By Marea Martlew
An unusual event that took place in Australia 50 years ago has given scientists rare insight into the fate of ancient carbon locked away in seagrass habitats when they are disturbed or destroyed. The study provides new evidence, that when seagrass ecosystems are disturbed the “blue carbon” that has been locked away in their sediments for thousands years disappears, and may be released into the atmosphere with potential major global warming consequences. While the results of the study, published in The Proceedings of the Royal Society B highlight the slow recovery rates for disturbed seagrass habitats, they also provide promising evidence that restoring seagrass meadows can offset carbon emissions and help mitigate climate change impacts. The study also reveals significant differences in the microbial community associated with disturbed and undisturbed habitats. Journal Reference: Proceedings of the Royal Society B, DOI: 10.1098/rspb.2015.1537 Read more here: ABC News: Damaged seagrass meadows release ancient carbon New Scientist: Seagrass gardens are needed to cap the ancient carbon bomb in the oceans |
Being the subject of a painting...I'm totally flattered to have been pained by St Joseph's College Geelong student, Antoine Saleh. When I asked him why on earth he would paint me he said:
"As I have a strong interest in nature and science, I am doing many maths and science subjects as school . To keep a balance with my subjects, as a year 11 student, I decided to do year 12 biology and Year 12 Studio arts. Throughout my Studio arts folio the theme I focused on was “Humans and Nature Bond” trying to capture the unique connection between Individuals and their environment. I met many people throughout the experience including, an aboriginal cultural heritage officer, Permaculture enthusiasts, “hippies”, a nudist, a florist, and yourself (Marine Ecologist). I focused on three main subject matter on how people are connected to their environments; culturally, spiritually, and through passion/occupation. Earlier in the year when I went diving a lot, I came across your video on YouTube of you snorkelling around Point Lonsdale. After watching your videos and seeing your interesting name (Dr Seagrass), I did some research where I came across your website. You seemed extremely passionate in what you do which inspired me to produce a painting of you." Thanks Antoine. I'm totally blown away. A+ mate! |
PhD student Stacey Trevathan-Tackett tells us what she's been doing for the past 3 years (and totally nails it...)"The refractory characteristics of carbon-containing compounds is one of the main factors that can influence the sequestration and storage of carbon in blue carbon ecosystems. The aim of this thesis was to unravel the processes and factors that influence, and even optimise, the preservation of refractory carbon in seagrass meadows beginning with the refractory carbon in live plants and following it through decomposition to storage in the sediments."
Well done Stacey! |
Pemika Apichanangkool giving her PhD dissertation talkSo proud of my PhD student Pemika Apichanangkool giving her final PhD talk. She made a compelling case that eutrophication in Thailand's seagrass meadows is causing loss of blue carbon.
Her research then tested an innovative solution: using artificial seagrass to help facilitate the recovery and maintenance of blue carbon stocks while waiting for natural seagrass recovery. Well done Pemika! |
Freshwater wetlands as potential carbon sinks on ABCPeter Macreadie talking about the importance of freshwater wetlands as carbon sinks with Tim Holt on ABC South East NSW
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Tackling unethical authorship deals in scienceThe research excellence of academics is often measured by the quantity and quality of their scholarly publications. But how do we know that all authors listed on a publication have actually been involved in the research? Check out our new article in The Conversation, led by Prof. Isaac Santos, on 'Tackling unethical authorship deals in science'.
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Paper published in GeoResJHolocene reconstructions of southern hemisphere environments are rare, yet they are becoming increasingly important for comparing modern-day climate changes against the backdrop of historical natural changes. Our manuscript provides a detailed investigation of the sedimentary responses of an east-coast Australian estuary to local, regional and global environmental changes. We identify significant down-core variation in sediment cores relating to sea-level rise, regional climate change, and human activity. By combining information generated from multiple proxies, we draw together our findings into a conceptual model that describes the development of the estuary; from the early- to mid-Holocene to present (i.e. the past ~9000 years). Our model suggests that sea-level rise and the highly variable (flood/drought) climate system caused the estuary to become periodically constricted from the ocean, which produced cyclic alternation between intervals of fluvially- and marine-dominated conditions. This occurrence is likely to be common to barrier estuaries under the influence of similar climate influences. Analysis of recent (~150 years) sediment demonstrates the strong influence of human activity on sedimentary processes, with urbanization causing significant increases in sediment accumulation rates and mud content.
We are pleased to be publishing our work in GeoResJ - a new open access journal for the earth sciences. Download a copy of the paper here. |
Paper just accepted in PNAS: Should we 'reef' obsolete oil platforms?Offshore oil structures are among the most productive fish habitats in the world (Claisse et al. 2014), but does this mean we should convert them into artificial reefs? In our PNAS letter we discuss some caveats in using fish production data to inform rig-to-reef policy, and provide some recommendations towards a multi-criteria decision framework for providing a more holistic approach to deciding the fate of obsolete oil structures in the oceans.
