Isle of May 2017 – Marine litter; there is no good, it’s just bad and ugly

Over the last couple of weeks the amount of marine litter and pollution that is currently in our oceans, especially plastic waste, has featured heavily in the news and social media, not to mention on millions of TV screens thanks to the BBC series Blue Planet 2. It’s great that so many people are becoming aware of this growing problem, as there are so many things everyone can do in their every day lives to help cut down the amount of human trash and chemicals that ends up in our seas. So this week, our blog is a beginner’s guide to a few of the types of marine litter that are currently causing problems for ocean life everywhere on the planet and why they are so dangerous.

Weaned grey seal pup that I disentangled last season (2016) on the Isle of May, with a loop of plastic caught around his neck.
Gannets are one sea bird species that uses man made debris in their nests, which can then entangle their chicks.

Pieces of trash and debris from man made objects represent a huge threat to all types of marine life, from small corals to large whales. Rubbish of all kinds, including plastic packaging, shopping bags, glass, old tyres and basically anything you can think of that goes into a landfill site can end up in the sea if it’s not properly disposed of. Human debris can harm wildlife in several ways; creatures may get stuck or wrapped in the trash and injured by it (entangled), the trash can get used as nesting material and cause harm to offspring and litter can also be mistaken for food and eaten by sea life, causing collections of plastic in marine mammal and turtle stomachs and guts.

Trying to combat the marine litter problem is proving challenging as it’s an issue that requires global co-operation to tackle. Once human debris is in the ocean, it can drift huge distances and cross many country boundaries. Debris can also collect together in certain marine areas due to ocean surface currents forcing litter into one place, forming regions in the middle of seas that have high concentrations of floating plastic. This month, the United Nations discused completely banning plastic waste entering the sea worldwide, in an effort to combat the problem. By stopping litter entering the ocean globally, and by encouraging member nations to clean up their coasts, it is hoped that real progress can be made to improve the state of our seas. With more than 200 member nations commiting to tackle the problem, it is hoped that a legally binding agreement can be reached on marine plastic in the coming years.

However, one of the few positive things about combating marine litter is that there are lots ways that everyone can make small changes in their lives to make real reductions in the plastic going into our environment. Here are just a few, try them and be part of the solution!

  1. Get a re-usable water bottle (or coffee mug if you drink more of that than water!), and use water fountains to refil it through the day rather than buy bottled water. If there isn’t a water dispenser at your place of work, talk to your bosses to get one installed for everyone to use.
  2. Get re-usable shopping bags to use instead of disposable ones from supermarkets.
  3. Say you don’t need a straw at bars and restuarants.
  4. If you don’t have any use for something you own anymore, try giving it to a charity shop, or making it into something new rather than throwing it to landfill. Coming up with creative ways to re-use things can be lots of fun, as well as saving you money and helping the environment.
  5. If you are out for a walk and see some litter blowing around, pick it up! Then you can dispose of it properly at the next opertunity. Ever piece of trash picked up and taken to a bin is one less piece of garbage that will end up in the sea.

It’s not only litter and plastics that make up the marine debris problem. Fishing gear can also be deadly for marine life, types include:

Many humpback whales bear scars from prior entanglements. They seem to be most vulnerable to entanglements when they are young, like this calf seen with it’s mother off Stellwagen bank, USA
The fishing hook removed from the flipper of one of our study seals on the Isle of May this year

Here on the Isle of May we live alongside the grey seals that breed here for two months every year, and the marks the seals bear from interacting with marine debris are often painfully obvious. Seal species typically develop entanglements around their necks, and if an individual cannot get free, the strands of rope bite into the flesh of a seal as it grows, making open fleshy wounds deep into the body. This can cut through the skin, blubber and muscle layers of the neck, becoming incredibly tight and ultimately killing the individual if the rope cannot be removed. Even when the rope is gone, seals frequently bear the deep scars from the problem for the rest of their lives. In 2017 we have seen a few ‘rope neck’ seals on the colony, however the worst man made item removed from a seal this year was from one of our study females, who had a fishing hook embedded in her hind flipper.

A female grey seal on the beach at Donna Nook in Lincolnshire, UK. She has a deep ‘rope neck’ scar from an entanglement with rope or fishing nets, and the rope may still be embedded in the wound.

Unfortunately, intact man made debris is only the tip of the iceberg in terms of man made substances in our oceans. Plastic dose not properly degrade naturally, rather it eventually breaks into smaller and smaller pieces as it becomes brittle and cracks, ultimately becoming ‘microplastics; tiny fragments of plastic that then persist in the seas or in the substrates of coastal environments. Microplastic pollution can also be generated when tiny pellets used in factories to make plastic items, called ‘nurdles’, are spilled into rivers or oceans. Microplastics are especially troublesome because they spread widely through marine environments and, unlike intact litter, they’re so small that cleaning them out of an area is very difficult. They are also readily eaten by a variety of marine life; either directly by small organisms such as zooplankton or indirectly by species feeding on zooplankton, which then transfers the microplastics up the food chain. Once eaten, microplastics tend to accumulate in organisms as plastic is so difficult to break down, and to date they have been found in the digestive systems of many marine species, including invertebrates, small fish, sharks and marine mammals. While scientists are still working to understand the impacts microplastic accumulation has on individual health and survival, many studies have already shown the negative affects they have on a variety of marine creatures, including:

