Life Sciences Commons^™

Carbon Sequestration By Australian Tidal Marshes, Peter I. Macreadie, Q. R. Oliver, J. J. Kelleway, Oscar Serrano, P. E. Carnell, C. J. Ewers Lewis, T. B. Atwood, J. Sanderman, J. Baldock, R. M. Connolly, C. M. Duarte, Paul Lavery, A. Steven, C. E, Lovelock

Research outputs 2014 to 2021

Australia’s tidal marshes have suffered significant losses but their recently recognised importance in CO2 sequestration is creating opportunities for their protection and restoration. We compiled all available data on soil organic carbon (OC) storage in Australia’s tidal marshes (323 cores). OC stocks in the surface 1 m averaged 165.41 (SE 6.96) Mg OC ha − 1 (range 14 – 963 Mg OC ha − 1). The mean OC accumulation rate was 0.55 ± 0.02 Mg OC ha − 1 yr − 1. Geomorphology was the most important predictor of OC stocks, with fluvial sites having twice the stock of OC …

Sediment Burial Stress Response, Bio-Indicators And Thresholds For A Tropical Multi-Species Seagrass Assemblage: Report Of Theme 5 - Project 5.5.2 Prepared For The Dredging Science Node, John Statton, Kathryn Mcmahon, Roisin Mccallum, Gary Kendrick, Paul Lavery

Research outputs 2014 to 2021

Deterioration in water clarity by resuspension of dredged sediments is presumed to be a major mechanism by which dredging can impact seagrasses. This report presents findings from a controlled light experiment that aimed to determine the effects of low light stress on the growth of three seagrass species found in the northwest of Western Australia.

Aims

• To determine the effects of sediment burial stress under dredge-simulated conditions on the growth and health of three seagrass species found in the northwest of Western Australia.
• Provide guidance and protocols for the application of the research outputs (e.g. seagrass burial stress:response relationships, sub-lethal …

Response And Recovery Of A Mixed Tropical Seagrass Assemblage To Variation In The Frequency And Magnitude Of Light Deprivation. Report Of Theme 5 - Project 5.5.3 Prepared For The Dredging Science Node, John Statton, Kathryn Mcmahon, Rosin Mccallum, Gary Kendrick, Paul Lavery

Research outputs 2014 to 2021

The capacity of seagrasses to cope with episodes of light deprivation from overlying turbid waters may not only depend on the absolute quantity of light they receive during that episode, but also on how the light deprivation varies through time. For example, turbidity and therefore light reduction may be relatively constant over the episode or it may fluctuate depending on the frequency of pulsed turbidity events.

This report presents findings from a controlled mesocosm experiment that aimed to determine the responses of seagrasses to, and recovery from, differences in the pattern of the delivery of light. The study focussed on …

Effects Of Dredging-Related Pressures On Critical Ecological Processes For Organisms Other Than Fish Or Coral. Report Of Theme 9 - Project 9.1 Prepared For The Dredging Science Node, Jessie Short, Matthew Fraser, Dianne Mclean, Gary Kendrick, Maria Byrne, Julian Caley, Doug Clarke, Andy Davis, Paul Ertemeijer, Stuart Field, Sam Gustin-Craig, John Huisman, John Keesing, Mick Keough, Paul Lavery, Ray Mansini, Kathryn Mcmahon, Kerrie Mergersen, Michael Rasheed, John Statton, Jim Stoddart, Paul Wu

Research outputs 2014 to 2021

This study reviewed environmental windows for organisms other than corals and fish such as sessile invertebrates, macroalgae and seagrasses. Environmental windows are periods of critical importance to the life history of a marine species, like reproduction and recruitment.