Journal: Proceedings of the National Academy of Sciences of the USA (PNAS) Authors: Fowler, Macreadie, and Booth |
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Drone workshopDeakin Drone Workshop, 12th-14th of November, 2014
Blue Carbon Lab members Paul Carnell (post-doc) and Carolyn Ewers (PhD candidate) joined Deakin colleagues from the School of Life and Environmental Sciences, Engineering, and IT, along with representatives from Victorian UAS (unmanned aerial systems) Training and Skymation at the Deakin Warrnambool campus to discuss the uses of UAVs (unmanned aerial vehicles, aka “drones”) in research. The group participated in a “fly day” using a drone to map part of the Tower Hill Wildlife Reserve. Later, Victorian UAS Training provided attendees with the opportunity to fly a small drone using the “buddy system” approach, utilizing two tethered control consoles, with the expert pilot on one end and the trainee on the other. On the second and third days, members from each represented group presented and discussed the process of UAV certification, potential applications in research, and projects for collaboration. We are very excited about the possible uses of drones to monitor blue carbon! Check back for updates on drone use in the Blue Carbon Lab. |
Grant success! Carbon sequestration by wetlands: A fresh(water) approach to tackling climate changeThis week we welcomed grant support of $10,000 from the Thomas Davies Research Grant, which is funded through a generous philanthropic bequest from the estate of the late Thomas Lewis Davies to the Australian Academy of Science.
Aims: This project aims to: 1) quantify carbon stocks in wetland soils in south-west Victoria; 2) assess the impact of restoration; and 3) simultaneously develop efficient, rapid and accurate indicators of carbon stocks. Outcomes: This research will: 1) undertake the first assessment of carbon stocks in south-west Victorian wetlands; 2) identify the impact of wetland restoration on those stocks; and 3) identify robust indicators of carbon stocks to enable rapid assessment of other wetlands. Thus, the research will enable natural resource managers and landholders to reliably estimate and enhance their carbon sequestration, adding to the global effort to address climate change. Investigators: Rebecca Lester, Peter Macreadie, and Jan Barton |
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Welcome to new intern, Ellen RochelmeyerEllen is taking a gap year mid-way through her BSc and will be working as an intern with the Blue Carbon Lab. We look forward to having Ellen on the team!
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Congratulations to Carolyn Ewers for winning best speed talk at Deakin's Science HDR retreat
Carolyn Ewers, a new PhD student in the lab, has taken out the prize for best speed talk at the 2014 Deakin Science HDR retreat.
Carolyn spoke about her upcoming plans to restore degraded blue carbon habitats in Western Port. A very impressive feat given she only arrived in the lab from the USA in August this year. Congratulations Carolyn! |
Seagrass nerds converge at ISBW11 in China
Looking forward to The 11th International Seagrass Biology Workshop in Sanya City, Hainan, China.
The theme of the conference is: “Declining seagrasses in a changing world” (Sounds a bit doomy and gloomy doesn't it?!) with the following symposia: (1) Key Ecological Processes; (2) Ecosystem Vulnerability and Resilience; (3) Biodiversity and Ecosystem Services; (4) Management and Restoration. I'll be giving a talk 'Hot spots and hot moments in seagrass 'blue carbon' science' #ISBW11 #seagrass |
Inspecting potential sites for a 'blue carbon' demonstration project
On 16 October 2014, representatives from UTS, Deakin University, Parks Victoria, Bass Coast Council, the Western Port Seagrass Partnership and Phillip Island Nature Parks inspected potential sites in Western Port Bay for mangrove, saltmarsh and seagrass restoration. Sad to see so much habitat loss, but good to see so much enthusiasm towards fixing the problem.
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#ScaredScientistsIn his black-and-white photography series "Scared Scientists," Nick Bowers captures a raw element not often associated with scientific knowledge. For the series, Bowers interviewed a selection of scientists in varying fields, capturing the frightened looks on their faces while they contemplated their findings. The photos are minimalist but intense, each wrinkle and crease pointing to a human unease we can all connect with.
Bowers told The Huffington Post he hopes to convey "the humanity and vulnerability of the scientists" through his work. "That they are as individuals concerned by climate change, separate from the scientific realm." The artist also had his daughter in mind while creating the series, hoping to use his artwork to create hope for a brighter future. "I constantly hear the word 'wealth' and the importance of passing this on. I'm inspired to pass on a better, more sustainable future," he explained. On his website, Bowers combines a striking portrait with the specific field, educational background, and future predictions of each scientist. Although their powerful words provide an interesting context for their expressions, we think the faces alone say more than enough. Read more in the HuffingtonPost |
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Trophic cascades blue carbon working group
Last week a small team of researchers converged at Deakin Burwood for a CIE funded workshop on 'The influence of trophic cascades on "blue carbon" landscapes'.
Project goals: 1) Provide a review on the occurrence of trophic cascades in coastal vegetated habitats 2) Develop general theoretical predictions for how trophic cascades could influence “blue carbon” in coastal vegetated habitats 3) Identify important research avenues on the effects of trophic cascades on blue carbon Participants: In person - Euan Ritchie, Trisha Atwood, Peter Macreadie, Cath Lovelock, and Jim Fourqurean. Remote - Rod Connolly, Graeme Hays, Jim Estes, and Mike Heithaus. |
Seminar 5 August 2014: Carbon sequestration by coastal vegetated habitats: is blue the new green?I'll be giving a public seminar (minus the tuxedo) on 'blue carbon' at Melbourne University on Tuesday 5th August. Everyone is welcome to attend.