The links between these negative impacts and microplastic exposure are still being uncovered, however it is thought that some of the problems associated with accumulating microplastics in the body may relate to the chemical pollutants held within the plastics. Several correlations between high microplastic ingestion rates and high concentrations of a variety of pollutants have been found marine species (e.g. these sea birds). However, correlations do not always equate to causality, and there are also studies showing no links between pollutant concentrations in plastic debris and pollutant burden in individuals eating the debris. One thing is sure however, microplastics in the marine environment are not going away anytime soon, and more work is needed to understand the problem and its consequences for marine organisms. The PHATS team that I am part of is working to uncover the physiological affects of persistent organic pollutants (or POPs, e.g. PCBs) on fat tissue from seals, and we need to understand how individuals get exposed to pollutants. Microplastic ingestion may represent an additional, significant route of exposure to these harmful chemicals in addition to those that are eaten when bound to the fatty tissues of prey speices, that have bioaccumulated up the food chain. Hopefully in the coming years, the mechanisms underlying POPs bound to microplastics, and their absorption into the tissues of marine organisms that ingest them, will become clearer.

MEANWHILE…

Study pup ‘Papa’ (who ironically is a girl) and her mother on the Isle of May. Here Papa is almost ready to wean, and you can see the beginnings of the laguno moult on her flippers and face
Study pup ‘Bumblebee’ at 5 days old with his mother.

Our research for the PHATS project on the Isle of May is going really well, and almost all of our study pups are now weaned from their mothers. Watching the pups go from skinny, fluffy newborns to massively fat, sleek weaners in just over two weeks is always a part of our work that fascinates me; it’s incredible that they can put on so much mass in such a short time frame. Soon the weaned pups will start leaving the island to go to sea for the first time, and their large blubber reserves will hopefully tide them over until they can learn how to fish by themselves.

Study pup ‘Sierra’ with her mother on the colony, you can see her white pup fluff (or laguno) coming off as her mother rubs her back!

As it’s getting into the late part of the season for the research team here on the island, we’ve also had lots of human comings and goings in the last week. We’ve had a film crew out from the BBC winter watch team, so hopefully footage of the Isle of May seals and some of the science done on the island will be coming to TV soon. Almost half of the research team has also returned back to the mainland, including the PHATS team leader Dr Kimberley Bennett, who has to get back to the University of Abertay to continue her lecturing duties. As the season continues, the team will probably drop to fewer than 4 people, who will stay out to finish the research work and then close up the island for the holiday season. We won’t be gone for long though, as the PHATS team are already planning our return in early January!

The boat going past the low light on the Isle of May, heading to Kirkhaven to take people off the island as the season comes to a close.

Isle of May 2017 – Seal pregnancies, from delayed implantation to fast births

A grey seal mother giving birth on the Isle of May breeding colony last week

The first two weeks of our field season on the Isle of May have been very busy ones, and we’re now well into the research that we need to get done on the island. In the last week the colony hit peak pupping time, which meant there was lots of amazing births to watch on the island. So, in honour of all the little lives I’ve witnessed come into this world over the last 2 weeks, this blog will be about the wonders of seal pregnancies and births. Births and young pups are fascinating to observe, but please keep in mind that all the observations and photographs we take are done under permit and from hides during research on the breeding colonies as part of scientific projects. Please do not approach or disturb seals during autumn, as they may be pregnant or with pups. Mothers may abandon pups if people come too close, and then the pups will starve to death.

Mother pup interactions are amazing to see, but please be careful where you go to see them and how close you get.

Birth is usually a rapid process in the grey seals here on the Isle of May; we often observe females give birth within ten minutes of visibly starting to push! Many females come to the island prior to giving birth, and either hang around the rocky coast of the island or make forays into the colony in the days before pupping. Female grey seals also show site fidelity (i.e. they go back to the same spot) to the place where they give birth, so we can not only find the same females every year on the Isle of May, but they are found in almost exactly the same places year after year with their current pup. Once a female has given birth to her pup she will usually instantly turn around to begin nosing and sniffing the pup, beginning the bonding process that will keep her by its side for the next 18 days. Grey seal mothers only have 18 days to nurse their pups before they must return to sea. Females don’t eat while they are on the colony, so they loose lots of weight while they are producing fat rich milk for their pups, usually dropping about a third of their mass from when they arrived at the island.

Grey seal mother giving birth in 8 minutes on the Isle of May!

