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 – Goodbye to Liege and Conference plans

Lipids extracts from our seal blubber samples, ready for organochloride pesticide (OCP) analysis.

Just like that, my time at the University of Liege has finished and I’m back at the Sea Mammal Research Unit in Scotland. I was successful in preparing all our grey seal blubber samples for analysis, and now we just need to wait for the results from the Gas Chromatography – Mass Spectrometry (GC-MS)

The spectacular Liege Guillemins railway station, waiting for my ride home!

machines. We will hopefully get all our results by July, and in the meantime I will get back to the bichemical analysis of the samples from the tissue culture experiments on the Isle of May last year. My last few days in Liege flew by, a whirl of labwork, tasty Belgian fries and one last trip to Masion du Peket to enjoy their delicious drinks!

 

Weaned grey seal pups interacting on the Isle of May

We’re not just focusing on labwork here on the PHATS team however. We’ve been working hard on analysing our data and are now ready to start getting our science out there! We’ll hopefully be attending conferences this year to present our findings, and if you are interested in our work do come and find us at the below venues. I will also hopefully be presenting some of my work on the hormone oxytocin and it’s affects on bonding, social and maternal behaviour in seals. While the blog will be on hiatus until we return to the field in October, we will update it when we attend or present at conferences, or if we publish any papers on our work so watch this space!

Upcoming conferences:

30th July – 4th August: Behaviour 2017 (ASAB summer meeting & 35th International Ethological Conference)

22nd – 27th October: 22nd Biennial Conference on the Biology of Marine Mammals (Society for Marine Mammology)

Study seals Alpha, Kilo and Hotel on the Isle of May, 2016

 

Liege 2017 – PCBs, PBDEs and OCPs

Samples undergoing acid purification and agitation for OCP analysis

My last week at the University of Liege has arrived, and I’m working hard to ensure that all the PHATS team’s labwork is complete before I leave to return home. All of our samples are now ready for analysis that will let us detect PCB and PBDE levels in our Scottish grey seals. PCBs and PBDEs are two types of the many persistent organic pollutants (POPs) that are present in our environment. I am currently working on preparing our samples for another type of analysis that will enable us to detect a third kind,  OCPs. As POPs in our environment, and PCBs in particular, are still currently in the news after the recent revelation of just how highly contaminated with PCBs some marine mammals are becoming, I thought I’d spend this blog introducing the three types of POP I work on and why they are so problematic.

Samples after acid purification, showing the clear fraction I need to collect for OCP analysis

PCBs, or polychlorinated biphenyls, are pollutants that are made up of two linked rings of carbon atoms with a varying number of hydrogen and chlorine atoms bound to the rings at different positions. There are many possible combinations of the number and locations of the hydrogen and chlorine atoms binding to the rings, and these give rise to the large variety of PCBs (called congeners) that exist. Approximately 130 different types of PCB are found in commercial products, and they can be divided into two groups (dioxin-like and non-dioxin-like) based on their structure and toxicity.  PCB production was banned in the USA in 1979 and by the Stockholm convention (signed by over 150 countries worldwide) in 2001, however they persist in our environment due to their slow degradation rates. One of the main reasons PCBs were previously manufactured and used in industry was their inert properties; only incineration at high temperatures can safely destroy them. Previous uses of PCBs include in coolants and lubricating oils, paints and electric wire coatings.

Orca have some of the highest measured POP concentrations in an organism worldwide due to their high position in the food chain.

PBDEs, or Polybrominated diphenyl ethers, are also made up of two carbon rings, but they have bromine bound to the rings rather than chlorine. The fewer the bromine atoms per molecule of PBDE, the more dangerous they are considered to be as congeners with between 1-5 bromine atoms bioaccumulate more effectively in living organisms. PBDEs are still being manufactured and widely used in many man-made products, the Stockholme convention which banned PCBs only restricted the production of some PBDEs. Some states in the USA have begun prohibiting their manufacture and use in the last decade however. PBDEs are flame retardant and are therefore commonly incorporated into electronics, plastics, fabrics and other building materials.

Bald eagles severely declined in the mid 20th centuary until the ban on DDT use in the USA. Bioaccumulation of the pesticide up the food chain affected the formation of their eggs, leading to thin shells that broke under the weight of an adult incubating them.

OCPs, or organochlorine pesticides, contain carbon, hydrogen and at least one bound chlorine atom but do not contain carbon ring structures like PCBs and PBDEs. There are many different types of OCP, however arguably the most well known is DDT (Dichlorodiphenyltrichloroethane) which was heavily used as a pesticide across the world to kill insects for both agricultural and disease control purposes. The famous book ‘Silent Spring’, written by Rachel Carson in the 1960s, is all about OCPs and the negative impact overuse of pesticides has on the environment. The production and use of some OCPs like DDT and heptachlor has been strictly limited by the Stockholme convention. Due to their efficiency at killing insects, their use is still permitted in some circumstances, such as the use of DDT to control mosquitoes that carry diseases like malaria.

