John Statton

University of Western Australia | UWA · Oceans Institute

Understanding sexual reproduction and recruitment in seagrasses is crucial to their conservation and restoration. Flowering, seed production, seed recruitment, and seedling establishment data for the seagrass Posidonia australis was collected annually between 2013 and 2018 in meadows at six locations around Rottnest Island, Western Australia. Varia...

Restoration is an important activity to assist the recovery of damaged or degraded ecosystems. Accessing healthy donor material can be challenging when restoring threatened ecological communities, but careful selection of donor material may improve the success and cost‐effectiveness of restoration projects. We aim to optimise restoration of the thr...

The seed bank of Halophila ovalis is crucial for resilience to disturbance through re-establishment. Understanding seasonal changes in abundance and quality of seeds in natural seed banks is critical for seed-based restoration. We selected an estuary in southwestern Australia and investigated the seasonal changes of seed distribution and viability...

This chapter summarizes our existing knowledge about seagrass seeds and their use and success in restoring seagrasses and enhancing recovery of damaged seagrass meadows, post-disturbance. The chapter is organised to introduce our interpretation of the evolution of these unique angiosperms, the processes of sexual reproduction, seed dormancy, seedli...

Posidonia australis is a slow-growing seagrass that forms extensive meadows in sheltered coastal locations which are often popular areas for recreational boating. Traditional block-and-chain boat moorings can directly impact P. australis meadows, with the action of heavy chains eroding the seafloor and creating bare sand scars that fragment meadows...

Three case studies involving two temperate Australian seagrass species – Pondweed (Ruppia tuberosa) and Ribbon Weed (Posidonia australis) – highlight different approaches to their restoration. Seeds and rhizomes were used in three collaborative programmes to promote new approaches to scale up restoration outcomes.

For millennia, coastal and marine ecosystems have adapted and flourished in the Red Sea’s unique environment. Surrounded by deserts on all sides, the Red Sea is subjected to high dust inputs and receives very little freshwater input, and so harbors a high salinity. Coral reefs, seagrass meadows, and mangroves flourish in this environment and provid...

The seagrass Halophila ovalis rapidly colonizes marine sediments from seed across a range of depth, light, and temperature conditions, making it ideal for restoration projects. Yet, presently, it is not a targeted restoration species as the biology of seed dormancy and germination is poorly understood. This study addresses that knowledge gap by exp...

Marine coastal (or “blue”) ecosystems provide valuable services to humanity and the environment, but global loss and degradation of blue ecosystems necessitates ecological restoration. However, blue restoration is an emerging field and is still relatively experimental and small-scale. Identification of the key barriers to scaling-up blue restoratio...

Reversing the decline of coastal marine ecosystems will rely extensively on ecological restoration. This will in turn rely on ensuring adequate supply and survival of propagules — for the main habitat-forming taxa of coastal marine ecosystems these are mainly fruits, seeds, viviparous seedlings, zoospores or larvae. The likelihood of propagule surv...

Seagrasses are important marine ecosystems situated throughout the world’s coastlines. They are facing declines around the world due to global and local threats such as rising ocean temperatures, coastal development and pollution from sewage outfalls and agriculture. Efforts have been made to reduce seagrass loss through reducing local and regional...

Populations at the edges of their geographical range tend to have lower genetic diversity, smaller effective population sizes and limited connectivity relative to centre of range populations. Range edge populations are also likely to be better adapted to more extreme conditions for future survival and resilience in warming environments. However, th...

The seagrass Posidonia australis has suffered large reductions in distribution since the early to mid-1900s and as such has been listed as endangered in six estuaries in New South Wales, Australia, and as a ‘Threatened Ecological Community’ in estuaries from Wallis Lake to Port Hacking. One of the ongoing causes of losses of Posidonia in NSW estua...

A central question in contemporary ecology is how climate change will alter ecosystem structure and function across scales of space and time. Climate change has been shown to alter ecological patterns from individuals to ecosystems, often with negative implications for ecosystem functions and services. Furthermore, as climate change fuels more freq...