Time and location: 12-1 pm in the Agar Theatre, Zoology Department Abstract: A few years ago the marine science world gave birth to a new term: ‘blue carbon’, which was created to describe the enormous and newly-recognised potential of the oceans to sequester carbon and help slow climate change. Early estimates of the power of blue carbon were staggering - they indicated that blue carbon habitats ranked among the most efficient and permanent sinks on the planet, far exceeding that of key terrestrial carbon sinks (e.g. rainforests). With recognition of the power of blue carbon sinks came concern that if disturbed they could leak vast amounts of stored carbon back into the atmosphere, thereby shifting them from being carbon sinks into carbon sources. This presentation will report on three years of research into blue carbon; spanning microbial processes, impacts of human and climate disturbances on blue carbon stocks, and opportunities to improve the management of blue carbon ecosystems to sequester more carbon. |
Seagrass is awesome!It's here!
The 'Seagrass is Awesome' Book by Year 6, Paynesville Primary School, Victoria has finally arrived. Get your copy through iTunes here. And don't miss the bonus story: 'Seagrass Superdude'. These books are all about the importance of seagrasses to our marine environment. Enviro-Stories is an innovative literacy education program that inspires learning about natural resources and catchment management issues. |
Are rebounding green sea turtles in Bermuda causing collapse of seagrass meadows?
Looking forward to hosting Prof. Jim Fourqurean next week for next week's workshop on 'The influence of trophic cascades on "blue carbon" landscapes'. Jim will be giving a talk on 1 August @ 3pm seminar on 'Are rebounding green sea turtles in Bermuda causing collapse of seagrass meadows?'
Jim Fourqurean is a marine and estuarine ecologist with a special interest in benthic plant communities, food webs, and nutrient biogeochemistry. He has published over 100 papers in the refereed scientific literature, spanning many ecosystems, from planktonic systems to mangrove forests. In particular, he has specialized in the application of elemental and stable isotopic composition of organisms as indicators of ecosystem processes. He is an expert in carbon storage and fluxes in coastal ecosystems, and the importance of these ecosystems to climate regulation and mitigation. In this role, he serves on both the Science and Policy Working Groups of the International Blue Carbon Initiative. He is also an expert on the impacts of energy exploration and oils spills on tropical coastal ecosystems. While working on the Water Quality Protection Program for the Florida Keys National Marine Sanctuary, has made contributions to the science and application of monitoring in Marine Protected Areas. For the past decade, his main research areas have been in Florida Bay and the back-reef environments of the Florida Keys, but he has also worked around the Gulf of Mexico, in Mexico, Panama and Bermuda, the western Mediterranean and Australia. He is currently a professor in the Department of Biological Sciences, Director of the Marine Research and Education Initiative, and a member of the Southeast Environmental Research Center at Florida International University in Miami, Florida. |
How much blue carbon exists in Victoria?
This week we kicked off a major sampling campaign that will determine how much blue carbon exists across the Victorian coast.
Soil samples will be taken from 100's of sites along a 2,000 km stretch of coastline. Saltmarsh, mangrove and seagrass habitats will be the focus of the sampling effort. The program is supported by Corangamite CMA, East Gippsland CMA, Glenelg Hopkins CMA, East Gippsland CMA, and Port Phillip & Westernport CMA, and a collaboration with Dr Jon Sanderman (CSIRO). A full report is expected by November 2014. This first expedition involved new lab member Paul Carnell. If you'd like to join any of the field expeditions please send me an email to [email protected]. But note, you will get muddy! |
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PhD student Alex Thomson highly-commended presentation at AMSA14
Congratulations to Alex Thomson who presented her research at the Australian Marine Science Association(AMSA) conference in Canberra this week and received the Ron Kenny Premier Conference Award Highly Commended Oral Presentation. Her presentation was titled 'Fiddler crabs: the hunter-gatherers of blue carbon'. Well done Alex!
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Top gun: aerial drones for mapping wetland vegetation
Unmanned aerial vehicles – commonly referred to as ‘drones’ – are revolutionising conservation projects around the world. Compared with traditional remote sensing technologies, such as satellite and airborne sensors, drones are significantly cheaper and much more accessible. In coastal environments, however, the performance and approaches for using drones to map vegetated habitat has not yet been validated. This project will for the first time investigate the use of drones (VUAS-X5) for mapping seagrass, saltmarsh, and mangrove habitat. The study site for this work will be the north-east corner of Western Port Bay, which is currently facing significant losses of coastal vegetated habitat (>0.5 m of shoreline per year) due to erosional forces. This project will produce geo-referenced and ground-truthed land use/cover maps for the region, which will help guide conservation and restoration efforts as part of a broader ‘green infrastructure’ program. The successful student will ideally be experienced in using GIS and needs to be comfortable working in the field (drivers licence required). The student will work as part of a team involving two PhD students, a research assistant, and members of the Western Port Seagrass Partnership. Good interpersonal skills are essential; the successful student will need to liaise with local farmers. |
Carbon sequestration by lakes: A fresh(water) approach to tackling climate change
Biosequestration is regarded as one of the single largest opportunities for CO2 emission reduction in Australia. The focus has so far been on terrestrial ecosystems (e.g. existing carbon farming initiative), yet recent data indicates that freshwater ecosystems have much higher (~50-times) carbon burial efficiencies than powerful terrestrial carbon sequestering ecosystems such as rainforests. However, the carbon sink capacity of Australian freshwater ecosystems is largely unknown. This study aims to fill this knowledge gap by measuring carbon stocks and carbon accumulation rates of freshwater lakes throughout Victoria. The project will involve a ‘road trip’ involving the collection of sediment cores (getting muddy!), followed by organic carbon content determination and radiometric dating. The successful student must be comfortable working in the field (drivers licence required), and experience in ecology, chemistry, and/or geology. Good interpersonal skills are critical – the successful individual will need to work as part of a team, and will be required to liaise with private land-holders. More information:
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Biosequestration on the Corangamite agendaInvestigating the impact of a changing climate on natural resource management (NRM) was the theme for an inaugural Corangamite CMA knowledge sharing conference.
