Coral, meet coral: how selective breeding may help the world’s reefs survive ocean heating

Anna Scott, Author provided

Emily Howells, Southern Cross University and David Abrego, Southern Cross UniversityA single generation of selective breeding can make corals better able to withstand extreme temperatures, according to our new research. The discovery could offer a lifeline to reefs threatened by the warming of the world’s oceans.

Our research, published in Science Advances, shows corals from some of the world’s hottest seas can transfer beneficial genes associated with heat tolerance to their offspring, even when crossbred with corals that have never experienced such temperatures.

Across the world, corals vary widely, both in the temperatures they experience and their ability to withstand high temperatures without becoming stressed or dying. In the Persian Gulf, corals have genetically adapted to extreme water temperatures, tolerating summer conditions above 34℃ for weeks at a time, and withstanding daily averages up to 36℃.

These water temperatures are 2-4℃ higher than any other region where corals grow, and are on a par with end-of-century projections for reefs outside the Persian Gulf.

This led us to ask whether beneficial gene variants could be transferred to coral populations that are naïve to these temperature extremes. To find out, we collected fragments of Platygyra daedalea corals from the Persian Gulf, and cross-bred them with corals of the same species from the Indian Ocean, where summer temperatures are much cooler.

Platygyra, a brain-shaped coral found in many parts of the world.
Emily Howells, Author provided

We then heat-stressed the resulting offspring (more than 12,000 individual coral larvae) to see whether they could withstand temperatures of 33°C and 36°C — the summer maximums of their parents’ respective locations.

Immediate gains

We found an immediate transfer of heat tolerance when Indian Ocean mothers were crossed with Persian Gulf fathers. These corals showed an 84% increase in survival at high temperatures relative to purebred Indian Ocean corals, making them similarly resilient to purebred Persian Gulf corals.

Genome sequencing confirmed that gains in heat tolerance were due to the inheritance of beneficial gene variants from the Persian Gulf corals. Most Persian Gulf fathers produced offspring that were better able to withstand heat stress, and these fathers and their offspring had crucial variants associated with better heat tolerance.

Conversely, most Indian Ocean fathers produced offspring that were less able to survive heat stress, and were less likely to have gene variants associated with heat tolerance.

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Gene editing is revealing how corals respond to warming waters. It could transform how we manage our reefs

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Survival of the fittest

Encouragingly, gene variants associated with heat tolerance were not exclusive to Persian Gulf corals. Two fathers from the Indian Ocean produced offspring with unexpectedly high survival under heat stress, and had some of the same tolerance-associated gene variants that are prevalent in Persian Gulf corals.

This suggests that some populations have genetic variation upon which natural selection can act as the world’s oceans grow hotter. Selective breeding might be able to accelerate this process.

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Read more:
Heat-tolerant corals can create nurseries that are resistant to bleaching

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We are now assessing the genetic basis for heat tolerance in the same species of coral on the Great Barrier Reef and in Western Australia. We want to find out what gene variants are associated with heat tolerance, how these variants are distributed within and among reefs, and whether they are the same as those that allow corals in the Persian Gulf to survive such extreme temperatures.

This knowledge will help us understand the potential for Australian corals to adapt to rapid warming.

Although our study shows selective breeding can significantly improve the resilience of corals to ocean warming, we don’t yet know whether there are any trade-offs between thermal tolerance and other important traits, and whether there are significant genetic risks involved in such breeding.

Platygyra larvae. It remains to be seen whether the genetic benefits of heat-tolerance genes persist throughout life.
Emily Howells, Author provided

Our study was done on coral larvae without the algae that live in close harmony with corals after they settle on reefs. So it will also be important to examine whether the genetic improvements to heat tolerance continue into the corals’ later life stages, when they team up with these algae.

Of course, saving corals from the perils of ocean warming will require action on multiple fronts — there is no silver bullet. Selective breeding might provide some respite to particular coral populations, but it won’t be enough to protect entire ecosystems, and nor is it a substitute for the urgent reduction of greenhouse emissions needed to limit the oceans’ warming.

Emily Howells, Senior Research Fellow in Marine Biology, Southern Cross University and David Abrego, Lecturer, National Marine Science Centre, Southern Cross University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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The Oceans in 1000 Years?

Oil Rigs Near Reefs?

The ocean is full of tiny plastic particles – we found a way to track them with satellites

Plastic fragments washed onto Schiavonea beach in Calabria, Italy, in a 2019 storm.
Alfonso Di Vincenzo/KONTROLAB /LightRocket via Getty Images

Christopher Ruf, University of MichiganPlastic is the most common type of debris floating in the world’s oceans. Waves and sunlight break much of it down into smaller particles called microplastics – fragments less than 5 millimeters across, roughly the size of a sesame seed.

