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Dead dugong found in Trang sent to Phuket

27 November 2018, The Thaiger (Thailand)

A dugong has been found dead in the sea off Trang province. The body was sent to Phuket for further examination.

Jatupohn Burutpat, director-general of the Department of Marine and Coastal says, “the dead dugong was found in the sea near Koh Libong in Trang.”

“It was a female dugong, 2 metres long and weighing 250 kilograms. No severe wounds were found on its body. The dead dugong was sent to Phuket Marine Biology Centre (PMBC) to find the cause of dead.”

“Dugongs are one of the protected animals and it is included in the list of CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora) as it is facing extinction.”

“Koh Libong and Koh Mook in Trang are an importance place where it is full of see grass and hope will increase the dugong numbers by 5-10%.”

“We hope that everyone will do their part to protect dugongs by not supporting illegal fishing and help take care of our environment.”

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Six dugongs found dead in Abu Dhabi as rogue fishing put species at risk

26 November 2018, The National (UAE)

A total of 20 dugongs have been found dead this year, up 25 per cent from the 2017 figures. PHOTO CREDIT: EAD

Six dugongs have been found dead on the Abu Dhabi coast – with environmental experts blaming illegal fishing practices for putting the protected species at risk.

The bodies of the creatures were found washed up from Al Silaa to Ghantoot, by Environment Agency – Abu Dhabi (EAD) rangers who regularly patrol the waters of the emirate.

The mammals, affectionately known as sea cows due to them feeding on sea-grass, are believed to have drowned in unmanned and abandoned drift nets.

The discovery brings the total number of dugong deaths in the UAE this year to 20 – up from 15 on the same period in 2017.

It is believed the dugongs became ensnared in lengthy and illegal netting after necropsy results indicated the most probable cause of their death was drowning.

The environment agency has renewed its call for strict punishments over the use of so-called hiyali nets, which are banned under federal law and are easily lost at sea and can ensnare wildlife.

The agency has led crackdowns on rogue fishermen, with inspectors swooping on locations used by commercial and recreational fishing boats after the discovery of five dead dugongs on Saadiyat Public Beach in February.

“The Agency will continue to prioritise the protection of dugong habitats and ensure that enforcement of the laws continues to be applied strictly, in partnership with the Critical Infrastructure & Coastal Protection Authority (CICPA),” said Dr Shaikha Salem Al Dhaheri, executive director of Terrestrial and Marine Biodiversity at EAD.

“We strongly urge all fishermen to cast their nets mindfully, prudently and responsibly and fish in a sustainable manner – in line with our local and federal laws.”

EAD, which has ramped up its inspections recently, has the power to impose harsh fines to anyone found flouting the law.

First-time offenders can receive fines of up to Dh50,000 and a jail term term of at least three months, while second-time offenders can be issued fines of up to Dh100,000 as well as a prison term of not less than one year.

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Officials: Seagrass plantings growing, flowering in river

23 November 2018,Sanibel-Captiva Islander (USA)

Efforts to restore lost seagrasses in the Caloosahatchee are proving promising, with planting taking hold, growing and flowering, according to the Charlotte Harbor National Estuary Program.

Efforts to restore lost seagrasses in the Caloosahatchee are proving promising, with planting taking hold, growing and flowering, according to the Charlotte Harbor National Estuary Program.

The toxic algae bloom prevented monitoring of the plantings for months; however, surveys of them recently week revealed the following:

- Site 1 (furthest downstream): Eelgrass was observed in four of the five GrowSAV Herbivory Exclusion Devices. The protective coverings were not removed during the initial inspection, but most likely has grazed upon grass inside as well.

- Site 2 and 3: Eight of the 10 planting sites had very dense eelgrass. The grass is expanding outside of the GrowSAV Herbivory Exclusion Devices and flowering inside. A total of two flowers appeared to have been germinated and are producing seeds. It is believe that this is the first time in the 21st Century where there has been seed pods growing in the lower river.

- Site 4: The one planting site (of five total) where the GrowSAV Herbivory Exclusion Devices was secured to the bottom had eelgrass growing. The other four sites were compromised by grazers.