Corangamite CMA Strategy Co-ordinator Chris Pitfield talked about the work involved in his NRM Planning for Climate Change Project, which seeks to identify climate change impacts on the region’s natural assets, including native vegetation, waterways, wetlands, coasts and soil. A presentation from Geoff Park, director of Natural Decisions Pty Ltd and Stephen Farrell, manager GIS and Cartography of Spatial Vision, included spatial representations on climate change impact scenarios for 50 and 90 years. Priority landscapes for carbon sequestration to help develop strategies to build landscape integrity and guide adaptation and mitigation actions to address climate change impacts on natural ecosystems were also identified. Peter Macreadie spoke of the the potential of blue carbon as a way of mitigating the impact of climate change within the Corangamite region. |
York and Macreadie win Isobel Bennett Marine Biology FellowshipDr Paul York (James Cook University) and Dr Peter Macreadie (UTS / Deakin) have won the 2014 Isobel Bennett Marine Biology Fellowship for research at the Lizard Island Research Station.
The Fellowship is named in recognition of the late Dr Isobel Bennett who was one of Australia's eminent marine biologists. The Hermon Slade Raiatea Foundation has provided funding to the Lizard Island Reef Research Foundation (LIRRF) to enable this fellowship. York and Macreadie will be studying the carbon sequestration capacity of deep water seagrasses. Queensland's deep-water seagrasses are among the most extensive on earth (>40,000 km2), but it is not known whether they play a major role in global carbon sequestration like their shallower-water counterparts. York and Macreadie will be combining forces during this trip with Dr Michael Rasheed's team who will using helicopters to gather samples from remote locations throughout the Great Barrier Reef. |
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New paper on seagrass dispersal just accepted in Estuaries and Coasts - Congratulations Alex!
PhD student, Alex Thomson, has just had her Honours work accepted for publication.
Thomson ACG, York PH, Smith TM, Sherman CDH, Booth DJ, Keough MJ, Ross DJ, and Macreadie PI. (accepted 14-6-14) Seagrass viviparous propagules as a potential long-distance dispersal mechanism.Estuaries and Coasts in press. |
Marine Pollution Bulletin Special Issue on Seagrasses
After two long years, the MPB Special Issue is finally here! Check out our article on 'Quantifying and modelling the carbon sequestration capacity of seagrass meadows - A critical assessment'
Highlights
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Factors affecting blue carbon remineralisation rates
After four long months, our laboratory remineralisation experiment has finally come to a close.
Thanks to Stacey, Kasper, Simon and Trish for working some crazy hours over the weekend to get the final microsensor profiles and extrude the sediment cores. Now our samples are off to Hawaii for geochemical analyses! |
New Honours projects
I currently have on offer the following Honours projects:
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Rigs to reefs: a homely solutionBy Terry Clinton
In summary:
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DSE Seagrass resilience writing retreat - Phillip Island
After three years of data collection, the DSE seagrass resilience team has come together to put it all together at a paper writing retreat in Phillip Island. Participants included Prof. Mick Keough (Uni of Melbourne), Dr Tim Smith (Deakin), Dr Paul York (JCU), Dr Craig Sherman (Deakin), Dr Jeff Ross (UTAS), and Dr Peter Macreadie (UTS/Deakin). In addition to writing papers, the team took some time to collect seagrass samples around Western Port.
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Remineralisation rates in saltmarsh, seagrass and mangroveThis week we kicked off a major project of the effects of environmental changes on remineralisation rates of blue carbon in mangrove, saltmarsh, and seagrass sediments. We had an epic week in the field, collecting >500 cores. The cores are now in the labs at UTS undergoing incubation. Cores will be pulled out of tanks for various analyses during the next 4 months. Participants include: Dr Trisha Attwood, Prof. Rod Connolly, Prof. Cath Lovelock, Prof. Peter Ralph, Simon Hardy, Dr Daniel Nielsen, Dr Maria Schmitz Fontes, Dr Justin Seymour, Dr Katherina Petrou and Dr Peter Macreadie (and possibly some others that i have forgotten to mention!).
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Impacts of bioturbators on the carbon sequestration capacity of seagrass meadowsPhD student Alex Thomson commences laboratory experiments this week to better understand the impacts of bioturbators on seagrass blue carbon. Her bioturbator subjects are Callianassid 'ghost shrimp', which are thought to have negative impacts on the carbon sequestration capacity of seagrass meadows.
