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 – 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.

Isle of May 2016 – Goodbye to the Island!

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

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

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

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

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

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

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

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

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

Isle of May 2016 – A lover or a fighter? Male mating tactics and the end of the field season is nigh…

Grey seals fighting
Male grey seals fighting for access to females on the Isle of May

Thus far in this blog I’ve mostly focused on talking about the grey seal mothers and pups which live on the breeding colony here on the Isle of May. The PHATS project only involves collecting data from mothers and pups at various ages, hence I’ve somewhat ignored the other occupants of the colony up to now. However, the other individuals on the colony show plenty of interesting behvaiours too, so this particular blog is going to be about the male grey seals that live on the Isle of May at this time of year, waiting to try to compete for opertunities to mate with the females.

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A male grey seal (right) with two females with pups on the Isle of May. Male grey seals are not significantly larger than the females like in some other pinniped species.

Male mating tactics in species of pinnipeds (seals and sea lions) tend to depend on how sexually dimorphic (differences in size or external features like horns between males and females) the species is and the type of habitat they breed in. Some pinniped species, such as elephant seals, have males that are much larger than the females of their species. This facilitates establishing a territory on a breeding colony that contains as many females within it as possible, defending it from rival males and keeping lots of females inside. These huge males will fight any other males that intrude in the territory to prevent them from entering and mating with the females within. Other pinniped species that breed on ice in the north and south poles of the world use physical features like breathing holes to define where males establish territories, like Weddell seals in Antarctica. Male Weddell seals are a similar size to their female counterparts and use complex vocal displays underwater to defend their territories around breathing holes rather than physically fighting with other males.

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Some pinniped species are highly sexually dimorphic in terms of body size, this is a male New Zeland fur seal which can be three to five times larger than the females.

Grey seal males show a variety of mating strategies on and around breeding colonies. Males in this species are not much bigger than the females, so creating and guarding large groups of females to mate with (a harem) is not possible. Some males do establish loosely defined territories across various areas of the breeding colonies, but these do not seem to be anchored to physcial features or resources in the colony. The males that compete to stay within the colony amongst the females are called as tenured males and they typically the largest males on the colony, fasting to hold their position in the colony for as long as they physically can before they must return to sea to feed. However, there are alternative mating strategies that males can use to gain opportunities to access receptive females, including intercepting females that are returning to sea when leaving the breeding colony and mating with females at sea. Some male grey seals do return to sea and engage in  shallow and deep diving behaviour during the breeding season, but whether these can be attributed to feeding, displaying to attract mates or aquatic mating with females is not currently know. Therefore there seems to be a variety of mating strategies that individual male grey seals can employ on breeding colonies to gain access to females, and future research will hopefully help us understand which are the most successful and how selection pressures have encouraged the development of the different mating tactics.

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Being big and winning fights is not the only way for grey seals males to win access to breeding females, but it’s frequently the most conspicuous!
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Delta playing in a tidal pool, the next time the tide comes in he will go out to sea with the receding tide.

The PHATS research project is almost complete as the end of the field season is quickly approaching. We only have two samples left to collect, then we will pack up and head off the island just in time for Christmas! Over half our study weaners have now gone to sea, there are only 13 left on the island. The oldest remaining seal is India at 49 days old, but we still have some fairly young weaners like Eel (not in the phonetic alphabet I know but we always run out of alphabet and have to start giving study weaners name codes like AA, BB, CC… and Eel is EE!) who is only 26 days old and still over 50kg. She could hang around the island for quite a long time with all that blubber mass, we have known weaners to remain on the colony for over a month after weaning.

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Eel checking me out. She is massive at over 50kg!
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Oscar in a tidal pool, meeting other weaners and learning how to swim before the tide comes in and he goes to sea.

Sadly, while doing the daily colony survey to find our study weaners I also found a weaner that had plastic wrapped around his neck. I managed to deprive him of his  ‘necklace’ and he swam off into a pool without serious harm, but it’s a sad reminder of how abundant marine litter is, and how it can cause deadly problems for marine life around our shores. Please be aware of your litter, whether you are on the coast or anywhere outdoors as many speices of creatures can end up trapped or eating the things we throw away, causing severe health problems that they frequently cannot alleviate by themselves.

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Marine litter causes significant health problems, and death, for many kinds of marine life from birds, to turtles to marine mammals. Please pick up your trash and dispose of it properly when you are by the sea!

