New publication – Oxytocin in Dolphins

Link to article: here

Download the paper for free until the 9th January: here

Or read the abstract on this site here

Bottlenose dolphin mother with a young calf in Scotland

I spend a lot of my time working on a hormone called oxytocin, it’s fascinating to study as it can act on many different kinds of social and parental behaviours in all kinds of animals (see this amazing reveiw for more information). However, most of the research done on the hormone so far is on laboratory animals, or captive individuals in zoos, and little is known about how the hormone functions in completely natural environments and populations. I have been trying to change this with my work on oxytocin in breeding grey seals here in Scotland, and I have also started to work on oxytocin in other wildlife species with the help of many wonderful collaborators. My new paper is all about the first of these new studies, where we detected oxytocin levels in a wild population of Bottlenose dolphins.

The aim of the study was to firstly see if it was possible to detect dolphin oxytocin, but also to see if there were any differences between age groups or different types of social groups. We worked with the Sarasota Dolphin Research Program (SDRP) in Florida, USA to collect samples from wild bottlenose dolphins over 3 years, and this enabled us to study adult males in breeding alliances, lone individuals and mothers with calves. The SDRP has studied the bottlenose dolphins living in and around Sarasota Bay since the 1970s and conducts occasional health checks on small portions of the population. This means that wild dolphins can be safely briefly captured so that measurements and samples can be collected, and any obvious injuries can be treated by vets. For example, one of the dolphins in our study had sting ray barbs in his head, which the vets were able to remove before he was released. The SDRP has enabled all kinds of research on dolphins to take place, from measuring aspects of their physiology to understanding dolphin cognitive abilities, and you can read more about the health checks and the research that comes from them on the SDRP website here.

Mother – calf pair of Bottlenose dolphins in Sarasota Bay, Florida. Photo courtesy of the Sarasota Dolphin Research Program, taken under NMFS Scientific Research Permit No. 20455

We found that we could use a test called an ‘enzyme linked immunosorbent assay’ or ELISA, to successfully detect dolphin oxytocin. By passing all the quality control checks to see if an ELISA is working properly with a new sample type, we know the values we are detecting are accurate and can be used in future studies. Most of the dolphins we studied had oxytocin levels that were comparable to other mammal species, and were relatively low. This surprisingly included the mothers that we sampled, in contrast to what we know about seal mothers who have high oxytocin levels up until they wean their pups. However, dolphin calves had much higher levels than other age classes, and these high levels were present across all ages that we studied (2-4 years old). Previous work on oxytocin in young mice, seals and humans have also showed that young infants have really high oxytocin levels compared to adults, but all these prior studies covered much shorter time frames (days or weeks). Our results suggest that the dolphin calves have elevated oxytocin levels for several years, covering the timeframe that they are still with their mothers.

This is important as oxytocin stimulates individuals to seek out and stay close to others that they share a bond with. Dolphin calves have to deal with regular separations from their mothers while they grow up, especially as mothers have to be able to shoot off in pursuit of prey while rearing calves. Previous studies indicate that dolphin calves must be able to cope with these separations or they will not survive, and that calves play an active role in reuniting with their mothers at sea. Elevated levels of oxytocin in this age class could be indicators of calves with strong bonds with their mothers and high motivation to re-unite with them when separated. In contrast, dolphin mothers may not have constantly elevated oxytocin because they must separate to successfully feed regularly. Continual hormonal stimulation for mothers to stay with a calf could therefore be completely inappropriate for this particular species. As dolphins have advanced cognitive and communication skills, oxytocin release in adults may instead be tied to specific signals from other individuals they share a bond with.

Bottlenose dolphins with a young calf in Scotland. One of the adults is likely the calf’s mother.

This study is just the first step in understanding how oxytocin works in socially complex dolphin species. It is important to understand hormone dynamics and how they impact on individual behaviour and survival as physiological mechanisms that act on these processes are often present across entire species. Oxytocin release and the behaviours this triggers to keep socially or maternally bonded individuals together can only happen if bonds can form in the first place. Bond formation relies on communication and interaction causing oxytocin release, often during critical time frames within an individual’s life. All wildlife species are facing increasing disturbance from human activities, and if individuals cannot form strong bonds or communicate to reinforce them via oxytocin release it could make life much harder for species that rely on group living like dolphins.

