This was by far the most important episode of the series. I am sure that many viewers were troubled by the scale of some of the issues touched upon in the programme; as biological scientists, we live in this state of concern perpetually, both professionally and personally. I tend to see a disconnect amongst the public, that the world we inhabit in our cities and towns are independent of ecological relationships that existed before humans, and now around humans, particularly when it comes to ocean life. In reality, this is not the case. Humans inhabit a unique ecological niche in the history of life on Earth, in that we are the only superpredators ever to regularly predate on the adult forms of other apex predators, in every environment on Earth. There has been talk of considering the era of humans a new geological epoch, defined by extinction, climate change and a stratigraphic layer of plastic for the geologists of the future. Accepting these problems are happening, let alone confronting them, can be depressing. I can’t speak for everyone, but taking a step back, as a scientist, and thinking of these as an interesting series of problems to be understood, is at least how I have decided apply myself to it. Entire books and feature length films have been made on each of the ecological issues in this final episode, so I will only focus on overfishing.

Unlike life on land, which has been drastically modified by humans for as long as we have existed, ocean life has only become heavily exploited more recently (although setting a baseline can be contentious). We have thought of life in the ocean as this resource which will  never be exhausted. Marine biologists have learned in the last few decades that this is not the case. A high profile example is the cod fishery off of Newfoundland, Canada, which was a plentiful food source for 500 years, thought to be the most productive fishery in the world. As fishing technologies improved, more fish could be caught more efficiently and in less time. After regulation failed to curb declines, the cod population completely collapsed in the early 1990s, and has still not recovered. With such a large amount of large predatory cod absent from the ecosystem, a trophic cascade occurred, where smaller fish severely declined and zooplankton, seals and crabs exploded in population. Meanwhile, cod in this area rarely reach adulthood here anymore. Managing the fishery like a resource by considering only population size, and not complex life histories and other ecological relationships, lead to this economic and biological catastrophe.

The wild caught fish that we eat is wildlife, and they shouldn’t be glossed over with the same brush as I sometimes see. Different commercially available fish are as ecologically different to each other as songbirds are to tigers. Tunas for example are apex predators, and although eating tigers, sharks and lions is unusual in the Western world, tuna consumption is extremely widespread. Imagine feeding tiger meat to your cat. Some bluefin tuna can grow to the size of a small car and have endangered or critically endagnered IUCN conservation status (on the same level as the Bengal tiger and black rhinoceros) and yet are still available at most sushi restaurants. There is always talk of ‘dolphin friendly’ tuna, but tuna themselves require urgent conservation as well. Despite improved scientific method, commercial fish species continue to decline worldwide, and faster than estimated.

I am sometimes asked: as a concerned citizen, what can I do in the face of these problems? Honestly, there is no easy answer. Some of the things I would recommend have been suggested a thousand times before, but I will make a few suggestions anyway:

• Only buy what you need. One third of all food is thrown out without being consumed – enough to feed two billion people in a time when one billion are malnourished – a tremendous waste of resources, and your own money. The same applies for all products – for everything you can buy to be produced, finite resources have had to be mined, extensive packaging has been used and goods have been shipped around the world.
• Use less packaging and bottles. 3 billion one-use coffee cups are thrown away in the UK every year, and less than 1% are recycled. This is one cup thrown away in the UK for every person in North and South America, Europe and Africa combined. Get a water bottle, reusable shopping bags and a refillable coffee cup. And is a straw really needed? This is one of the easiest changes to make.
• If you are going to eat seafood, be aware of where it comes from, and what kind of animal you are actually eating. As a general rule, it is better to eat lower down the food chain – sardines, jellyfish and shellfish for instance, and pole and line caught fish minimises bycatch associated with longlines and the habitat destruction associated with trawls. None of this is confidential information – a quick search and you can find plenty of information from the Marine Conservation Society (they even have iOS and Android apps) about where different species come from and how they are caught.
• Similarly, different foods require different resources. As a general rule, a diet with the least amount of environmental impact consists primarily of fruits, vegetables and grains and little or no meat. And if you can, buy produce that has not travelled a long way – less air miles, and less wastage from spoilage during long transits. See video below.
• Above all else, understand these issues – to me, this takes away their overwhelming amorphous terror. Start by learning about the human species in context. I cannnot recommend Elizabeth Kolbert’s incredible Pulitzer-winning The Sixth Extinction  enough, as a highly readable introduction to the concept. She interviews scientists watching their life’s work go extinct, visits an island made of bleached coral on the Great Barrier Reef and talks about how perceptions take a generation or so to change. Those more interested in marine life specifically should try Callum Roberts’ The Unnatural History of the Sea, who meticulously ploughs through archaic records from early fishermen, pirates and explorers to set a new baseline for human impacts on the ocean.

Despite grave threats facing the ocean, life is remarkably resilient, and where beneficial alternatives are provided, there are success stories. Despite resistance from the fishing industry, no-take zones like those in New Zealand have proved highly successful at restoring fully mature fish and species not seen in decades, protecting biodiversity and then being available for fishing as well. For us, the four-year Blue Belt plan aims to protect 4 million square kilometres of marine habitat, an area larger than India, across 7 UK Overseas Territories. Ultimately, getting business to prioritise conservation, and large scale international cooperation on legislation are ultimate goals, but these large scale changes always begin with small groups of scientist, campaigners and passionate citizens. Some of this has come from our university. If you can convince your place of work to waste less food or use less plastic, then why not do it? You can also go here to check if your local MP is on board with the Blue Belt plan, and contact them to tell them to vote in its favour. As a country with the fifth largest area of marine habitat in its jurisdiction, having this go through UK parliament would be globally significant.