Aims

• To review the scientific literature on the timing and spatial extent of critical ecological processes relevant to tropical WA for marine primary producers and invertebrates (i.e. organisms other than coral and finfish) and the state of knowledge regarding potential effects of dredging on these key ecological processes. The review also had a particular focus on ecological processes in marine primary producers …

Residence Time In Coastal Canopies, Maryam Abdolahpour

Theses: Doctorates and Masters

Aquatic canopies provide important ecosystem services such as improved water quality, oxygen flux, sediment stabilisation and trapping and recycling of nutrients. The ecological health of coastal canopies and the significant ecosystem services they provide depends largely on the continuous exchange of dissolved and particulate materials across the canopy boundaries. In coastal environments, where flow is typically wavedominated, vertical mixing is believed to be the dominant process controlling residence time and, therefore, exchange. However, experiments have shown that wave-driven flows over rough boundaries, such as canopies, generate strong onshore mean currents (75% of the orbital velocity far above the canopy) near …

Freshwater Future: The Influence Of Exposure To Extreme Summer Rainfall Events On The Resistance And Recovery Patterns Of An Estuarine Seagrass, Chanelle Webster

Theses : Honours

Restoring and maintaining the ecological resilience of seagrass ecosystems will be a major challenge of the 21st century. The decline of seagrasses worldwide is attributed to the erosion or elimination of their ecological resilience driven by human impacts, extreme climate events and climate change. Ecological resilience refers to the ability of ecosystems to resist or recover from disturbances whilst maintaining their integral structure and function. Seagrass resilience is influenced by life history, meadow form (transitory or enduring) and habitat type. The purpose of this honours project was to investigate the influence of extreme climate events and meadow form on a …

Current State Of Knowledge Regarding The Effects Of Dredging-Related ‘Pressure’ On Seagrasses: Report Of Theme 5 - Project 5.1.1 Prepared For The Dredging Science Node, Kathryn Mcmahon, Paul Lavery, John Statton, Roisin Mccallum, Udhi Hernawan

Research outputs 2014 to 2021

This review summarises our understanding, from a northwest of Western Australia and global perspective, the pressures seagrasses are exposed to from dredging, their tolerance thresholds and responses to dredging related stressors, and the bioindicators of dredging related stressors. From this information, we also identified gaps in our knowledge and areas where environmental management and monitoring approaches could be improved.

Aims

To determine the levels of stress (light reduction/sediment deposition) that occur under dredging conditions and evaluate the likely effect of these levels of pressure based on the existing seagrass literature, considering the range of variability and environmental quality conditions associated …

Genetic Variability Within Seagrass Of The North West Of Western Australia: Report Of Theme 5 - Project 5.2 Prepared For The Dredging Science Node, Kathryn Mcmahon, Udhi Hernawan, Kor-Jent Van Dijk, Michelle Waycott, Ed Biffin, Richard Evans, Paul Lavery

Research outputs 2014 to 2021

This study was the first of its kind to examine the patterns of genetic diversity in seagrasses in the Pilbara region of WA. Three species were assessed: Halophila ovalis (6 populations), Halodule uninervis (8 populations) andThalassia hemprichii (3 populations) at a range of spatial scales, within a meadow (centimetres−metres), among meadows at a local scale (2−60 km) and among meadows at a regional scale (up to 500 km). Due to the varied distribution of species all species across the same spatial scale and range of environments could not be sampled, so a nested approach was designed, with sites …

Seagrasses Of The North West Of Western Australia: Biogeography And Considerations For Dredging-Related Research: Report Of Theme 5 - Project 5.1.2 Prepared For The Dredging Science Node, Kathryn Mcmahon, John Statton, Paul Lavery

Research outputs 2014 to 2021

This review was undertaken to identify which seagrass primary producers (species or different functional groups) that collectively cover the bio-geographic range of key primary producers in the northwest of Western Australia are most appropriate for the focus of subsequent research into thresholds and indicators of response to dredging-related pressures (i.e. Theme 5). An assessment framework was developed based on six criteria: biogeographic range; ecological relevance (life-history strategy, habitats, natural dynamics and ecological services); current knowledge on thresholds and bioindicators; likelihood that species are sensitive and resilient to dredging related stressors; extent of improvement in applied knowledge; and likelihood of being …

Natural Dynamics: Understanding Natural Dynamics Of Seagrasses Of The North West Of Western Australia. Report Of Theme 5 - Project 5.3 Prepared For The Dredging Science Node, Mat Vanderklift, Douglas Bearham, Mick Haywood, Hector Lozano-Montes, Roisin Mccallum, James Mclaughlin, Kathryn Mcmahon, Nick Mortimer, Paul Lavery

