By Will Bevan

This past month at UK Youth for Nature we have been celebrating our oceans and the incredible diversity of life which depends on them, including us. I have focused on birds as often overlooked inhabitants of the marine environment, heavily dependent on it as we are for food, the air we breathe, and the regulation of our climate. This time we complete our journey, finally arriving in the ‘High Seas’, the parts of our ocean beyond national jurisdiction which cover a staggering 50% of our planet’s surface area! Along the way we have discovered how a great wealth of bird species rely upon the UK’s coastlines and territorial waters all year round, including our overseas territories, and we have talked about how our country has a huge responsibility to protect globally important bird populations.

However, most of these birds are not just tied to one country but are international in their lifestyles. For example, almost the entire world population of Manx shearwaters (Puffinus puffinus) breed in the UK, but they only spend part of the year on our shores. From July to March they migrate and winter in the South Atlantic, mainly off the coasts of Brazil and Argentina. Even during the breeding season they can feed many hundreds of kilometres away if conditions are right, way beyond the national jurisdiction of any country. Whilst we can try to protect birds at their breeding grounds or within territorial waters, in order to ensure a stable future for all bird species this needs to happen in all of the areas which are important for them, including the High Seas.

What exactly are the ‘High Seas’?

The High Seas exist beyond national borders and are a global commons to be used collectively by all nations, although these international waters have been historically hard to govern. The United Nations Law of the Sea Convention (UNCLOS) tries to regulate specific activities within the High Seas, such as deep-sea mining and overexploitation of fish stocks, but only 1.2% is formally protected. Human rights abuses and illegal activity are rife, and where there is regulation or oversight it is in relation to resource extraction rather than ocean protection. Whilst there is no clear legal framework for the management and development of Marine Protected Areas (MPAs) in the High Seas, what is clear is that these vast and deep waters support an incredible amount of biodiversity, much of which we know hardly anything about!

Birds without borders

At one time the movements of birds throughout the oceans were a complete mystery, with anecdotal evidence of individuals seen by ships or washed ashore providing only small clues as to their movements. The development of ringing schemes began to enlighten us, with birds caught and given unique metal bands which allowed us to identify individuals if they were ever recaptured. It is the staggering pace of development in tracking technology within recent years however which has now given us unparalleled insights into their exact movements at sea, although we have still only scratched the surface.

For example, we now know that Manx shearwaters have a hugely complex migration pattern with many stopovers, travelling south from the UK along the coastlines of western Europe and Africa, eventually crossing over to South America, where they spend the winter in the highly productive waters (see Part 2) off the Patagonian Shelf. After wintering here they then head North, following the coast up to North America before crossing over the Atlantic and back to the UK for the breeding season. Though there is some variation to this route, a Manx shearwater which lived to 50 years old could have travelled around 8 million kilometres in its lifetime, which is roughly ten trips to the moon and back! Another astounding migration is made by one of our rarest breeding birds, the red-necked phalarope (Phalaropus lobatus), with only a handful of breeding pairs in Shetland and the Western Isles. In 2012 geolocators revealed that one male bird had left Shetland in August and crossed the Atlantic Ocean to Canada, from where it moved down to Florida, crossed the Gulf of Mexico into the Pacific Ocean, and spent winter between the Galapagos Islands and South America until April, when it returned by the same route.

In a comprehensive recent study, an international team of researchers found that some of the more extensively seafaring species, the albatrosses and large petrels, spend almost 40% of their lives in the High Seas – birds such as the Tristan albatross (Diomedea dabbenena), 99% of which breed on Gough Island, a British overseas territory. Though tied to the colony around the central South Atlantic during the breeding season, non-breeders move extensively throughout the southern oceans, using areas off of South America and South Africa, searching for locations with high ocean productivity where food is abundant. Incredibly, increasing evidence suggests that these birds – which belong to the ‘procellariformes’ or ‘tubenoses’ – may be able to smell their way across the oceans, using odours to pinpoint foraging locations and find their colonies.

The importance of a High Seas Treaty

Unfortunately for birds living extensively in the High Seas, this is a large proportion of their lives where they are even more vulnerable to threats such as being caught in fishing gear or losing food resources to overfishing, threats that are easier to deal with in territorial waters. Many of these species are therefore some of the most threatened, and whilst bilateral agreements exist between certain countries to protect birds which occur in their territorial waters, such as between Japan and Australia, the High Seas are the most important at-sea area overall for albatrosses and large petrels. Species breeding in the UK and its overseas territories have some of the strongest links to the High Seas, as well as to countries such as Brazil and Argentina. What is clear is that coordinated cooperation between the UK and other nations to protect birds both within territorial and international waters is the best chance we have of halting and even reversing the path to extinction.