Many dolphin species have to live and rear their calves in areas that are increasingly disturbed by human activities, like this mother calf pair off the coast of a major tourist destination on Ibiza, Spain.

MEANWHILE: This month has been pretty hectic as I submitted my first ever fellowship application. Fingers crossed that my application will get to the interview stage, although the odds are low unfortunately with only about 1 in 10 applications being successful. In more positive news, I’ve also been working on the final version (aka the publisher proofs) of another oxytocin paper. This is a big review article that I worked on with a number of great oxytocin scientists. We met at a conference in 2018 and all work on different animal species to study various aspects of how the hormone works. We have joined forces and written a review about all the model animal species that have been used to study neuropeptide hormones. This should be out soon so watch this space!

Two New Publications – Pollutant levels in Scottish seals over 15 years and how these chemicals alter fat tissue function in seal pups.

Two weaned grey seal pups on the Isle of May, Scotland

Link to paper on pollutant patterns over 15 years in Scottish seals: link

Link to paper on how pollutants impact fat tissue function in seal pups: link

Or read the abstracts on this site here (pollutant levels over 15 years) and here (pollutant effects on fat tissue).

It has been a while since the last update about the PHATS team, which is led by Dr Kimberley Bennett at Abertay University, and in the time that has passed we have been busy finalising our lab work, analysing our results and of course, writing papers. We have published two studies since our previous PHATS blog about finishing our last field season on the Isle of May back in late 2017. One paper came out in October 2018 and the other came out last week as part of a special issue to celebrate the Sea Mammal Research Unit’s (SMRU) 40th birthday.

Our new paper is all about how some pollutants can stay in the environment for a very long time. We know that persistent organic pollutant (POP) concentrations fell dramatically after they were first banned decades ago. However, we know much less about pollutant trends in recent times. We compared persistent organic pollutant (POP) levels found in young seals on the Isle of May 15 years ago to the POP levels the PHATS team measured in young seals on the same island between 2015-2017. We found that there was an overall decrease in the amounts of some POPs, such as the total PCB concentrations if you add all the different types (or congeners) together. However, other types like DDT and its breakdown products had not significantly fallen over this timeframe. One complication that we found is that concentrations of some pollutant types are so low, it is difficult to detect small declines with certainty. It is clear that long term studies recording pollutant levels over many decades are needed to truly be able to say that these substances are decreasing, but such studies are very expensive, time consuming and take a long time before any results are seen. Despite this, monitoring these chemicals in the natural environment is really important, as even low concentrations of these pollutants can impact an individual’s physiology and health, which we demonstrated in our other paper…

Weaned grey seal pups on the Isle of May, ready to go to sea for the first time

Our other study (published in October last year) demonstrated how potentially disruptive pollutant effects can be, even at low concentrations. We studied blubber from the seal pups on the Isle of May and found that metabolic characteristics of the blubber was linked to the amount of POPs the seals had accumulated in their fat. These pups had been exposed to pollutants via their mother’s milk, which accumulates in their fat tissue. The seals cannot break down the POPs easily, which means concentrations inside the pups increase as they drink more milk, or as they eat more fish when they eventually go out to sea to hunt. We found out that POPs in the blubber are preventing the tissue from working correctly: the more PCBs a seal pup had in its blubber tissue, the less glucose was used by its fat cells. It is quite alarming that this is already happening in the seal pups, who have only been alive for a few weeks and have much lower levels than adult seals that have been eating fish and accumulating pollutants in their blubber their whole lives.