MEANWHILE Away from the colony,we had some visitors for the day this week as some people from Scottish Natural Heritage came out to the island to prepare for the field station closing down for the winter. There are people living on the island almost every month of the year as bird researchers come out in the spring and stay studying the birds until early october, then the seal researchers move in until mid December. However, between December and spring there are a few weeks when no one is living and working at the field station so everything had to be cleaned, packed away and locked up against the winter storms. It was nice to see some new faces after 2 months of seclusion and everyone had a great day despite the choppy sea conditions getting to and from the island!

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The SNH guys leaving the island after their visit, hopefully the trip back was drier than the trip out!

The island has also become noticeably more noisy in the last week as the cliffs have become covered in sea birds returning from offshore early to roost. We currently have lots of guillemots

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Noisy fulmars on the Isle of May cliffs

and fulmars on the cliffs and it is lovely to see some more life on the island, especially now there are so few seals around. With the seals departing, and our project coming to an end this year, we will likely be leaving the island in the next week to head home. Going back to mainland after a few months away from society is always a little strange, but everyone is looking forward to seeing their loved ones (and getting regular showers again!).

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Fulmar in flight around the cliffs, the strong winds around the island provide excellent opertunities to watch the fulmars soaring around, looking for roosting sites.

Isle of May 2016 – Late season births and Charlie goes to sea!

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Grey seal mother with her newborn pup on the Isle of May, taken this week.

Even though it’s december and the vast majority of the seals on the Isle of May breeding colony have already raised their pups and returned to the sea, we are still seeing a few newborn pups from mothers that are late season breeders. Most of the colony is quiet now as the majority of adult females have gone, leaving their weaned pups (weaners) in their 2-3 week post-weaning fast (see this blog for more details about the post-weaning fast in seal pups).

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Things are all quiet now it’s late season, just lots and lots of weaners playing and dozing everywhere!

We don’t really know why some females give birth so late in the season, but doing so tends to have a big impact on how likely they are to raise their pups to weaning, with late season mothers typically having lower pupping success than early season mothers. While there are very few adult females on the colony, and therefore less problems with aggressive neighboring females, there are still plenty of adult males around looking to mate. The ratio of females to males on the colony changes through out the breeding season, and goes from lots of females to every male in the early season to at least one male per female late in the season, if not more. This means that a female trying to raise a pup in the late season has to deal with a lot more male harassment than the females in the early part of the season, and as a result she spends less time nursing and caring for her pup. There is also evidence that females breeding in the late part of the season are younger and therefore are more inexperienced mothers, but what age females start to transition to become early season breeders, if they do at all, is still a mystery, especially as most of our study mothers seem to give birth exactly the same time each year, to the day in some cases.

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Male harassment can be a big problem for grey seal mothers trying to raise a pup

Back at the PHATS lab, things are starting to wind down. We had to ship all the samples we had generated so far from the cell culture experiments off the island this week as we had filled the minus 80 freezer on the island! The tissue, media and blood samples we’ve collected over the last 6 weeks will give us plenty to study back on the mainland in the new year. Our daily surveys of the study weaners have shown that two of our weaners, Charlie and Alpha, have left the island and gone to sea! Charlie was 35 days old when she left the colony, and Alpha was 43 days old. Some of our study weaners don’t seem very keen to go, both Bravo and Delta are 43 days old and still happily playing around on the island! Some of our seals are making their way through the colony and the rocky tidal region of the shore towards sea, like Foxtrot who is 40 days old and is on the southern edge of the island.

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Delta playing around in a pool
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Foxtrot in amongst the rocks of the southern edge of the island
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Bye everyone!

MEANWHILE the research team on the island has dropped to just 4 people as half the team left the island this week to return home, the remaining two researchers from the Durham University seal behaviour team and two research assistants from the Sea Mammal Research Unit of St Andrews. We also were lucky enought to be visited by one of the bird researchers from the Center for Ecology and Hydrology again, as they keep track of the ringed sea birds (shags) on the island during the winter. During this visit they caught and ringed a wild short-eared owl and were kind enought to show us before they released her, beautiful!

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Short eared owl that was ringed on the Isle of May, just before release

 

Isle of May 2016 – Go to sea or stay and play? Weaner dilemmas

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PHATS team photo! From left to right, Holly Armstrong (research assistant), Dr Kimberley Bennett (team leader) and myself (research fellow) all geared up for an afternoon of studying seals on the Isle of May.