The role of environmental-stress gradients in driving trophic processes like grazing, has potential to shape ecosystem responses to environmental change. In subtidal seagrass systems, however, the variation in top-down processes along stress gradients are poorly understood. We deployed herbivory assays using the five most common seagrass species of...

Comprehensive list of fish species found in the Eastern embayment of Shark Bay, Western Australia. Table has been adapted from Travers and Potter (2002), Jackson et al. (2007), Belicka et al. (2012), Heithaus et al. (2012) and Walker et al. (2012). (DOCX)

Desalination has the potential to provide an important source of potable water to growing coastal populations but it also produces highly saline brines with chemical additives, posing a possible threat to benthic marine communities. The effects of brine (0%, 50%, 100%) were compared to seawater treatments with the same salinity (37, 46, 54 psu) for...

In Australia, the states and territories have the primary responsibility for coastal waters. However, the Environmental Protection and Biodiversity Conservation (EPBC) Act 1999 describes when the Australian Federal Government needs can assist. The EPBC focusses on nine matters of national environmental significance (MNES). These include World Herit...

Since the first version of this book almost 30 years ago, significant losses of seagrass meadows have continued to be reported from around Australia as a result of natural and human induced perturbations. Conservative estimates indicate losses over the past two decades have more than doubled that estimated in the late 1990s. Conservation and mitiga...

Bioturbating animals have the potential to influence the distribution and survival of seagrass seeds and seedlings within unvegetated substrates. Such disturbances could act as demographic bottlenecks, or restrictions, to seedling recruitment and impede population recovery in degraded systems. This study evaluated the influence of sediment bioturba...

Existing mitigations to address deterioration in water clarity associated with human activities are based on responses from single seagrass species but may not be appropriate for diverse seagrass assemblages common to tropical waters. We present findings from a light experiment designed to determine the effects of magnitude and duration of low ligh...

Seagrass meadows are highly productive ecosystems that provide ecosystem services to the coastal zone but are declining globally, particularly due to anthropogenic activities that reduce the quantity of light reaching seagrasses, such as dredging, river discharge and eutrophication. Light quality (the spectral composition of the light) is also alte...

Seagrass roots host a diverse microbiome that is critical for plant growth and health. Composition of microbial communities can be regulated in part by root exudates, but the specifics of these interactions in seagrass rhizospheres are still largely unknown. As light availability controls primary productivity, reduced light may impact root exudatio...

While light availability plays a critical role in seagrass growth and distribution, there is limited understanding of how changes in light exposure impact belowground processes. We investigated the effect of prolonged and fluctuating reductions in light on root growth and exudation by three colonizing seagrasses: Cymodocea serrulata, Halophila oval...

Identifying early life-stage transitions limiting seagrass recruitment could improve our ability to target demographic processes most responsive to management. Here we determine the magnitude of life-stage transitions along gradients in physical disturbance limiting seedling establishment for the marine angiosperm, Posidonia australis. Transition m...

The seagrass, Halophila ovalis plays an important ecological and sediment stability role in estuarine systems in Australia with the species in decline in many sites. Halophila ovalis is a facultative annual, relying mainly on recruitment from the sediment seed bank for the annual regeneration of meadows. Despite this, there is little understanding...

Dredging can have significant impacts on benthic marine organisms through mechanisms such as sedimentation and reduction in light availability as a result of increased suspension of sediments. Phototrophic marine organisms and those with limited mobility are particularly at risk from the effects of dredging. The potential impacts of dredging on ben...

Seagrass meadows provide crucial ecosystem services to the coastal zone but are threatened globally. Seagrass loss to date has mainly been attributed to anthropogenic activities that reduce light quantity (amount of photosynthetic photon flux density), such as dredging, flooding and eutrophication. However, light quality (wavelengths of light withi...

Accurate estimation of connectivity among populations is fundamental for determining the drivers of population resilience, genetic diversity, adaptation and speciation. However the separation and quantification of contemporary versus historical connectivity remains a major challenge. This review focuses on marine angiosperms, seagrasses, that are f...

Poster presented at The Australian Microbial Ecology (AusMe2017), Melbourne, 2017

Background and Aims: Organisms occupying the edges of natural geographic ranges usually survive at the extreme limits of their innate physiological tolerances. Extreme and prolonged fluctuations in environmental conditions often associated with climate change, and exacerbated at species’ geographical range edges, are known to trigger alternative re...