In August of this year, the UN General Assembly will meet for the Intergovernmental Conference on Marine Biodiversity of Areas Beyond National Jurisdiction (BBNJ) to work on a treaty which will decide on the “…conservation and sustainable use of marine biological diversity of areas beyond national jurisdiction…”. This is a once in a generation chance to modernise governance of the High Seas with a strong treaty which can help to reach the target of 30% protection of the oceans by 2030. Proper protection of important marine areas for birds can help to regulate or even exclude fisheries with damaging practices which are one of the main reasons for the declines in albatrosses and large petrels. This, coupled with other measures such as the eradication of invasive predators decimating breeding colonies will allow populations to become much more resilient in the face of climate change, the effects of which we are already beginning to feel. Whilst it is too much to go into here, there are a lot of great resources explaining the High Seas Treaty and the desired outcomes by the High Seas Alliance and Greenpeace, for example.

We have come to the end of our journey for UK Youth for Nature’s oceans campaign, and I hope that I have managed to convey just how connected the fate of the birds which call our shores home are to the health and protection of the entire ocean, not just our own waters. Protecting the incredible abundance and variety of these species depends upon dealing with threats both where they breed and spend their time at sea, and I hope that future generations will be able to marvel at their incredible lifestyles as I do, as I hope now you will too.

By Will Bevan

In my last blog post for UK Youth for Nature’s oceans campaign, I looked at how our coasts are crucial in supporting a huge diversity of bird species all year round. This time I’ll be travelling further out into our territorial waters, to see how the fate of the seabirds which call our shores home are inextricably tied to the health of our oceans.

What do we mean by territorial waters?

The term ‘territorial waters’ is often used as a broad term to encompass the seas which are under the jurisdiction of a government. This includes the territorial sea, which extends 12 nautical miles from the coastline, and the Exclusive Economic Zone, which extends a further 200 nautical miles out – unless there is another country within these limits. In the UK’s territorial waters, the government has control over all economic activity including fishing, mining, and energy production. It also has a responsibility to protect the incredibly diverse wildlife which calls these waters home, to make sure that we are surrounded by thriving, healthy seas.

It might surprise you to find out that the UK has the fifth largest Exclusive Economic Zone in the world, as it is responsible for the waters surrounding its overseas territories as well. This includes such far flung places as South Georgia and the South Sandwich Islands, Saint Helena, Gough Island, Tristan de Cunha, and the Pitcairn Islands. These overseas territories hugely increase the UK’s influence over the oceans, as well as the wildlife it is responsible for – a responsibility which is shared with the local governments of these territories. This also vastly increases the number of seabird species which occur in waters under UK jurisdiction, giving us an even greater role on the world stage in protecting them. For example, these territories are home to a quarter of the world’s penguins and a third of the world’s breeding albatrosses!

Why are our territorial waters important for seabirds?

Most seabirds are hugely dependent on the ocean as a source of food and are drawn to ‘hotspots’ of high productivity where prey is more abundant. These ‘hotspots’ are especially important during the breeding season, as seabirds need to have plenty of nutritious food within close range of their colonies so that they can provide enough for their hungry, growing chicks. The distances and locations they travel to find food will vary depending on the species, and even between individual birds, but seabirds must be able to balance feeding their chicks with their own energy needs. If they cannot, the adults must prioritise their own survival over that of their chicks, opting to try again the next year. Therefore seabirds thrive and successfully raise chicks in colonies where they can access abundant, reliable sources of food that they can travel to without exhausting themselves completely. The seas around the UK are highly productive, and this combined with the wide range of suitable habitats along our coastlines support the huge numbers and diversity of seabirds which live here. This is also true for UK overseas territories, with places like Gough Island supporting large colonies of breeding seabirds, including endangered sooty albatrosses, Atlantic yellow-nosed albatrosses, and the critically endangered Tristan albatross.

The availability of prey can be influenced by numerous factors which often interact in complex ways, such as ocean temperature, ocean currents, the topography of the seabed, and the time of year. Seabirds must time their breeding efforts for when conditions are just right and there will be plenty of food to raise their young. This means that their populations are highly sensitive to any changes in the marine environment that might affect how much prey there is, where it will be, and when it is around.

Our territorial waters are not just important during the breeding season, with some seabirds staying through the winter months whilst others disperse out into the open ocean or migrate to other shores. The birds that stay need to be able to find food to sustain them through the cold winter months, and whilst they are not tied to feeding their chicks at the colonies, stormy weather can rapidly deplete energy supplies and affect their ability to feed, with exhausted birds dying from hunger and exposure. These seabird ‘wrecks’ can be particularly bad in some years, such as in 2014, when thousands of dead birds washed up on our shores. Bad weather in winter can also have knock on effects in the breeding season, with storms in late winter and early spring influencing the ability of seabirds to get in prime condition for courtship and the demands of raising young.

