‘Bright white skeletons’: some Western Australian reefs have the lowest coral cover on record


Corals at Scott Reef in 2012, and at the same site during the 2016 mass bleaching.
James Gilmour/AIMS

James Paton Gilmour, Australian Institute of Marine Science and Rebecca Green, University of Western Australia

Diving on the remote coral reefs in the north of Western Australia during the world’s worst bleaching event in 2016, the first thing I noticed was the heat. It was like diving into a warm bath, with surface temperatures of 34⁰C.

Then I noticed the expanse of bleached colonies. Their bright white skeletons were visible through the translucent tissue following the loss of the algae with which they share a biological relationship. The coral skeletons had not yet eroded and collapsed, a grim reminder of what it looked like just a few months before.

I spent the past 15 years documenting the recovery of these reefs following the first global coral bleaching event in 1998, only to see them devastated again in the third global bleaching event in 2016.




Read more:
Western Australia’s coral reefs are in trouble: we mustn’t ignore them


The WA coral reefs may not be as well known as the Great Barrier Reef, but they’re just as large and diverse. And they too have been affected by cyclones and coral bleaching. Our recent study found many WA reefs now have the lowest coral cover on record.

When my colleague, Rebecca Green, witnessed that mass bleaching for the first time, she asked me how long it would take the reefs to recover.

“Probably not in my lifetime” was my reply – an abrupt but accurate reply considering the previous rate of recovery, future increases in ocean temperatures … and my age.

The worst mass bleaching on record

A similar scene is playing out around the world as researchers document the decline of ecosystems they have spent a lifetime studying.

Our study, published in the journal Coral Reefs, is the first to establish a long-term history of changes in coral cover across eight reef systems, and to document the effects of the 2016 mass bleaching event at 401 sites across WA.




Read more:
The third global bleaching event took its toll on Western Australia’s super-corals


Given the vast expanse of WA coral reefs, our assessment included data from several monitoring programs and researchers from 19 institutions.

These reefs exist in some of the most remote and inaccessible parts of the
world, so our study also relied on important observations of coral bleaching from regional managers, tourist operators and Bardi Jawi Indigenous Rangers in the Kimberley.

Our aim was to establish the effects of climate change on coral reefs along Western Australia’s vast coastline and their current condition.

The heat stress in 2016 was the worst on record, causing mass bleaching and large reductions in coral cover at Christmas Island, Ashmore Reef and Scott Reef. This was also the first time mass bleaching was recorded in the southern parts of the inshore Kimberley region, including in the long oral history of Indigenous Australians who have managed this sea-country for thousands of years.

The mass bleaching events we documented were triggered by a global increase in temperature of 1⁰C above pre-industrial levels, whereas temperatures are predicted to rise by 1.5⁰C between 2030 and 2052.

In that scenario, the reefs that have bleached badly will unlikely have the capacity to fully recover, and mass bleaching will occur at the reefs that have so far escaped the worst impacts.




Read more:
The world’s coral reefs are in trouble, but don’t give up on them yet


The future of WA’s coral reefs is uncertain, but until carbon emissions can be reduced, coral bleaching will continue to increase.

Surviving coral reef refuges must be protected

The extreme El Niño conditions in 2016 severely affected the northern reefs, and a similar pattern was seen in the long-term records.

The more southern reefs were affected by extreme La Niña conditions – most significantly by a heatwave in 2011 that caused coral bleaching, impacted fisheries and devastated other marine and terrestrial ecosystems.

Since 2010, all of WA’s reefs systems have bleached at least once.

Frequent bleaching and cyclone damage have stalled the recovery of reefs at Shark Bay, Ningaloo and at the Montebello and Barrow Islands. And coral cover at Scott Reef, Ashmore Reef and at Christmas Island is low following the 2016 mass bleaching.

In fact, average coral cover at most (75%) reef systems is at or near the lowest on record. But not all WA reefs have been affected equally.

In 2016 there was little (around 10%) bleaching recorded at the northern inshore Kimberley Reefs, at the Cocos Keeling Islands, and at the Rowley Shoals. Coral cover and diversity at these reefs remain high.

And during mass bleaching there were patches of reef that were less affected by heat stress.

These patches of reef will hopefully escape the worst impacts and retain moderate coral cover and diversity as the world warms, acting as refuges. There are also corals that have adapted to survive in parts of the reef where temperatures are naturally hotter.