Seal pregnancies are very different to human ones, as they can delay implantation of the growing embryo in the womb, so that it stops developing for a certain time period before it implants and the pregnancy continues normally. This enables grey seals to give birth at the same time every year, despite mating when they leave the colony on day 18 and having pregnancies than only last about 9 months. Many species of mammals, especially carnivores, show delayed implantation, or embryonic diapause, and it is widespread in the pinniped species (seals, sea lions and walrus). However, recent research has found some seal species, like the Weddell seal that lives in Antarctica, may not have delayed implantation. New studies to understand the environmental, nutritional and population pressures driving the evolution of delayed implantation in types of seal will hopefully help us figure out why some species have this physiological adaptation and others do not.

Weddell seal hauled out on D’Hainaut Island, Mikkelsen Harbor, Trinity Island, Antarctica courtesy of Andrew Shiva / Wikipedia / CC BY-SA 4.0

Birth and rearing a young infant is always a testing time for a mammalian mother, and in marine mammals, newborn infants face an additional challenge to their wellbeing. Marine mammals typically have high persistent organic pollutant (POP) burdens due to their top trophic positions in the food chain and the bioaccumulation of the POPs in predators. As these substances are lipophilic (they combine with fat tissues in the body, like blubber) this means that infant marine mammals are at risk from the pollutant burden of their mothers. Some transfer of POPs occurs during pregnancy across the placenta, but once the pup or calf is born, mothers have to produce fat rich milk to feed their offspring with. To do this, mothers typically mobilise the fat reserves in their blubber, and as this tissue has high POP concentrations, these go into the milk she’s producing. By having to drink milk with elevated POP concentrations, newborn marine mammals are continuously ingesting proportions of their mother’s pollutant burden up until they wean, which can have serious negative impacts on their immune system and chance at survival. The PHATS team I’m currently working with is trying to uncover more about the physiology underlying the impact POPs have on fat tissue function and an individual’s ability to generate and utilise blubber properly. By using novel tissue culture techniques in wild breeding colony locations (LINK), we’re hoping to provide new insights and develop new methods to investigate physiological problems caused by such man-made changed to the environments.

Grey seal pup nursing from its mother on the Isle of May

MEANWHILE I’d like to introduce you to some of our study seals! They are all named after the phonetic alphabet, and we watch them from birth, to weaning and beyond to gather data and samples from them. This means that at any one time, we have white coat pups that are still with their mothers, pups that have just weaned and are moulting their white baby fur (or lanugo) and pups that are well into their 1-4 week post-weaning fast, with their spotty adult fur. Below are a few of our study seals, and I’ll post updates about how they are all doing on the blog every week.

Kilo and his mother on the edge of the colony, on the road that leads to Kirkhaven harbour on the Isle of May. He is starting to moult his white baby fur on his flippers and face.

 

Oscar pestering his mother for milk on the colony!

 

Foxtrot weaned from her mother several days ago, and has moulted most of her white pup fluff off

Isle of May 2017 – The last PHATS field season begins

The PHATS team 2017 geared up to head out to the island

The PHATS team is back out on the Isle of May! For the rest of the year, we’ll be out here studying the breeding grey seals and how the physiology of fat tissue in wild animals is affected by persistent organic pollutants (POPs). This year we have 4 team members; Dr Kimberley Bennett and her new PhD student Laura Oller have come from Abertay University, Holly Armstrong has come up from Plymouth University and I’ve come from the Sea Mammal Research Unit at the University of St Andrews.

Driving the lab gear out to the Isle of May

This year the field season has had a rather unconventional start, as for the first week of the breeding season Dr Bennett and I were away in Canada for the 22nd Biennial Marine Mammal Conference (more on this later). So back in mid October we had to do an early provision run to get most of the laboratory gear we need for the 2 month long field season out onto the island. The other field teams working on the seals then arrived while we were still in Canada, and when we finally arrived last week we had to hit the ground running as there were already lots of potential study animals for the PHATS project. Even though we’ve only been on the island for three days, we’ve already found the first five seals for this year’s study cohort, who have duely been named Alpha through to Echo from the phonetic alphabet. We’ll be here until mid december to try and collect all the data we need to finish the PHATS study, as this is the last field season that is planned for the project.

A 1-2 day old grey seal pup on the Isle of May, with a still healing umbilical cord

Outside of the lab we’ve set up on the island, the breeding season is in full swing for the grey seals that have come here to give birth and mate. The number of mother-pup pairs is steadily rising and the large males are already starting to battle for position among the females. There aren’t too many weaned pups around yet, but within a few weeks there will be loads all around the edges of the colony as their 18 days with their mothers comes to an end and the females return to sea, leaving their pups to fend for themselves. Every week I’ll write about a different aspect of the breeding colony and the PHATS project for this blog, with updates on how our study seals are doing and what the field team are getting up to. You can check back here or find me on twitter for updates.

