WAMSI research finds northwest seagrass in a world of its own

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Groundbreaking research into the sensitivity of seagrasses off the northwest coast has uncovered unique behaviour that could lead to a re-think in the way the region is managed.

The seagrasses off Western Australia are the most extensive and diverse of any region in the world with 26 species in 11 genera, accounting for more than 35 per cent of all species currently described globally.

The submerged flowering plants play a vital role in supporting biodiversity, filtering harmful chemicals and nutrients, and sequestering CO2 from the atmosphere. Tropical seagrasses are also a critical food source for fauna such as dugong and green turtles, but little is known about populations off the subtropical northwest .

A Western Australian Marine Science Institution (WAMSI) Dredging Science Node project has brought together researchers from Edith Cowan University (ECU), The University of Western Australia (UWA) and the Commonwealth Scientific and Industrial Research Organisation (CSIRO) to measure the effects of light reduction and sediment burial to determine the capacity for northwest seagrasses to withstand change.

Tolerance levels have previously been determined for seagrasses in the southwest but they are very different to the species off the far northwest coast according to ECU Professor Paul Lavery.

“In the southwest, the dominant species of seagrasses have large storage organs and carbon reserves, and produce large non-dormant seeds,” Professor Lavery said. “Because of their considerable carbon reserves, when they are placed under stress by dredging operations, they draw on those carbon reserves and can survive for several months.

James McLouglin and Roisin McCallum establish a field experiment at Thevenard Is. to determine the mechanisms and rate of seagrass recovery
James McLouglin and Roisin McCallum establish
a field experiment at Thevenard Is. to determine
the mechanisms and rate of seagrass recover

“The seagrass species up north are much smaller, producing small dormant seeds that lay waiting in sediments. They appear to be much more sensitive to changes in light and sediment cover. However we need to be cautious,” he said. “While they may show a rapid response to dredging-induced changes, we don’t really understand yet if they can recover quickly from those impacts. It’s possible that a few months after complete loss, the meadow returns from seed.”

The researchers are conducting a combination of field studies and controlled laboratory experiments.

“We’re working in the Pilbara areas around Exmouth Gulf and Thevenard Island (about 20km off Onslow),” Professor Lavery said. “We’ve been going up every few months to measure characteristics of the meadows, from when they grow, to when they die off and how much biomass there is. This is information we just don’t have for seagrasses in the north.”

Northern sites_Mick Haywood
Research sites in the Pilbara areas around Exmouth Gulf and Thevenard Island

The research program is focused on gaining information that is useful and relevant in a systematic way. An initial recommendation from the research is that pre-development surveys and ongoing monitoring programs for seagrass should consider the time of year. In the month of June, for example, there appears to be no seagrass meadows. It’s not until September that they start to grow back.

“This most basic and fundamental piece of information we didn’t understand before,” Professor Lavery said. “This in turn will save money for companies as they often conduct costly surveys when seagrass is not naturally present.”

We’ve now conducted field studies in several locations to see if the same sort of patterns exist in each location and so far we’re finding that different places have different patterns, which makes things more complicated and is going to make advising government and industry more challenging.”

Off Thevenard Island the researchers removed seagrasses from both shallow and deep water meadows to observe how the system recovers.

“We wanted to see if the meadows can recover from seed or by material drifting in from elsewhere,” Professor Lavery said. “So far we aren’t seeing any recovery by seed. There seems to be a need to have vegetative material available for it to grow back. So it’s back to the lab now to find out the capacity for the seagrasses to withstand change.”

 

The WAMSI Dredging Science Node is made possible through $9.5 million invested by Woodside, Chevron and BHP as environmental offsets. A further $9.5 million has been co-invested by the WAMSI Joint Venture partners, adding significantly more value to this initial industry investment. The node is also supported through critical data provided by Chevron, Woodside and Rio Tinto Iron Ore.

Category:

Dredging Science

Seagrass helps protect natural ‘carbon sinks’, study finds

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The disappearance of seagrass meadows could be contributing to greenhouse gas emissions, an international study has found.

As ABC online reports, research conducted at Oyster Harbour in Albany found centuries-old carbon dioxide deposits have been created by seagrass meadows.