The public engagement from this new Blue Planet series has been extremely heartening. It was so popular in China that it slowed down the internet there, and is the third most watched series of the last five years. I look forward to seeing what people inspired by the series will do in the future.

Feel free to ask me any further questions on Twitter @kieranyes.

The post Blue Planet 2 | Episode 7 | Our Blue Planet appeared first on Exploring our Oceans .

But the expedition also provided an opportunity to collect data about the environment – in particular, the temperature and salinity of water at different depths. Whenever we explore the oceans, I think it’s important to collect all the data we can, especially when we’re visiting remote places such as the poles and the deep ocean.

The environmental changes taking place in the Antarctic are complex – an intricate interplay between ocean, atmosphere, land ice and sea ice – with different Antarctic regions changing in different ways (e.g. Steig et al., 2009). It’s not a simple story of “more carbon dioxide traps more heat in the atmosphere that then melts the ice” (the changes in the Arctic are perhaps more straightforward in that regard, as this summary by David Shukman, BBC News Science Editor, explains).

That’s why thousands of scientists have been investigating different aspects of what’s happening in Antarctic over decades, to untangle the complex knot of processes involved.  And as well as interacting with each other, the strands of that knot (ocean, atmosphere, land ice, sea ice) are also affected by natural variability (e.g. Mulvaney et al., 2012), can sometimes be influenced by changes elsewhere on our planet such as the equatorial Pacific (e.g. Ding et al., 2011), and by changes that we have made to the atmosphere – not just adding carbon dioxide to it overall (e.g. Marshall et al., 2004; Goosse et al., 2008), but also through the depletion of the ozone layer above Antarctica affecting winds around the continent (e.g. Thompson & Solomon, 2002).

The complexity of what’s happening in the Antarctic is all the more reason to take every opportunity to collect more data points, like these during our expedition:

On their own, our measurements of ocean temperature and salinity at different depths during the Blue Planet II expedition don’t tell us much – of course you can’t really understand processes or measure changes from one set of measurements in one place at one time. But the expedition’s data are archived so that scientists can compare them with other measurements, taken at other times and in other locations and combined into large datasets by international research programmes, to help towards building a more detailed picture of what’s going on.

For Blue Planet II, we were working at the northern tip of the “Antarctic Peninsula”, the narrow finger of land that points up towards South America. What’s clear from previous studies is that this particular part of Antarctica has seen some rapid recent changes, such as:

• an overall increase of around 1.8 degrees C in annual average air temperatures since the late 1940s, recorded at Argentina’s Esperanza Base (data available here), which was the closest weather station to where we were working:

• …and that’s consistent with the general pattern of warmer annual average air temperatures recorded by other weather stations towards the tip of the Antarctic Peninsula over that period (Vaughan et al., 2003).  In the last few years some parts of the Peninsula have seen cooler summers again (Turner et al., 2016), possibly as a result of the regeneration of the ozone layer above Antarctica affecting the winds around it, but that doesn’t reverse the large surface air temperature increase in this region of Antarctica since the mid-twentieth century;
• Esperanza Base also holds the record for the warmest surface air temperature ever recorded in mainland Antarctica and its surrounding islands: 17.5 degrees C on 24 March 2015. That one-off warm day was probably caused by a “Foehn Wind” (which we’ll explore later);
• an increase of more than 1 degree C in summer sea surface temperatures around the tip of the Antarctic Peninsula since the 1960s (Meredith & King, 2005);
• the retreat of 88% of the glaciers on the Antarctic Peninsula since the 1940s (Cook et al., 2005; Cook et al., 2016), and the total collapse of floating ice shelves such as Larsen A in 1995 and Larsen B in 2002 (Cook & Vaughan, 2010).

Some of the changes on the Antarctic Peninsula may lie within the range of natural variations recorded in ice cores over the past 2000 years, but the recent warming is unusually rapid (Mulvaney et al., 2012). And the last time that any changes like these occurred, floating ice shelves such as Larsen B did not collapse (Domack et al., 2005), and there weren’t 7.6 billion of us who could be affected by what is going on. That’s what takes us into uncharted territory today.

Glaciers, floating ice shelves, and sea level rise

Sea level rise is one change that can affect us all, and it involves changes in the rate at which ice forms on land and flows into the ocean. Snow that falls on Antarctica eventually compresses under its own weight to form ice, building up ice sheets on the land. As more ice builds up, it flows out in glaciers and ice streams towards the coast, where it then floats out over the sea, forming the floating “tongues” of glaciers and more massive floating ice shelves. Eventually, the ice breaks off those floating tongues and shelves to form icebergs of fresh water, sometimes hundreds of metres thick.

The “calving” of icebergs from the ends of glaciers is a natural process, as the amount of snow falling on land gradually builds up more ice over time. During the Blue Planet II expedition, I was particularly interested in how that process delivers “dropstones” to the ocean floor – rocks scoured from the land by the glaciers and carried out to sea on the underside of icebergs, from which they fall to provide “islands” of rocky habitat for different types of animals on the seafloor.  Glaciologists can monitor numbers of icebergs and the flow of glaciers using satellites, but I also had an opportunity to make some closer observations of bergs from the air, to try to understand more about how they deliver dropstones that we saw on the ocean floor during dives.

