAMS a team of researchers study a handful of the 40 species of marine microalgae known to naturally produce bio-toxins that are harmful to people and the environment.
Dinoflagellates, such as Alexandrium tamarense, are not dependent on sunlight and can gain energy from nutrients in the surrounding waters.
“Both toxic (group I) and non-toxic (group III) strains of A.tamarense can be found in UK waters,” said Professor Keith Davidson, head of the microbial and molecular biology department at SAMS.
“The group I strain is more prevalent in waters around Shetland and Orkney, and can be found around coastal regions of Scotland. Group III prefers warmer waters further south. However, with warming sea surface temperatures in the north, this non-toxic group is pushing into higher latitudes,” Professor Davidson explained.
Commercially farmed bivalve molluscs, such as mussels and oysters, filter feed on drifting phytoplankton. Although bio-toxins are relatively harmless in low doses, the toxins can build up in the edible flesh of shellfish and although there is no apparent effect to the animal, human consumers can suffer far more significant consequences. In Scotland, shellfish farming is worth around £8.9 million at first sale, and so the presence of harmful algae in the area can have detrimental effects on the economy.
EU legislation requires all member states to have an “official control” monitoring system. SAMS is part of the UK-wide, official HABs team that monitors all active classified shellfish production and relaying areas. The team analyses more than 100 shellfish samples every week, and 100 water samples every month, as part of the programme to stop the harvesting or sale of products containing biotoxins above prescribed EU limits.
Keith, who is a lecturer on the undergraduate course at SAMS, was awarded a professorship by the University of Highlands and Islands in 2013 and has generated a great deal of research into HABs.
“I don’t spend much time in the lab anymore,” he said, but he is always willing dive in to help his PhD students who continue to investigate HABs.
Keith is currently supervising six PhD students: Grigorios (Greg) Moschonas, Silje-Kristin Jensen, Caroline Sharpes, Rebecca Weeks, Iona Campbell and Ruth Paterson.
Ruth is trying to find out how dinoflagellate Azadinium spinosum operates and the conditions it thrives in, because it produces biotoxins that lead to Azaspiracid Shellfish Poisoning (AZP). Although its effects are similar to diuretic shellfish poisoning, the toxins “appear more severe, with long term effects spanning weeks rather than days and is a major issue in aquaculture,” Ruth explained.
Azadinium spinosum unusually produces toxins during autumn and winter when “you wouldn’t expect there to be many phytoplankton around,” said Ruth who often works in the field.
“Most research has been conducted under laboratory conditions, which aren’t very representative of coastal and environmental conditions. Temperature, salinity and wind can have an effect on algal growth,” she added.
Keith’s work, supported by a vast network of loyal and hard-working colleagues is well on its way to saving the world one harmful algal bloom at a time. As a natural part of ecosystem processes the aim is not to ‘get rid’ of the problem, but to work around it by knowing how to “think like phytoplankton” and avoid the potential impacts by evolving technologies and minds to better mitigate the effects of harmful algal blooms.

Laken is in her 4th and final year of a BSc in Marine Science based at SAMS.

Follow her on twitter @NQS_Laken and take a look at her personal blog here.

A Corryvreckan Collaboration: The Sound of a whirlpool

By Andy Crabb, for the project Òrain na Mara/ Songs of the Scottish Sea 

Corryvreckan, May 2014

After many months of diary deliberations and failed attempts  to coincide busy schedules, The Songs Of the Scottish Sea finally nailed down a suitable date for an adventure into the wild waters of The Gulf of Corryvreckan on Sea Life Adventures’ Porpoise II.

On board were the project’s principle artistic collaborators, musicians Catriona McKay and Chris Stout and filmmaker Andy Crabb, together with producer Frances Higson and members of the scientific community at host institution the Scottish Association for Marine Science (SAMS): Dr Tom Wilding, Shane Rodwell and Chris Beveridge. Finally to keep us right and more importantly afloat, the skipper David Ainsley (a Marine Biologist and filmmaker in his own right) and his wildlife guide and zoologist Sarah Frost, and not forgetting local boat maestro and independent ferry operator Duncan MacEachen.

The weather gods or perhaps the resident sea witch the Cailleach Bheur had been playing merry hell with wind and rain for weeks before, but as predicted by the forecasting gurus at XC Weather, the storms let up right on schedule to allow us access to the Gulf.

The Corryvreckan is considered unnavigable when the weather and tides combine at their worst, and is famously home to the world’s third largest whirlpool. The very same whirlpool that sucked the Norse Prince Bhreacan and his crew to their mythological doom and in more recent history almost succeeded in killing off George Orwell and several young members of his family. An accident, which had it ended fatally, would have put an abrupt halt to the creation of 1984, the prophetic novel that Orwell was busy writing at Barnhill, a remote farmhouse at the north end of Jura, very close to the whirlpool.