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Restoring carbon stocks with artificial seagrassPhD student Pemika Apichanangkool returns from Thailand where she has deployed artificial seagrass within the Haad Chao Mai National Park to investigate the feasibility of using artificial seagrass to assist recovery of below-ground carbon stocks following degradation of natural seagrass. Pemika's research has previously shown that much of the seagrass 'blue carbon' stock derives from terrestrial sources - as opposed to carbon production due to photosynthesis by the seagrass plants themselves - and therefore she proposes that artificial seagrass may produce similar results to natural seagrass with respect to recovering carbon stocks. The artificial seagrass also 'comes to life' as it becomes colonised by epiphytes, which subsequently attract invebrates and fish.
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ANSTO supports blue carbon research
Through it's AINSE Research Award scheme, ANSTO has generously supported two projects (ALNGRA14031 and ALNGRA14004) that seek to understand the stability of ancient 'blue carbon' within seagrass meadows.
The project involves iTRAX, age dating (210Pb and 14C), microbial analyses, stable isotope analyses, and other geochemical proxies. Investigators include: Macreadie, Skilbeck, Trevathan-Tackett, Jacobsen, Zawadzki, Heijnis, Gadd, Levchenko, Connolly, and Thomson. |
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Just accepted: Resilience of Zostera muelleri seagrass to small-scale disturbances: the relative importance of asexual vs. sexual recovery. Ecology and EvolutionAuthors: Macreadie PI, York PH, Sherman CDH.
There is urgent need to understand the mechanisms that underpin seagrass seagrass resilience – the ability to recover from disturbance without shifting to an alternative stable state. In this study, we used manipulative disturbance-recovery experiments in the field to investigate factors that mediate seagrass resilience. The experiment, which lasted 65-weeks, was performed at 4 sites within Lake Macquarie (Australia’s largest coastal lake), and involved Zostera muelleri, which is regarded as a threatened and globally significant congeneric species. We found that resilience of Z. muelleri varied significantly with disturbance intensity and mode of recovery. Specifically, recovery from low intensity disturbances (i.e. where only the above-ground plant material is removed - typical of herbivore grazing) occurred within a couple of weeks, whereas recovery from high intensity disturbances took up to 18-times longer. Furthermore, we found no recovery in situations that depended on sexual regeneration (i.e. seeds), yet analyses of genotypic diversity suggested the capacity for sexual regeneration at fine scales, as indicated by the relatively high number of genotypes within plots. We discuss environmental factors that appear to influence recovery rates. Overall, this study shows that asexual regeneration via rhizome extention (as opposed to sexual regeneration via seeds) is the rapid and consistent mode of recovery of Z. muelleri in response to small-scale disturbances. These findings have important implications for efforts to facilitate recovery of seagrasses in denuded areas. |
Thank you for visiting!Thanks for visiting this site. I hope you found something useful here. It's been a steep learning curve for me setting up a website, but it's been fun putting all the photos and videos to good use. I will try to keep up with doing regular updates as the science develops. If you have any suggestions for improvement please let me know.
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Research meeting in Moreton Bay to discuss 'blue carbon' projects within Australia
Understanding the important role of Australia’s coastal and marine wetlands in storing atmospheric carbon dioxide was the focus of the 2-day meeting. The meeting drew together scientists from institutions around Australia, including: the University of Technology, Sydney, University of Western Australia, University of Queensland, Griffith University, University of New South Wales, Australian Institute of Marine Science, Southern Cross University and Edith Cowan University.
Unfortunately, due to government media embargoes I cannot tell you what actually happened, or photos/video of who was there, but I can show you these pretty pictures of the scenery around Moreton bay. |
CERF2013
Just returned from the 22nd Biennial Conference of the Coastal and Estuarine Research Federation (CERF): Toward Resilient Coasts and Estuaries, Science for Sustainable Solutions
Keynote addresses were delivered by iconic Hollywood Producer, Jerry Zucker, and Acting Under Secretary of Commerce for Oceans and Atmosphere and Acting NOAA Administrator, Dr. Kathryn Sullivan. It was a pleasure to be a speaker in the 'Coastal and Estuarine Carbon Cycling' theme, convened by Matt Kirwin, Thomas Mozdzer, James Fourqurean, and Catherine Lovelock. Quote of the conference by Dr Paul Montagna (winner of the William A. Niering Award for Outstanding Educator): "It's amazing what you can accomplish in science if you don't care who gets credit" |
Just accepted: Molecular indicators of chronic seagrass stress: a new era in the management of seagrass ecosystems? Ecological Indicators
We argue that molecular indicators for early detection of chronic stress in seagrasses will significantly improve the effectiveness of seagrass management and conservation efforts. Given recent progress towards developing molecular indicators of seagrass stress, we can expect that within the next couple of years we will see the first demonstration of molecular indicators of seagrass stress.