Some reefs across WA will persist, thanks to these refuges from heat stress, their ability to adapt and to expand their range. These refuges must be protected from any additional stress, such as poor water quality and overfishing.




Read more:
Even the super-corals of Australia’s Kimberley are not immune to climate change


In any case, the longer it takes to curb carbon emissions and other pressures to coral reefs, the greater the loss will be.

Coral reefs support critical food stocks for fisheries around the world and provide a significant contribution to Australia’s Blue Economy, worth an estimated A$68.1 billion.

We are handing environmental uncertainty to the next generation of scientists, and we must better articulate to everyone that their dependence on nature is the most fundamental of all the scientific concepts we explore.The Conversation

James Paton Gilmour, Research Scientist: Coral Ecology, Australian Institute of Marine Science and Rebecca Green, Postdoctoral research associate, University of Western Australia

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

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Coral reproduction on the Great Barrier Reef falls 89% after repeated bleaching


Morgan Pratchett, James Cook University

The severe and repeated bleaching of the Great Barrier Reef has not only damaged corals, it has reduced the reef’s ability to recover.

Our research, published today in Nature, found far fewer baby corals are being produced than are needed to replace the large number of adult corals that have died. The rate at which baby corals are settling on the Great Barrier Reef has fallen by nearly 90% since 2016.

While coral does not always die after bleaching, repeated bleaching has killed large numbers of coral. This new research has negative implications for the Reef’s capacity to recover from high ocean temperatures.

How coral recovers

Most corals reproduce by “spawning”: releasing thousands of tight, buoyant bundles with remarkable synchronisation. The bundles burst when they hit the ocean surface, releasing eggs and/or sperm. Fertilised eggs develop into larvae as they are moved about by ocean currents. The larvae settle in new places, forming entirely new coral colonies. This coral “recruitment” is essential to reef recovery.




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Explainer: mass coral spawning, a wonder of the natural world


The research team, led by my colleague Terry Hughes from the ARC Centre of Excellence for Coral Reef Studies, measured rates of coral recruitment by attaching small clay tiles to the reef just before the predicted mass spawning each year. These settlement panels represent a standardised habitat that allows for improved detection of the coral recruits, which are just 1-2mm in size.

Almost 1,000 tiles were deployed across 17 widely separated reefs after the recent mass bleaching, in late 2016 and 2017. After eight weeks they were collected and carefully inspected under a microscope to count the number of newly settled coral recruits. Resulting estimates of coral recruitment were compared to recruitment rates recorded over two decades prior to the recent bleaching.

Australian Academy of Science.

Rates of coral recruitment recorded in the aftermath of the recent coral bleaching were just 11% of levels recorded during the preceding decades. Whereas there were more than 40 coral recruits per tile before the bleaching, there was an average of just five coral recruits per tile in the past couple of years.




Read more:
Tropical marine conservation needs to change as coral reefs decline


Reef resilience

The Great Barrier Reef (GBR) is the world’s largest reef system. The large overall size and high number of distinct reefs provides a buffer against most major disturbances. Even if large tracts of the GBR are disturbed, there is a good chance at least some areas will have healthy stocks of adult corals, representing a source of new larvae to enable replenishment and recovery.

Larvae produced by spawning corals on one reef may settle on other nearby reefs to effectively replace corals lost to localised disturbances.

It is reassuring there is at least some new coral recruitment in the aftermath of severe bleaching and mass mortality of adult corals on the GBR. However, the substantial and widespread reduction of regrowth indicates the magnitude of the disturbance caused by recent heatwaves.

Declines in rates of coral recruitment were greatest in the northern parts of the GBR. This is where bleaching was most pronounced in 2016 and 2017, and there was the greatest loss of adult corals. There were much more moderate declines in coral recruitment in the southern GBR, reflecting generally higher abundance of adults corals in these areas. However, prevailing southerly currents (and the large distances involved) make it very unlikely coral larvae from southern parts of the Reef will drift naturally to the hardest-hit northern areas.

It is hard to say how long it will take for coral assemblages to recover from the recent mass bleaching. What is certain is low levels of coral recruitment will constrain coral recovery and greatly increase the recovery time. Any further large-scale developments with also greatly reduce coral cover and impede recovery.