Scientists at The University of Western Australia’s Oceans Institute, in conjunction with overseas researchers, discovered the meadows act as carbon “sinks”, preventing the erosion of carbon deposits and the subsequent release of carbon dioxide into the atmosphere.

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Going with the flow in the Kimberley

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A Western Australian Marine Science Institution (WAMSI) project is using genetics to see how ocean currents in the Kimberley transport marine organisms from one reef to another.

Bardi-Jawi rangers, Mayala traditional owners and researchers from four WAMSI partner institutions recently conducted field studies along the remote and rugged coastline, collecting samples on exposed reefs at low tide between the 12 metre tidal surges around the Dampier Peninsular and Buccaneer Archipelago.

“We collected seagrasses, corals, fishes and trochus shells that live in the intertidal zone which is exposed at low tide,” CSIRO’s Dr. Oliver Berry said.

“We selected these species to represent the types of organisms that are common in the Kimberley. Some are also commercially, recreationally or culturally important like the trochus shell and stripey snapper, or form key habitats like seagrass and corals.”

Sites sampled Dampier Peninsular and Buccaneer Archipelago

Sites sampled Dampier Peninsular and Buccaneer Archipelago

 

The researchers are using scans of the organisms’ genomes to measure the genetic relationships between different reefs and seagrass beds. The more genetically similar the organisms from different reefs are, the more movement occurs between them.

“When you consider managing a marine resource you have to understand what drives population dynamics,” Dr. Berry said. “For some populations whether they are growing or shrinking is driven locally by births and deaths. But, especially in places where there are strong tides and currents, it’s possible that even populations quite distant from each other are strongly interdependent because organisms move between them a lot.”

“A seemingly large area like the Kimberley can be very linked if hydrodynamics (ocean currents) drive those population linkages. So if there was a disaster at one location, if that population was insular, or locally driven, it may take a long time for it to recover. But if the population was linked to other areas then it may recover more rapidly. What we’re trying to do is to better understand these relationships between populations.

“Of course it’s a difficult thing to study because most movement in marine species occurs when they are tiny eggs, seeds, or larvae. Genetics is a way to indirectly measure movement, and it’s becoming increasingly cost-effective and powerful with the development of genome sequencing technologies,” Dr. Berry said.

The research being undertaken by WAMSI with scientists from Edith Cowan University, AIMS, Department of Fisheries, WA and the Western Australian Museum, is expected to uncover a range of different patterns reflecting the exposure to currents of different reefs and the different life histories of the organisms.

“For example, looking at the patterns in the trochus shell, we know it has a short larval stage and that some fishes have longer ones,” Dr Berry said. “We expect this to mean fish get transported further and that these differences will be reflected in the genetic relationships between populations.”

“This is the first time anyone has attempted anything like this in the Kimberley, and anywhere in the world in such a macro-tidal environment,” he said.

“Now that there is increasing interest in developing the region we need to get a baseline understanding of how the ecosystem works, so that it can be managed effectively,” Dr Berry said. “We expect to have some results by the end of this year.”

 

[The $30 million Kimberley Marine Research Program is funded through major investment supported by $12 million from the Western Australian government co-invested by the WAMSI partners and supported by the Traditional Owners of the Kimberley.]

 

 

 

Category:

Kimberley Marine Research Program

Perth Canyon: first deep sea exploration

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A group of acclaimed scientists will go where few others have gone before when they set out to unlock the secrets of a deep ocean canyon off Perth the size of the Grand Canyon in the US.

A research team headed by The University of Western Australia’s Oceans Institute’s Professor Malcolm McCulloch, together with researchers from theWestern Australian Museum, Commonwealth Scientific and Industrial Research Organisation (CSIRO), and the Institute of Marine Sciences in Italy. will be among the first to explore life in the vast Perth Canyon, about 50km off Fremantle.

Professor McCulloch will lead the research team’s expedition on board the Schmidt Ocean Institute’s Research Vessel, R/V Falkor, during a 12-day trip departing on Sunday, 1 March.