Visual abstract from our 2018 paper highlighting the main findings from the study, that higher PCB concentrations in seal pup blubber lead to decreases in glucose uptake rates

These two papers show us that POPs are still hanging around in the marine environment and the organisms that live there, and that even low concentrations can have significant impacts on the physiology of individuals. This might be especially important for young individuals, or for other vulnerable age groups. Currently we do not know what the potential health and energetic consequences of these changes to blubber function are, but they certainly are not helping the seal pups get the best start in life. It is really important for blubber tissue to function properly in all marine mammals, as they need a healthy blubber layer to keep them warm in the cold seas and to provide them with reserves to live off when they cannot find fish for a period of time. It is important to take into account the subtle negative effects of pollutant exposure when monitoring population dynamics and making conservation management plans, as anything that effects energy balance in individuals is likely to impact on their survival and their ability to breed. While we have found this result in grey seal pups, this problem is one that all marine mammals face as they all bioaccumulate POPs into their blubber across their lifetimes, with some of the highest concentrations occurring in top predators like killer whales. Hopefully researchers working on other marine mammals will be able to use our findings to help understand and better conserve their own study species. In fact, our work was recently included in a report made by Canadian Fisheries and Oceans exploring threats to the northern and southern resident killer whale populations.  We still have lots of data left to analyse from the PHATS project, so will continue to uncover the effects these pollutants are still having on grey seal, which will enable us to better understand the reasons some marine wildlife species are struggling to thrive.

Killer whale pod in Iceland. Killer whales have some of the highest POP levels in their blubber which could cause serious negative health consequences

Our paper on pollutants in seals was just one of the fascinating articles in the SMRU special issue. Check out the other amazing papers that were published there, including studies on monitoring grey seals, harbour seals and dolphins in the UK and further afield, research into how human activities are disturbing marine mammals physically and acoustically and novel ways to try and avoid this.

Scottish bottlenose dolphins in the Moray Firth Special Area of Conservation.

New publication – Oxytocin is linked to increased rates of mass gain in seal pups

Newly weaned grey seal pup with a very healthy blubber layer. Pups have to go from about 15kg to over 30kg in just 18 days to stand a chance of surviving their first year of life.

Link to article:

Download the paper for free until the 22nd October here:

Or read the abstract on this site here

It has been a while since the last blog update on this site (for a very good reason, but more on that later), and in the time that has passed the PHATS team has been busy finalising our lab work, analysing our results and of course, writing papers. I’ll be uploading a post soon about two papers on pollutants that the PHATS team have been published since the last update (or you can read one of the papers here, the other one is still in press!). But right now, I’m going to talk about my latest paper on the hormone oxytocin and mother-infant bonding, behaviour and development.

Grey seal mother-pup pair on the Isle of May, Scotland

This paper is the last to come from my NERC funded PhD work with the Sea Mammal Research Unit, University of St Andrews. During my PhD I collected lots of different types of information on the wild grey seals breeding on the Isle of May  and North Rona, two island colonies that I would visit for months at a time to study seals. I have previously published papers showing that the more oxytocin a mother has, the closer she stays to her pup and an experiment that showed that high oxytocin definitely causes seals to seek others out and stay close to them. However, I wanted to investigate what the oxytocin levels in young pups were like when they were still with their mothers, and if there were any interesting dynamics going on, whether there were any developmental consequences for the pups.

What I found out was very exciting. It turns out that mothers with high oxytocin levels produce pups with high oxytocin levels, and I think this is due to positive feedback loops being created in both the mother and pup once they have bonded. This happens because oxytocin is often released when someone interacts with another individual they are bonded to, and the high oxytocin levels created cause the individuals to stay close together, meaning they can be exposed to even more interactions and even more oxytocin release! This has been theorised to exist in mothers and infants before, and there is evidence that it happens in socially bonded individual, even between humans and their pet dogs! However, my study provided the first evidence that these positive loops exist in completely wild animal populations living in natural environments.