It’s currently my favourite time of year on grey seal breeding colonies, when the  weaned pups (weaners) start to out number the adults on the island. I do enjoy watching the huge variety of behaviour the adults display, from the caring maternal behaviour mothers exhibit to the impressive battles males fight for access to females, but the weaners are without a doubt my favourite. This is because they typically spend several weeks on the island after weaning in a post-weaning fast, where they stay on the breeding colony despite there being no food for them, and they usually spend this time playing and exploring their surroundings. They can be very curious, and some will even come right up to you when you’re hiding in the colony to see what you are, play with youre belongings or even fall asleep on you!

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While hiding amongst the stone walled parts of the Isle of May to survey the seals, you can get unexpected visitors at this time of year!

Post weaning fasts are common in Phocid (true seal) seal species around the world, from the huge elephant seals to the two species we get in the UK, grey and harbour seals. No one really knows conclusively why weaners stay on the breeding colony for several weeks after their mothers wean them, although there are lots of theories. Grey seal pups can lose half a kilogram of mass every day they remain on the colony after weaning, and as having large amounts of blubber increases the chances that the pup will survive it’s first year of life, it seems very strange that pups stay on the island rather than go to sea to learn to forage and catch fish. However, there is evidence that during the post weaning fast, pups undergo physiological changes which prepare them for going to sea for the first time, so they can hold their breath and perform deep dives so they can catch fish successfully. In grey seal pups, the amount of oxygen they can store in their blood increases during the post weaning fast due to changes in the volume of blood they have and its components, with increases in substances such as hemoglobin that bind oxygen. The more oxygen a pup can store in it’s blood before it dives, the longer it can hold it’s breath and forage underwater, and in theory the more successful at catching fish it will be.

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Going to sea and learning to survive there is a crucial step in a weaner’s life, but one with many difficulties and dangers.

There are still many unanswered questions about the post weaning fast phocid seal pups go through and what happens once weaners leave the colony for the first time. To try and answer some of these questions, one of the senior scientists (Dr Sean Twiss of Durham University) here on the Isle of May is currently looking for a PhD student to investigate “Patterns of individual variation in post-weaning behvaiour in wild grey seals“, and the project is being co-supervised by my boss, PHATS team leader Dr Kimberley Bennett of Abertay University! The deadline for applicants is the 20th January 2017, and if you are interested, the details of the project and how to apply are found here. Whoever gets the PhD will get to come out to the Isle of May next year and will meet me and the rest of the PHATS team! Matt Carter of Plymouth University, another PhD student that Dr Bennett co-supervises, is also currently investigating the development of foraging behaviour in pups leaving breeding colonies, so hopefully in the coming years we will gain a much better understanding of the factors driving weaner behaviour before and after they go to sea for the first time.

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Charlie is getting leaner as she loses blubber during her post weaning fast, which has been 17 days long so far, and at 35 days old she may go to sea soon and leave the island.
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Our CO2 incubator filled with plates of blubber tissue explants for our pollutant work.

In the lab here on the island the PHATS project is just over halfway to completion this year. As it gets later in the breeding season we are getting more and more study weaners to keep an eye on, although some of the first weaners that we included in our study are approaching the time when they may go to sea for the first time, at about a month of age. Charlie is now 35 days old and much leaner than when she first weaned from her mother 17 days ago, having lost 9.6kg across those 17 days. This seems like a lot, but considering she put on 22.2kg of blubber in the 18 days she was with her mother, she is still large enough to successfully go to sea. Kilo has now fully moulted and has a very distinct pattern of spots that we can identify him from. We also have a new study weaner (Oscar) that has moulted and turned out to be completely black!

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Oscar, one of our latest study weaners.
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Kilo, now fully moulted with spotty fur, playing with the plant life on the island

MEANWHILE away from the colony, it briefly got a little bit harder to escape from the seals as a female came right up outside our doorstep with her pup for the first time! She has thankfully moved on a little further from the house so we don’t disturb her, but it was a suprise to open the door one morning and find the pair of them staring at us!

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Suprise! A grey seal mother has never had a pup right by the house before on the Isle of May

Sadly two members of the research team here have had to leave the island in the last week, Dr Twiss and Dr Bennett both had to return to the mainland to resume their teaching duties at their universities. They will be missed, and it marks the beginning of the end of the field season as the majority of the researchers here will also leave in the coming week. The PHATS team will stick it out until mid December, but it’s always sad to see people go!