Researchers will use a deep-diving remotely operated vehicle (ROV) to discover and collect deep-sea corals and sea water from the canyon.  Chemical and biological analyses of these rare samples will provide critical new data about the canyon’s marine ecosystems.  This will help determine the likely future impacts of warming seas and ocean acidification on the deep-sea life and waters in these remote and previously inaccessible habitats.

If you would like to find out how they fare, visit the blog
www.schmidtocean.org/story/show/3036

Deep sea expedition dives into Perth canyon

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A group of acclaimed scientists from The University of Western Australia’s Oceans Institute will go where few others have gone before when they set out to unlock the secrets of a deep ocean canyon off Perth the size of the USA’s Grand Canyon.

A UWA team headed by Professor Malcolm McCulloch, together with researchers from the Western Australian Museum, CSIRO and the Institute of Marine Sciences in Italy, will be among the first to explore life in the vast Perth Canyon, about 50km off Fremantle.

The underwater canyon formed over tens of millions of years and extends from the continental shelf edge of Western Australia to depths of more than four kilometres to the abyssal sea floor.  Major up-swelling of essential nutrients in the canyon makes it a global marine hotspot, attracting blue whales and other large fauna that migrate to the waters seasonally to feed.  Despite being so close to Perth and Fremantle, little is known about life in its deep abyss.

Professor McCulloch and his team will lead the research expedition on board the Schmidt Ocean Institute’s Research Vessel, R/V Falkor, during a 12-day trip departing on Sunday, 1 March.

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Turtle and shark tagging part of new Ningaloo Reef research partnership

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Ningaloo Reef is the largest fringing reef in the world, extending for 300 kilometres along the northwest coast of Australia.

The five-year, jointly-funded $5 million research program will include both deep and shallow reef research, turtle and shark tagging, a PhD scholarship scheme and opportunities to engage the local community, including BHP Billiton Petroleum employees, in Exmouth, WA.

Minister for Industry and Science Ian Macfarlane, joined CSIRO Executive Director Environment, Dr Andrew Johnson, and BHP Billiton Petroleum General Manager, Doug Handyside to launch the partnership in Perth.

Mr Handyside said the investment in marine science would help the oil and gas industry to better understand the reef and help target conservation efforts.

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Tiger sharks are big movers

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WA research has uncovered extraordinary details about the movements of tiger sharks with evidence suggesting their local range extends thousands of kilometres from Indonesia to Esperance.

Despite common beliefs that tiger sharks are almost exclusively a tropical water species, scientists have found they are capable of travelling vast distances in often colder climates.

The Australian Institute of Marine Science, WA’s Fisheries Department, the University of WA and CSIRO have been carrying out a program aiming to break new ground in the understanding of the species.

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Rare Ruby seadragon uncovered in WA

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A new species of seadragon has been discovered off the coast of Western Australia by researchers at the Western Australian Museum.
 
The bright red Ruby Seadragon (Phyllopteryx dewysea) is only the third species of seadragon ever recorded in the world.
 
Culture and the Arts Minister John Day said the discovery was nearly 100 years in the making after the first recorded seadragon specimen was washed up on Cottesloe Beach in 1919.  
 

“For many years the specimen found in Cottesloe and another subsequent find were thought to be a common seadragon,” Mr Day said.

 
But through a combination of modern DNA sampling technology and research linking it to other specimens, the Ruby Seadragon was shown to be a new species. It was identified and classified by WA Museum scientist Dr Nerida Wilson and her colleagues. 
 
“This is an amazing find in Western Australian waters and clearly shows the value of our museum collections in informing current and future scientific research.”

 

Category: 

Dredging Science Kimberley Marine Research Program

A new look at the Leeuwin Current

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New research has revealed further insights into the formation of the globally unusual poleward-flowing Leeuwin Current and the role it plays in sustaining the marine ecosystems of the Ningaloo Reef.

In a recently published study researchers from The University of Western Australia and the Australian Institute of Marine Science investigated three-dimensional ocean circulation on the continental shelf as part of WAMSI’s Ningaloo Research Program.