Authors: Macreadie PI, Schliep MT, Rasheed MA, Chartrand K, & Ralph PJ. |
Just accepted by the Ocean & Coastal Management: A multi-decision approach to decommissioning of offshore oil and gas infrastructureThousands of the world’s offshore oil and gas structures are approaching obsolescence and will require decommissioning within the next decade. Many nations have blanket regulations requiring obsolete structures to be removed, yet this option is unlikely to yield optimal environmental, societal and economic outcomes in all situations. We propose that nations adopt a flexible approach that allows decommissioning options to be selected from the full range of alternatives (including ‘rigs-to-reefs’ options) on a case-by-case basis. We outline a method of multi-criteria decision analysis (Multi-criteria Approval, MA) for evaluating and comparing alternative decommissioning options across key selection criteria, including environmental, financial, socioeconomic, and health and safety considerations. The MA approach structures the decision problem, forces explicit consideration of trade-offs and directly involves stakeholder groups in the decision process. We identify major decommissioning options and provide a generic list of selection criteria required for inclusion in the MA decision process. To deal with knowledge gaps concerning environmental impacts of decommissioning, we suggest that expert opinion feed into the MA approach until sufficient data become available. We conducted a limited trial of the MA decision approach to demonstrate its application to a complex and controversial decommissioning scenario; Platform Grace in southern California. The approach indicated, for this example, that the option ‘leave in place intact’ would likely provide best environmental outcomes in the event of future decommissioning. In summary, the MA approach will allow the environmental, social, and economic impacts of decommissioning decisions to be assessed simultaneously in a transparent manner.
In a nutshell:
Authors: Fowler AM, Macreadie PI, Jones DOB, Booth DJ |
Just accepted by the Journal of Molluscan Studies: Effects of Pinna clams on benthic macrofauna and the possible implications of their removal from seagrass ecosystems
Pinna clams – also known as ‘razor clams’, ‘razor fish’, ‘razor shells’, and ‘pen shells’ (Fig. 1a) – are habitat-forming bivalves that occur within seagrass meadows in many of the world’s oceans. In Lake Macquarie (New South Wales), Australia’s largest coastal lake, local residents and recreational users of the Lake have called for eradication of Pinna clams from seagrass meadows due to the hazard they pose to swimmers. Their broad posterior margins are razor-sharp - hence the name ‘razor’ - and throughout the summer a considerable number of swimmers require hospitalisation after standing on the clams. Although Pinna clams have always resided within the Lake, there have been anecdotal reports of a ‘population boom’. The Lake Macquarie City Council is therefore considering a Pinna clam removal program, which would see the clams physically removed from popular swimming areas.
The goal of this study was to assess the potential importance of Pinna sp. in Lake Macquarie for the seagrass community - namely benthic macrofauna - and/or the seagrass itself. Our primary interest was whether removal of Pinna sp. is likely to negatively impact the seagrass ecosystem within which they live – i.e. would eradication of Pinna sp. from seagrass meadows within the Lake have a major impact on the seagrass community? To address this question, we performed a series of surveys and manipulative experiments; the details of which can be found in the Supplementary Section. In brief, these involved: (1) a survey of site-to-site variability in Pinna sp. clam densities and sizes; (2) a survey of organic matter content and infaunal macroinvertebrates associated with natural Pinna sp. populations compared with seagrass and bare sand; and (3) a manipulative experiment to parse out the relative importance of Pinna sp. clams versus seagrass in providing habitat for benthic macrofauna. In the context of our results, as well as other published work, we then consider the implications of Pinna sp. removals on the future viability of the Pinna sp. populations within the Lake, keeping in mind that Pinna sp. clams are long-lived (up to 18 years) and make relatively limited investment towards reproduction. Authors: Peter I. Macreadie, David L. Kimbro, Valentin Fourgerit, Jason Leto, A. Randall Hughes |
New paper provides the first assessment of the value of Australian oil and gas rigs as fish habitat
Congratulations to Nico Pradella (the 'Italian Stallion') and the team (particularly Ash Fowler) on the acceptance of another paper: 'Fish assemblages associated with oil industry structures on the continental shelf of Northern Australia' in the Journal of Fish BIology.
Thank you also to our oil industry partners for making their ROV footage available to us for this research. Authors: Pradella N, Fowler AM, Booth DJ, and Macreadie PI |
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Decommissioning Ecology Group
The Decommissioning Ecology Group has launched their new website:www.rigtoreef.com
Photo: Peter Macreadie, David Booth, and Ash Fowler |
ABC Radio National's Off Track program covers seagrass research by JCU and UTS
By Joel Werner
Saturday 5 October 2013 1:30PM Front lawn to the ocean, seagrass has long been known to play an essential role in the marine ecosystem. It acts as a nursery for fish species, food for turtles and dugongs, and is a natural mesh that holds the coastline together, preventing erosion. But recently, scientists have begun to understand the plant's unique capacity to sequester carbon; seagrass meadows capture and store carbon at a rate forty times faster than a tropical rainforest - and they can store that carbon for thousands of years. This week, Off Track heads to Green Island, 27km offshore from Cairns in Far North Queensland, to visit a research laboratory that's 18m under the sea. Listen to the program @http://www.abc.net.au/radionational/programs/offtrack/seagrass/4999016 |
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What's it all about? SeagrassThe extended video of week 1 of seagrass research at Gladstone
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Video - Queen of the seagrassA short video of Cath Bryant (from JCU) in action. Notice how she continues to smile even when she's crawling through the mud. Ah, the life of a seagrass biologist!
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Video - Seagrass research at GladstoneFirst week of Gladstone fieldwork almost done; only 10 weeks left to go! Here's a short video of the first few days of fieldwork, starring: Capt. Paul Leeson, Paul York, Cath Bryant, Aurora Ricart, and Pete Macreadie.