Male grey seals fighting on the Isle of May colony, biting another seal’s hind flippers while they run away appears to be the ultimate insult!
Giving my talk at the marine mammal biennial in Halifax, Canada

MEANWHILE as mentioned above, team leader Dr Bennett and I have been travelling, heading to Halifax, Canada for the 22nd Biennial Marine Mammal Conference to present the findings of the PHATS project so far. It’s always fantastic to get to meet up with fellow marine mammal scientists, hear what discoveries have been made in the last 2 years and show people what you’ve been working on. I also go to take part in a workshop dedicated to a subject that’s become especially important to me, marine mammal endocrinology. It was great to meet all the other people working on the challenging topic of marine mammal hormones, and to hear about the inventive ways people get around working with tricky species like whales out at sea. I’ve had a pretty busy year for conferences in 2017, hopefully we’ll keep finding out new, interesting things from both my PhD on oxytocin and from the PHATS project so we can go to some more next year!

Dr Bennett and I exploring the coast of Canada near Halifax

 

 

The SOI Early Career Network, October talks and upcoming Isle of May field season

Pregnant female grey seals and yearlings hauled out on the rocks around the Isle of May, Scotland

It’s that time of year once again, autumn is here and that means I’m making inventories and packing equipment for the PHATS team’s field season on the Isle of May. We’ll be heading out to the island at the end of October to begin our last data collection season for the project, and we’ll be living on the island and studying the grey seals until mid December. Before we head out though I’ve got a busy month ahead of me, as I’ll be presenting PHATS work, my PhD work on oxytocin and talking to the public about grey seals. But before we get onto where and when I’ll be presenting, I’m quickly going to give a shout out to a new group I’ve been involved with setting up over the last few months, the SOI Early Careers Network.

This grew out of a group of friends from the Scottish Ocean’s Institute (SOI) meeting to help each other practise for presentations, to give feedback on each other’s ideas and to chat and share resources about the various issues early career scientists face. We then decided to open the gatherings up to any early career researcher at the SOI, and the group has grown ever since. We meet at least every week, sometimes more, to discuss anything our members currently need help or advice with. Right now we are having lots of conference poster and talk preparation sessions with the biologging meeting and the marine mammal biennial happening in September and October. We’ve also discussed loads of topics including statistical methods, funding awards and public outreach.

If you are an early careers researcher at the SOI you are very welcome to join us, our meetings aim to address whatever our members feel they currently need, providing a responsive support system with a relaxed, friendly environment. Please visit our new website here to find out more, see when our next meetings are and sign up to the mailing list, or you could come along to our welcome day event on Tuesday 3rd October (next week) to meet some of us and chat about the group and early career life.

A SOI early career network meeting for practising talks and sharing presentation ideas

I’ll certainly be practising the various presentations I need to give in the coming month at the ECN! I’ve already been to one conference this month, the wonderful meeting of the British Neuroendocrinology Society in Nottingham where I got to present my work on oxytocin and behaviour in seals. Next I’ll be talking to the public about any and all aspects of grey seal life on the Isle of May, during their annual seal weekend. This happens to celebrate the start of the grey seal breeding season, and afterwards the island is then closed to the public for the rest of the year to protect the breeding seals from disturbance.

Presenting my oxytocin work at the BNS 2017 conference in Nottingham

I’ll then be travelling to the University of Edinburgh to talk about my work on oxytocin and behaviour on the 10th October. I can’t wait to meet everyone at the Centre for Integrative Physiology and hear all about their amazing research on neuroendocrinology, I got to meet a few lab members at the BNS 2017 conference and their studies on modelling oxytocin dynamics are fascinating. Finally I’ll be heading out to Canada towards the end of October to present our PHATS work at the 22nd Biennial Conference on Marine Mammals. Phew, it’s going to be a crazy month! If you’d like to know more about any of my work, feel free to say hi at any of these events, or you can keep up with me on Twitter (@KJRscience).

EVENTS:

1st October – Isle of May seal weekend

10th October – 3pm talk at the Centre for Integrative Physiology, University of Edinburgh

22nd-27th October – 22nd Biennial Conference on Marine Mammals, Halifax, Canada

Hauled out grey seals in East Tarbet in the north part of the Isle of May, Scotland

 

New Publication – An explant approach to studying fat tissue function in wild animals

Adult male grey seal hauled out on a rocky seashore. Even in wild conditions, the PHATS team is bringing cell culture into the field!

Link to article: https://www.nature.com/articles/s41598-017-06037-x

Or read the summary here on this site.

Behaviour 2017’s fantastic closing dinner party, complete with a live band featuring 6 ukuleles!

I have now returned from an incredibly successful week at Behaviour 2017 (link), and what a spectacular conference it was! The sheer variety of science that people were talking about was incredible and inspiring, plus I got a great response to both my symposium talk on seal oxytocin and the poster I presented on aggression. I meet so many wonderful people, heard lots of interesting talks and I even managed to avoid getting roasted in the blazing Portuguese sun! I had never previously been to a behaviour conference of any kind, but this one has really encouraged me to keep an eye out for future ASAB meetings to present at. Huge thanks to the lovely people working as part of the SoHaPi research group for inviting me to speak at your symposium, I look forward to meeting up with you all in the future!