But when it comes to sea level rise, what’s important is the rate at which ice flows from the land into the sea via this process. The floating ice shelves and floating ends of glaciers act as buttresses for the ice, slowing its slide into the ocean.  The buoyant force exerted by the ocean on the end of the floating “tongue” of a glacier, or across the front of a floating ice shelf, pushes back against the downhill flow of ice from the land.  If the floating glacier tongue or ice shelf becomes thinner, or retreats so that the “grounding line” where it starts to float out from the land is further inshore, then it offers less resistance to the flow of ice from land into the ocean (there’s a really good diagram explaining the forces involved here).

So if the floating “tongues” of glaciers or more massive floating ice shelves become thinner or disintegrate, then ice flows more rapidly from land into the sea. Because ice on land is not yet afloat, when it reaches the sea it pushes up the water level, like dropping ice cubes into a drink. In contrast, “sea ice” – the skin of ice only a few metres thick created when the surface of the ocean freezes – does not have the same effect on sea level, because it’s formed from water that is already in the ocean.  What matters then, for Antarctica’s role in sea level rise, is how the floating tongues of glaciers, floating ice shelves, and flow of ice from land to sea are changing.

Antarctica in three parts

Antarctica is huge: its land area (~14 million km²) is about 50 percent larger than the United States. To understand what’s going on for sea level rise, we need to divide Antarctic into three parts, because what’s happening is different in these regions:

• the Antarctic Peninsula, which is the narrow finger of land that points up towards South America (and we were working at the tip of the Peninsula for the Blue Planet II expedition);
• the area covered by West Antarctic Ice Sheet, and in particular the coastline on the Amundsen Sea where several glaciers drain that ice sheet into the ocean;
• the area covered by the much more massive East Antarctic Ice Sheet, which covers most of the interior of the continent and the South Pole.

Fortunately, there isn’t that much ice on land on the Antarctic Peninsula, where air and sea temperatures are changing the most, to drive much sea level rise from there. Further south, the West Antarctic Ice Sheet has the potential to drive much more, and some of its floating ice shelves are thinning and retreating, because of an upwelling of warm deep water. Meanwhile the enormous East Antarctic Ice Sheet fortunately appears stable, though one particular glacier outlet could be changing in ways similar to some of the glaciers draining the West Antarctic Ice Sheet.

Changes to glaciers draining into the sea on the Antarctic Peninsula

596 out of 674 (i.e. 88% of) sea-ending glaciers on the Antarctic Peninsula have retreated since records began in the 1940s (Cook et al., 2016), and 7 out of 12 of its floating ice shelves have retreated significantly or collapsed completely (Cook & Vaughan, 2010). The retreat of glaciers and floating ice shelves on the Antarctic Peninsula is driven by two different processes, one operating on each side of the Peninsula. On the western side, the floating ends of glaciers are mainly being eroded from underneath by an upwelling of warmer deep ocean water, rather than changes in air temperature. But on the eastern side of the Peninsula, more frequent warm winds create melt ponds that eat through floating ice shelves from above.

Most of the retreating glaciers of the Antarctic Peninsula are on its western side, along the coast of the Bellingshausen Sea, where there has been upwelling of warmer “Circumpolar Deep Water” to depths of 100-300 m (Cook et al., 2016). That upwelling of warmer deep water to melt those glacier tongues is a different process to the warming of sea surface temperatures further north on the Peninsula – and not a result of the warming air temperatures on the Peninsula either – but instead driven by changes in wind patterns around Antarctica that in turn drive some changes in ocean circulation (e.g. Peck et al., 2015).

Meanwhile, and in contrast, on the eastern side of the Antarctic Peninsula, the demise of the Larsen A floating ice shelf in 1995, and the Larsen B floating ice shelf in 2002, was probably hastened by warm Foehn winds, which cause melt ponds to form on the surface of floating ice shelves, eventually eating through them and breaking them up.

Foehn winds are warm winds created when a wind drops down the side of a mountain, compressing the air and thereby warming it. On the Antarctic Peninsula, circumpolar winds get pushed up against the western side of the mountains of the peninsula, and when they spill over the top or through gaps to the eastern side, they drop down and create the Foehn warming effect there, contributing to the break-up of floating ice shelves (Cape et al., 2015). There’s a useful BBC News feature about the phenomenon – and its effect on ice shelves on the eastern side of the Antarctic Peninsula – here.

(As an aside, the factors behind the huge iceberg that recently broke off the Larsen C ice shelf, and whether the remainder of that floating ice shelf will similarly collapse soon, are even more complex, as discussed here).

Immediately after Larsen B ice shelf collapsed in 2002, scientists measured an acceleration in the slide of ice from the land there into the sea, contributing to sea level rise (Rignot et al., 2004). Fortunately, the Antarctic Peninsula is only a narrow strip of land and there’s not so much ice on land there: if all the ice on the Antarctic Peninsula slid into the sea, it would raise global sea level by about 24 centimetres (Pritchard & Vaughan, 2007), and what really matters is how quickly that process happens.  To put that in context, the current rate of global sea level rise is about 3 millimetres per year, and ice loss from the Antarctic Peninsula is currently contributing around 0.16 mm per year to global sea level rise (Pritchard & Vaughan, 2007).

Changes to glaciers draining ice into the sea from the West Antarctic Ice Sheet

Further south, the Western Antarctic Ice Sheet contains much more ice locked up on land than on the Antarctic Peninsula, and changes in the much larger glaciers draining it into the Amundsen Sea (e.g. Pine Island Glacier and Thwaites Glacier) are the main concern here. If those glaciers fail as buttresses, the impact on sea level rise could be much greater than from the Antarctic Peninsula.