Aims Seedling establishment is a crucial life history stage in seagrasses, yet factors that affect seedling health are poorly characterized. We investigated if organic matter (OM) additions to sediments provided nutritional benefits for seagrass seedlings through microbial degradation. Methods We tested the effects of sedimentary OM additions on P...

In a recent paper by Thomson et al. (2014), vivipary is implied for the eastern Australian Zostera, Zostera nigricaulis (revised from Zostera tasmanica; Kuo 2005). However, the definition of vivipary (production of genetically distinct offspring resulting from sexual reproduction) needs to be fully explored in terms of the experimental claims by th...

We investigated the phenology and spatial patterns in Halophila decipiens by assessing biomass, reproduction and seed density in ~400 grab samples collected across nine sites (8 to 14m water depth) between June 2011 and December 2012. Phenology correlated with light climate which is governed by the summer monsoon (wet period). During the wet period...

Photosynthesis of most seagrass species seems to be limited by present concentrations of dissolved inorganic carbon (DIC). Therefore, the ongoing increase in atmospheric CO2 could enhance seagrass photosynthesis and internal O2 supply, and potentially change species competition through differential responses to increasing CO2 availability among spe...

A key issue in habitat restoration are the changes in ecological processes that occur when fragments of habitat are lost, resulting in the persistence of habitat-degraded margins. Margins often create or enhance opportunities for negative plant-herbivore interactions, preventing natural or assisted re-establishment of native vegetation into the deg...

Background The broad aims of this study were to test the vulnerability of seagrasses to declining water quality, in particular, changes associated with flooding. This project was established in response to extensive seagrass loss that occurred from 2009 to 2011 in the Great Barrier Reef when there was above average run-off for multiple wet seasons,...

A movement ecology framework is applied to enhance our understanding of the causes, mechanisms and consequences of movement in seagrasses: marine, clonal, flowering plants. Four life-history stages of seagrasses can move: pollen, sexual propagules, vegetative fragments and the spread of individuals through clonal growth. Movement occurs on the wate...

Extreme climatic events can trigger abrupt and often lasting change in ecosystems via the reduction or elimination of foundation (i.e., habitat-forming) species. However, while the frequency/intensity of extreme events is predicted to increase under climate change, the impact of these events on many foundation species and the ecosystems they sup-po...

Extreme climatic events will dictate the response of ecosystems to climate change, yet are understudied in marine ecosystems. The interaction of stressors from such events has the potential to amplify negative impacts and drive ecosystems into alternate states.Here, we show a drastic response of a temperate seagrass species (Amphibolis antarctica)...

Seed represents a potentially ecologically sustainable source of planting units for restoring seagrasses, particularly for seagrasses where transplanting negatively impacts donor beds. However, newly germinated seeds may be nutrient limited as their underdeveloped root systems may constrain capacity to access sediment-based resources. We conducted...

Marine ecosystems where habitat-forming species exist near their thermal tolerance limits are prone to temperature-related perturbations that cause dramatic shifts in community structure and function. In a global biodiversity hotspot in Western Australia, at the transition between temperate and tropical zones, we documented the rapid decline of the...

Seeds of the seagrass Posidonia australis are desiccation sensitive and as there is no seed dormancy seeds cannot be stored for use in restoration projects. To realize the restoration potential of seed-based restoration of Posidonia, this study investigated preconditioning seedlings of Posidonia in aquaculture facilities before transplanting to ext...

In Shark Bay, World Heritage Area, seagrass habitat has been degraded. To inform scientists and managers about strategies used in revegetation and the variability of success, we take a ‘lessons learnt’ approach from analogous systems. No discrete approach could be used with confidence to proceed with a large-scale revegetation program, particularly...

Global seagrass losses parallel significant declines observed in corals and mangroves over the past 50 years. These combined declines have resulted in accelerated global losses to ecosystem services in coastal waters. Seagrass meadows can be extensive (hundreds of square kilometers) and long-lived (thousands of years), with the meadows persisting p...