Australia’s hidden opportunity to cut carbon emissions, and make money in the process



A seagrass meadow. For the first time, researchers have counted the greenhouse gases stored by and emitted from such ecosystems.
NOAA/Heather Dine

Oscar Serrano, Edith Cowan University; Carlos Duarte, King Abdullah University of Science and Technology; Catherine Lovelock, The University of Queensland; Paul Lavery, Edith Cowan University, and Trisha B Atwood, Utah State University

It’s no secret that cutting down trees is a main driver of climate change. But a forgotten group of plants is critically important to fixing our climate — and they are being destroyed at an alarming rate.

Mangroves, tidal marshes and seagrasses along Australia’s coasts store huge amounts of greenhouse gases, known as blue carbon.

Our research, published in Nature Communications, shows that in Australia these ecosystems absorb 20 million tonnes of carbon dioxide each year. That’s about the same as 4 million cars.




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Worryingly, the research shows that between 2 million and 3 million tonnes of carbon dioxide is released each year by the same ecosystems, due to damage from human activity, severe weather and climate change.

This research represents the world’s most comprehensive audit of any nation’s blue carbon. Around 10% of such ecosystems are located in Australia — so preserving and restoring them could go a long way to meeting our Paris climate goals.

A pile of washed-up seaweed and beach erosion at Collaroy Beach on Sydney’s northern beaches. Storms can damage blue carbon ecosystems.
Megan Young/AAP

Super-charged carbon dioxide capture

Blue carbon ecosystems are vital in curbing greenhouse gas emissions. They account for 50% of carbon dioxide sequestered by oceans — despite covering just 0.2% of the world’s total ocean area — and absorb carbon dioxide up to 40 times faster than forests on land.

They do this by trapping particles from water and storing them in the soil. This means tidal marsh, mangrove and seagrass ecosystems bury organic carbon at an exceptionally high rate.

Globally, blue carbon ecosystems are being lost twice as fast as tropical rainforests despite covering a fraction of the area.

Since European settlement, about 25,000km² of tidal marsh and mangroves and 32,000km² of seagrass have been destroyed – up to half the original extent. Coastal development in Australia is causing further losses each year.

When these ecosystems are damaged — through storms, heatwaves, dredging or other human development — the carbon stored in biomass and soils can make its way back into the environment as carbon dioxide, contributing to climate change.

In Western Australia in the summer of 2010-11, about 1,000km² of seagrass meadows at Shark Bay were lost due to a marine heatwave. Similarly, two cyclones and several other impacts devastated a 400km stretch of mangroves in the Gulf of Carpentaria in recent years.

The beach and Cape Kimberley hinterland at the mouth of the Daintree River in Queensland.
Brian Cassey/AAP

Such losses likely increase carbon dioxide emissions from land-use change in Australia by 12–21% per year.

Aside from the emissions reduction benefits, conserving and restoring blue carbon ecosystems would also increase the resilience of coasts to rising sea level and storm surge associated with climate change, and preserve habitats and nurseries for marine life.

How we measured blue carbon – and why

The project was part of a collaboration with CSIRO and included 44 researchers from 33 research institutions around the world.

To accurately quantify Australia’s blue carbon stocks, we divided Australia into five different climate zones. Variations in temperature, rainfall, tides, sediments and nutrients mean plant productivity and biomass varies across regions. So ecosystems in a tropical climate such as North Queensland store carbon dioxide at a different rate to those in temperate climates such as southeastern Australia.




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We estimated carbon dioxide stored in the vegetation above ground and soils below for each climate area. We measured the size and distribution of vegetation and took soil core samples to create the most accurate measurements possible.

Blue carbon must be assessed on a national scale before policies to preserve them can be developed. These policies might involve replanting seagrass meadows, reintroducing tidal flow to restore mangroves or preventing potential losses caused by coastal development.

Seagrass at Queensland’s Gladstone Harbour.
James Cook University

There’s a dollar to be made

Based on a carbon price of A$14 per tonne – the most recent price under the federal government’s Emissions Reduction Fund – blue carbon projects could be worth tens of millions of dollars per year in carbon credits. Our comprehensive measurements provide greater certainty of expected returns for financiers looking at investing in such projects.

Restoring just 10% of blue carbon ecosystems lost in Australia since European settlement could generate more than US$11 million per year in carbon credits. Conserving such ecosystems under threat could be worth between US$22 million and US$31 million per year.




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Blue carbon projects cannot currently be counted towards Australia’s Paris targets, but federal environment authorities are developing a methodology for their inclusion. The reintroduction of tidal flow to restore mangrove and tidal marsh ecosystems has been identified as the most promising potential activity.

Other activities being explored include planning for sea level rise to allow mangrove and tidal marsh to migrate inland, and avoiding the clearing of seagrass and mangroves.