Finally if you’d like to see Dr Bennett talking about seals or the PHATS project, she will be giving some public presentations in the coming weeks in Scotland:

6pm, Tuesday the 13th December at the D’Arcy Thompson Zoology museum at Dundee University: Public talk on seal biology

10.00-16.30, Wednesday the 14th December in the Ninth Scottish Symposium on Environmental Analytical Chemistry at the Dalhousie Building, Dundee University: presentation of persistent organic pollutant findings from the PHATS project

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Dr Bennett and Dr Twiss setting off from Altarstanes to return home.

Isle of May 2016 – Pup survival 101: get fat fast, lose your fluff, find some fish

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PHATS study pups Foxtrot (in the background) and Golf (in the foreground), both at different stages of moulting their white baby fur.

As it gets later into the breeding season here on the Isle of May, more and more of the grey seal mothers are weaning their pups and returning to sea to fish. Grey seals, like most species of true seals (called ‘phocids‘, including all earless seals), have one of the shortest dependant periods (the time the infant has to stay with the mother to survive) of all mammals, just 18 days. After that, mothers leave the colony and it’s up to the pups to look after themselves. Left to their own devices, newly weaned pups (called ‘weaners‘) soon find their way out of the colony or into nooks and crannies out of the way of the adult seals where they can rest and play, moulting their white baby fur (called lanugo) so they are ready to go to sea for the first time.

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A fully moulted grey seal ‘weaner’ on the Donna Nook breeding colony in Lincolnshire.

Moulting pups are usually much larger than when they were born despite only being 18 days old. Grey seal mothers produce milk with such a high fat content that pups can put on over 1.5kg a day in blubber tissue. Pups that are born at just over 10kg can therefore easily reach over 40kg in mass at weaning, and for seal pups the fatter they are at weaning the better as it means they are more likely to survive their first year of life. During their first year, a weaner’s body composition will dramatically change and they will go from the fat, round shape like in the above photo to a leaner look, like the yearling in the picture below. As a juvenile, a grey seal’s body composition is only about 12% fat of its total mass, a huge difference to the 45% fat individuals can have as weaners. These big changes in body composition are completely natural for the seals, but it means that it is vital for their fat tissue to function correctly both when they are rapidly generating blubber or mobilising it when they don’t have any food. That’s why the PHATS team are investigating whether the high persistent organic pollutant (POPs) burden that all marine mammals have in their blubber tissue is disrupting the seal’s ability to generate and utilise their fat reserves.

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A lean yearling grey seal on the coast of North Rona, Scotland

We now have 12 study weaners this year, all named after the phonetic alphabet as their identifying code in our project is a single letter. The largest of our pups is Lima, a male weighing 54kg! I introduced you to Charlie in the last blog when she had just weaned from her mother and still had lots of lanugo covering her body, she’s changed a lot in the last week! She’s moulted completely now and has really pale fur with subtle spots.

Charlie now she has fully moulted, these spotty patterns will stay the same on her fur for her entire life.

The other weaners in our study vary from pups that are almost completely covered in lanugo to fully moulted, and its interesting seeing the different patterns the weaners have hiding under their white baby fur. Here are some more introductions to our new study weaners, you can see Foxtrot (female) and Golf (male) in the photo at the top of the blog, and below are pictures of Alpha (male), the oldest pup in our study, and Kilo (male) snuggled up together and Delta (male) playing around with his flippers.

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Alpha (left) and Kilo (right) interacting
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Delta playing around
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The super moon the night after it was at its largest

MEANWHILE away from the seals, we were all very keen to see the super moon, unfortunately the weather on the island did not co-operate and we didn’t get to see it in it’s full glory. We did all manage to see it before the sun rose the following morning and the next night, which was still very impressive!

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The high tides from the super moon submerging the pier at Kirkhaven harbour on the island.

Even though we didn’t get to see the super moon properly, we still felt it’s impact as we had huge tides on the island, and all the seals near the coast found the ocean encroaching where it doesn’t normally reach! The resulted in lots of seal pups getting swimming lessons with worried mothers in tow, and even some underwater nursing attempts.

Sadly it’s getting to the time in the season where some of the team have to think about leaving the island, including our team leader Dr Kimberley Bennett who has to go back to the Abertay University to continue teaching. It’s likely Holly and I will stay on the island until mid December to complete our work on the weaners, so we’ll be getting to know them very well in the coming weeks!

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A grey seal mother trying to feed her pup during the high tides generated by the super moon