Read more:
The 2016 Great Barrier Reef heatwave caused widespread changes to fish populations


Reducing carbon emissions

This study further highlights the vulnerability of coral reefs to sustained and ongoing global warming. Not only do adult corals bleach and die when exposed to elevated temperatures, this prevents new coral recruitment and undermines ecosystem resilience.

The only way to effectively redress global warming is to immediately and substantially reduce global carbon emissions. This requires that all countries, including Australia, renew and strengthen their commitments to the Paris Agreement on climate change.

While further management is required to minimise more direct human pressure on coral reefs – such as sediment run-off and pollution – all these efforts will be futile if we do not address global climate change.The Conversation

Morgan Pratchett, Professor, ARC Centre of Excellence for Coral Reef Studies, James Cook University

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

Bleaching has struck the southernmost coral reef in the world


Tess Moriarty, University of Newcastle; Bill Leggat, University of Newcastle; C. Mark Eakin, National Oceanic and Atmospheric Administration; Rosie Steinberg, UNSW; Scott Heron, James Cook University, and Tracy Ainsworth, UNSW

This month corals in Lord Howe Island Marine Park began showing signs of bleaching. The 145,000 hectare marine park contains the most southerly coral reef in the world, in one of the most isolated ecosystems on the planet.

Following early reports of bleaching in the area, researchers from three Australian universities and two government agencies have worked together throughout March to investigate and document the bleaching.

Sustained heat stress has seen 90% of some reefs bleached, although other parts of the marine park have escaped largely unscathed.

Bleaching is uneven

Lord Howe Island was named a UNESCO World Heritage site in 1982. It is the coral reef closest to a pole, and contains many species found nowhere else in the world.

Coral bleaching observed at Lord Howe in March 2019.
Author provided

Two of us (Tess Moriarty and Rosie Steinberg) have surveyed reefs across Lord Howe Island Marine Park to determine the extent of bleaching in the populations of hard coral, soft coral, and anemones. This research found severe bleaching on the inshore lagoon reefs, where up to 95% of corals are showing signs of extensive bleaching.

However, bleaching is highly variable across Lord Howe Island. Some areas within the Lord Howe Island lagoon coral reef are not showing signs of bleaching and have remained healthy and vibrant throughout the summer. There are also corals on the outer reef and at deeper reef sites that have remained healthy, with minimal or no bleaching.

One surveyed reef location in Lord Howe Island Marine Park is severely impacted, with more than 90% of corals bleached; at the next most affected reef site roughly 50% of corals are bleached, and the remaining sites are less than 30% bleached. At least three sites have less than 5% bleached corals.

Healthy coral photographed at Lord Howe marine park in March 2019.
Author provided

Over the past week heat stress has continued in this area, and return visits to these sites revealed that the coral condition has worsened. There is evidence that some corals are now dying on the most severely affected reefs.

Forecasts for the coming week indicate that water temperatures are likely to cool below the bleaching threshold, which will hopefully provide timely relief for corals in this valuable reef ecosystem. In the coming days, weeks and months we will continue to monitor the affected reefs and determine the impact of this event to the reef system, and investigate coral recovery.

What’s causing the bleaching?

The bleaching was caused by high seawater temperature from a persistent summer marine heatwave off southeastern Australia. Temperature in January was a full degree Celsius warmer than usual, and from the end of January to mid-February temperatures remained above the local bleaching threshold.

Sustained heat stressed the Lord Howe Island reefs, and put them at risk. They had a temporary reprieve with cooler temperatures in late February, but by March another increase put the ocean temperature well above safe levels. This is now the third recorded bleaching event to have occurred on this remote reef system.

Satellite monitoring of sea-surface temperature (SST) revealed three periods in excess of the Bleaching Threshold during which heat stress accumulated (measured as Degree Heating Weeks, DHW). Since January 2019, SST (purple) exceeded expected monthly average values (blue +) by as much as 2°C. The grey line and envelope indicate the predicted range of SST in the near future.
Source: NOAA Coral Reef Watch

However, this heatwave has not equally affected the whole reef system. In parts of the lagoon areas the water can be cooler, due to factors like ocean currents and fresh groundwater intrusion, protecting some areas from bleaching. Some coral varieties are also more heat-resistant, and a particular reef that has been exposed to high temperatures in the past may better cope with the current conditions. For a complex variety of reasons, the bleaching is unevenly affecting the whole marine park.