To understand how microplastic pollution is affecting the ocean, scientists need to know how much is there and where it is accumulating. Most data on microplastic concentrations comes from commercial and research ships that tow plankton nets – long, cone-shaped nets with very fine mesh designed for collecting marine microorganisms.

But net trawling can sample only small areas and may be underestimating true plastic concentrations. Except in the North Atlantic and North Pacific gyres – large zones where ocean currents rotate, collecting floating debris – scientists have done very little sampling for microplastics. And there is scant information about how these particles’ concentrations vary over time.

Researchers deploy plankton sampling nets in Lake Michigan.
NOAA, CC BY-SA

To address these questions, University of Michigan research assistant Madeline Evans and I developed a new way to detect microplastic concentrations from space using NASA’s Cyclone Global Navigation Satellite System. CYGNSS is a network of eight microsatellites that was launched in 2016 to help scientists predict hurricanes by analyzing tropical wind speeds. They measure how wind roughens the ocean’s surface – an indicator that we realized could also be used to detect and track large quantities of microplastics.

This story is part of Oceans 21

Our series on the global ocean opened with five in depth profiles. Look out for new articles on the state of our oceans in the lead up to the UN’s next climate conference, COP26. The series is brought to you by The Conversation’s international network.

Looking for smooth zones

Annual global production of plastic has increased every year since the 1950s, reaching 359 million metric tons in 2018. Much of it ends up in open, uncontrolled landfills, where it can wash into river drainage zones and ultimately into the world’s oceans.

Researchers first documented plastic debris in the oceans in the 1970s. Today, it accounts for an estimated 80% to 85% of marine litter.

The radars on CYGNSS satellites are designed to measure winds over the ocean indirectly by measuring how they roughen the water’s surface. We knew that when there is a lot of material floating in the water, winds don’t roughen it as much. So we tried computing how much smoother measurements indicated the surface was than it should have been if winds of the same speed were blowing across clear water.

This anomaly – the “missing roughness” – turns out to be highly correlated with the concentration of microplastics near the ocean surface. Put another way, areas where surface waters appear to be unusually smooth frequently contain high concentrations of microplastics. The smoothness could be caused by the microplastics themselves, or possibly by something else that’s associated with them.

By combining all the measurements made by CYGNSS satellites as they orbit around the world, we can create global time-lapse images of ocean microplastic concentrations. Our images readily identify the Great Pacific Garbage Patch and secondary regions of high microplastic concentration in the North Atlantic and the southern oceans.

Tracking microplastic flows over time

Since CYGNSS tracks wind speeds constantly, it lets us see how microplastic concentrations change over time. By animating a year’s worth of images, we revealed seasonal variations that were not previously known.

This animation shows how satellite data can be used to track where microplastics enter the water, how they move and where they tend to collect.

We found that global microplastic concentrations tend to peak in the North Atlantic and Pacific during the Northern Hemisphere’s summer months. June and July, for example, are the peak months for the Great Pacific Garbage Patch.

Concentrations in the Southern Hemisphere peak during its summer months of January and February. Lower concentrations during the winter in both hemispheres are likely due to a combination of stronger currents that break up microplastic plumes and increased vertical mixing – the exchange between surface and deeper water – that transports some of the microplastic down below the surface.

This approach can also target smaller regions over shorter periods of time. For example, we examined episodic outflow events from the mouths of the China’s Yangtze and Qiantang rivers where they empty into the East China Sea. These events may have been associated with increases in industrial production activity, or with increases in the rate at which managers allowed the rivers to flow through dams.

These images show microplastic concentrations (number of particles per square kilometer) at the mouths of the Yangtze and Qiantang rivers where they empty in to the East China Sea. (A) Average density year-round; (B) short-lived burst of particles from the Qiantang River; (C and D) short-lived bursts from the Yangtze River.
Evans and Ruf, 2021., CC BY

Better targeting for cleanups

Our research has several potential uses. Private organizations, such as The Ocean Cleanup, a nonprofit in The Netherlands, and Clewat, a Finnish company specializing in clean technology, use specially outfitted ships to collect, recycle and dispose of marine litter and debris. We have begun conversations with both groups and hope eventually to help them deploy their fleets more effectively.

Our spaceborne imagery may also be used to validate and improve numerical prediction models that attempt to track how microplastics move through the oceans using ocean circulation patterns. Scholars are developing several such models.

A solar-powered barge that filters plastic out of water, designed by Dutch NGO The Ocean Cleanup, deployed in the Rio Ozama, Dominican Republic, in 2020.
The Ocean Cleanup, CC BY

While the ocean roughness anomalies that we observed correlate strongly with microplastic concentrations, our estimates of concentration are based on the correlations that we observed, not on a known physical relationship between floating microplastics and ocean roughness. It could be that the roughness anomalies are caused by something else that is also correlated with the presence of microplastics.