Oxytocin causes mothers and pups to stay close together on a breeding colony

The next step was to see if there were links between the oxytocin levels in pups and any of their growth characteristics before they weaned from their mothers. My data showed that there was a strong relationship between oxytocin and the rate that pups gain mass. The higher the level of oxytocin, the more mass a pup gained ever day it was with its mother. While this was exciting, there might have been a straightforward reason for this, that the pups with high oxytocin are motivated to interact more with their mothers, which includes drinking milk from them. Seals have very fat rich milk, so the more a pup drinks, the more mass it will gain per day. However, I had already studied the impacts of oxytocin on the behaviour of mother-pup pairs, and found no relationship between high oxytocin and the frequency or duration of time pups spend drinking milk. Could it be true that the high oxytocin pups were somehow gaining more mass without drinking more milk? Luckily there was another way to test if this was happening, by analysing the mass change rates of the mothers.

Grey seal mothers don’t eat anything while they are on a breeding colony raising their pups. They have to build up a big fatty blubber layer throughout the year and rely on this energy store while they are on the breeding colony. The time that mother grey seals spend rearing their pups is short to help them cope with this, mothers and pups are only together for 18 days before weaning happens and the mother goes back to sea for some well-earned fish. However, this puts an incredible energetic strain on these poor seal mothers, they have to give birth, produce high fat milk and look after their pups all without eating anything. So, as seal mothers will usually loose a large amount of body mass over the 18 days they are rearing their pups, I could use the mass loss rates of the mothers in my study to see if the ones with these high oxytocin pups were losing mass at a faster rates. This would indicate they were producing more milk, or higher fat milk, for their pups to drink, causing increase mass gain in their pups. However, when I analysed the data there was no link between oxytocin levels and mass loss in the mothers. Somehow, the high oxytocin pups are able to gain more mass without any additional strain on their mothers.

Grey seal mothers are usually large and fat when they give birth (left), and newborn pups only have a thin layer of blubber under their skin. By the time pups are approaching weaning on day 18 after birth, they need to have put on a lot of weight, causing the mothers to deplete their blubber stores to generate fat rich milk for them (right).

There are a few potential explanations for the high mass gain rates I found in the high oxytocin pups. Firstly, we know that oxytocin affects behaviour and seal pups with high oxytocin are likely motivated to stay snuggled up to their mothers. This could help them save energy in two ways, firstly the pups would not be wandering around the colony, burning energy and getting into trouble with neighbouring seals. Secondly, pups that spend more time close to their mothers may be more sheltered from weather conditions, meaning they wouldn’t have to use as much energy keeping warm on the cold, wet Scottish breeding colonies. Both of these potential explanations demonstrate that, rather than putting on more mass per day, these high oxytocin pups may actually be reducing activities that divert energy away from putting on mass.

A heavy rain storm approaches the seal breeding colony on North Rona. Strong winds and wet conditions are common on Scottish seal colonies. All the white dots on the island are seal pups, resting beside their mothers.

There are also potential physiological explanations for the increased rates of mass gain in pups. A few laboratory studies have shown that oxytocin can act on development, with elevated oxytocin increasing fat tissue, impacting on muscle development and bone mass accumulation. Several studies have already proposed the physiological mechanism by which oxytocin can alter mass changes regardless of the food an individual is eating. It is possible then, that the high levels of oxytocin in the pups is altering their physical development and giving the pups a good start in life by helping them put on weight as fast as possible.

Any factor that helps seal pups put on weight is really important. The likelihood a seal pup will survive its first harsh year at sea, learning to survive in the wild, is directly tied to how fat it managed to get while still with its mother. But a seal mother cannot just pour all their resources into one pup, as the energy she uses up during one breeding season negatively impacts on how she will cope with rearing subsequent pups. So this relationship between oxytocin and mass gain rates in pups may be important, as it would enable pups to get as big as possible before weaning without getting seal mothers to invest more energy in rearing them.

Yearling grey seals on the Isle of May in the summer. Surviving their first year at sea is tough for young seals.

It’s not just seals that would benefit from this hormone-development link in infants either. Oxytocin, or oxytocin like peptides, are present in every vertebrate animal group and their function is remarkably similar across all these different species. Infancy is a crucial time, and in all species, gaining mass and developing physically is vital for offspring to survive. In humans alone, problems with infant nutrition and development are estimated to cause 45% of deaths in children under five and if we can better understand the physiology underlying weight gain in infants, we have a better chance at developing ways to help those that are sadly failing to thrive. This work so far has shown that oxytocin release may connect optimal parental or social environments with direct advantages for infant development, which could be important for different fields of biological, medical and veterinary science, and I’m hoping to keep working on this phenomenon in the coming years.