Coral bleaching is the greatest threat to the sustainability of coral reefs worldwide and is now clearly one of the greatest challenges we face in responding to the impact of global climate change. UNESCO World Heritage regions, such as the Lord Howe Island Group, require urgent action to address the cause and impact of a changing climate, coupled with continued management to ensure these systems remain intact for future generations.


The authors thank ProDive Lord Howe Island and Lord Howe Island Environmental Tours for assistance during fieldwork.The Conversation

Tess Moriarty, Phd candidate, University of Newcastle; Bill Leggat, Associate professor, University of Newcastle; C. Mark Eakin, Coordinator, Coral Reef Watch, National Oceanic and Atmospheric Administration; Rosie Steinberg, PhD Student, UNSW; Scott Heron, Senior Lecturer, James Cook University, and Tracy Ainsworth, Associate professor, UNSW

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

Shark Bay: A World Heritage Site at catastrophic risk



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Shark Bay was hit by a brutal marine heatwave in 2011.
W. Bulach/Wikimedia Commons, CC BY-SA

Matthew Fraser, University of Western Australia; Ana Sequeira, University of Western Australia; Brendan Paul Burns, UNSW; Diana Walker, University of Western Australia; Jon C. Day, James Cook University, and Scott Heron, James Cook University

The devastating bleaching on the Great Barrier Reef in 2016 and 2017 rightly captured the world’s attention. But what’s less widely known is that another World Heritage-listed marine ecosystem in Australia, Shark Bay, was also recently devastated by extreme temperatures, when a brutal marine heatwave struck off Western Australia in 2011.

A 2018 workshop convened by the Shark Bay World Heritage Advisory Committee classified Shark Bay as being in the highest category of vulnerability to future climate change. And yet relatively little media attention and research funding has been paid to this World Heritage Site that is on the precipice.




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Shark Bay stromatolites at risk from climate change


Shark Bay.
Openstreetmap.org/Wikimedia Commons, CC BY-SA

Shark Bay, in WA’s Gascoyne region, is one of 49 marine World Heritage Sites globally, but one of only four of these sites that meets all four natural criteria for World Heritage listing. The marine ecosystem supports the local economy through tourism and fisheries benefits.

Around 100,000 tourists visit Shark Bay each year to interact with turtles, dugongs and dolphins, or to visit the world’s most extensive population of stromatolites – stump-shaped colonies of microbes that date back billions of years, almost to the dawn of life on Earth.

Commercial and recreational fishing is also extremely important for the local economy. The combined Shark Bay invertebrate fishery (crabs, prawns and scallops) is the second most valuable commercial fishery in Western Australia.

Under threat

However, this iconic and valuable marine ecosystem is under serious threat. Shark Bay is especially vulnerable to future climate change, given that the temperate seagrass that underpins the entire ecosystem is already living at the upper edge of its tolerable temperature range. These seagrasses provide vital habitat for fish and marine mammals, and help the stromatolites survive by regulating the water salinity.

Stromatolites are a living window to the past.
Matthew Fraser

Shark Bay received the highest rating of vulnerability using the recently developed Climate Change Vulnerability Index, created to provide a method for assessing climate change impacts across all World Heritage Sites.

In particular, extreme marine heat events were classified as very likely and predicted to have catastrophic consequences in Shark Bay. By contrast, the capacity to adapt to marine heat events was rated very low, showing the challenges Shark Bay faces in the coming decades.

The region is also threatened by increasingly frequent and intense storms, and warming air temperatures.

To understand the potential impacts of climatic change on Shark Bay, we can look back to the effects of the most recent marine heatwave in the area. In 2011 Shark Bay was hit by a catastrophic marine heatwave that destroyed 900 square kilometres of seagrass – 36% of the total coverage.

This in turn harmed endangered species such as turtles, contributed to the temporary closure of the commercial crab and scallop fisheries, and released between 2 million and 9 million tonnes of carbon dioxide – equivalent to the annual emissions from 800,000 homes.