Threats in our waters

What is clear is that seabirds require healthy, biodiverse, and productive oceans in order to give them the best chance of breeding and surviving all year round, and we therefore have a responsibility to ensure that this is the case where we have jurisdiction. However, some of our internationally important populations of seabirds, such as northern fulmars, European shags, Arctic skuas, and black-legged kittiwakes are declining alarmingly.For other species the picture is mixed, with Atlantic puffins doing poorly in places like Shetland and the Isle of May in the Northeast but faring better at Skomer and Skokholm Islands in Wales. Whilst the causes are often unclear as to exactly why these trends are occurring, with complex interactions between multiple stressors, we can identify some key factors in these declines:

Climate change

Warming oceans are affecting the availability of some prey species, such as sandeels, which are heavily relied on by birds like puffins and kittiwakes during the breeding season as a source of plentiful, nutritious food. Climate change is also increasing the incidence of severe storms, resulting in more seabird ‘wrecks’. The European shag is suffering this fate, being a coastal species which does not venture far from its colonies and having plumage which is not as waterproof as other seabirds it finds it difficult to escape bad weather and is therefore more susceptible to death by exposure. Climate change is going to be difficult to deal with, but the best way to ensure resilience against it is to deal effectively with other threats, such as overfishing, which are easier to deal with.

Overfishing

Commercial fisheries, especially those which target specific species, can be devastating for seabird populations which rely on these species. For example, in Scotland, commercial sandeel fisheries were found to be creating food shortages for kittiwakes by depriving them of this crucial resource during the breeding season. In this case, a seasonal ban was introduced on fishing during this time, demonstrating that we can act accordingly when we understand the causes of declines, although food shortages are still an issue as a result of climate change. Overfishing is also thought to have contributed to the decline of naturally nesting populations of Herring gulls, combined with changes in fisheries practices such as a reduction in discards, and this species has started to find more reliable food sources in our towns and cities. Over exploitation of fisheries is also happening in overseas territories, with populations of sooty terns on Ascension Island plummeting as a result.

We can deal with overfishing and other damaging economic activities by introducing bans and limits at certain times or year or by creating Marine Protected Areas (MPA’s). However, whilst nearly a quarter of the territorial waters around the UK are designated MPA’s, this is often in name only, with harmful activities such as fishing, bottom trawling and dredging still allowed. We therefore need immediate strengthening of these protections.

Fisheries bycatch

Like many other marine animals, such as dolphins, sharks, and turtles, seabirds can end up being killed unintentionally by fishing vessels. Birds such as albatrosses are particularly vulnerable, getting caught on the baited hooks of longline fishing vessels and being dragged underwater, for example. Whilst progress is being made in reducing bycatch by developing new technologies, increased monitoring, and education, dealing with this problem requires international cooperation as these species often roam large distances through the territorial waters of multiple nations.

Invasive species

Though not strictly a marine problem, invasive alien species such as mice, rats, and cats are a massive problem for seabirds, with chicks and incubating birds often helpless against predation, and they can decimate populations on some islands. Removal of invasive species will be one of the most effective ways to prevent seabird declines across many colonies, with restoration projects such as the one currently being undertaken on Gough Island hopefully improving their prospects. On Lundy Island in the Bristol Channel, rats were eradicated in 2006, and since then the seabird population has more than trebled, proving the effectiveness of dealing with this threat.

Pollution

Oil pollution can ruin the waterproofing of seabirds feathers, affecting feeding and thermoregulation and eventually resulting in death by exposure. Plastic pollution is a growing menace, within many species consuming large amounts of plastic and feeding it to their chicks. To them, as well as looking like food, plastic can also even smell like food, picking up a compound called dimethyl sulphide which is usually given off by some microorganisms when they break down, such as when they are being eaten. The seabirds can use this smell to detect prey which are eating the microorganisms, an amazing instinct which is unfortunately resulting in many deaths when birds eat the wrong things. Whilst plastic pollution is not a major cause of population declines at the moment, more and more plastic enters the oceans every day and production keeps increasing, and so it is vital to curb this threat now.

Next time, join me for the final part of this series, where I will be looking at the ‘High Seas’, the oceans beyond national jurisdiction which cover around 50% of the planet! Here there is often a crucial lack of protection for seabirds, with some species spending a large proportion of their time in these waters. The threats I touched on in this article are often much worse in the high seas, where there is usually no oversight, monitoring, or legal protection. I’ll be looking in depth at this overlooked part of our oceans and show that in order to halt drastic seabird declines, the UK needs to be a key player in the upcoming negotiations for a ‘High Seas Treaty’, which will ensure a legally binding commitment to conservation and sustainable development in areas beyond national jurisdiction.