POPs have been connected to a wide range of negative health impacts in both people and wildlife, and chronic exposure to any type of POP will cause problems for any organism. All POPs are carcinogenic (cancer causing) and are potent endocrine disruptors, interfering with growth and development, immune function and reproductive systems. There is growing evidence that POPs impact on obesity, leading them to be labelled as ‘obesogens’. The PHATS project I am part of is hoping to uncover some of the underlying physiological and genetic mechanisms that influence fat tissue function and determine how POPs can interfere with these processes. By studying a marine mammal species which has lots of fat and lots of bioaccumulated POPs, we can gain a better understanding of how these chemicals have such far reaching and devastating impacts on our health and the environment.

One of the PHATS team study animals from the Isle of May 2016, ‘Mike’, a newly weaned grey seal pup. Even though she is only a month old, ‘Mike’ will likely have high concentrations of POPs in her tissue due to the high position in the food chain (trophic level) seals occupy in the UK and the fact that mothers pass a large proportion of their accumulated pollutants onto their infants via their milk.

Liege 2017 – PCBs in the news, the most contaminated whale in the world

Purification columns being prepared with hexane for the lipid extracts from our blubber samples to be added.

It’s been another busy week here in chemistry labs at the University of Liege. I’ve completed extracting all the PHATS team’s blubber samples for persistent organic pollutant (POP) analysis, and now am moving on to the purification part of the sample preparation process. I’ve only got two weeks left to get all the sample preparation completed, so hopefully all the lab work will go according to plan! The purification process isn’t too complicated but it does have lots of time consuming steps, from multiple standard spikes, to acid clean-up on columns, to concentrating the samples down via nitrogen evaporation. So it’s just a case of getting your head down and getting on with it all, as the sooner it’s done the sooner we’ll have some interesting results to look through.

Purification columns, with samples from Echo to Kilo undergoing acid clean up. You can see how ‘dirty’ the samples are from the brown/black sludge that builds up in the columns!

The results of POP studies are frequently worrying as well as interesting. A good example of this happened last week, when the Scottish Marine Animal Stranding Scheme (SMASS) got some lab results back showing the PCB concentrations in one of the stranded whales they had examined last year, ‘Lulu’, one of Scotland’s few resident orca. She sadly had one of the highest ever recorded concentrations of PCBs in her body, and there are concerns that the other members of her pod will have similarly high levels. Another interesting (and sad) aspect of Lulu’s case is that she had never produced a calf, despite the fact she was about 20 years old and orca usually have their first calves at around 14 years of age. It is well known that POPs negatively impact on individual health, including fertility, therefore it is possible Lulu failed to reproduce due to her high pollutant burden. Even more concerning however, is what might have happened to Lulu’s high PCB concentrations if she had produced a calf.

Orca pod with young calves. The females will unwittingly pass large proportions of their pollutant burden to their infants, meanwhile males will steadily accumulate POPs all their lives.

Female marine mammals pass approximately 60% of certain types of the pollutants they have accumulated in their blubber to their first calf, some passing through the placenta but the majority transferring via the fat rich milk marine mammals produce. Therefore, if Lulu had produced a calf, it also could have had one of the highest PCB burdens ever recorded in a marine mammal. Male marine mammals typically have much higher POP concentrations than adult females due to this phenomenon, although even male orca in populations considered to be ‘highly contaminated’ (251.2mg/kg) have far lower concentrations than Lulu did (957mg/kg). This sex pattern in pollutant concentrations is present throughout all marine mammals, and after first reproduction an adult female’s POP concentration will gradually decrease with each infant she produces. This means that infant marine mammals are typically exposed to dangerously high concentrations of POPs as soon as they are born. Interestingly, in the two marine mammal species that appear to show menopause (orca and short-finned pilot whale), upon reproductive senescence a female’s POP concentrations begin to increase once again.

Humpback whale eating sand eels off the coast of North America. POP concentrations in fish eating marine mammals are usually lower than those that eat other marine mammal species to survive, but are also effected by how industrialised the environment where they forage is.

Another major cause of patterns in POP concentrations in marine mammals is their position in the food chain (their trophic level) and the region they obtain their food from. Orca represent a fascinating opportunity to study these patterns as through-out the species, there are different populations that specialise in eating either fish or other marine mammals, or in other words different orca populations can occupy different tropic levels of a food chain. Groups that eat marine mammals, such as seals, sea lions and porpoises, typically have over double the concentrations of POPs in them than fish eating groups. This happens because the pollutants have become concentrated up the food chain due to bioaccumulation, where a predator eating lots of smaller prey gets all the pollutants in each individual it eats. A whale eating lots of seals to survive will accumulate all the pollutants all the seals were exposed to, and all the pollutants all the fish those seals ate too. Meanwhile a fish eating individual will ‘only’ accumulate the pollutants from the fish it eats. Additionally, individuals that hunt in highly industrialised areas have higher concentrations than those in ‘pristine’ areas, because the more POPs that are in a local area, the higher the concentrations in all the organisms from the bottom of the food chain to the top.

Studying patterns of POP concentrations in different types of individuals can therefore lead to a better understanding of how these persistent pollutants ‘move’ through organisms and can be transferred into later generations. It is not hard to see why POPs continue to be a problem for animal and human health, despite being banned decades ago.