One possibility is surfactants on the ocean surface. These liquid chemical compounds, which are widely used in detergents and other products, move through the oceans in ways similar to microplastics, and they also have a damping effect on wind-driven ocean roughening.

Further study is needed to identify how the smooth areas that we identified occur, and if they are caused indirectly by surfactants, to better understand exactly how their transport mechanisms are related to those of microplastics. But I hope this research can be part of a fundamental change in tracking and managing microplastic pollution.

[The Conversation’s science, health and technology editors pick their favorite stories. Weekly on Wednesdays.]

Christopher Ruf, Professor of Climate and Space Sciences and Engineering, University of Michigan

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Climate change is making ocean waves more powerful, threatening to erode many coastlines

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Thomas Mortlock, Macquarie University; Itxaso Odériz, Universidad Nacional Autónoma de México (UNAM); Nobuhito Mori, Kyoto University, and Rodolfo Silva, Universidad Nacional Autónoma de México (UNAM)Sea level rise isn’t the only way climate change will devastate the coast. Our research, published today, found it is also making waves more powerful, particularly in the Southern Hemisphere.

We plotted the trajectory of these stronger waves and found the coasts of South Australia and Western Australia, Pacific and Caribbean Islands, East Indonesia and Japan, and South Africa are already experiencing more powerful waves because of global warming.

This will compound the effects of sea level rise, putting low-lying island nations in the Pacific — such as Tuvalu, Kiribati and the Marshall Islands — in further danger, and changing how we manage coasts worldwide.

But it’s not too late to stop the worst effects — that is, if we drastically and urgently cut greenhouse gas emissions.

An energetic ocean

Since the 1970s, the ocean has absorbed more than 90% of the heat gained by the planet. This has a range of impacts, including longer and more frequent marine heatwaves, coral bleaching, and providing an energy source for more powerful storms.

Since at least the 1980s, wave power has increased worldwide as more heat is pumped into the ocean.
Shutterstock

But our focus was on how warming oceans boost wave power. We looked at wave conditions over the past 35 years, and found global wave power has increased since at least the 1980s, mostly concentrated in the Southern Hemisphere, as more energy is being pumped into the oceans in the form of heat.

And a more energetic ocean means larger wave heights and more erosive energy potential for coastlines in some parts of the world than before.

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Ocean warming threatens coral reefs and soon could make it harder to restore them

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Ocean waves have shaped Earth’s coastlines for millions of years. So any small, sustained changes in waves can have long-term consequences for coastal ecosystems and the people who rely on them.

Mangroves and salt marshes, for example, are particularly vulnerable to increases in wave energy when combined with sea level rise.

To escape, mangroves and marshes naturally migrate to higher ground. But when these ecosystems back onto urban areas, they have nowhere to go and die out. This process is known as “coastal squeeze”.

These ecosystems often provide a natural buffer to wave attack for low-lying coastal areas. So without these fringing ecosystems, the coastal communities behind them will be exposed to more wave energy and, potentially, higher erosion.

Mangrove forests are among the most imperilled ecosystems as sea levels rise and ocean waves crash harder against the coast.
Shutterstock

So why is this happening?

Ocean waves are generated by winds blowing along the ocean surface. And when the ocean absorbs heat, the sea surface warms, encouraging the warm air over the top of it to rise (this is called convection). This helps spin up atmospheric circulation and winds.

In other words, we come to a cascade of impacts: warmer sea surface temperatures bring about stronger winds, which alter global ocean wave conditions.

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Curious Kids: why are there waves?

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Our research shows, in some parts of the world’s oceans, wave power is increasing because of stronger wind energy and the shift of westerly winds towards the poles. This is most noticeable in the tropical regions of the Atlantic and Pacific Oceans, and the subtropical regions of the Indian Ocean.

But not all changes in wave conditions are driven by ocean warming from human-caused climate change. Some areas of the world’s oceans are still more influenced by natural climate variability — such as El Niño and La Niña — than long-term ocean warming.

In general, it appears changes to wave conditions towards the equator are more driven by ocean warming from human-caused climate change, whereas changes to waves towards the poles remain more impacted by natural climate variability.

Ocean waves are generated by winds blowing across the ocean surface.
Shutterstock

How this could erode the coasts

While the response of coastlines to climate change is a complex interplay of many processes, waves remain the principal driver of change along many of the world’s open, sandy coastlines.

So how might coastlines respond to getting hit by more powerful waves? It generally depends on how much sand there is, and how, exactly, wave power increases.