The West Antarctic Ice Sheet is also a “marine ice sheet”, which means that its base, although inland, actually lies below sea level.  This may make it particularly susceptible to a “runaway” effect if the ice shelves buttressing its flow into the ocean weaken, potentially allowing the ice that is currently inland to become afloat and thereby drive up sea levels substantially (Joughin & Alley, 2011).

The floating end of Pine Island Glacier already appears to be thinning and retreating (e.g. Wingham et al., 2009), as a result of warm deep water upwelling to melt its underside (Jenkins et al., 2010). As a result of such changes, the amount of ice sliding from land into sea from the Western Antarctic Ice Sheet has increased, and already contributes around 10% of the observed rise in global sea level (Rignot et al., 2008). If all the ice in the West Antarctic Ice Sheet ended up in the ocean (perhaps unlikely, though it has declined substantially in the more distant past, e.g. Pollard & DeConto, 2009), there’s enough ice there in total to raise global sea level by around 3.3 metres (Bamber et al., 2009).

Changes to the East Antarctic Ice Sheet

On the other side of the Antarctic continent, the even larger East Antarctic Ice Sheet contains yet more ice on land – more than ten times the amount locked up in the West Antarctic Ice Sheet. The good news here is that it appears to be stable – in fact, increased snowfall over central Antarctica means that the East Antarctic Ice Sheet is actually gaining mass at the moment (King et al., 2012). And where it drains into the sea via glaciers, there aren’t upwelling warmer waters flowing close inshore to erode the floating ends of the glaciers and the floating ice shelves that buttress the ice flow.

There is one exception, however: at the Totten Ice Tongue, there are seafloor channels bringing warm deep waters to the underside of the floating end of the glacier, causing it to get thinner (Rintoul et al., 2017). That may be unique for a glacier draining the East Antarctic Ice Sheet, but the “catchment area” of land ice for the Totten Ice Tongue is almost as large as the whole West Antarctic Ice Sheet, so changes in Totten alone could make quite a contribution to sea level rise (and there’s a useful Nature news feature about the “sleeping giant” of Totten here).

How does all this affect us?

Changes in the Antarctic are not the only factor contributing to global sea level rise, of course. Roughly half of the currently observed sea level rise (which is around 3 mm per year total at the moment) comes from thermal expansion of the ocean – as the ocean absorbs heat from the atmosphere, its volume of water expands as it gets warmer.  And changes in other ice sheets and glaciers elsewhere in the world, such as Greenland, also contribute to sea level rise.

Predictions of sea level rise by the year 2100 for the Intergovernmental Panel on Climate Change are almost as much as 1 metre from 1990 levels, depending on how much greenhouse gas we continue to add to the atmosphere (and there’s an excellent set of slides explaining those predictions here). But scientists are still trying to understand how ice sheets, particularly in the Antarctic, could contribute to sea level rise.  A recent study suggests that Antarctic ice sheets alone could drive a metre of sea level rise by 2100 (DeConto & Pollard, 2016), while others scientists are examining whether such rapid changes are physically possible (Ritz et al., 2015).

More than 300 million people live in coastal areas already being affected by or at risk of impacts from predicted sea level rise, including 130 coastal cities each with more than 1 million inhabitants.  But sea level rise isn’t the same everywhere, like adding water to a bathtub – instead, its effects will vary on different coasts, for example as water sloshes around the oceans through currents and local variations in gravity.  A new analysis shows which coasts are connected to changes in particular ice sheets – with changes in the Antarctic Peninsula being particularly relevant for Sydney, Australia (Larour et al., 2017; and here’s an interactive website from that research that allows you to explore how different cities are affected by sea level changes from ice in different areas).

Unless we adapt for predicted sea level rise with new defences and relocations, the financial costs in damages from storm surges and coastal flooding each year could total nearly ten percent of the world’s Gross Domestic Product by 2100 (Hinkel et al., 2014).  Even if you don’t live near the coast personally, you will be affected by sea level rise through the global economy. So although the processes involved are complex, what’s happening right now in the Antarctic – along with changes in other places where ice drains from land into the ocean – affects us all.

I’d like to thank the BBC Natural History Unit’s Blue Planet II team for the opportunity to join their Antarctic expedition, and the ship’s crew, sub team, and expedition members aboard the  Alucia, whose hard work gave us a new view of life on the ocean floor around Antarctica, and the chance to collect some more data to help scientists understand how the environment is changing there.

There are days when I love my job, & today was one of them, thanks to the hard work of the whole team aboard the research ship #Alucia pic.twitter.com/mTb5Mk9Pjr

— Dr Jon Copley (@expeditionlog) December 14, 2016

The post Exploring environmental changes in the Antarctic with Blue Planet II appeared first on Exploring our Oceans .

We have a tendency to take our coastlines for granted. It is by far the most accessible and relatable marine habitat, with thousands flocking there every day for their primary source of food, watersports, or just to relax. The UN estimates 40% of the world’s population live in coastal areas. They provide the most extensive economic and social benefits of any natural habitat, encompassing 77% of the services provided to us by all ecosystems. It is where most of us began our love for the sea. In the UK, you are never more than 70 miles away from it. Yet it is easy to forget it is a place of extremes, and as important as any other marine habitat.