Taking the stage at Behaviour 2017 to talk about my work on oxytocin in wild seals

More good news was waiting for me when I arrived home from Portugal; our PHATS team leader, Dr Kimberley Bennett, let us know that the first paper the PHATS team have worked on was coming out at last! This paper details our work investigating whether an explant approach (basically blobs of many living cells) would work for culturing fat (or adipose) cells collected from wild animal species in field conditions. Additionally, we wanted to know whether we could manipulate the explants during culture to

100mg explants of adipose tissue weighed out and ready for transfer to culture plates for their 24 hour exposures to different treatments on the Isle of May, Scotland.

uncover the physiological consequences of changes in the nutrients or hormones the cells have access to. We found we could not only keep our cells alive once collected from wild seals on the coast of Scotland, but once transported back to the lab we could culture the cell explants for at least 24 hours. During this time we could expose the adipose cells to different treatments, such as high glucose concentrations in the cell culture media (the sugary, salty goo that cells are suspended in during culture to keep them alive) or difference hormone additions, such as hydrocortisone. We found significant differences in the metabolic profiles of adipose cells given different treatments, demonstrating this technique could be used to test the responses of wild animal tissue to a variety of substrates an individual may physiologically generate, or be exposed to.

Studying wildlife physiology is always challenging because collecting samples is tricky, typically giving small samples sizes in less than ideal conditions for complex labwork. However our work to bring cell culture techniques to the wild regions of Scotland shows that even difficult processes like cell culture, which require sterile conditions, aseptic technique and specialised equipment, are possible with thought and preparation beforehand. Studying cell function in wild animals is important as how different tissues function in response to different environmental challenges will impact on how individuals survive. Fat tissue is especially crucial for survival as it represents the energy stores animals have to rely on when conditions are tough, and also helps keep individuals warm in cold environments. By understanding how fat tissue functions, we can better understand why different species in changing environments can either adapt to meet new energetic challenges or be overwhelmed by them.

Even in muddy, windy or wet conditions, cell culture experiments can be possible if you are careful! (grey seal mothers and pups on the Isle of May, Scotland)

Speaking of ‘the wild regions of Scotland’, it’s that time of year when I start prepping all the field equipment for the PHATS team’s annual research trip to the Isle of May grey seal breeding colony, off the east coast of Scotland. Join us here for our fieldwork blog, bringing you all the adventures we have running a tissue culture lab on an island full of seals. We are scheduled to leave in late October, and will stay on the island studying the seals for about 2 months, heading home just in time for Christmas (hopefully!). I’ve also got two more conferences to attend before I go off into the field, one in September in Nottingham, UK with the British Society for Neuroendocrinology and one in October in Halifax, Canada with the Society for Marine Mammalogy. If you are going to either and want to say hello I look forward to meeting you there!

Weaned grey seal pups occupying the path down to Kirkhaven harbour on the Isle of May, Scotland

Attending Behaviour 2017 and other upcoming conferences

Hear about all the hormone, behaviour and adipose tissue function work I’ve done with seals at any of the three conferences I’m attending this year!

I’m going to Behaviour 2017 in Portugal next week!

Conference information: link

I’m going to be talking about my work on oxytocin and maternal and social behaviour in grey seals on monday afternoon, plus I’m presenting a poster on the development of aggressivness in seal pups on wednesday and thursday.

Symposium talk: Syposium 1 on Monday 31st July at 17:35 – 18:05

The symposium is titled ‘How Social Behaviour can impact individual health and fitness’. It will feature talks looking at how social living can impact on a range of aspects of an individual’s physiology, and the potential fitness costs and benefits associated with them. The talks cover primate species, fish and of course seals in my case!

Poster: Poster 278, Wed + Thurs, 2nd-3rd August 14:00 – 16:00

If you’re going to the conference and would like to find out more about my work it would be great to meet you there!

Please do say hello if you would like to talk to me about my research, my crazy ginger hair usually make me easy to find!

I’m also attending two other conferences this year, one to (hopefully) talk about my oxytocin work and the other to talk about the tissue culture work I’ve done

(TBC) Oxytocin work – 10th – 12th September
British Society for Neuroendocrinology, Nottingham (conference site: link)

Tissue Culture work – 22nd – 27th October
22nd Marine Mammal Biennial, Canada (conference site: link)
“An explant approach to understand adipose tissue function; metabolic profiles of blubber tissue differs between tissue depth, cell culture conditions and energetic state.”

So if you are attending either of these conferences you can catch me there too!

Safe travels!

New Publication – IV oxytocin causes pro-social behaviour in seals

Grey seals on the Isle of May, Scotland. Staying together is important for mother-infant pairs, especially on a dangerous seal colony.

Link to article: http://rspb.royalsocietypublishing.org/content/284/1855/20170554

Or read the summary here on this site.

This week has turned out to be a hectic but good one, I’ve returned from the University of Liege just in time for my next paper to be published in the Proceedings of the Royal Society B. The paper comes from the research in my NERC funded PhD with the Sea Mammal Research Unit, University of St Andrews on the hormone oxytocin and its impacts on social and maternal behaviour, rather than the pollutant research I’m currently doing with the PHATS team. Like much of my work, the study was done with weaned grey seal pups on the Isle of May, and involved giving the seals specially designed doses of oxytocin to see what (if any) social behaviours the hormone affected.