- Site 5 (furthest upstream): Sparse eelgrass was present, though this area appears to be negatively impacted by water depth and grazing from blue crabs.

The Charlotte Harbor National Estuary Program, Calusa Waterkeeper, and Sea & Shoreline Aquatic Restoration have been working with residents and volunteers to replant seagrasses in the tidal Caloosahatchee. The project aims to restore the tidal Caloosahatchee's submerged aquatic vegetation - or SAV - communities.

"Making progress in restoring the seed source for the lost seagrass beds in the tidal Caloosahatchee is a tremendous achievement," Jennifer Hecker, executive director of the Charlotte Harbor National Estuary Program, said. "Seagrasses are the base of our aquatic food chain, supporting everything from crabs to endangered manatees. Continuing this project to learn how and where we can replenish them will have a significant impact in improving our ability to restore water quality and the ecology in the area."

The species planted are Ruppia maritime (commonly known as Ruppia) and Vallisneria Americana (commonly known as tapegrass or eelgrass). Aquatic vegetation is an important part of estuarine ecosystems, providing vital reproductive and nursery habitat for fish in addition to food for grazers, such as manatees and turtles. It also improves water quality and clarity by removing nutrients and sediment. The Caloosahatchee has historically supported vast seagrass beds. However, much coverage has been lost in recent years due in part to alterations in water flows to the tidal Caloosahatchee.

The project has entailed creating five planting areas covered by herbivore exclusion cages, which protect the seedlings while they are getting established, in five locations on the north and south shores of the Caloosahatchee between the Interstate 75 and US 41 bridges.

The sites were selected to be along waterfront residents who wanted to participate. CHNEP and Calusa Waterkeeper staff and volunteers, along with staff from Sea & Shoreline, installed the plantings and cages and have been participating in the ongoing maintenance and monitoring efforts.

"It feels really good to field verify the extensive research documenting the methods to re-establish beneficial eelgrass in waterways. Due to the significant investment of water storage/release north of the Franklin locks, this project will only get better with time," Carter Henne, president of Sea & Shoreline and a contractor for the project, said. "However, what encourages me most is that it allows waterfront homeowners to make a significant positive impact to their property. I am very happy to see local stakeholders taking an active role in restoring trophic food webs and the nutrient buffering capacity in the river. I believe this model of local engagement can and should be encouraged in other areas of the state suffering from lack of submerged aquatic habitat."

The exclusion cages are to be removed in the next month or so, with monitoring ongoing for a few more months thereafter. The results of the project will also be used to inform ongoing seagrass restoration efforts.

"Though promising to see some seagrass growth as a result of this project, significantly better water quality and flow management regulations will be needed to sustain it and allow it to grow year-round in order to restore the lost seagrass beds," John Cassani, with Calusa Waterkeeper, said.

The project was funded by the CHNEP, which applied for and was awarded a grant from the Florida Department of Environmental Protection's Florida Coastal Management Program, with monies provided by the National Oceanic and Atmospheric Administration.

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The dugong's tears: Madagascar's gentle giants bounce back

19 November 2018, UN Environment (press release)

Fishing is a way of life in Andranomavo village, but a growing population in and around the Nosy Hara Marine National park is putting species under pressure. PHOTO CREDIT: UN Environment / Lisa Murray

Life is slow in Andranomavo. Here, surrounded by mudflats and mangroves, time is governed by the tides and the seasons. When to go fishing, when to plant and harvest the rice—these are the markers that matter.

But the current of change is running through this tiny community in Madagascar’s Nosy Hara Marine Protected Area, one of 20 villages in northern Madagascar embracing incentive-based conservation as a strategy to preserve and restore the region’s natural heritage.

Nosy Hara is home to over 330 coral species, as well as 270 species of fish, five types of sea turtles, and migrating dolphins and whales. But the undisputed star of the marine protected area is the reclusive dugong.

Once there were many, now there are few

“Forty years ago, there was a big dugong population... Every time you went to the sea, you saw dugong,” fisherman Jaozafy says. “Now it is rare. A fisherman might only see dugong four times a year.”