Coastal species have to endure excruciating changes in their environment twice a day. Marine animals can be categorised based on their preferences and adaptability to two primary conditions: temperature and salinity (‘saltiness’). A change in salt might be nothing to one of us as we are osmoregulators (we regulate our internal environment) – for an osmoconformer, like a sea cucumber or starfish, this can be devastating. Too little salt, and your internal water diffuses out, and too much, and outside water will pass in until your cells burst. In the ocean, these conditions remain relatively stable – you can assume that they are unlikely to change dramatically in the next few metres, or few hours. However, if you live in the intertidal zone, you are likely to be bombarded with really hot temperatures at low tide, dramatic changes in salinity if you live in an estuary or at a river mouth, and running out of oxygen if you are caught in a rockpool. To make matters worse, the coast itself is constantly shifting, as shown in the programme. You have to be very hardy and resilient to live here.

Coastal management is a huge challenge anywhere in the world – there is always a trade off between using the coastline for economic and recreational ventures, but not at the sacrifice of the coast’s ecology and longevity. Although only covering 20% of the Earth’s surface, 41% of the world’s population are coastal inhabitants. For example Guyana, a country larger than the UK, 90% of its population lives on a narrow coastal plane, and only a narrow sea wall protects its inhabitants from the ocean. 21 of the world’s 33 megacities are found on the coast, including Tokyo, Lagos, New York and Buenos Aires. With a globally increasing population, how do we ensure coastlines are sustainably developed and not overxploited?

I have noticed that the UK’s coastlines are a severely underrated habitat among many wildlife enthusiasts. Since the establishment of Lundy Island as the first MCZ (Marine Conservation Zone) in January 2010, a total of 50 sites now make up an area the same size as Wales. These are designated to protect rare and threatened species, and also the wide diversity of life found here. We were lucky enough to conduct some camera drop surveys of the maerl beds of the Fal Special Area of Conservation – a red calcareous algae, superficially similar to corals – of which the UK has in several locations. Maerl can be up to 8000 years old, and provide habitat for rare species like Couch’s goby, much like coral reefs do in the tropics. Additionally mudflats, estuaries and sandbanks are not the most glamorous marine habitats but have still been highlighted for conservation as part of global efforts to conserve biodiversity. Just as an example to the importance of this Blue Belt initiative, seagulls are a red list species in the UK due to their overall declines across the country due to habitat loss. This will come as a surprise to many. They are widely considered pests as they have been increasing in urban areas, partly because of abundant food, and partly because they have nowhere else to go.

Appreciating and conserving the marine environment does not just encompass tropical coral reefs, the great whales of the open ocean and the polar ice caps that many of us will only ever admire through a screen. Declines in biodiversity are all-encompassing and are essential for the future of habitats, and ultimately, our own wellbeing. We in the UK are just as responsible for protecting our marine species as any other country, and you don’t have to fly to the tropics to be close to the Blue Planet.

The post Blue Planet 2 | Episode 6 | Coasts appeared first on Exploring our Oceans .

As mentioned in previous posts, each Blue Planet 2 episode has had a strong conservation message of its own, told from the perspective of the affected animals. This episode, however, will have quite a different tone and a serious message to share, featuring stories from the perspectives of the animals themselves and the scientists studying them. Our Blue Planet will explore the human impacts on some of the most loved characters from the series, something Executive Producer, James Honeyborne viewed as a natural conclusion to the series. Expect to see the corals, turtles and albatrosses back again, but this time to tell the heart-wrenching stories of their lives in a rapidly changing world. Sir David Attenborough is also expected to feature heavily throughout the episode, with his own personal look at the problems facing our oceans, along with scientists and conservationists from around the world, including our very own Dr Jon Copley. As one of the chief scientific correspondents to the series, Jon will appear in the upcoming episode to express his personal experience of our changing ocean, most likely regarding Antarctica, where he was a member of the team that descended to 1,000 m in the Alucia submersibles for ‘The Deep‘ episode.

Experience Dr Jon Copley’s Antarctic adventure as scientific correspondant for Blue Planet 2.

It is now (almost) universally recognised that human activity is having a profound effect on our blue planet and that the ocean is experiencing great change at an alarming rate. The problems that marine fauna face are widespread and ever-increasing – warming, acidification, overfishing, noise pollution, seabed mining, ecotoxicology and plastic pollution – each a human-induced threat. In 2017 alone, a great number of studies have been published exploring the effect of these threats on marine life, including on the recovery of the North Atlantic right whale, the effective functioning of both tropical and cold-water coral reefs, and the distribution of Southen Ocean seabirds. I predict the strongest message from the episode is likely to concern plastics, something which Sir David feels strongly about. A changing ocean is not only a threat to the marine environment – as we’ve seen in each previous episode, all life is intertwined with the ocean so any change can heavily effect humans too, from the decimation of fish stocks to rising sea levels. I, therefore, believe that the upcoming episode will have a profound effect on the audience, after all, the episode is titled Our Blue Planet.

As with the final episode of Planet Earth 2, there will also inevitably be a message of hope. Conservation and citizen science success stories are being shared by individuals around the world – from the recovery of kelp forest ecosystems in Monterey Bay (as seen in Green Seas) to the protection of sea turtle nesting beaches by Caribbean communities, these accounts are sure to be highlighted towards the end of the episode. Let us not forget the progress made at home too – the implementation of Marine Protected Areas and Special Areas of Conservation around the UK has allowed our marine wildlife to bounce back, and local initiatives to rescue stranded marine mammals and conduct beach cleans are helping to combat our plastic pollution problem.

As ever, feel free to share any comments or questions regarding Our Blue Planet – I hope you enjoy the final episode of the amazing series, Blue Planet 2!

The post What to expect from Blue Planet 2 – Our Blue Planet appeared first on Exploring our Oceans .