There have been lots of studies that show certain behaviours are linked to oxytocin concentrations (including some of my own grey seal work!), but the problem with correlations is that you have no idea which side of the relationship is driving things. For example, it would be impossible to tell using only correlations whether increased social behaviours are causing high oxytocin levels, or high oxytocin levels are triggering more social behaviours. Understanding causality in such hormone-behaviour relationships is important so you can identify the ‘cause’ and the ‘effect’ within the correlation. It can be difficult to do outside of laboratory settings however, as the only way to test for causality is to either increase the hormone’s concentration in an individual via manipulations or knock out the functionality of the hormone using antagonists. Due to these difficulties, there is only one study (apart from the one I published today) that has ever given oxytocin to wild individuals, and while they did find changes in pro-social behaviours they had no prior knowledge of the natural oxytocin-behaviour systems in their study animals.

We know high oxytocin grey seal mothers stay closer to their pups, but does the hormone cause the behaviour or does being near to their pup for more time cause greater oxytocin release?

In our study we were testing whether oxytocin triggers individuals to stay close to each other, as we know from grey seal mothers that the higher their oxytocin concentrations, the more time they spend close to their pups. We gave oxytocin and saline (control) treatments to weaned grey seals that had never previously met, and recorded their behaviours after the treatments. We found that oxytocin not only triggered individuals that had never met before to spend more time together, but also reduced aggression between the two and the amount the seals investigated each other, an indication of familiarity. This makes our study the first to verify a naturally existing oxytocin-behaviour relationship in wild individuals, which is very exciting. Studies like this have been done in captivity using domestic, laboratory or zoo animals but it’s crucial to study behaviour and physiology in natural settings with wild individuals, as no matter how hard you try you will never truly re-create all the complex aspects of wild environments in a captive setting.

Weaned grey seal pups associating on the Isle of May, Scotland

The treatments were all given intravenously (IV), as the more common, intranasal route of oxytocin manipulation was not possible with the weaned seal pups; they can close their nostrils and hold their breath for a long time! The success of this route of administering the manipulation means that other animal species, that may not be suitable for intranasal manipulations, could potentially have similar studies done on them in the future to help us understand more about oxytocin’s important role in bonding and behaviour. We also spent considerable effort designing the oxytocin dose given to the seals to be as low as possible while still having a behavioural affect. Many doses used in the scientific literature are much higher than natural concentrations, and there are concerns that generating high levels in study individuals could trigger behaviours that would never naturally happen, or have unexpected, and unwanted, side effects.

Weaned grey seal pups having a disagreement on the Isle of May. Reduction of aggression between familiar individuals happens naturally without oxytocin release in seals, but manipulations also trigger this behavioural change with seals that are complete strangers.

Despite the effort we went to in replicating natural oxytocin concentrations as much as possible for our study, the treatments still triggered some behaviours that are not naturally correlated to oxytocin release in seals. Low aggression and reduction of investigative behaviours are indications that seals recognise each other, and naturally occur after several days of living together, independently of oxytocin release. The behavioural changes in our study seals also unexpectedly persisted for several days, long after the dose would have been metabolised and broken down in the bloodstream. These unexpected effects show that we still have a lot to learn about oxytocin’s role in the formation and maintenance of social and parental bonds. If the hormone is going to be used to safely and successfully treat human psychological conditions such as schizophrenia, autism spectrum disorders and post traumatic stress disorder (and there have already been clinical oxytocin trials for such conditions in human subjects), then more research is needed into the powerful effects oxytocin can have on our behaviour and neurobiology.

Weaned grey seal pup on the Isle of May.

Liege 2017 – A brief introduction to blubber tissue

Minced blubber biopsies in cells ready to be capped and put through accelerated solvent extraction, to obtain all the lipids from a samples for further analysis.
Weighing a ASE vial after ASE is finished and the solvent has been evapourated off to calculate lipid mass in the sample. This is from one of Foxtrot’s biopsies from last year, and it had 0.42g of lipid in it, meaning 80% of the original biopsy was fat.

Well my first week at the University of Liege working with CART has flown by, and I’ve been working on the blubber biopsies we collected from the grey seals last year on the Isle of May. All the lipids (fats) need to be extracted from the blubber tissue before we can move forward with the pollutant analysis, so all the samples must be carefully prepared and put through Accelerated Solvent Extraction (ASE). This process uses high pressure and temperature conditions plus chemicals called solvents (like hexane and acetone) to remove all the lipids from the sample in the cells. This process gives us a completely liquid solution of lipids and solvents at the end of it, and we can then evaporate the solvent to leave just the lipids from our sample. This step is important as it gives the lipid mass of our sample, and allows us to work out how many nanograms of pollutant per gram of lipid in our sample there is (ng/g) . While ASE of our samples is an important step in the lab work, there isn’t really much more to say about it so I’m going to use the rest of the blog this week to give a brief introduction to blubber tissue, a crucial part of the anatomy of all marine mammal species worldwide.