For example, if there’s an increase in wave height, this may cause increased erosion. But if the waves become longer (a lengthening of the wave period), then this may have the opposite effect, by transporting sand from deeper water to help the coast keep pace with sea level rise.

Sandy beaches, including those around South Australia and Western Australia, may see greater risk of erosion in coming decades as wave power increases.
Shutterstock

For low-lying nations in areas of warming sea surface temperatures around the equator, higher waves – combined with sea level rise – poses an existential problem.

People in these nations may experience both sea level rise and increasing wave power on their coastlines, eroding land further up the beach and damaging property.
These areas should be regarded as coastal climate hotspots, where continued adaption or mitigation funding is needed.

It’s not too late

It’s not surprising for us to find the fingerprints of greenhouse warming in ocean waves and, consequentially, along our coastlines. Our study looked only at historical wave conditions and how these are already being impacted by climate change.

But if warming continues in line with current trends over the coming century, we can expect to see more significant changes in wave conditions along the world’s coasts than uncovered in our backward-looking research.

However, if we can mitigate greenhouse warming in line with the 2℃ Paris agreement, studies indicate we could still keep changes in wave patterns within the bounds of natural climate variability.

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Seabirds are today’s canaries in the coal mine – and they’re sending us an urgent message

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Still, one thing is abundantly clear: the impacts of climate change on waves is not a thing of the future, and is already occurring in large parts of the world’s oceans.

The extent to which these changes continue and the risk this poses to global coastlines will be closely linked to decarbonisation efforts over the coming decades.

This story is part of Oceans 21

Our series on the global ocean opened with five in depth profiles. Look out for new articles on the state of our oceans in the lead up to the UN’s next climate conference, COP26. The series is brought to you by The Conversation’s international network.

Thomas Mortlock, Senior Risk Scientist, Risk Frontiers, Adjunct Fellow, Macquarie University; Itxaso Odériz, Research assistant, Universidad Nacional Autónoma de México (UNAM); Nobuhito Mori, Professor, Kyoto University, and Rodolfo Silva, Professor, Universidad Nacional Autónoma de México (UNAM)

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Like the ocean’s ‘gut flora’: we sailed from Antarctica to the equator to learn how bacteria affect ocean health

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Eric Jorden Raes, Dalhousie UniversityAboard an Australian research vessel, the RV Investigator, we sailed for 63 days from Antarctica’s ice edge to the warm equator in the South Pacific and collected 387 water samples.

Our goal? To determine how the genetic code of thousands of different micro-organisms can provide insights into the ocean’s functional diversity — the range of tasks performed by bacteria in the ocean.

Our research was published yesterday in Nature Communications. It showed how bacteria can help us measure shifts in energy production at the base of the food web. These results are important, as they highlight an emerging opportunity to use genetic data for large-scale ecosystem assessments in different marine environments.

In light of our rapidly changing climate, this kind of information is critical, as it will allow us to unpack the complexity of nature step by step. Ultimately, it will help us mitigate human pressures to protect and restore our precious marine ecosystems.

Why should we care about marine bacteria?

The oceans cover 71% of our planet and sustain life on Earth. In the upper 100 meters, the sunlit part of the oceans, microscopic life is abundant. In fact, it’s responsible for producing up to 50% of all the oxygen in the world.

Marine bacteria provide the energy and food for the entire marine food web, from tiny crustaceans to whales.
Shutterstock

Much like the link recently established between human health and the human microbiome (“gut flora”), ocean health is largely controlled by its bacterial inhabitants.

But the role of bacteria go beyond oxygen production. Bacteria sustain, inject and control the fluxes of energy, nutrients and organic matter in our oceans. They provide the energy and food for the entire marine food web, from tiny crustaceans to fish larvae, whales and the fish we eat.

These micro-organisms also execute key roles in numerous biogeochemical cycles (the carbon, nitrogen, phosphorus, sulphur and iron cycles, to name a few).

So, it’s important to quantify their various tasks and understand how the different bacterial species and their functions respond to environmental changes.

Fundamental questions

Global ocean research initiatives — such as GO-SHIP and GEOTRACES — have been measuring the state of oceans in expeditions like ours for decades. They survey temperature, salinity, nutrients, trace metals (iron, cobalt and more) and other essential ocean variables.

Only recently, however, have these programs begun measuring biological variables, such as bacterial gene data, in their global sampling expeditions.

On board the RV Investigator, we departed Hobart in 2016, beginning our 63-day journey to sample microbes in the South Pacific.
Eric Raes, Author provided

Including bacterial gene data to measure the state of the ocean means we can try to fill critical knowledge gaps about how the diversity of bacteria impacts their various tasks. One hypothesis is whether a greater diversity of bacteria leads to a better resilience in an ecosystem, allowing it to withstand the effects of climate change.