But while they might be rare, the dugong are an important part of this vibrant ecosystem, as well as a barometer of its health. These shy herbivores depend on seagrass meadows to survive, each dugong grazing a territory of around 0.4 ha, contributing to nutrient cycling as they stir up sediment, and boosting seagrass growth as they fertilise the seabed with their dung. A healthy dugong population is both a sign of, and a contributor to, a thriving seagrass ecosystem.

Just like coral reefs and mangrove forests, seagrass meadows are a vital part of coastal marine ecosystems. They provide habitat and breeding grounds for fish and shellfish, improve water quality and protect coasts from storm impacts.

Seagrass also plays a key role in the fight against climate change, accounting for 10 per cent of the annual carbon sink capacity of the oceans, with healthy seagrass meadows storing up to 10 times as much carbon as the same area of healthy rainforest.

But with 29 per cent of the world’s seagrass already gone, and an additional 11,000 ha disappearing every year—an area the size of a football pitch every thirty minutes—today, these marine ecosystems are amongst the most threatened on earth.

“Coastal resources have been taken for granted for too long, not only in terms of their ecological function, but in terms of the human benefits they provide and their economic value,” UN Environment biodiversity expert Max Zieren says.

“As a result, these ’open resources’ are increasingly becoming degraded and even disappearing due to mismanagement—from dredging to coastal reclamation, water pollution, and overexploitation.”

From dugong hunters to conservation ambassadors

With the dugong flying as its standard, the Global Environment Facility and UN Environment-backed Dugong and Seagrass Conservation Project is working to preserve these ecosystems at over 100 sites across eight countries (Indonesia, Madagascar, Malaysia, Mozambique, the Solomon Islands, Sri Lanka, Timor-Leste and Vanuatu), building awareness, developing policy, undertaking research and working with local communities to provide incentives for effective conservation.

Accessible only by boat or a series of rough roads through the surrounding hills, Andranomavo epitomises the development challenges faced by many of Madagascar’s coastal communities. Generations of villagers here have relied on the sea to survive, supplementing their catch with subsistence rice and vegetable farming. So when Nosy Hara was declared a marine protected area in 2007, balancing local livelihoods and conservation became a top priority.

Dugong were once a sought-after catch for Madagascar’s fishermen, prized not only for their meat, but for medicine, with everything from their bones to their fat used in traditional remedies for a variety of ailments. In parts of Southeast Asia, dugong tears are believed to be a powerful love potion...

But their long lifespans, slow breeding rates, and long gestation and nursing periods make dugong populations particularly vulnerable to overhunting. While they can live as long as 70 years, female dugongs only begin to breed at between six and 17 years of age, with a single calf born after a 13–14-month gestation period, followed by 18 months of suckling their young, and a further six years before the calf becomes independent. All of this means that even under the best of circumstances, the dugong population is only capable of increasing at a maximum of five per cent a year—far from a robust figure in the face of human predation and widespread habitat degradation.

Building community awareness of the important role the dugong plays in the marine environment, as well as the importance of healthy seagrass ecosystems for their own livelihoods, has been a top priority for the Dugong and Seagrass Conservation Project and local partner C3 Madagascar.

Damo, 56, is one of 40 conservation ambassadors trained by the project to help spread the message about marine conservation. Her role is also to help monitor the marine protected area and report infractions of regulations on fishing and other activities to park authorities.

“I try to tell people not to kill the dugong because if their numbers decrease, there will be no fish,” Damo explains. “The fishermen will suffer, they will not be able to make a living.”

In a community where 80 per cent of the population are fishermen, it’s a message that hits home, and one that has helped create the conditions for a slow return of the gentle giants to feeding grounds in Nosy Hara.

“Before the project, the dugong were very rare because they were still being caught by the fishermen,” Damo says. “But since the project arrived and we have been building awareness on protecting the dugong, it has improved.”

Putting people first

Just as important as changing community attitudes, though, has been addressing the development challenges facing Andranomavo’s 300 residents.

“Conservation efforts with poor and disadvantaged communities always need to put people first,” Zieren says. “That means focusing on health, education and welfare.”

In Nosy Hara, this has meant incentivising the community to take an active hand in managing the marine protected area, along with introducing livelihood alternatives that reduce pressure on the bay.