Read more:
Climate change threatens Western Australia’s iconic Shark Bay


Some aspects of Shark Bay’s ecosystem have never been the same since. Many areas previously covered with large, temperate seagrasses are now bare, or have been colonised by small, tropical seagrasses, which do not provide the same habitat for animals. This mirrors the transition seen on bleached coral reefs, which are taken over by turf algae. We may be witnessing the beginning of Shark Bay’s transition from a sub-tropical to a tropical marine ecosystem.

This shift would jeopardise Shark Bay’s World Heritage values. Although stromatolites have survived for almost the entire history of life on Earth, they are still vulnerable to rapid environmental change. Monitoring changes in the microbial makeup of these communities could even serve as a canary in the coalmine for global ecosystem changes.

The neglected bay?

Despite Shark Bay’s significance, and the seriousness of the threats it faces, it has received less media and funding attention than many other high-profile Australian ecosystems. Since 2011, the Australian Research Council has funded 115 research projects on the Great Barrier Reef, and just nine for Shark Bay.

Coral reefs rightly receive a lot of attention, particularly given the growing appreciation that climate change threatens the Great Barrier Reef and other corals around the world.

The World Heritage Committee has recognised that local efforts alone are no longer enough to save coral reefs, but this logic can be extended to other vulnerable marine ecosystems – including the World Heritage values of Shark Bay.

Safeguarding Shark Bay from climate change requires a coordinated research and management effort from government, local industry, academic institutions, not-for-profits and local Indigenous groups – before any irreversible ecosystem tipping points are reached. The need for such a strategic effort was obvious as long ago as the 2011 heatwave, but it hasn’t happened yet.




Read more:
Marine heatwaves are getting hotter, lasting longer and doing more damage


Due to the significant Aboriginal heritage in Shark Bay, including three language groups (Malgana, Nhanda and Yingkarta), it will be vital to incorporate Indigenous knowledge, so as to understand the potential social impacts.

And of course, any on-the-ground actions to protect Shark Bay need to be accompanied by dramatic reductions in greenhouse emissions. Without this, Shark Bay will be one of the many marine ecosystems to fundamentally change within our lifetimes.The Conversation

Matthew Fraser, Postdoctoral Research Fellow, University of Western Australia; Ana Sequeira, ARC DECRA Fellow, University of Western Australia; Brendan Paul Burns, Senior Lecturer, UNSW; Diana Walker, Emeritus Professor, University of Western Australia; Jon C. Day, PSM, Post-career PhD candidate, ARC Centre of Excellence for Coral Reef Studies, James Cook University, and Scott Heron, Senior Lecturer, James Cook University

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

There’s insufficient evidence your sunscreen harms coral reefs


Terry Hughes, James Cook University

In the face of persistent heatwaves, Australians are reaching for the sunscreen. But you might have heard some mixed messages about its harm to the environment – specifically to coral reefs.

In July 2018, Hawaii passed a law to prohibit the future sale of sunscreens containing benzophene-3 and octinoxate, claiming these two chemicals increase coral bleaching, and have significant harmful impacts on Hawaii’s marine environment.




Read more:
Marine heatwaves are getting hotter, lasting longer and doing more damage


In October 2018, the Republic of Palau followed suit, and banned “reef-toxic” sunscreens. Like most reefs throughout the tropics and subtropics, coral reefs in Hawaii and Palau have already severely bleached multiple times during recent, unusually hot summers, causing extensive loss of corals.

Key West, in Florida, may be the latest area to follow this trend, with a proposed ban to be voted on in early February.

However, medical and skin cancer specialists have warned of the public health risks of a ban on widely used sunscreens, describing the prohibition as risky and unjustified, in part because the few studies that have addressed the environmental impacts of sunscreens experimentally “are not representative of real world conditions”.

For example, the way in which coral tissues were exposed to sunscreen in experiments does not mimic the dispersal and dilution of pollutants from a tourist’s skin (and other sources) into reef waters and onto corals growing in the wild.

Experiments that expose corals to sunscreen chemicals typically use far higher concentrations than have ever been measured on an actual reef. A recent review of the amount of benzophne-3 in reef waters found that, typically, concentrations are barely detectable – usually, a few parts per trillion. One much higher report of 1.4 parts per million, in the US Virgin Islands, is based on a single water sample.

The environmental concerns over sunscreens on coral reefs are centred overwhelmingly on just two studies. The first, published in 2008, noted that there was no previous scientific evidence for an impact of sunscreens on coral reefs.