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Just accepted in PLOS ONE: Physiological and morphological responses of the temperate seagrass Zostera muelleri to multiple stressors - investigating the interactive effects of light and temperature
Authors: Paul H. York, Renee K. Gruber, Ross Hill, Peter J. Ralph, David J. Booth, Peter I. Macreadie
While there has been a good deal of research into understanding how individual stressors affect seagrass populations, we know relatively little about how multiple environmental stressors interact to affect seagrass health, even though seagrasses are typically faced with more than one stressor during disturbance events. In this study, we studied how Zostera muelleri (a globally significant and threatened congeneric species) responds to two common environmental stressors - temperature and light – over a 3-month period in laboratory mesocosms (one of the longest running laboratory-based studies on Zosteraphysiology). During the study, we intensively monitored a number of proxies of seagrass health, including; photosynthetic yield (>11,000 PAM measurements), growth and survival, photosynthetic pigments, photosystem II photochemistry, and chlorophyll fluorescence. We identified the temperature for optimal growth (27°C), and found that sustained summer maximum temperatures (where the seagrasses were collected; 32°C) are enough to cause rapid seagrass mortality, suggesting that the seagrass populations under investigation are living close to their thermal tolerance. Seagrasses were found to be relatively resilient (survivorship was maintained) to low light levels (up to 75% shading of ambient conditions); however, there were costs, including: reduced growth, upregulation of photochemical efficiency (photosystem II), and suppression of photosynthetic yield. Surprisingly, we did not detect interactive effects of light and temperature on seagrass health, despite these two stressors having significant effects on seagrass health in isolation. |
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Razor clams as bioindicators of heavy metal pollutionThis week the razor clam bioindicator team (Kevin McCauley, Jess Reeves, David Bishop, Ben Kefford, Aziz Rahman, Ross Jeffries, Patricia Gadd, Henk Heijnis, David Booth, Peter Macreadie) are running another batch of razor clam (Pinna bicolor) shells on LA-ICP-MS (@ UTS) and iTRAX (@ ANSTO). The goal of the project is to see whether the clams can be used to assess historical pollution within Lake Macquarie.
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Welcome Aurora!
Aurora M Ricart, a PhD student from University of Barcelona, is visiting us at UTS:C3 for the next four months. Her thesis research focusses on landscape and community ecology to study habitat fragmentation in seagrasses and its consequences on nutrient dynamics and species diversity.
During her stage in our research group she is going to run experiments on the edge effects on carbon stocks on seagrass meadows. When a habitat is in regression, as most of the seagrasses over the world, one of the main consequences is the loss of habitat structure. Seagrass meadows become in small patches, and more edge of the habitat is exposed to adjacent habitats and subjected to new interactions. Understanding habitat edge dynamics is essential to follow the new functionality of the habitat, particularly on the carbon stored by seagrass meadows in terms of the irreversible climate change. This work will be develop in Gladstone Harbour, Queensland, as a part of a project in collaboration with James Cook University. |
PhD student Stacey Trevathan-Tackett takes out FRDC Award
Congrats to Stacey Trevathan-Tackett for winning the Fisheries Research Development Corporation Award for Best Poster Presentation On Natural Resources Sustainability or Industry Development at last week's Australian Marine Sciences Association (AMSA) conference on the Gold Coast.
Stacey adressed the issue of microscale sediment chemistry during seagrass decomposition. Seagrass meadows are a globally significant sink for biologically derived sedimentary organic carbon with seagrass detritus playing an important role in coastal carbon biogeochemistry and accumulation. Over three months Stacey studied the decomposition of above- and belowground biomass from the dominant temperate seagrass Zostera muelleri under controlled laboratory conditions. The effects of seagrass leaf and root/rhizome degradation on sediment oxygen and hydrogen sulfide levels were followed using electrochemical microsensors. The aims of this study were to provide insight into the biogeochemical processes involved in seagrass organic carbon remineralisation, as well as to eventually link this data to other factors related to seagrass degradation including seagrass decay rates, changes in seagrass C:N:P and microbial abundance under the different temperature and nutrient treatments. |
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New paper: Loss of 'blue carbon' from coastal salt marshes following habitat disturbance
Read the paper in Plos One (Open Access) at http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0069244
Increased recognition of the global importance of salt marshes as ‘blue carbon’ (C) sinks has led to concern that salt marshes could release large amounts of stored C into the atmosphere (as CO2) if they continue undergoing disturbance, thereby accelerating climate change. Empirical evidence of C release following salt marsh habitat loss due to disturbance is rare, yet such information is essential for inclusion of salt marshes in greenhouse gas emission reduction and offset schemes (e.g. UN-REDD+). Here we investigated the stability of salt marsh (Spartina alterniflora) sediment C stocks following seagrass (Thallasia testudinum) wrack accumulation; a form of disturbance common in salt marshes throughout the world causing ‘halos’ of bare sand. At our study site (St Joseph Bay, Florida, USA), we recorded 296 halos in a salt marsh meadow the size of a soccer field (7 275 m2). In the halos examined (7.5 ± 2.3 m2; mean ± SE), which were 3-12 months old, we found that the organic C of subsurface sediment zones (1 – 5 cm depth) was ~30% lower than the subsurface sediments of the surrounding undisturbed salt marsh. Further sampling and analysis revealed that halos had lost their below-ground plant (salt marsh) biomass, which otherwise forms the main component of the long-term ‘refractory’ C stock. We conclude that disturbance to salt marsh habitat leads to significant release of below-ground C, likely shifting salt marshes from C sinks to C sources. This mechanism of C release from salt marsh habitats is likely to increase in the future due to sea levels rise; which will increase wrack production due to increasing storminess, and will facilitate delivery of wrack into salt marsh zones due to higher and more frequent inundation. |
Talking seagrass with our PM Julia Gillard and former PM John Howard
On the evening of Thursday June 6 2013, the American Australian Association (AAA) held its 2013 Benefit Dinner at the Sydney Convention Centre to honour Andrew Liveris, President, Chairman and CEO of The Dow Chemical Company and Richard (Dick) Warburton AO LVO, Chairman of Westfield Retail Trust, Magellan Flagship Fund, Citigroup Pty Ltd and Manufacturing Australia.