Whilst studying at the University of Southampton, I’ve learned a lot about the ecology of our coasts, specifically that of sandy and rocky shores. During a field course to the Dale Peninsula in West Wales, we explored the challenges that coastal fauna face on a daily and seasonal basis – over-exposure to heat in rockpools during the ebbing tide forces crabs and other coastal invertebrates to take shelter under seaweed like bladderwrack; the high wave action of exposed shores can be rewarding in terms of food and oxygen supply, but also risky for animals without top adhesive properties; and the race for space in a competitive rocky shore environment leaves a distinctive, territorial pattern of limpet home-ranges across each boulder. During this week’s episode, expect to see similar stories of the daily life-and-death struggle of coastal animals, specifically those that live along diverse rocky shores and in vibrant rock pools; and, of course, lots of gorgeous time-lapse footage.

Since the coast forms such an important oasis for seabirds like puffins, sanderlings and penguins, I believe that the lives of seabirds will feature heavily in this episode. Penguins are obviously a fan-favourite, but the heartbreaking sequence on wandering albatrosses in Big Blue captured the public’s imagination too. Puffins are also marvellous birds, with incredibly strong wills – they must travel for miles to find food to feed their young that nest along the clifftops of the coast, dealing with challenges like battering weather and competition from other seabirds along the way. However, puffin populations are in danger, with many fledgelings suffering from starvation due to shifting fish populations and resultantly increased competition (yet another impact of a warming climate). Expect to see some seabird family drama in this weeks episode!

Coasts are also the closest and most accessible marine environment for us as humans – in the UK, you are never more than 70 miles from the sea. We have a close connection with our coasts, both socially and economically – many of us visit the beach regularly for surfing, sunbathing and rockpooling, but coasts around the world are also lined with industrial ports and fisheries. This human element of the coast is likely to be highlighted during the episode, most probably continuing the pattern of displaying human impact on the wildlife. Expect to see a sequence much like that seen in the final episode of Planet Earth 2, Cities, where the tragic story of light pollution impacts on Hawksbill turtle hatchlings unfolded.

Feel free to share any comments or questions regarding Coasts – I hope you enjoy the episode!

Inspired by the episode? Help us clean up our coasts!

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There is plenty about this episode to talk about. Phytoplankton – an umbrella term for a menagerie of different photosynthesizing organisms –  prop up all other life in the ocean and provide 50% of oxygen for the entire Earth. Despite only covering 0.1% of the Earth’s surface, ‘blue forests’ (seagrass meadows, kelp forests, salt marshes and mangroves) capture about a third of carbon dioxide produced since the Industrial Revolution. Stacey Felgate’s excellent post talked a great deal about ‘blue carbon’ and wetland decline’s consequences for global climate change. Elin correctly predicted sea otter trophic cascades making an appearance – there are fascinating other examples of this from Yellowstone Park to the extinction of giant Ice Age animals. The scenes showing octopus and cephalopod ingenuity could warrant several extensive essays on some of their incredible capabilities, and equally some of the challenges with defining ‘intelligence’ in order to study animal cognition.

I’ll talk specifically about mangrove forests, a tropical coastal habitat characterised by marine adapted trees. Mangroves are an extremely interesting, and extreme, habitat. They have to endure the dramatic changes in salinity and temperature that characterise the intertidal zone. To cope with living in salty water, the mangrove trees have had to evolve to excrete salt from their leaves or by depositing it in roots or bark. These trees are also considered ‘viviparous’ – meaning they give birth to live young (it sounds strange, but this is the correct term!) – as young trees fall straight out of the adult tree and stick straight into the sand or mud like daggers. These ‘baby trees’ are called propagules, and in other cases they may float for weeks across the ocean. Mangroves only cover 0.1% of the Earth’s surface, but account for around 14% of total terrestrial carbon input to the ocean. They provide a link between the ocean and the land, which an extensive menagerie of different species utilise and have adapted to.

As well as being home to many species of juvenile fish, they also provide shelter and resources for dolphins, manatees and dugongs, hundreds of species of birds, and even monkeys. Borneo’s distinguished proboscis monkey is a mangrove specialist. Biodiversity value aside, charismatic animals attract tourists and fish nurseries promote the availability of fish for consumption, particularly important when the majority of people around them rely on fish for their primary source of protein. The tree roots also stabilise the environment, making it easier for other species to live in. The role of mangroves in storm and tsunami protection has provided more incentives to protect them, particularly as extreme storms are becoming more frequent with climate change.

The simple fact is, if you are eating cheap shrimp today, it almost certainly comes from a turbid, pesticide-and-antibiotic filled, virus-ridden pond in the tropical clines of one of the world’s poorest countries

But not all is hopeless – mangrove restoration projects exist all over the world, and are reasonably successful. More robust protection is needed worldwide, and this starts with awareness, which Blue Planet II is doing superbly, and will continue to into the future. And, of course, think twice next time you buy cheap shrimp.

The post Blue Planet 2 | Episode 5 | Green Seas appeared first on Exploring our Oceans .

When we think of the ocean we largely picture a vast, blue wilderness, as witnessed in last week’s episode of Blue Planet 2 – Big Blue. This week we’ve been promised a glimpse inside the ocean’s ‘Green Seas‘ – the most productive, and arguably most important expanses of the marine environment.