The team made a variety of detailed field measurements that extended along a large portion of the Ningaloo coast (~70 km), enabling a whole-of-reef scale synoptic view of variability over several spring and summer months.

“This was the first time anyone had attempted field oceanographic observations on such a broad scale at Ningaloo,” team member UWA Professor Greg Ivey said. “It was exciting to be able to use the data to start looking into how seasonal transitions affect local ocean dynamics, upwelling and downwelling and how this could then be affecting oceanographic features of statewide importance, such as the Leeuwin Current.”

Detailed analysis of the comprehensive dataset has now shown that variability in the currents offshore from Ningaloo were important in controlling the variability in the strength of Leeuwin Current as it progresses down the southern WA coast. It was also found to be important in the localised transport of nutrient rich water from deep below the ocean surface to Ningaloo Reef, a vital process that supports the coral reefs and fisheries of the region. 

“The interesting thing is that the Leeuwin Current is very weak on the North West Shelf, just north of Ningaloo,” Professor Ivey said, “yet to the south, it is the dominant current feature of southwestern Australia.”

“Our results confirm that the Ningaloo Peninsula and Shelf region can be considered one of the important formation regions for the Leeuwin Current, and therefore understanding the dynamics of the current at Ningaloo increases not only our local knowledge but also the variability of the Leeuwin current and hence the ecosystems that it supports further south,” AIMS Co-author Dr Richard Brinkman said.

The study: Observations of the shelf circulation dynamics along Ningaloo Reef, Western Australia during the austral spring and summer, published in the international peer-reviewed journal Continental Shelf Research, was also supported by the Australian Research Council.

 

Testing Industry-Government partnership concepts

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With expanding offshore development near the Pilbara, the decision to test a bold concept to share the load, and cost, of observing and modelling metocean conditions that would improve operational decisions, especially around severe weather events, has proven timely.

Initial results show there is support across Government and industry for the Pilbara Regional Observing System for Prediction and Enhanced Research (PROSPER).

The concept being investigated by the Western Australian Marine Science Institution (WAMSI) and the WA node of the Integrated Marine Observing System (IMOS) would provide improved regional monitoring to enhance confidence in models and risk assessments through a shared network of monitoring and data. 

The initial findings clearly leaves the door open for a continuing conversation in this area identifying that a range of factors are aligning that will make a more collaborative approach to data, modelling and observing a real possibility in the near future.

The concept was tested late last year by an independent consultant, alongside a representative of WAIMOS, through face to face interviews with key industry.

“The independent interview process was important to establish the genuine willingness of industry and others for this concept, or to consider alternative approaches to better partnerships in this area,” Professor Chari Pattiaratchi, then node-leader of the WAIMOS said. “Of course the research sector is already sold on the idea of shared costs for modelling and better access to industry data.”

The major outcome of the PROSPER project was that it was perceived to be too soon for the many stakeholders in the Pilbara region to see the benefit in supporting a collective operational ocean observing and prediction system in the Pilbara. The concept of sharing real-time data collection infrastructure was fresh but reservations quickly crept in about sharing of broader historical data sets and sensitive company knowledge.

Most interviewees agreed enhanced monitoring and predictive capacity was important.  But while the concept was supported in principle, industry was not ready to commit to the full PROSPER framework at this time.

“The PROSPER concept in its entirety was always ambitious and the interviews show there is genuine support for certain parts of the concept around data sharing and modelling, that means we’ll continue to work with industry and government to grow collaboration in this area,” Professor Pattiaratchi said.

WAMSI CEO Patrick Seares said the process has provided a lot of useful feedback that needs to take seriously but two things stand out.

“Firstly, our colleagues in the offshore industry are suffering ‘concept fatigue’ from all the various ideas proposed by different groups in the research sector. I think we need to be more coordinated to manage this,” he said.

“Secondly, while this wasn’t the right time, a number of different factors are converging that may make something akin to PROSPER feasible in the northwest soon. So we need to take on the advice about being a little more focussed and specific about operational implications but keep the conversation with operators and Government going in this area.”

The good news is that even now operators in the oil and gas industry are voluntarily exploring ways to make some of their information more accessible. WAMSI partners are assisting in that effort.