There are still questions to be answered about exactly how blue carbon can be used to mitigate climate change. But our research shows the massive potential in Australia, and allows other countries to use the work for their own blue carbon assessments.The Conversation

Oscar Serrano, ARC DECRA Fellow, Edith Cowan University; Carlos Duarte, Adjunct professor, King Abdullah University of Science and Technology; Catherine Lovelock, Professor of Biology, The University of Queensland; Paul Lavery, Professor of Marine Ecology, Edith Cowan University, and Trisha B Atwood, Assistant Professor of aquatic ecology, Utah State University

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

Dingoes found in New South Wales, but we’re killing them as ‘wild dogs’



One in four of nearly 800 animals genetically tested were pure dingo.
Michelle J Photography

Kylie M Cairns, UNSW; Brad Nesbitt, University of New England; Mathew Crowther, University of Sydney; Mike Letnic, UNSW, and Shawn Laffan, UNSW

There is a widespread belief dingoes are as good as extinct in New South Wales and nearly all dog-like animals in the wild are simply wild dogs. This belief is bolstered by legislation and policies in NSW, which have removed the word dingo and refer only to “wild dogs”.

But our research, recently published in the journal Conservation Genetics, challenges this assumption. We performed DNA ancestry testing, much like the ancestry tests available to people, on 783 wild canines killed as part of pest control measures in NSW.




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Roughly one in four of the animals we tested were pure dingoes, and most were genetically more than three-quarters dingo. Only 5 of the 783 animals we tested turned out to be feral domestic dogs with no dingo ancestry.

If it looks like a dingo, acts like a dingo and shares dingo genes… there’s a pretty good chance it’s a dingo.
Michelle J Photography, Author provided

Dingo hotspots

Studies carried out by the CSIRO in the 1980s and ‘90s examined the skulls of wild canines in southeastern Australia, and concluded they were largely hybrids of dingoes and dogs.

In NSW all wild dogs are classified as pest animals. Under the NSW Biosecurity Act 2015 all landholders have a duty to control wild dogs to minimise the risk of negative impacts on neighbouring land.

This policy requires all public and private landholders in NSW to display signs warning when poison baits have been laid to kill wild dogs.

But our DNA testing found three hotspots of high dingo ancestry within northeastern NSW: Washpool National Park; the coast north of Port Macquarie; and the Myall lakes region.

There were more pure dingoes in these areas. Despite these positive findings, dingo-dog hybridisation is still very prevalent in NSW. Three-quarters of wild animals carry some domestic dog ancestry.




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This is not entirely surprising. Domestic pet and working dogs have lived alongside dingoes for centuries. Widespread killing of dingoes also increases the risk of hybridisation because it breaks family groups apart, giving domestic dogs the opportunity to mate with dingoes. Small populations also have a higher risk of hybridisation.

1080 poison baits are affecting dingoes as well as feral dogs.
Mike Letnic

Hybridisation is generally considered detrimental to conservation because it alters the genome. In the case of dingoes, hybridisation is a problem because hybrids may be different to dingoes and “true” dingoes will eventually disappear.

While our results show dingoes still exist and their genes are predominate, their conservation will be greatly helped if we can prevent further interbreeding with domestic dogs.

Time to resurrect the dingo

Our study has important implications for both how we describe dingoes, and the future conservation of dingoes in NSW. Most of the animals labelled as wild dogs in NSW had predominantly dingo DNA, and fewer than 1% were actually feral dogs.

The term wild dog obfuscates the identity of wild animals whose genes are mostly dingo but sometimes carry dog genes. For all intents and purposes, these animals have dingo DNA, look like dingoes and behave like dingoes, and consequently should be labelled as dingoes rather than escaped pets gone wild.




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Hotspots with high dingo ancestry have significant conservation value and urgently need new management plans to ensure these pure dingo populations are protected from hybridisation. These populations could be protected by restricting the killing of dingoes in these areas and restricting access to domestic dogs on public land such as state forests.

Animals long thought to be wild dogs are actually predominantly dingoes.
Michelle J Photography, Author provided

Further ancestry testing should be conducted in more areas to determine whether there are other pockets of high dingo purity in NSW.

Undeniably, dingoes can negatively impact livestock producers, especially sheep farmers. Non-lethal strategies such as electric or exclusion fencing, and livestock guarding animals such as dogs, llamas and donkeys, may balance the need to conserve dingoes and protect vulnerable livestock.




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In some circumstances, dingoes can benefit farmers because they reduce numbers of native and feral herbivores like kangaroos, feral goats, rabbits and pigs, boosting pasture growth for livestock.

If lethal control is justified, then targeted strategies such as shooting and trapping may be more suitable in high dingo conservation areas rather than landscape-wide poison aerial baiting.

It is time to resurrect the dingo. The term dingo needs to come back into official language, and we need practical strategies for limiting dingo-dog hybridisation and protecting dingo hotspots.




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The Conversation


Kylie M Cairns, Research fellow, UNSW; Brad Nesbitt, Adjunct Research Fellow, University of New England; Mathew Crowther, Associate professor, University of Sydney; Mike Letnic, Professor, Centre for Ecosystem Science, UNSW, and Shawn Laffan, Associate professor, UNSW

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