Research outputs 2014 to 2021

Relatively little is known of the spatial and temporal dynamics of seagrass meadows in the northwest of Western Australia, but such knowledge is needed when designing and evaluating studies that aim to detect potential dredging-related impacts on seagrass, and when making predictions about the likelihood of, and speed of recovery from such impacts. This study was undertaken to improve our understanding of the spatial and temporal patterns in seagrass composition, abundance and reproductive phenology in the Pilbara. We also characterised key environmental parameters, especially light, that influence seagrass survival and can be altered by dredging.

Aims

To improve our understanding …

Muddy Waters: Unintentional Consequences Of Blue Carbon Research Obscure Our Understanding Of Organic Carbon Dynamics In Seagrass Ecosystems, E. Fay Belshe, Miguel-Angel Mateo, Lucy Gillis, Martin Zimmer, Mirta Teichberg

Research outputs 2014 to 2021

The recent surge in research on organic carbon sequestration by seagrass ecosystems has begun to reveal the complexity of the carbon cycle within these ecosystems. In this prospective we discuss two areas of investigation that require further scrutiny: (1) why organic carbon is stabilized in seagrass sediments, and (2) how long organic carbon resides within these sediments. By delving into these topics, pointing out current pitfalls, and highlighting methodological advances, our motive is to focus future efforts and provide a frame work to manage the complexity found within the diverse seagrass bioregions. The high rate of seagrass degradation and loss, …

Species Distribution Model Of Invasive Alien Species Acacia Nilotica For Central-Eastern Indonesia Using Biodiversity Climate Change Virtual Laboratory (Bccvl), Sutomo, Eddie Van Etten

Research outputs 2014 to 2021

Climate change may facilitate alien species invasion into new areas. This study uses Biodiversity and Climate Change Virtual Laboratory to develop a species distribution model (SDM) of Acacia nilotica (L.) Willd. ex Delile. based upon its naturalized distribution to project the potential distribution of A. nilotica throughout tropical environment of Indonesia under current and future climate conditions. Global biodiversity information facility database was utilized to obtain the species occurrences data. The climate factors were precipitation and temperature layers, available in Worldclim current conditions (1950-2000) at 2.5 arcmin. We used Generalized Linear Model. The result was then projected to the year …

Ecology Of Savanna Ecosystems In Indonesia, Sutomo

Theses: Doctorates and Masters

Tropical savannas in South East Asia are important yet understudied ecosystems. In fact, the description of savanna is limited in the Indonesian Archipelago, a region which, based on climate alone, would be expected to have mostly forest. In this thesis, I compared and contrasted the vegetation characteristics of four savannas in the wetter part of the Indonesian archipelago (Java – Bali – Lombok) to understand how fire and grazing influence their dynamics, and searched for evidence of savanna origins, maintenance, invasion by exotic/woody species and possible ecosystem transitions. Vegetation surveys, remote sensing techniques and statistical models were used to spatially …

A Marine Heat Wave Drives Massive Losses From The World’S Largest Seagrass Carbon Stocks [Dataset], Ariane Arias-Ortiz, Oscar Serrano, Pere Masqué, Paul Lavery, Ute A. Mueller, Gary A, Kendrick, Mohammad Rozaimi, Alba Esteban, James W, Fourqurean, Núrià N. Marbà, Miquel-Angel Mateo, Kathy Murray, Michael Rule, Carlos M. Duarte

Research Datasets

The database compiles published data (in Arias-Ortiz et al., 2018) on biogeochemical characteristics (density, organic carbon, stable carbon isotopes and sediment grain size) of soils underneath seagrass meadows in Shark Bay, Western Australia. Pb-210 concentrations of the first 20 cm are included along with C-14 raw ages. The dataset compiles data for a total of 49 cores, 25 - 300 cm-long (11 cores with Pb-210 and C-14 data). Enquiries about the dataset may be sent to Ariane Arias-Ortiz: ariane.arias@uab.cat