In our paper, we addressed a fundamental question in this global field of marine microbial ecology: what is the relationship between bacterial identity and function? In other words, who is doing what?

What we found

We showed it’s possible to link the genetic code of marine bacteria to the various functions and tasks they execute, and to quantify how these functions changed from Antarctica to the equator.

The functions that changed include taking in carbon dioxide from the atmosphere, bacterial growth, strategies to cope with limited nutrients, and breaking down organic matter.

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Marine life is fleeing the equator to cooler waters. History tells us this could trigger a mass extinction event

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Another key finding is that “oceanographic fronts” can act as boundaries within a seemingly uniform ocean, resulting in unique assemblages of bacteria with specific tasks. Oceanographic fronts are distinct water masses defined by, for instance, sharp changes in temperature and salinity. Where the waters meet and mix, there’s high turbulence.

The change we recorded in energy production across the subtropical front, which separates the colder waters from the Southern Ocean from the warmer waters in the tropics, was a clear example of how oceanographic fronts influenced bacterial functions in the ocean.

An oceanographic front, where it looks like two oceans meet.
Shutterstock

Tracking changes in our ecosystems

As a result of our research, scientists may start using the functional diversity of bacteria as an indicator to track changes in our ecosystems, like canaries in a coal mine.

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Half of global methane emissions come from aquatic ecosystems – much of this is human-made

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So the functional diversity of bacteria can be used to measure how human growth and urbanisation impact coastal areas and estuaries.

For example, we can more accurately and holistically measure the environmental footprint of aquaculture pens, which are known to affect water quality by increasing concentrations of nutrients such as carbon, nitrogen and phosphorus – all favourite elements utilised by bacteria.

Likewise, we can track changes in the environmental services rendered by estuaries, such as their important role in removing excessive nitrogen that enters the waterways due to agriculture run-off and urban waste.

With 44% of the world’s population living along coastlines, the input of nitrogen to marine ecosystems, including estuaries, is predicted to increase, putting a strain on the marine life there.

Ultimately, interrogating the bacterial diversity using gene data, along with the opportunity to predict what this microscopic life is or will be doing in future, will help us better understand nature’s complex interactions that sustain life in our oceans.

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Humans are polluting the environment with antibiotic-resistant bacteria, and I’m finding them everywhere

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Eric Jorden Raes, Postdoctoral researcher Ocean Frontier Institute, Dalhousie University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Circulating Oceans

Plastic in the ocean kills more threatened albatrosses than we thought

Lauren Roman, Author provided

Richelle Butcher, Massey University; Britta Denise Hardesty, CSIRO, and Lauren Roman, CSIRO

Plastic in the ocean can be deadly for marine wildlife and seabirds around the globe, but our latest study shows single-use plastics are a bigger threat to endangered albatrosses in the southern hemisphere than we previously thought.

You may have heard of the Great Pacific garbage patch in the northern Pacific, but plastic pollution in the southern hemisphere’s oceans has increased by orders of magnitude in recent years.

We examined the causes of death of 107 albatrosses received by wildlife hospitals and pathology services in Australia and New Zealand and found ocean plastic is an underestimated threat.

Plastic drink bottles, disposable utensils and balloons are among the most deadly items.

Albatrosses are some the world’s most imperiled seabirds, with 73% of species threatened with extinction. Most species live in the southern hemisphere.

We estimate plastic ingestion causes up to 17.5% of near-shore albatross deaths in the southern hemisphere and should be considered a substantial threat to albatross populations.

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These are the plastic items that most kill whales, dolphins, turtles and seabirds

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Magnificent ocean wanderers

Albatrosses spend their entire lives at sea and can live for more than 70 years. They return to land only to reunite with their mate and raise a single chick during the warmer months.

Although the world’s largest flying birds are rarely seen from land, human activities are driving nearly three quarters of albatross species to extinction.

The great albatrosses are the largest flying birds in the world, circumnavigating the southern oceans in search of food.
Lauren Roman, Author provided

Each year, thousands of albatrosses are caught as unintended bycatch and killed by fishing boats. Introduced rats and mice eat their chicks alive on remote islands and the ocean where they spend their lives is becoming increasingly warmer and filled with plastic.

Young Laysan albatrosses with their bellies full of plastic are not just a tragic tale from the remote northern Pacific. Albatrosses are dying from plastic in the southern oceans, too.

When a Royal albatross recently died in care at Wildbase Hospital after eating a plastic bottle, it was not an isolated incident.

Single-use plastics hit albatrosses close to home

Veterinarian Baukje Lenting treating a light-mantled albatross at The Nest Te Kōhanga at Wellington Zoo.
Wellington Zoo, Author provided

Eighteen of the world’s 22 albatross species live in the southern hemisphere, where plastic is currently considered a lesser threat. But the amount of discarded plastic is increasing every year, mostly leaked from towns and cities and accumulating near the shore.