With healthcare amongst the top priorities of the local community, the Dugong and Seagrass Conservation Project is supporting regular visits by a doctor and a midwife to Andranomavo—a welcome change in a village where seeing a doctor previously meant a two-hour walk to the nearest clinic, whether pregnant, elderly or infirm.

The project is also helping diversify livelihoods around the region to ease reliance on the marine environment. Working with local women’s associations, the C3 Madagascar team has provided training and equipment to kickstart new businesses in hospitality, handicrafts and animal husbandry.

Alongside her role as a conservation ambassador, Damo is one of 20 women who have taken up duck farming to supplement her income from fishing for shrimp and crabs. “The duck farm gives us an advantage because we don’t have to rely so heavily on fishing,” she says.

Damo’s duck business might seem like a small change at on an international level, but with over 1 million hectares of dugong habitat now under improved conservation management across 30 sites in Madagascar alone–and another 41 projects underway worldwide—these individual changes have the potential to stack up to big wins for the dugong and other species that rely on seagrass globally, including us.

The health of seagrass and other coastal habitats is key to protecting marine species we all like, such as dugong and sea turtles,” UN Environment’s Max Zieren says, “but even more to sustain local economies and people’s welfare.”

Meanwhile, as the tide rolls in in Andranomavo, there is a sense of optimism: thanks to the efforts of people like Damo, the dugong are back again.

The Dugong and Seagrass Conservation Project is the world’s first globally coordinated initiative to conserve dugong and their seagrass habitats. The $US6 million project is supported by the Global Environment Facility and implemented by UN Environment with the coordination of the Mohamed bin Zayed Species Conservation Fund. The Dugong and Seagrass Conservation Project currently supports 42 national projects managed by 34 local partners in Indonesia, Madagascar, Malaysia, Mozambique, Sri Lanka, Solomon Islands, Timor-Leste and Vanuatu.

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Abu Dhabi to study climate change threat facing sea creatures

14 November 2018, The National (UAE)

The impact of climate change on seagrass and the mangrove areas of Abu Dhabi is to be evaluated in a new government partnership with French energy supplier Total.

A research agreement has been signed with the Environment Agency - Abu Dhabi will assess the impact of increasing global temperatures on the region’s dugong populations.

The program aims to explore the relationship between dugongs and their marine environment, before evaluating the impacts of climate change on the seagrass communities of Abu Dhabi.

A research study will place a special emphasis on the dugong in order to develop new strategies to protect the species in the future.

“This study is crucial towards enhancing our understanding of Abu Dhabi’s extensive seagrass meadows, which support the world’s second largest dugong population, as well as over four thousand green sea turtles,” said Dr Shaikha Salem Al Dhaheri, executive director of the Environment Agency – Abu Dhabi’s Terrestrial and Marine Biodiversity Sector.

“The International Union for Conservation of Nature (IUCN) has listed Abu Dhabi’s dugong population as ‘vulnerable’ for the last sixteen years.

“This program would help the Agency take focused action on mitigating the impacts of climate change on our local dugong and other seagrass communities and protecting this vital marine ecosystem.”

The seagrass meadows of the Arabian Gulf provide critical support to regionally and internationally significant populations of dugongs, as well as many other marine species. They also play an important role in climate change mitigation through their ability to sequester carbon.

In the Gulf region, seagrasses are exposed to large seasonal variations in water temperature and salinity – meaning that they are probably already living at the edge of their tolerance.

The impacts of climate change are expected to put the seagrasses of Abu Dhabi under even more stress, which will, in turn, have a real impact on the dugongs that rely on seagrass for food.

Total, the world’s fifth largest international oil and gas company, was the key sponsor of EAD’s Dugong Conservation programme from 1999 to 2018.

“Total in the UAE long-term partnership with the Environment Agency - Abu Dhabi (EAD) is part of our ongoing strategy with the Total Foundation to act in a sustainable and responsible manner,” said Hatem Nuseibeh, president of Total E&P in the UAE.

“We are proud to be in partnership with organisations that support actions committed to finding solutions to the challenges of climate change in the UAE.”

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Oceans are losing a football field of seagrass every 30 minutes

15 November 2018, Quartz

 

Seagrasses are flowering marine plants that live in shallow coastal waters almost everywhere in the world.