Blubber tissue enables marine mammals to endure cold aquatic environments, like this Orca family living off the coast of Iceland.

All marine mammals, from the largest whale to the smallest seal, have a layer of fat underneath their skin called blubber. This layer of fat is extremely important for the survival of marine mammals for two reasons:

  1. It enables them to keep warm (thermoregulate) in freezing oceans.
  2. It provides a store of energy for individuals to utilise when they are not feeding, which happens in many marine mammal species at various points throughout their lives due to breeding or moulting.
A blubber biopsy from one of our seals. Blubber samples for pollutant analysis must be stored in glass or wrapped in foil to prevent loss of pollutants from the sample to any plastic they come into contact with.

Fat tissue deposits in all animal species perform these same two functions, however other species frequently have additional ways to thermoregulate (such as fur in land mammals) or do not endure long periods of fasting repeatedly while migrating or breeding as many marine mammals do. The importance of this tissue has lead to substantial blubber thickness evolving in marine mammals, and a stratified structure throughout the depth of the tissue is present so that it can perform both functions at the same time. Typically, blubber tissue can be roughly divided into three sections as you go from the part closest to the skin (the outer blubber) to the part closest to the inside of the seal (the inner blubber). The inner blubber is the most metabolically active, and this is where lipids are mobilised to provide energy for an individual when it either cannot find food or is purposefully fasting. The mid blubber is the most variable in thickness across individual marine mammals, and in thin individuals can be completely absent. It is thought it acts as a more long term storage tissue, and that its thickness is influenced by seasonal food availability. The outer blubber is typically of stable thickness within a species regardless of the nutritional state of an individual, and is thought to be primarily for thermoregulation. Hence even starving individuals will always have some blubber tissue to keep them from freezing, as the outer blubber is not mobilised as an energetic resource.

Blubber is a fascinating tissue to study and several different approaches can be used to analyse it in many contexts, like this recent study by one of my friends, Joanna Kershaw, who measured the hormone cortisol in blubber from porpoises to validate it’s use as a biomarker of body condition. The PHATS project I work on uses both established techniques (investigating pollutant concentrations) and novel protocols (the explant approach for tissue culture experiments that our team leader pioneered in seals) to make the most of the blubber samples we collect from our study animals to explore the prevalence of persistent organic pollutants in the marine environment and it’s impact on energy balance in seals.

A particulary tubby looking Charlie from last year’s study group on the Isle of May. Her fat reserves in her blubber layer will help her survive the tough first year at sea she faces when leaving the breeding colony.

MEANWHILE I am settling back into Liege life quite happily outside of the lab. I am not staying in the university accomodation this year, and have a lovely little flat not far from the campus to retreat to. In my time away from the lab I’m trying to keep up with the usual paper and grant writting that all resarchers need to keep on top of, plus greatly enjoying bebing reunited with the amazing macaroons they make here! Seriously, why can’t they be this good in Scotland…

Happiness is macaroons =D

PHATS project progress, ELISA validations and my return to Liege

Moulting grey seals hauled out on the Isle of May
Remember please send all ringed shag sightings to shags@ceh.ac.uk

Welcome back to my corner of the internet and the PHATS blog! The first four months of 2017 have flown by as the team has headed back into their labs to analyse all the samples we collected over the winter on the Isle of May grey seal breeding colony (to read about our fieldwork adventures, see these blogs here). I was lucky enough to escape to perform a survey of the Isle of May in January, to see if there were any grey seals that were moulting early in the year. There were plenty of them as it turned out, which bodes well for the fieldwork we are planning next year to try and look at moulting seal physiology. The island already looks so different to how it was when the seals breed there in the winter, much greener and all the seabirds are starting to come back. The cliffs were lined with guillemots, razorbills and shags; some were even getting started on gathering nesting material. The puffins had not returned yet, they arrive later in the year closer to summer, but we did see a few on the water during the boat crossing to the island.

Large grey seal haul out on the North East coast of the Isle of May
Is there anything better than well organised samples?

Inside the lab, I’ve been working on biochemical analysis of the cell culture media from all the blubber sample experiments last year (see here for more info) and am now two thirds through the samples we generated. By measuring the metabolic profiles of the various blubber culture experiments, we can see if the pollutant or hormone treatments had any impact on the blubber cells we collected from the seals. I’m also working on validating ELISAs (Enzyme-linked immunosorbent assays) to detect a variety of hormones in the blood samples we collected from the seals last year, so we can see if an individual’s hormone profiles are linked to their pollutant burden.