With these legendary and literary associations combined with nearby development of renewable energy sources: Seaweed culture and tidal turbine arrays, the Corryvreckan serves as an ideal focal point for the Power of The Sea thread of the Songs of The Sea project.

All the collaborators arrived ahead of schedule at David’s base at Clachan Seil. Which was just as well, as any delays would have seen us stranded for several hours by the very low tide . From there we headed out past the lonely Garvellachs and into the Grey Dogs, the rather more compact wee sibling of the Corryreckan. Smaller it may be, but the tidal race of the Grey Dogs can be a daunting prospect in its own right, with  standing waves that at times can be measured in meters.


At the mouth of the Grey Dogs we paused a while for electronics wizard Shane Rodwell to carry out a test flight with his most recently constructed quad-copter. With a Go pro camera lashed to its hi-tech belly the four limbed flying machine buzzed up  from the deck of the boat and virtually disappeared into the brooding sky above. It was strange to watch this electronic aerial creature going about its business with an HD eye recording us and the all watery world spread out below, and appearing to all apart from the expert pilot behind the radio controls, to have a life of its own. 

Shane made several valiant attempts  to land the wee beastie back on the deck, but on a constantly moving boat with only a few square metres of deck-space to play to play with, he eventually opted to test out the recently added flotation with a controlled landing in the sea next to the Porpoise…..the boat that is, not one of the pod of porpoise who were spotted lazily surfacing nearby.


From there we headed through the standing waves of the Dogs and on around the coast of that great wedge of an island called Scarba. Scarba has no resident human population, but as we rounded the corner we caught sight of three Golden Eagles circling above us effortlessly…. no rotors or recharging of batteries required by those majestic eyes in the sky. As we approached the Great Race, The whirlpool was not yet running at full spate but the water was already starting to boil and bubble and the sea all about was forming the kind of bizarre gravity defying shapes that are never usually associated with water.

Moving to the relative shelter of  a small seaweed festooned bay on the Scarba shoreside, Chris and Catriona pulled out their fiddle and the harp. As Chris tuned up his fiddle, Catriona held up her harp to the wind and encouraged it to play the strings untouched by human hand. For those few moments the Corryvreckan was allowed to play a haunting tune all of its very own.


Chris & Catriona then settled themselves down on the wooden benches to play a suitably spine-tingling improvised piece, dramatically supported by the backdrop of standing waves and increasingly turbulent sea. The small but select audience on board the boat appeared spellbound by both the unique performance and venue, and news of the one-off event obviously travelled fast as we were soon joined on the nearby island shore by a gang of wild and well horned white goats.

The amazing music and the whirlpool combined to weave an entrancement of which the Cailleach herself would have been proud. But perhaps the mighty hag of winter felt that these upstart musical magicians were stealing too much of her thunder, as soon after the rain started and the instruments were forced rapidly back into their cases.
 
It was fascinating to be back in the Corryvreckan again having spent time working with the incredibly detailed 3D seabed maps of the area produced by SAMS for the INIS Hydro project. This return visit has literally given a whole new dimension after being able to virtually fly through the astonishing landscape beneath these waves. The previously unseen landscape which allied with the power of the tides produces the extraordinary turbulence that has made this place famous around the world.
 
Next we headed by dinghy to a landing in the Bay of Pigs, a sheltered spot on the remote north coast of Jura, not far the small rocky islet where Orwell and his family had been shipwrecked 66 years before. Some of the team went cave hunting in the nearby cliffs while others headed up onto the Jura hillsides to gather images of the gulf from the land. At one point a monstrous freak wave was spotted out in the midst of the maelstrom that looked like it could have easily swamped the boat had we been foolish enough to still be there to taunt it.

Once the Jura landings were complete it was back to the Porpoise II. With the sun shining again, and the height of the whirlpool passed its peak, Chris & Catriona performed the second set of a micro-concert that I’m sure will live long in the memories of the fortunate few to witness it, before the early spring chill set in and it was time to head for home.

The journey back to Seil was full of good craic and wild-west coast sights to match. After all…..it was a unique day that is as difficult to capture in words as it was to organise, so I will stop trying….. But I would like to say a big thanks to all the collaborators on board for their contributions and making the long planned adventure into such a compelling and memorable experience ….and if even a glimmer of the magic has made its way through the lens and microphone and into the camera then we will hopefully have something special to share with others, and to fire the film-music collaboration still to come.