During my time studying at the University of Southampton, I’ve learned a great deal about our ‘green seas’. Phytoplankton, or microscopic marine algae, drives all photosynthetically-derived life in our ocean and forms the basis of global marine food webs, playing a role in the oceans similar to that of plants on land. Phytoplankton blooms occur seasonally and are especially characteristic of the temperate North Atlantic Ocean, coastal waters, and sub-polar regions – some phytoplankton blooms are even seen from space!  These blooms provide temporary, bountiful feasts for zooplankton (consisting of gelatinous animals, larvae, and microscopic invertebrates), and in turn, smaller plankton-feeding ‘bait’ fish like anchovies, sardines, and herring. As we saw in the Big Blue’s ‘boiling seas’, large shoals of small fish can attract the ocean’s largest and greatest predators including dolphins, whales, seals and sharks, so expect to see another spectacular feeding extravaganza in this episode.

Another ‘green sea’ likely to make an appearance are the great giant kelp forests of the north-east Pacific, a personal favourite of mine. During our first-year marine ecology lectures, we learnt about a phenomenon coined the trophic cascade, and a specific case study from the kelp forests off the west coast of the USA. A trophic cascade occurs when a top predator is removed from the food web, thereby freeing the lower trophic levels from predation and allowing their herbivorous populations to thrive. In the kelp forest case study, the predacious sea otter was removed from the system, hunted almost to extinction by humans during the 18th and 19th century for their thick fur pelts. As a result, herbivorous sea urchins were allowed to thrive in numbers, grazing on the giant kelp to such an extent that vast areas of the dynamic and diverse kelp forests were cleared, and ‘urchin barrens’ left in their wake. Thankfully, legislation was put in place and conservation programmes successfully established to protect the remaining sea otters, allowing sea otter populations, and consequentially the health of the entire kelp forest ecosystem, to fully recover. This is possibly one of the greatest conservation success stories of all time, so I fully expect the tale to be told by the Blue Planet 2 team (not to mention that sea otters are undeniably adorable!).

Green seas also play an important role in the global carbon cycle and in controlling atmospheric carbon dioxide levels. Phytoplankton absorb carbon dioxide for photosynthesis on a scale equivalent to that of terrestrial forests, and transfer about ten gigatonnes of carbon from the atmosphere to the deep sea each year, via the biological carbon pump. I hope this episode not only highlights the importance of our ‘green seas’ on an ecological scale, for example with mangrove forests providing nurseries for many fish species, but also on a global climatic scale, with each ‘green sea’ ecosystem a significant and altogether vital carbon sink.

Feel free to share any comments or questions regarding Green Seas – I hope you enjoy the episode!

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Huge shoals of plankton move from the deep sea and back every day as the sun rises and sets. There are massive migrations of small fish and squid that follow them to exploit this resource, as well as larger predators which hunt them. This enormous movement of biomass from the deep sea to surface and back happens every single day.

Despite the colossal size of this environment, Attenborough very rightly points out that it is still by no means hugely separated from human life. As well as the famous Pacific Garbage Patch that Elin talked about in another post, there is plastic and other marine waste in the most pristine and remote coral reefs. I have heard stories from fellow divers in the Indo-west Pacific about seeing used nappies floating past on dives. I was lucky enough to be involved with a school trip to Baubau near Sulawesi in Indonesia, and we spent a few hours on an uninhabited island cleaning up trash. On another island in Malaysia I found a DVD player and a washing machine on the beach. These are unusual exceptions – polystyrene, plastic bags and straws are ubiquitous in the ocean anywhere in the world. It’s no different in the UK – the Marine Conservation Society at Southampton spend hundreds of hours removing rubbish from beaches on the South coast. When we see pollution in an area we can all agree it is unpleasant, but as a scientist we understand it in context of this colossal, global and unprecedented problem.

This affects all levels of the marine food web. We tend to think of the deep sea as being this remote alien world, but it is still inextricably linked to human life. Microplastics accumulate in deep sea sediments – at 10,000 times higher concentrations than at the surface. Up to 90% of seabirds have plastic in their guts. Another aspect not explored in the programme is that other pollutants dissolved in water – fouling paint, oil and other contaminants – accumulate on plastics, and so make plastic even more toxic to marine life. Pollution becomes more concentrated in higher levels of the food chain in a process known as ‘biomagnification’, where smaller fish with some pollution in them are eaten in large quantities by larger fish. This means that top predators like tuna, sharks and marine mammals are the most contaminated. And as well as being concerning for environmental reasons, the seafood we eat are no exception – plastic has been found in a third of UK-caught fish, and shellfish lovers may consume up to 11,000 plastic particles per year.

Biodegradable plastic is not biodegradable in the sense one might think. These plastics are held together with degradable fibres, so they break down into smaller components. Eventually, they break down into ‘microplastics’, which then spread into every corner of the ocean. It has been suggested that a layer of plastic will be what will distinguish the human era in the fossil record of the future.

It is extremely heartening to see the reactions to this problem, and some countries (most recently Kenya) have even completely banned plastic bags outright. Hopefully Blue Planet will encourage more people than ever to think twice about whether they need that straw or bag, and eventually encourage governments and large companies to move away from the excessive use of this material.

The post Blue Planet | Episode 4 | Big Blue appeared first on Exploring our Oceans .

Known as the world’s greatest wilderness, the ocean is a vast environment stretching over 70% of the world’s surface. In contrast to the sheltered reefs and coastal shelves that border our shores, the open ocean is not unlike a desert with little food and protection for marine life; yet some of the ocean’s most remarkable species make this ‘big blue’ their home. These animals have thrived here by exploiting specialist ecological niches, such as the fast-swimming striped marlin that navigate the open ocean in search of their widely-dispersed prey, sardines, or the three-metre-long oceanic sunfish that specialise in jellyfish hunting.