Single-use items make up most of the trash found on coastlines around the world. Seven of the ten most common items — drink bottles, food wrappers and grocery bags — are made of plastic.

When albatrosses are found struggling near the shore in New Zealand, they are delivered to wildlife hospitals such as Wildbase Hospital and The Nest Te Kōhanga. A recent spate of plastic-linked deaths spurred us to dig a little deeper into the risk of plastic pollution to these magnificent ocean wanderers.

A thousand cuts: plastic and other threats

Of the 107 albatrosses of 12 species we examined, plastic was the cause of death in half of the birds that had ingested it. In the cases we examined, plastic deaths were more common than fisheries-related deaths or oiling.

We compared these cases with data on plastic ingestion and fishery interaction rates from other studies. Based on our findings, we used statistical methods to estimate how many albatrosses were likely to eat plastic and might die from ingesting it, and how these figures compared to other major threats such as fisheries bycatch.

We found that in the near-shore areas of Australia and New Zealand, the ingestion of plastic is likely to cause about 3.4% of albatross deaths. In more polluted near-shore areas, such as those off Brazil, we estimate plastic ingestion causes 17.5% of all albatross deaths.

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Plastic poses biggest threat to seabirds in New Zealand waters, where more breed than elsewhere

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Because albatrosses are highly migratory, even those birds that live in less polluted areas are at risk as they wander the global ocean, travelling to polluted waters. Our results suggest the ingestion of plastic is at least of equivalent concern as long-line fishing in near-shore areas.

For threatened and declining albatross species, these rates of additional mortality are a serious concern and could result in further population losses.

Deadly junk food for marine life

The remains of two balloons in the stomach of an endangered grey-headed albatross.
Lauren Roman, Author provided

Not all types of plastic are equally deadly when eaten. Albatrosses can regurgitate many of the indigestible items they eat.

Soft plastic and rubber items (such as latex balloons), in particular, can be deadly for marine animals because they often become trapped in the gut and cause fatal blockages, leading to a long, slow death by starvation. Plastic is difficult to see with common scanning techniques, and gut blockages often remain undetected.

A 500ml plastic bottle and balloon fragments were found in the stomach of a southern royal albatross which died in care at Wildbase Hospital.
Stuart Hunter, Author provided

Albatrosses like to eat squid, and inexperienced young birds are especially prone to mistaking balloons and other plastic for food, with potentially lethal consequences.

We recommend that wildlife hospitals, carers and biologists consider gastric obstruction when sick albatrosses are presented. Our publication includes a checklist to help in the detection of gastric blockages.

Global cooperation to reduce leakage of plastic items into the ocean — such as the Basel Convention and the recommendations by the High Level Panel for a Sustainable Ocean Economy — are first steps towards preventing unnecessary deaths of marine animals.

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Read more:
We need a legally binding treaty to make plastic pollution history

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Stronger adherence to multilateral agreements, such as the Agreement on the Conservation of Albatrosses and Petrels which aims to reduce the impact of activities known to kill albatrosses, would help prevent the decline of breeding populations to unsustainably low levels.

If populations fall to critically endangered levels, intensive remediation including the expansion of chick and nest protection programmes, invasive species eradication and seabird translocations, may be required to prevent species extinction.

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We would like to acknowledge our New Zealand and Australian colleagues who contributed to this research project. Veterinarians Baukje Lenting and Phil Kowalski care for injured seabirds and other wildlife at The Nest Te Kōhanga at Wellington Zoo. Veterinarian Megan Jolly cares for injured wildlife at Wildbase Hospital and vet pathologist Stuart Hunter provides a nationwide wildlife pathology service at Wildbase pathology at Massey University. David Stewart conducts threatened species research and monitoring at the Queensland state government’s Department of Environment and Science.

Richelle Butcher, Veterinary Resident at Wildbase, Massey University; Britta Denise Hardesty, Principal Research Scientist, Oceans and Atmosphere Flagship, CSIRO, and Lauren Roman, Postdoctoral Researcher, Oceans and Atmosphere, CSIRO

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Marine protection falls short of the 2020 target to safeguard 10% of the world’s oceans. A UN treaty and lessons from Antarctica could help

John B. Weller, Author provided

Natasha Blaize Gardiner, University of Canterbury and Cassandra Brooks, University of Colorado Boulder

Two-thirds of the world’s oceans fall outside national jurisdictions – they belong to no one and everyone.

These international waters, known as the high seas, harbour a plethora of natural resources and millions of unique marine species.

But they are being damaged irretrievably. Research shows unsustainable fisheries are one of the greatest threats to marine biodiversity in the high seas.