From left to right: Andy Crabb, Duncan MacEachen, Catriona McKay, Shane Rodwell, Chris Stout, Frances Higson, Tom Wilding, Sarah Frost, Christine Beveridge & David Ainsley.
Thanks to: Chris Beveridge, Shane Rodwell and Tom Wilding for use of photos.

Werewolves in the Arctic

By Dr Kim Last
In the Arctic, January 2014

All about there is an eerie silence only broken by the occasional faint howls of huskies in the distance. The snow has stopped falling and the clouds are slowly thinning; the twinkle of millions of stars across the Milky Way becoming ever more apparent.

The marine laboratory has been blacked out, the streetlamps leading to the pier are dark, even my head torch is dimmed red. I shuffle about in my clumsy Polar clothing. My backpack contains a sensitive light meter, especially designed for the job at hand. I point it towards the east and take a reading. Nothing. Zero light. We have to wait some more. It is cold, bitterly so and I crumple my toes in my boots in an attempt to get some warmth into them. And I wait for nothing very much continuous to happen: this is the life of a scientist de facto.

Then, very slowly, the full moon begins to rise. The land is gradually bathed with cold white light, which illuminates the tips of the snow covered hills and then creeps at a molluscan pace down to the glaciers that snake their way into the fjord.

The sea begins to shimmer and the snow around me twinkles and sparkles. The dogs howl feverishly like a lunar dawn chorus and as I gaze into the black fjord I know that something very big is stirring in the depths. I imagine denizens of the deep, aquatic werewolves on the run, as billions of tiny creatures start to move away from the moonlight. I hold my light meter high and it flickers to life – we have light! A collective cry goes out to man the action stations: grab your nets boys, gun the boats girls, throw the surveillance robots into the sea and rally the dive team. The time has come to catch those elusive werewolves of the deep!

Now this may all sound a little bit dramatic, but it is not really that far removed from the truth. I have joined an expedition to Ny Alesund on the western side of the Svalbard archipelago to help try and figure out what happens to animals, those tiny creatures of the deep or, more scientifically, zooplankton, at this time of year when there is virtually no daylight.

For some years now we have been gathering data from our acoustic sensors on the seabed which have shown something quite remarkable. At a time when zooplankton should be in hibernation, more properly known as diapause, they are migrating as regular as clockwork up and down in the water. Questions immediately arise: There are many kinds of zooplankton, so which ones are doing the migrating? Why are they bothering to migrate in the first place? And, perhaps most importantly, what are the implications of such migrations to the Arctic ecosystem since this is, after all, the largest by mass daily migration on the planet?

Sediment trap for collecting zooplankton poo.

SAMS scientists Colin Griffiths (L) & Finlo Cottier (R) get down to business.

Image: K.S. Last.

Good questions are the cornerstone to great science and Jorgen Berg, the scientific leader of the CIRCA project likes good questions. But as we know from my lunar light measurements, science can be slow and tedious. It takes a long time to be sure that the data you have painstakingly collected actually reflects what might be going on in the real world and ideally you need to know what you are doing. So Jorgen collected a team of scientists from many countries, experts in many different disciplines to try and answer such fundamental questions.

The zooplankton are well known to migrate in response to light at a time when the sun is above the horizon. They feed on plants or algae in the surface waters at night and then migrate into the depths during the day, the hypothesis is that they do this to avoid predators and follow isolumes or light gradients as they migrate. But what about during December and January in the Arctic when only moonlight, starlight and on occasion, the fantastic light show of the aurora borealis light the sky? The most obvious light candidate with reference to overall intensity is moonlight and when we make correlations between the migration intensity of the zooplankton from our acoustic instruments and the phase of the moon with its angle above the horizon, the result is a strong relationship between the two.

The list of jobs of the CIRCA project is hugely diverse and tasks span many years. Julie Grenvald, a PhD student (from UNIS, the University Centre in Svalbard), is painstakingly collecting zooplankton from different depths and then identifying and counting the animals she finds. Laura Hobbs, also a PhD student (from the Scottish Association of Marine Science) is processing acoustic data from all over the Arctic Sea, including the North Pole, to determine the extent of the migrations. And the postdoc Gérald Darnis (from Akvaplan-niva AS, Tromsø) is very carefully catching zooplankton excrement, which you may think is rather an odd use of time. But quite the contrary, the composition and amount of zooplankton faeces can inform us about the amount of carbon which is captured by the animals in the surface waters and transported to the deep sea. This, would you believe, may provide an important piece of data in informing future climate predictions.

And what am I doing in all this apart from switching on a light meter? What small piece of the jigsaw am I attempting to piece together? All organisms that we know of possess a biological clock. This clock enables animals and plants to predict a future cyclic change in their environment. Our own circadian clock sets the tempo of many physiological and behavioural processes and most of the time we are not even aware of it, unless we fly across many time zones and experience jet-lag.