This study exposed small fragments of corals (branch tips) to high levels of benzophenone-3 and other chemicals by incubating them for a few days inside plastic bags. The fragments in the bags quickly became diseased with viruses and bleached. The authors concluded “up to 10% of the world reefs are potentially threatened by sunscreen-induced coral bleaching”.

Bleaching is a stress response by corals, where they turn pale due to a decline in the symbiotic micro-algae that lives inside their tissues. You can make a coral bleach experimentally by torturing it in any number of ways. However, coral bleaching at a global and regional scale is caused by anthropogenic heating, not sunscreen. We know the footprint of bleaching on the Great Barrier Reef in 1998, 2002, 2016 and 2017 is closely matched to where the water was hottest for longest in each event.

Even the most remote reefs are vulnerable to heat stress. The physiological mechanisms and timescale of thermal bleaching due to global heating is very different from the rapid responses of corals to experimental exposure to high concentrations of sunscreen chemicals.

The second and most-widely cited study of sunscreen toxicity on corals is also laboratory-based. Published in 2016, it focused mainly on the responses of the day-old larvae of one coral species, as well as isolated coral cells. This study did not examine intact coral colonies.

The larvae were placed in 2-3 centilitres of artificial seawater containing a range of concentrations of sunscreen chemicals and a solvent to disperse them. After a few hours, the coral larvae became increasingly pale (bleached) with higher concentrations of oxybenzone.




Read more:
Why there’s still hope for our endangered coral reefs


This study also measured the concentration of benzophenone in sea water at six locations in Hawaii. These samples were unreplicated (one per location), and all of them had unmeasureable amounts of sunscreen chemicals. In the US Virgin Islands, the authors found higher concentrations of benzophenone at four out of ten locations, although they did not report results for any blank samples (to control for contamination). The study concluded that oxybenzone threatens the resilience of coral reefs to climate change.

In conclusion, there is actually no direct evidence to demonstrate that bleaching due to global heating is exacerbated by sunscreen pollutants. Similarly, there is no evidence that recovery from thermal bleaching is impaired by sunscreens, or that sunscreens cause coral bleaching in the wild.The Conversation

Terry Hughes, Distinguished Professor, James Cook University

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

Exploring Australia’s ‘other reefs’ south of Tasmania



File 20181217 27779 1tg4cyr.jpg?ixlib=rb 1.1
Solenosmilia coral reef with unidentified solitary yellow corals.
CSIRO

Nic Bax, CSIRO and Alan Williams, CSIRO

Off southern Tasmania, at depths between 700 and 1,500 metres, more than 100 undersea mountains provide rocky pedestals for deep-sea coral reefs.

Unlike shallow tropical corals, deep-sea corals live in a cold environment without sunlight or symbiotic algae. They feed on tiny organisms filtered from passing currents, and protect an assortment of other animals in their intricate structures.

Deep-sea corals are fragile and slow-growing, and vulnerable to human activities such as fishing, mining and climate-related changes in ocean temperatures and acidity.

This week we returned from a month-long research voyage on CSIRO vessel Investigator, part of Australia’s Marine National Facility. We criss-crossed many seamounts in and near the Huon and Tasman Fracture marine parks, which are home to both pristine and previously fished coral reefs. These two parks are part of a larger network of Australian Marine Parks that surround Australia’s coastline and protect our offshore marine environment.

The RV Investigator criss-crossed the Huon and Tasman Fracture marine parks.
CSIRO

The data we collected will answer our two key research questions: what grows where in these environments, and are corals regrowing after more than 20 years of protection?




Read more:
Explainer: the RV Investigator’s role in marine science


Our eyes on the seafloor

Conducting research in rugged, remote deep-sea environments is expensive and technically challenging. It’s been a test of patience and ingenuity for the 40 ecologists, technicians and marine park managers on board, and the crew who provide electronics, computing and mechanical support.

But now, after four weeks of working around-the-clock shifts, we’re back in the port of Hobart. We have completed 147 transects covering more 200 kilometres in length and amassed more than 60,000 stereo images and some 300 hours of video for analysis.

The deep tow camera system weighs 350 kilos and has four cameras, four lights and a control unit encased in high-strength aluminium housings.
CSIRO

A deep-tow camera system designed and built by CSIRO was our eye on the seafloor. This 350 kilogram system has four cameras, four lights and a control unit encased in high-strength aluminium housings.