According to a 2019 global assessment report on biodiversity and ecosystem services, 66% of the world’s oceans are experiencing detrimental and increasing cumulative impacts from human activities.

In the high seas, human activities are regulated by a patchwork of international legal agreements under the 1982 UN Convention on the Law of the Sea (UNCLOS). But this piecemeal approach is failing to safeguard the ecosystems we depend on.

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The world’s ocean is bearing the brunt of a changing climate. Explore its past and future in our new series

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Empty pledges

A decade ago, world leaders updated an earlier pledge to establish a network of marine protected areas (MPAs) with a mandate to protect 10% of the world’s oceans by 2020.

But MPAs cover only 7.66% of the ocean across the globe. Most protected sites are in national waters where it’s easy to implement and manage protection under the provision of a single country.

In the more remote areas of the high seas, only 1.18% of marine ecosystems have been gifted sanctuary.

The Southern Ocean accounts for a large portion of this meagre percentage, hosting two MPAs. The South Orkney Islands southern shelf MPA covers 94,000 square kilometres, while the Ross Sea region MPA stretches across more than 2 million square kilometres, making it the largest in the world.

Currently, the world’s largest marine protected area is in the Ross Sea region off Antarctica.
Natasha Gardiner, CC BY-ND

The Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) is responsible for this achievement. Unlike other international fisheries management bodies, the commission’s legal convention allows for the closing of marine areas for conservation purposes.

A comparable mandate for MPAs in other areas of the high seas has been nowhere in sight — until now.

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Read more:
An ocean like no other: the Southern Ocean’s ecological richness and significance for global climate

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A new ocean treaty

In 2017, the UN started negotiations towards a new comprehensive international treaty for the high seas. The treaty aims to improve the conservation and sustainable use of marine organisms in areas beyond national jurisdiction. It would also implement a global legal mechanism to establish MPAs in international waters.

This innovative international agreement provides an opportunity to work across institutional boundaries towards comprehensive high seas governance and protection. It is crucial to use lessons drawn from existing high seas marine protection initiatives, such as those in the Southern Ocean, to inform the treaty’s development.

The final round of treaty negotiations is pending, delayed by the COVID-19 pandemic, and significant detail within the treaty’s draft text remains undeveloped and open for further debate.

Lessons from Southern Ocean management

CCAMLR comprises 26 member states (including the European Union) and meets annually to make conservation-based decisions by unanimous consensus. In 2002, the commission committed to establishing a representative network of MPAs in Antarctica in alignment with globally agreed targets for the world’s oceans.

The two established MPAs in the high seas are far from an ecologically representative network of protection. In October 2020, the commission continued negotiations for three additional MPAs, which would meet the 10% target for the Southern Ocean, if agreed.

But not a single proposal was agreed. For one of the proposals, the East Antarctic MPA, this marks the eighth year of failed negotiations.

Fisheries interests from a select few nations, combined with complex geopolitics, are thwarting progress towards marine protection in the Antarctic.

CCAMLR’s two established MPAs (in grey) are the South Orkney Islands southern shelf MPA and the Ross Sea region MPA. Three proposed MPAs (hashed) include the East Antarctic, Domain 1 and Weddell Sea proposals.
C. Brooks, CC BY-ND

CCAMLR’s progress towards its commitment for a representative MPA network may have ground to a halt, but the commission has gained invaluable knowledge about the challenges in establishing MPAs in international waters. CCAMLR has demonstrated that with an effective convention and legal framework, MPAs in the high seas are possible.

The commission understands the extent to which robust scientific information must inform MPA proposals and how to navigate inevitable trade-offs between conservation and economic interests. Such knowledge is important for the UN treaty process.

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As the high seas treaty moves closer to adoption, it stands to outpace the commission regarding progress towards improved marine conservation. Already, researchers have identified high-priority areas for protection in the high seas, including in Antarctica.

Many species cross the Southern Ocean boundary into other regions. This makes it even more important for CCAMLR to integrate its management across regional fisheries organisations – and the new treaty could facilitate this engagement.

But the window of time is closing with only one round of negotiation left for the UN treaty. Research tells us Antarctic decision-makers need to use the opportunity to ensure the treaty supports marine protection commitments.

Stronger Antarctic leadership is urgently needed to safeguard the Southern Ocean — and beyond.

Natasha Blaize Gardiner, PhD Candidate, University of Canterbury and Cassandra Brooks, Assistant Professor Environmental Studies, University of Colorado Boulder

This article is republished from The Conversation under a Creative Commons license. Read the original article.