Of particular interest is that Arctic zooplankton that are responding to the daily rising and setting of the moon may have a very different kind of a clock, or even a special circadian one that can not only tell the time of the rising and setting of the sun but, during the winter months at least, the rising and setting of the moon. Whereas the sun takes precisely 24 hours, the moon takes about an hour longer. So my experiments require me to catch animals and place them in chambers in complete darkness and constant temperature and then measure swimming activity. If the clock exists then the animals will be active spontaneously every 25 hours and will show that moonlight can indeed control the denizen's clock. However, my experiments will also tell us more about the ancestral proto-clock that first evolved in algae ~2 billion years ago on a planet that was very different from today and where the influence of the moon cycle was much stronger, to the extent that a day may have been only four hours long, but that's another story.

So now the stations have been manned, the nets filled and the robots recovered, the time has come to work up the data. The light meter is packed and my toes are truly cold. The moon is gradually sinking beyond the hills and the few hours of light give way to complete darkness again. Time to head into the warmth of the laboratory and, albeit slowly, try to figure out what those elusive werewolves of the deep are up to.

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Links:

http://www.sams.ac.uk/kim-last/

http://www.mare-incognitum.no/index.php/circa

http://www.sams.ac.uk/finlo-cottier/panarcive

http://www.sams.ac.uk/news-room/new-project-to-investigate-arctic-plankton-dynamics/

Into the night with lunartick zooplankton

By Dr Kim Last

In the Arctic, December 2013

“But are you sure those blobs are real?” asked Jørgen Berg (project leader of the CIRCA project) after looking quizzically at the coloured data chart lying on the table in front of us.

I fidgeted, the data was showing something that we hadn’t expected during the Polar Night.

The “blobs” represented zooplankton that seemed to be migrating in response to moonlight, not sunlight.

“Probably,” I replied.

Jorgen paused and in typical Norwegian no-nonsense fashion said, “Well then, let’s go find out”.

Little did I know I had inadvertently started a whole field campaign, based on some coloured “blobs”!

Facing the darkness

For the last few years we have been studying zooplankton migrating up and down in the water in response to sunlight. Using acoustics, patterns are emerging that show very clear synchronised migrations in the autumn and spring but limited activity during the darkest months of December and January. Now, using new data analysis and visualisation techniques (normally associated with studying biological rhythms in flies, mice and humans) we are seeing patterns in zooplankton migration which are quite new. During the time of the full moon these small organisms appear to migrate with a new cycle, not the 24 hour cycle of the rising and setting of the sun which we are so familiar with, but one of the rising and setting of the moon, a lunar-day or lunidian cycle close to 25 hours!

The main aim of the field campaign this December is to go “fishing” during the time of the full and new moon with various types of nets and cameras to find out who is doing the migrating. Specifically how deep do they migrate, and how fast, and can they anticipate the rising and setting of the moon? To this end we also want to know if the zooplankton possess a biological clock? We already know that just about every animal and plant possesses an in-built clock, the best known of which is the circadian clock. Many of us are even familiar with its workings, or rather when it stops working so well when it becomes re-set during long-haul flights and we experience jet-lag as a consequence. So we can hypothesis that the migrating zooplankton may also have a clock. Therefore another aim of this trip is to catch some live zooplankton and study them in the lab under constant conditions without moonlight. If they still behave as though they were out in the sea by becoming active when they “think” the moon is up, then we will know that they possess a lunar clock. This would help explain how they manage to migrate to the surface from the dark ocean depths where currently our light sensors cannot detect any light.

Working in the Arctic during the polar night is no mean feat with total darkness 24 hours a day and often the thermometer falls to -20^oC for weeks on end. Although Jørgen is a toughened Polar scientist, I am not, and as I sit here on the flight to Svalbard in December clutching my laptop with the infamous “blobs” I am experiencing just a little trepidation. Looking out the window of the plane to the north I can see the night stretching out in front of me, like a big heavy blanket, the last of the sunshine left behind somewhere over mainland Norway. I wonder perhaps whether my own clock may become a little dysfunctional over the next weeks without any form of solar re-setting and I look up and see the moon as only a silver sickle and wonder what is going on down there in the deep dark waters… well, it’s time to find out!

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Other people involved from SAMS: Finlo Cottier, Collin Griffiths and our student Laura Hobbs

Links:

http://www.sams.ac.uk/kim-last/

http://www.mare-incognitum.no/index.php/circa

http://www.sams.ac.uk/finlo-cottier/panarcive

http://www.sams.ac.uk/news-room/new-project-to-investigate-arctic-plankton-dynamics/