An operations planner plots “flight-paths” down the seamounts, adding a one-kilometre run up for the vessel skipper to land the camera on each peak. The skipper navigates swell, wind and current to ensure a steady course for each one-hour transect.

An armoured fibre optic tow cable relays high-quality, real-time video back to the ship. This enables the camera “pilot” in the operations room to manoeuvre the camera system using a small joystick, and keep the view in focus, a mere two metres off the seafloor.

This is an often challenging job, as obstacles like large boulders or sheer rock walls loom out of the darkness with little warning. The greatest rapid ascent, a near-vertical cliff 45m in height, resulted in highly elevated blood pressure and one broken camera light!

Reaching into their world

Live imagery from the camera system was compelling. As well as the main reef-building stony coral Solenosmilia variabilis, we saw hundreds of other animals including feathery solitary soft corals, tulip-shaped glass sponges and crinoids. Their colours ranged from delicate creams and pinks to striking purples, bright yellows and golds.

To understand the make-up of coral communities glimpsed by our cameras, we also used a small net to sample the seafloor animals for identification. For several of the museum taxonomists onboard, this was their first contact with coral and mollusc species they had known, and even named, only from preserved specimens.

A deepwater hippolytid shrimp with large hooked claw, which it uses to clean coral and get food.
CSIRO

We found a raft of undescribed species, as expected in such remote environments. In many cases this is likely to be the only time these species are ever collected. We also found animals living among the corals, hinting at their complex interdependencies. This included brittlestars curled around corals, polychaete worms tunnelling inside corals, and corals growing on shells.

We used an oceanographic profiler to sample the chemical properties of the water to 2,000m. Although further analysis is required, our aim here is to see whether long-term climate change is impacting the living conditions at these depths.

A curious feature of one of the southern seamounts is that it hosts the world’s only known aggregation of deep-water eels. We have sampled these eels twice before and were keen to learn more about this rare phenomenon.

Using an electric big-game fishing rig we landed two egg-laden female eels from a depth of 1,100 metres: a possible first for the record books.

Dave Logan of Parks Australia with an eel landed from more than a kilometre under the sea.
Fraser Johnston/CSIRO

In a side-project, a team of observers recorded 42 seabird species and eight whale and dolphin species. They have one more set of data towards completing the first circum-Australia survey of marine birds and mammals.

More coral pedestals than we realise

An important finding was that living S. variabilis reefs extended between the seamounts on raised ridges down to about 1,450m. This means there is more of this important coral matrix in the Huon and Tasman Fracture marine parks than we previously realised.

In areas that were revisited to assess the regrowth of corals after two decades of protection from fishing, we saw no evidence that the coral communities are recovering. But there were signs that some individual species of corals, featherstars and urchins have re-established a foothold.




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Sludge, snags, and surreal animals: life aboard a voyage to study the abyss


In coming months we will work through a sub-sample of our deep-sea image library to identify the number and type of organisms in certain areas. This will give us a clear, quantitative picture of where and at what depth different species and communities live in these marine parks, and a foundation for predicting their likely occurrence both in Australia and around the world.


The seamount corals survey involved 10 organisations: CSIRO, the National Environmental Science Program Marine Biodiversity Hub, Australian Museum, Museums Victoria, Tasmanian Museum and Art Gallery, NIWA (NZ), three Australian universities and Parks Australia.The Conversation

Nic Bax, Director, NERP Marine Biodiversity Hub, CSIRO and Alan Williams, Researcher, CSIRO

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

Cities can grow without wrecking reefs and oceans. Here’s how



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Cairns has lots of hard grey infrastructure but much less green infrastructure that would reduce the impacts of the city’s growth.
Karine Dupré, Author provided

Silvia Tavares, James Cook University and Karine Dupré, Griffith University

What happens if the water temperature rises by a few degrees?” is the 2018 International Year of the Reef leading question. While the ocean is the focus, urbanisation is the main reason for the rising temperatures and water pollution. Yet it receives little attention in this discussion.

In turn, rising temperatures increase downpours and urban floods, adding to the pressures on urban infrastructure.