China’s Belt and Road mega-plan may devastate the world’s oceans, or help save them

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Mischa Turschwell, Griffith University; Christopher Brown, Griffith University, and Ryan M. Pearson, Griffith University

China’s signature foreign policy, the Belt and Road initiative, has garnered much attention and controversy. Many have voiced fears about how the huge infrastructure project might expand China’s military and political influence across the world. But the environmental damage potentially wrought by the project has received scant attention.

The policy aims to connect China with Europe, East Africa and the rest of Asia, via a massive network of land and maritime routes. It includes building a series of deepwater ports, dubbed a “string of pearls”, to create secure and efficient sea transport.

All up, the cost of investments associated with the project have been estimated at as much as US$8 trillion. But what about the environmental cost?

Coastal development typically damages habitats and species on land and in the sea. So the Belt and Road plan may irreversibly damage the world’s oceans – but it also offers a chance to better protect them.

A map showing sea and land routes planned under the Belt and Road initiative.
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Controversial deals

China’s President Xi Jinping announced the Belt and Road initiative in 2013. Since then, China has already helped build and operate at least 42 ports in 34 countries, including in Greece, Sri Lanka and Pakistan. As of October this year, 138 countries had signed onto the plan.

The Victorian government joined in 2018, in a move that stirred political controversy. Those tensions have heightened in recent weeks, as the federal government’s relationship with China deteriorates.

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Victorian Premier Daniel Andrews recently reiterated his commitment to the deal, saying: “I think a strong relationship and a strong partnership with China is very, very important.”

However, political leaders signing up to the Belt and Road plan must also consider the potential environmental consequences of the project.

Victorian Premier Daniel Andrews is committed to the Belt and Road initiative.
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Bigger ports and more ships

As well as ports, the Belt and Road plan involves roads, rail lines, dams, airfields, pipelines, cargo centres and telecommunications systems. Our research has focused specifically on the planned port development and expansion, and increased shipping traffic. We examined how it would affect coastal habitats (such as seagrass, mangroves, and saltmarsh), coral reefs and threatened marine species.

Port construction can impact species and habitats in several ways. For example, developing a site often requires clearing mangroves and other coastal habitats. This can harm animals and release carbon stored by these productive ecosystems, accelerating climate change. Clearing coastal vegetation can also increase run-off of pollution from land into coastal waters.

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Ongoing dredging to maintain shipping channels stirs up sediment from the seafloor. This sediment smothers sensitive habitats such as seagrass and coral and damages wildlife, including fishery species on which many coastal communities depend.

A rise in shipping traffic associated with trade expansion increases the risk to animals being directly struck by vessels. More ships also means a greater risk of shipping accidents, such as the oil spill in Mauritius in July this year.

Dredging can cause sediment to smother seagrass.
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Ocean habitat destroyed

Our spatial analysis found construction of new ports, and expansion of existing ports, could lead to a loss of coastal marine habitat equivalent in size to 69,500 football fields.

These impacts were proportionally highest in small countries with relatively small coastal areas – places such as Singapore, Togo, Djibouti and Malta – where a considerable share of coastal marine habitat could be degraded or destroyed.

Habitat loss is particularly concerning for small nations where local livelihoods depend on coastal habitats. For example, mangroves, coral reefs, and seagrass protect coasts from storm surges and sea-level rise, and provide nursery habitat for fish and other marine species.

Our analysis also found more than 400 threatened species, including mammals, could be affected by port infrastructure. More than 200 of these are at risk from an increase in shipping traffic and noise pollution from ships. This sound can travel many kilometres and affect the mating, nursing and feeding of species such as dolphins, manatees and whales.

Noise pollution from ships can affect threatened species such as manatees.
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But there are opportunities, too

Despite these environmental concerns, the Belt and Road initiative also offers an opportunity to improve biodiversity conservation, and progress towards environmental targets such as the United Nations’ Sustainable Development Goals.

For example, China could implement a broad, consistent environmental framework that ensures individual infrastructure projects are held to the same high standards.

In Australia, legislation helps prevent damage to wildlife from port activities. For example, go-slow zones minimise the likelihood of vessels striking iconic wildlife such as turtles and dugongs. Similarly, protocols for the transport, handling, and export of mineral concentrates and other potentially hazardous materials minimise the risk of pollutants entering waterways.

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The Belt and Road initiative should require similar environmental protections across all its partner countries, and provide funding to ensure they are enacted.

China has recently sought to boost its environment credentials on the world stage – such as by adopting a target of net-zero carbon emissions by 2060. The global nature of the Belt and Road initiative means China is in a unique position: it can cause widespread damage, or become an international leader on environmental protection.

Mischa Turschwell, Research Fellow, Griffith University; Christopher Brown, Senior Lecturer, School of Environment and Science, Griffith University, and Ryan M. Pearson, Research Fellow, Griffith University

This article is republished from The Conversation under a Creative Commons license. Read the original article.