Seagrasses are flowering marine plants that live in shallow coastal waters almost everywhere in the world. The more than 70 species of seagrass provide an important habitat for thousands of ocean animals, from tiny invertebrates, crabs, and turtles to large fish and birds.

Equally if not more important, seagrasses also are natural carbon sinks—even more effective at soaking up heat-trapping carbon pollution than forests on land. They soak up carbon in their leaves, and when they die, they decompose far more slowly than terrestrial plants, so that carbon remains buried for hundreds of years.

“Seagrasses are the ultimate natural carbon sink,” said Richard K.F. Unsworth, a lecturer in marine biology at Swansea University in the UK. “In healthy seas, seagrasses are so productive you can see oxygen rapidly bubbling through the water column as they photosynthesize on a sunny day.”

Emilia Röhr, a doctoral student at Åbo Akademi University in Finland who recently led a study on carbon storage in seagrasses, agreed. “In addition to the huge potential seagrasses possess for carbon sequestering—and therefore buffering against climate change—seagrasses offer multiple other ecosystem services essential for human livelihoods such as fish nurseries, protection from erosion, water quality management, and nutrient regulation,” she said.

But overfishing and coastal pollution have taken a toll on seagrasses, depleting them at an alarming rate. Recent studies from places such as Florida, Singapore, Indonesia and the UK have documented widespread seagrass loss, according to Unsworth. The authors of one study released last year, in fact, said that a football field of seagrass is disappearing roughly every half-hour.

“The biggest threat to seagrass around the world remains poor water quality,” Unsworth said. “Seagrasses are photosynthetic, they need lots of light to grow. The more sediments, nutrients and other pollutants that come down our rivers, the more turbid our coastal seas become and the faster algal competitors of seagrass suffocate these plants.”

Because society has neglected the conservation of these ecosystems for so long, there is little detailed data available to understand how much seagrass once existed and how rapidly it has been lost, he added. Furthermore, “we don’t know nearly enough about where seagrass is,” he said. To that end, Unsworth has created a website that allows citizen scientists to help map the location of seagrass.

“Where we do have long-term data there are many examples of seagrass loss,” he said. “There are also many instances from human memory around the world where whole estuaries and bays that were once full of seagrass are now just muddy, turbid environments devoid of these prairies of the sea.”

New research underlined the value of natural ecosystems in fighting climate change. It called for preserving forests, farmlands, grasslands and seagrasses, all of which scrub carbon pollution from the atmosphere. The study, published in Science Advances, further found that strengthening these carbon sinks could shrink the country’s net annual carbon output by up to 21%.

The paper called for reviving grasslands, planting more trees in forests, and waiting longer to harvest timber. It also recommended that farmers plant cover crops when their fields otherwise would be bare. Cover crops draw carbon out of the atmosphere and return it to the soil. The study further called for curbing water pollution to protect seagrass, restoring lost seagrass, and allowing new seagrass to grow in areas flooded by rising seas.

“There is value in restoring seagrasses, and in creating new seagrass meadows, because these actions cause more carbon to get stored in the soils underneath,” said James W. Fourqurean, director of Florida International University’s Center for Coastal Oceans Research, and a co-author of the paper.

Fourqurean has modeled what happens when seagrasses vanish. One study he conducted estimated the ongoing loss of seagrasses could release up to a billion metric tons of carbon dioxide into the atmosphere each year, an amount that is close to the annual carbon emissions of Japan. Still, conservatively, he says the real number is probably less than half a billion metric tons annually, roughly the carbon output of France.

There are potential solutions to the problems facing seagrass. In Indonesia, for example, “we’ve just led a project that planted thousands of trees along river banks to stop sediments and nutrients flushing into the ocean, and we’re also just commencing projects to plant seagrass in Wales,” Unsworth said. But, he added, “conservation is certainly the best bet, as restoration is unreliable, difficult, and very expensive.”

The “best example of seagrass hope” comes from Tampa Bay, where locals have radically improved water quality, Unsworth said. Seagrass is more now abundant there than it was in the 1950s, although recent hurricanes may have reversed some of this growth.