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Design for flooding: how cities can make room for water


Protecting the reef as Cairns grows

Cairns is an expanding Queensland city located between two World Heritage sites – the Great Barrier Reef and the Daintree Rainforest. While important research focuses on these sites themselves, not much is known about how the surrounding urban areas influence these natural environments. Similarly, little is known about how urban planning and design contribute to the health of the inner city and surrounding water bodies, including the ocean.

Cairns is a major Australian tourism destination with a unique coastal setting of rainforest and reef. This attracts growing numbers of visitors. One effect of this success is increased urbanisation to accommodate these tourists.

There are many opportunities to promote sustainable and socially acceptable growth in Cairns. Yet this growth is not without challenges. These include:

  • impacts of climate change, including sea-level rise and ocean warming
  • lack of comprehensive urban infrastructure strategy
  • lack of comprehensive assessment of the benefits of integrated urban design to maximise coastal resilience and the health of streams and oceans.
Rain gardens are common in Singapore.
Roger Soh/Flickr, CC BY-SA

As with most Australian cities, Cairns has an urban layout based on wide streets, mostly with little or no greenery. Rain gardens, for instance, are rare. Bioswales that slow and filter stormwater are present along highways, but seldom within the city.

The arguments for not adding greenery to the urban environment are familiar. These typically relate to costs of implementation and maintenance, but also to the speed with which water is taken out of streets during the tropical rainy season. This is because green stormwater solutions, if not well planned, can slow down the water flow, thus increasing floods.

However, cities can be designed in a way to imitate nature with solutions that are an integral part of the urban system. This can include dedicated areas of larger wetlands and parks, which capture water and filter pollution and undesired nutrients more efficiently, reducing polluted runoff to the reef.




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Integrated urban design

Integrated urban design is an aspect of city planning and design that could be further developed to ensure the whole system works more efficiently. This involves integrating the three elements that make up urban infrastructure:

  1. the green – parks, residential gardens, rain gardens, green roofs and walls, bioswales, etc
  2. the grey – built drains, footpaths, buildings, underground vacuum
    system
    , etc
  3. the blue – streams, stormwater systems, etc.
A rain garden, which absorbs rain and stores water to help control run-off from impervious hard surfaces, in Wellington, New Zealand.
Karine Dupré

Urban infrastructure, therefore, can and should be planned and designed to provide multiple services, including coastal resilience and healthier water streams and oceans. To achieve this, a neighbourhood or city-wide strategy needs to be implemented, instead of intermittent and ad hoc urban design solutions. Importantly, each element should coordinate with the others to avoid overlaps, gaps and pitfalls.

This is what integrated urban design is about. So why don’t we implement it more often?

Challenges and opportunities

Research has shown that planning, designing and creating climate-resilient cities that are energy-optimised, revitalise urban landscapes and restore and support ecosystem services is a major challenge at the planning scale. To generate an urban environment that promotes urban protection and resilience while minimising urbanisation impacts and restoring natural systems, we need to better anticipate the risks and have the means to take actions. In other words, it is a two-way system: well planned and designed green and blue infrastructures not only deliver better urbanised areas but will also protect the ocean from pollution. Additionally, it helps to manage future risks of severe weather.

The uncertainties of green infrastructure capacity and costs of maintenance, combined with inflexible finance schemes, are obstacles to integrated urban solutions. Furthermore, the lack of inter- and transdisciplinary approaches results in disciplinary barriers in research and policymaking to long-term planning of the sort that generates urban green infrastructure and its desired outcomes.

On the bright side, there is also strong evidence to suggest sound policy can help overcome these barriers through technical guides based on scientific research, standards and financial incentives.




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Collaborative partnerships are promising, too. Partnerships between academia and industry tend to be more powerful than streamlined industry project developments.

Finally, and very promisingly, Australia has its own successful green infrastructure examples. Melbourne’s urban forest strategy has been internationally acclaimed. Examples like these provide valuable insights into local green infrastructure governance.

Cairns has stepped up with some stunning blue infrastructure on the Esplanade which raises awareness of both locals and visitors about the protection of our oceans.

This is only the start. Together academics, local authorities, industry stakeholders and communities can lead the way to resilient cities and healthier oceans.

Cairns Esplanade Lagoon helps raise awareness of the need to protect the ocean as the city grows.
Karine Dupré, Author provided



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The Conversation


Silvia Tavares, Lecturer in Urban Design, James Cook University and Karine Dupré, Associate Professor in Architecture, Griffith University

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