The positive oxytocin feedback loop system in grey seal mother-pup pairs and the energetic dynamics in both individuals (from Robinson et al. 2019, Psychoneuroendocrinology, vol 110).

MEANWHILE I’ve had a baby! This is the reason that there haven’t been any updates for so long, I’ve been busy being a parent. I am still working on the PHATS project and my other research looking at oxytocin and social behaviour in mammals, but everything takes a lot longer now! I did get to go and present some of our findings at the Society of Experimental Biology conference in Seville over the summer, and we all had a great time making new science friends, hearing about amazing research and enjoying the Spanish sun. My daughter took the conference in her stride and I must say that the SEB were wonderfully supportive of me being there with a young baby. I will be writing another blog post soon about my great first experience going to a conference as a mother, especially as there are plenty of other conferences that are not doing such a good job and all the things the SEB did would work in other places. Being able to go to meetings like this makes such a difference to parents trying to get back into their careers after having a baby, so it is important for societies to include things like breastfeeding rooms and childcare options when they are planning conferences.

In the meantime, I will be working on more publications from the PHATS project and my oxytocin work plus grant applications so I can continue my research, so wish me luck and watch this space (or twitter) for updates!

My daughter enjoying her first conference and flying the flag for the PHATS team!

Isle of May 2017 – Goodbye to the island… for now!

Time for the PHATS team to say goodbye to the Isle of May for 2017

Once again the time for the PHATS team to leave the Isle of May has come round, and this year the field season has absolutely flown by. As sad as it is to leave, we’ve had an incredibly successful time on the island and collected all the data that we were hoping to gather, which is great as this will be the last breeding season we have to work on before the PHATS project ends in August. I’m already back on the mainland as earlier in the week I brought off all the samples we collected to make sure they were safely transferred to Abertay University without getting defrosted, and the last three members of the team will be coming home tomorrow.

The Lady of the Lake in 2017 on Fluke street, her spotty pelage pattern clearly visable
The Lady of the lake in 2016 with her pup, right outside our front door!

The colony has emptied over the last week and there are hardly any weaned seals left anymore, let alone adults. We did get to see a familiar seal face during December however, as one particular female seal came up beside our house on the island to rear her pup last year, and this year she did exactly the same! Known affectionately as the ‘Lady of the Lake’ due to her habit of going for a swim in the reservoir at the end of Fluke street (where our house is), she is a particularly laid back seal who has successfully raised two pups in that location over the last two years. We don’t know why she decided to come up the road to raise her pup so far away from the other seals, but now she’s been here for two years it would be interesting to see if she continues to return to that spot in the future, or if other female seals followed her example. How breeding seals form new colonies and why some parts of the island are really dense with seals while other parts are empty are all a mystery currently so we can’t really guess what is motivating her to chose such an unusual location to rear her pup. When studying the seals on the island, we often have to look for flipper tags to recognise them, but as grey seals have stable spotty patterns on their fur you can also use that to identify the same individual every year, if you have a picture of them. This is how we know the ‘Lady’ is the same seal, and such photo ID methods are pretty common in the marine mammal world to repeatedly identify individuals in the wild.

Flipper tags, like this orange one on a yearling in a tidal pool on the Isle of May, can help you identify individual seals, but reading them can be tricky!

This is sadly the last large field season for the PHATS team, as our project grant is coming to an end in the summer of 2018. We will be working hard in the lab and at our desks analysing and writting up all of our data into new publications about the seals and POPs, and we will update the blog when we have new discoveries to share with you. In the meantime we all wish you Merry Christmas, a Happy New Year and hopefully see you in 2018!

Me working on the seal colony during november, the busy time for the breeding season.

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.


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).


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:

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!