While much attention in recent years has focused on coral reefs, Unsworth believes that marine conservation must broaden to include seagrasses. Corals may be more exotic and pretty, but one should never dismiss the richness and importance of seagrass, Unsworth said.

“Seagrass is green, sometimes a little slimy and not seen as exciting,” Unsworth said. “The abundant and diverse animal life in it hide—that’s why they’re there. So it often appears to contain few fish. This couldn’t be further from the truth. Seagrass is certainly the poor cousin of coral, but another way of thinking about it could be the story of the ‘Ugly Duckling.’ Maybe we’re starting to see signs of feather development. In years to come, seagrass may become the beautiful swan.”

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Research calls for new approach to tropical marine conservation

06 November 2018, EurekAlert (press release)

In an article in Current Biology, Dr Richard Unsworth from the University's College of Science, has revealed that people are relying on coral reefs less for their livelihoods as the reefs are increasingly under threat and facing an uncertain future due to increasing rates of climate change and rising global temperatures.

Instead, the article shows that people are looking to seagrass meadows as a means for fisheries support, but this is putting these habitats under increasing threat around the world. There is now an urgent need to broaden the focus of tropical marine conservation. Although seagrass is globally widespread, there is evidence of rising levels of degradation due to local water problems and physical disturbance, but these are factors that can be managed at local scales. Unsworth said "With the right support there can be a brighter future for seagrass".

While the decline of coral reefs has garnered a great deal of attention and conservation efforts, Dr Unsworth says that the time is right for the tropical marine conservation community broadened its focus and become more realistic. Conservation efforts, it is argued, can no longer afford to focus exclusively on coral reefs but need to also safeguard seagrass into the future. There is an increasing focus on costly fanciful ideas to save coral reefs, but no recognition of thinking across the broader tropical marine seascape to rationalise where resources could be more efficiently focussed.

Dr Unsworth said: "Governments, NGOs and communities need to increase and reprioritise conservation efforts and use their limited conservation resources in a more targeted manner in order to attain sustainable systems. For seagrass, there are practicable conservation opportunities to develop sustainable ways to respond to increased resource use. Targeted action now could restore and protect seagrass meadows to maintain and many ecosystem functions they provide."

The article details the number of ways in which seagrass conservation would be benefit people and planet as seagrass meadows play a vital role in a number of key areas including:-

  • supporting global fisheries production
  • playing a vital role in our global carbon cycle
  • acting as important bio-filters in our coastal eco-systems

Dr Unsworth ,who published the paper with collaborators at Cardiff University, Uppsala University and James Cook University said: "There are some coral reef conservation 'bright spots' that indicate the potential for some coral reef survival. But in order for our tropical seas to continue to be able to support fisheries and people, we urgently need to focus on protecting ecosystems and biodiversity that provide the most critical ecosystem services while having the capacity to remain intact in a future climate.

"Seagrass meadows are one of those ecosystems and their conservation is paramount for the continued livelihoods and food security of many hundreds of millions of people. The time is right for global conservation efforts to conserve seagrass ecosystems."

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Dugong rescued and set free

06 November 2018, The Hindu (India)

In a joint operation, the Wildlife Institute of India (WII), Tamil Nadu Forest department and Omcar Foundation rescued and released an adult female Dugong, which had got entangled in a fishing net in the Palk Straits at Keezhathottam near Peravurani in Thanjavur district.

Local fisherman Balamurugan and five of his colleagues were fishing in the high seas on Thursday when they inadvertently caught a Dugong, weighing about 500 kg. Finding that the marine mammal had got entangled in the net, they pulled it gently to the shore.

Thanks to the ‘Friends of Dugong’ a capacity building training programme launched by WII involving fishermen in the coastal districts, the fishermen cut a portion of the net so that the mammal could reach the surface and breath till officials arrived.

K. Madhu Magesh, Researcher, WII, said officials reached the spot around 4 a.m. and released the mammal back into the sea.

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Seagrass, protector of shipwrecks and buried treasure

02 November 2018, The Conversation AU (Australia)

Roman amphorae from a late Roman shipwreck in South Prasonisi islet, Greece, surrounded by seagrass meadows. PHOTO CREDIT: T. Theodoulou.