Over 500 guests attended the dinner including dignitaries, leaders of the Sydney business and philanthropic community and performers who will salute the extraordinary achievements of both Andrew Liveris and Richard (Dick) Warburton AO LVO. The event was hosted by television presenter and financial commentator David Koch and there were be tributes on the night to Andrew Liveris and Richard (Dick) Warburton AO LVO from Prime Minister Julia Gillard and former Prime Minister John Howard OM AC. Entertainment on the evening will be provided by Silvie Paladino and the Qantas Choir, alongside members of the Boston Children's Chorus. World renowned French artist Jean-Pierre Blanchard will attend the event to uniquely document the celebration. And of course, there was an opportunity to talk about how awesome seagrass is! And especially great to have babysitters so my lovely wife could join the fun. More information: http://www.americanaustralian.org.au/ |
Dow supports blue carbon research
Special thanks to Craig Arnold (Dow CEO, Australia) and Andrew Livers (Dow CEO, Global) for providing the opportunity (via the AAA Education Fund) for me to work with leading scientists in the USA on devising ways to maximise carbon storage in blue carbon ecosystems, and minimise carbon leakage. It's been a pleasure to contribute to Dow's 'Vision Zero'.
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International Blue Carbon Working Group at UTS - 15-17th May 2013
The Blue Carbon Initiative is a global program working to mitigate climate change through the restoration and sustainable use of coastal and marine ecosystems. The Initiative currently focuses on mangroves, tidal marshes and seagrasses. The Blue Carbon Initiative brings together governments, research institutions, non-governmental organizations and communities from around the world. The Initiative is coordinated by Conservation International (CI), the International Union for Conservation of Nature (IUCN), and the Intergovernmental Oceanographic Commission of the United Nations Educational, Scientific, and Cultural Organization (IOC-UNESCO).
More information: http://thebluecarboninitiative.org/category/about/the-initiative/ Photo by Marea Martlew |
PADI Foundation supports 'blue carbon' researchCongratulations to Stacey Trevathan-Tackett on being awarded the 2013 PADI FOUNDATION grant to investigate 'Dynamics of sedimentary carbon in seagrass meadows in Australia'.
With the rapid escalation of greenhouse gases, the need to reduce emissions has become paramount. Recently, seagrass meadows have been advocated as primary, natural, long-term carbon sinks. This project focuses on how a dominant Australian seagrass, Zostera muelleri, functions as a carbon sink. |
Scholarships
Check out the 'Prospective students' tab for information on Honours, Masters, and PhD scholarships within C3.
Mid-year intake Honours students are eligible for a $6,000 scholarship. |
Link to media HERE
Failure to protect seagrasses may cost $45B
Australia is losing massive amounts of seagrass and the effects of those losses could be counted in billions of dollars, say environmental experts.
See full article at:http://www.abc.net.au/rural/telegraph/content/2013/s3688556.htm Audio link below |
starts at 13:00
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Nuclear fallout
By FRANCES RAND Feb. 6, 2013, 7:28 a.m.
IN the 1960s 11 holes were blown into one of the country’s largest seagrass meadows. It was at Hole in the Wall in Booderee National Park, when seismic testing was used to check ground stability for a proposed nuclear testing facility. Nearly 50 years later, the holes are clearly visible on Google Earth and aren’t expected to grow back for another 100 years. This week marine ecologist Dr Peter Macreadie will be taking sediment cores from the damaged areas and measuring the carbon loss from the area. Continued ... See full article HERE |
Prime time for Zostera nigracaulis
Microsatellite primers now completed for Zostera nigracaulis!
(This opens up new research opportunities to investigate genetic connectivity among seagrass populations) Smith et al. (2013) Microsatellite primer development for the seagrass Zostera nigricaulis(Zosteraceae). Conservation Genetics Resources. |
Too scared to eat
Which has greater influence in structuring marine food webs: predation, or the fear of being eaten? This growing area of research - termed 'The Ecology of Fear' - is being tackled by Nate Geraldi, Pete Peterson, and Pete Macreadie in oyster reefs of North Carolina, which are facing decline due to urbanisation and fishing pressures. It turns out that an unlikely hero is emerging in this story: oyster toadfish, a sit-and-wait ambush predator, could facilitate recovery of oyster reefs by scaring small crabs (mud and blue crabs) that eat juvenile oysters. Read more about their findings in the following peer reviewed papers:
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