Expect to see the day-to-day problems and perils that these animals face – raising your young in this wilderness can be a huge challenge, leaving scientists perplexed about where and how many species accomplish such a task. It is well-known that sea turtles, for example, lay their eggs in the sands of specific beaches across the world; however, we are still unsure where the hatchlings go for several years of their life after they make their dash to the freedom, and dangers, of the sea. As ever, advancements in technologies such as satellite tracking juvenile sea turtles is helping to progress the study of open ocean animals.

Another scene we’re likely to enjoy is a feeding frenzy of dolphins, tuna, and sharks, as a shoal of smaller fish trapped near the surface provides a momentary but plentiful feast in the wilderness. Whilst this scene of ocean predators attacking large bait balls (tightly packed shoals of small fish) is one that we have previously experienced through The Blue Planet, the Blue Planet 2 team has taken the frenzy to the next level with new aerial technology revealing the truth behind ‘boiling seas’.

I am also confident that this episode will continue to reinforce a key message from previous episodes, that despite its enormity, we are having a large and undeniable impact on our ocean and the marine life within. We have previously seen the detrimental effects of climate change through the eyes of a walrus mother and calf struggling to find sea ice in the warming Arctic, deep-sea trawling devastating cold-water coral reefs, and distressing scenes of coral bleaching along the Great Barrier Reef. Marine litter, especially plastics, is another increasing threat to life in our ocean, with around 8 million tonnes of plastic dumped into the ocean annually. It is therefore unsurprising that plastic has quickly become one of the most worrying and serious impacts that we are having on the marine environment – blanketing surface waters in some regions (for one, the great Pacific garbage patch is twice the size of Texas) and mimicking food sources like jellyfish for many marine animals. After experiencing making Blue Planet 2, Sir David Attenborough recently stated that plastics are one of his biggest concerns for the ocean, urging global action for the reduction of plastics consumption, so expect some heart-wrenching footage of its effect on the ‘big blue’.

Feel free to share any comments or questions regarding The Big Blue – I hope you enjoy the episode!

Inspired by the episode? Get involved in ocean conservation!

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It is therefore extremely concerning that reefs are in the worst state they have ever been in. The programme was not exaggerating how serious this is. No reef anywhere on Earth is what it was 20 years ago, and is barely recognisable from 100 years ago. One important consideration in ecological science is setting a baseline – a ‘pristine’ environment, or a ‘fully grown’ fish – to act as a control with which to assess the extent of change. This is usually a nearby area, or the same location a few months or years before. What is problematic is that these baselines change generation to generation (2).

As a young person, the places I have dived and snorkelled that I consider ‘amazing’ would be considered degraded to senior divers who started diving 50 years ago. On a fieldcourse in Bermuda this summer I was struck by the beauty of an offshore reef we visited to measure coral cover – I was surprised to hear the scientists working at BIOS considered this site degraded. The same issue occurs with fisheries, where what is considered a ‘big fish’ by one generation would have been considered a juvenile by a great grandparent. The programme’s spectacular footage from French Polynesia represents the kind of community that most coral reefs would have possessed at one time – today represented by very few extremely remote places. It is thought that before human interference, apex predators like groupers and sharks would have made up the majority of biomass in a reef community (3). Perspective is powerful, and as scientists we must select ours carefully.

Additionally, the corals on which the entire reef ecosystem depends are imperilled worldwide. The largest living structure on Earth, the Great Barrier Reef, bleached two consecutive years in 2016 and 2017 – the first time this has ever happened – in the worst bleaching event in its history. Corals in the Caribbean have declined by 40% in the last five decades (4). Something that I have found as fascinating as shocking considering contemporary life on Earth in the context of its entire history. This decline is a geologically significant event – such large formations dying en mass in a blink of an eye in terms of Earth history is an unusual freak event. The science is increasingly showing that humans are the most influential species of vertebrate in the history of life on Earth.

There have been encouraging suggestions of long-term adaptability – some of the research coming from the Coral Reef Lab at NOC. Some reefs in the Middle East have showed less extreme responses to bleaching. However, I attended a seminar by Dr. Leonard Nurse of University of the West Indies in Barbados a few weeks ago, who is involved in Caribbean coastal management and the Intergovernmental Panel on Climate Change. He made no qualms about mentioning that “no evidence exists that corals can adapt to unabated thermal stress over decadal timescales”.

Change is occurring at both regional and global scales, and although reefs are already declining globally, regional management, intergovernmental climate change agreements and robust science are key to boosting reef longevity and resilience. Seeing the enormous engagement and widespread reaction to the Blue Planet episode is extremely encouraging, and I look forward to seeing a new generation inspired to understand and protect these beautiful habitats.

1. Pascal, N. et al. Economic valuation of coral reef ecosystem service of coastal protection: A pragmatic approach. Ecosyst. Serv. 21, 72–80 (2016).
2. Roberts, C. The Unnatural History of the Sea. (Island Press/Shearwater Books, 2008).
3. Friedlander, A. M. & DeMartini, E. E. Contrasts in density, size, and biomass of reef fishes between the northwestern and the main Hawaiian islands: the effects of fishing down apex predators. Marine Ecology Progress Series 230, 253–264 (2002).
4. Gardner, T. A., Côté, I. M., Gill, J. A., Grant, A. & Watkinson, A. R. Long-Term Region-Wide Declines in Caribbean Corals. Science (80-. ). 301, 958–960 (2003).

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