For more than 6,000 years, seagrass meadows in Australia’s coastal waters have been acting as security vaults for priceless cultural heritage.

They’ve locked away thousands of shipwrecks in conditions perfect for preserving the fragile, centuries-old timbers of early European and Asian explorers, and could even hold secrets of seafaring by Aboriginal Australians.

Seagrass meadows accumulate marine sediments beneath their leaves, slowly burying and safeguarding wrecks in conditions that museum curators can only dream of. It’s a process that takes centuries, as mats of seagrass and sediments cover the wrecks and all their buried treasure.

Seagrass sedimentary deposits also hold archives of wider environmental change over millennia and are important sinks for atmospheric carbon dioxide, known as Blue Carbon.

But human development, climate change and storms are threatening fragile seagrass meadows around the world, and that risks the loss of the important cultural heritage they protect as well as some of the world’s most productive marine ecosystems.

Our research, carried out by an international team of scientists in Australia, Denmark, Saudi Arabia and Greece, shows that seagrass meadows, hidden beneath our oceans, gradually build up the seafloor over millennia by trapping sediments and particles and depositing those materials as they grow.

The organic and chemical structure of seagrass sedimentary deposits is key to its ability to protect shipwrecks and submerged prehistoric landscapes. These structures are extraordinarily resistant to decay, creating thick sediment deposits that seal oxygen away from archaeological sites, preventing ships’ timbers and other materials from rotting away.

Seagrass meadows are under environmental stress due to climate change, storms and human activity. Recent disturbances and losses have exposed shipwrecks and archaeological artefacts that were previously preserved beneath the sediment. Once the protective cover of seagrass is gone, the ships and other sites begin to break down. If you lose seagrass, you lose cultural heritage.

Seagrass meadow losses in the Mediterranean have exposed Phoenician, Greek and Roman ships and cargo, many of which are thousands of years old. Unless these effects can be stemmed, the frequency of exposures is likely to increase. This has already put European archaeologists and marine scientists in a race against the clock.

Around 7,000 shipwrecks are thought to lie in Australia’s coastal waters. Seagrass disturbance led to the unearthing in 1973 of the James Matthews, a former slave ship that sank in 1841 in Cockburn Sound, Western Australia, and the Sydney Cove, which ran aground off Tasmania’s Preservation Island in 1797, forcing survivors to walk 700km to Sydney.

Artefacts and pieces of the James Matthews’ hull have been recovered and studied at the WA Museum. Meanwhile, the recovery of beer bottles from the Sydney Cove has led, remarkably, to 220-year-old brewing yeast being cultivated and used to create a new beer – fittingly enough called The Wreck.
Revealing wrecks

We and our colleagues are aiming to match shipwreck data with seagrass meadow maps. From there, we hope new acoustic techniques for below-seabed imaging will allow exploration of underwater sites without disturbing the overlying seagrass meadows. Controlled archaeological excavation could then be undertaken to excavate, document and preserve sites and artefacts.

We also believe there’s significant potential to find archaeological heritage of early Indigenous Australians buried and preserved in seagrass meadows. Sea level around Australia rose around 6,000 years ago, potentialy submerging ancient indigenous settlements located in coastal areas, which may now be covered by seagrass.

The danger of not putting these protections in place is evidenced by treasure-hunters off the Florida coast, who have adopted a destructive technique called “mailboxing” to search for gold in Spanish galleons. This involves punching holes into sediment to find and then pillage wrecks, an action that damages seagrass meadows and archaeological remains.

The accumulated sediments in seagrass meadows could also help build a record of environmental conditions, including fingerprints of human culture. These archives can be used to reconstruct prehistoric changes in land use and agriculture, mining and metallurgical activities, impacts of human activities on coastal ecosystems, and changes associated with colonisation events by different cultures. Think of it as a coastal equivalent to polar ice cores. Seagrass records could even help us understand, predict and manage the effects of current environmental changes.

But to do all this, we first need to realise what a truly valuable resource seagrass is. Granted, it doesn’t look spectacular, but it can do some pretty spectacular things – from sucking carbon out of the skies, to underpinning entire ecosystems, and even guarding buried treasure.

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