Using ELISAs on wild animal species like grey seals can be tricky, as they use antibodies as part of a binding process to detect the hormone you are interested in. These antibodies will have come from a specific species of mammal, usually rodent or domestic animal species that lots of scientists study, and the company making the ELISA kit will provide a list of species they know the kit works with. As a hormone’s protein structure is not always the same in different species of animals, the antibodies used in a widely available ELISA kit may not react properly with samples from unusual species that has never been tested with that kit before. Unfortunately seals often fall into the ‘unusual’ category, so we need to test the kits (validate them) before we use them to run lots of our samples, to make sure the results we are getting from the kits are accurate. There are several things to check when validating an ELISA, some of the most important are:

  1. Test for linearity. By diluting some of your samples (e.g. to half the concentration, then a quarter, then an eighth etc) you can make a serial dilution series to run on the kit. You can then see whether the curve the dilution series produces is parallel to the standard curve, which is what the kit uses to determine hormone concentrations. If the curve is not parallel to the standard curve, then the hormone in your samples is not binding correctly to the kit components.
  2. Test for recovery. By spiking a sample with a known quantity of the hormone you are interested in studying, you can tell how much the kit is detecting and how much is ‘lost’ during the analysis process.
  3. Test for consistency across kits and within kits. Many studies have lots of samples and need to use more than one kit to analyse them all. You must make sure the results of one kit are comparable to the others (inter-assay coefficient of variance), and the easiest way to do this is to run the same sample on each kit you use. You can then calculate the coefficient of variance across all the kits you have run. It’s also important to check the kit’s internal consistency (intra-assay coefficient of variance) by running one sample multiple times on a plate and seeing how similar the results are, and by running all samples in duplicate on the kit.

Our seal blood samples are proving to be rather tricky currently, and we’re still working on which are the best kits to use to measure the hormones we are interested in. The biochemistry analysis is going very well though, and we’re all looking forward to having some data to play with in the coming months.

Two ELISA plates at different stages of incubation. The different intensities of colour indicate different concentrations of hormone.

The biochemistry and ELISA work I’m doing is currently on hold however, as I have returned to the University of Liege in Belgium to work with the Centre de Recherche Analytique et Technologique (CART) to detect the amounts of persistent organic pollutants (POPs) in the blubber of our study seals from the Isle of May last year. We will be using Gas Chromatography – Mass Spectrometry (GC-MS) again, which requires a lengthy extraction and clean up process before the blubber tissue can be analysed (see these blogs from last year for more details) so I will be here for a month to work on our samples (and I will update the blog every week while I am visiting CART). It is always interesting, and more than a little sad, to find out how many pollutants all the seals have inside them after we got to know so well during the field season…

Unfortunately Alpha and Kilo, like all young marine mammals, will have large concentrations of POPs in their tissue from the high fat milk they drink from their mothers.

Isle of May 2016 – Goodbye to the Island!

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A curious weaner watches us load up the boat and leave the island

The time has come for the PHATS team to pack up and go home as almost all the grey seals have left the Isle of May and returned to sea. We have all got back to mainland safe and sound, and everyone is looking forward to some well earned rest after almost two months of fieldwork. All of our laboratory equipment and samples were packed up and shipped off the island without incident, and everything is now at our labs at Abertay University and the Sea Mammal Research Unit, ready for analysis in the new year.

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Walking down to meet the boat at sunrise, ready to leave the island yesterday morning

There were only nine of our study weaners still on the island during our last survey, and the majority of them are on the edges of the colony ready to go to sea. Oscar is still hanging out in his pool off the south end of the island, and Papa and X-ray have both made it to the bottom of the southern cliffs and are playing and dozing with a bunch of other weaners there. Hopefully they will all find their way out to sea and learn to forage and catch fish in the coming months. Even if they do survive their risky first year, it’s sadly unlikely that we’ll see them anytime soon on the island again. Grey seals usually don’t come back to breed for at least five years if they are female and even longer if they are male. If they do return to the colony however, we’ll be able to identify them from the number on their orange flipper tags, and if you see any seals with tags please do let us know so we can work out which of our study animals you saw.

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Papa (right foreground) with a gang of other weaners, ready to go to sea at the base of the south cliffs on the Isle of May

These kind of mark-recapture methods are used in all sorts of studies on many different animal species, which I was reminded of during the last weaner survey before we left. While searching the southern cliffs I came across a shag with a ring on its leg, which marks it as one of the study individuals the Centre for Ecology and Hydrology has captured, ringed and released back into the wild to help collect data on seabird population dynamics and behaviour. If you see a ringed shag (the leg rings can be several different colours, not just yellow with black writing like the one I saw below) please email the sighting information to shags@ceh.ac.uk and if you are interested in the project’s work then you can keep track of what is happening through their twitter feed @CEHseabirds. This particular bird was ringed as a chick in 2000 on the Isle of May, which makes her 16 years old and she has raised 26 chicks so far in her life (information courtesy of the Centre for Ecology and Hydrology).

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The shag I saw on the southern cliffs of the Isle of May, with ‘DDJ’ on her coloured leg band

The PHATS team will be back out in the field in January 2017, when we will return to the Isle of May to look for moulting grey seals. The majority of individuals will enter the moult later in the year at around March/April time, but there are always some seals that start early. We will resume blog updates then, so in the meantime we all wish you Merry Christmas, a Happy New Year and hopefully see you in 2017!

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Goodbye for now… grey seals hauled out on the north eastern shore of the island, with the Low Light, the Beacon and the Main Light above them.