Separation Point Easement : baseline benthic mapping and faunal survey

The Batavia Coast Marine Centre forms part of the Separation Point Marine Precinct in Geraldton, Western Australia, a collaborative initiative between the Mid West Development Commission, Department of Fisheries, City of Geraldton and the Department of Education and Training. To service an aquaculture facility planned as part of the Batavia Coast Marine Centre, a salt water intake pipe is being constructed on the coast adjacent to the facility..

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

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 north west of Western Australia (NWWA) 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 able to grow seagrass species successfully in mesocosms. For each criterion, one or more assessment metric was developed. These were then used in a hierarchical decision-making process to identify the species most appropriate for the focus of subsequent research. The first step identified those species with the broadest biogeographic range, which were found in the most regions and habitats and which had the greatest ecological significance and prioritised the species for further investigation (Priority 1, 2 and 3). The second step identified species that encompassed a range of sensitivities and resilience to dredging and which, collectively, offered the greatest opportunity to improve our knowledge and understanding of primary producer responses to dredging-related pressures..

Review of coast and marine ecosystems in temperate Australia demonstrates a wealth of ecosystem services

© Copyright © 2020 Gaylard, Waycott and Lavery. Temperate Australia has extensive and diverse coast and marine habitats throughout its inshore and offshore waters. The region includes the southernmost extent of mangroves, over 500 estuaries and coastal embayments, home to extensive meadows of seagrasses and tidal saltmarsh. In areas of hard substrate, rocky reefs are abundant and productive with large forests of macroalgae. Coastal regions can be densely populated by humans and often habitats can be degraded, polluted or lost, while some remain relatively isolated and pristine. These habitats provide services to society including provision of food, regulate our climate through sequestration of carbon, treating our waste and protecting our shorelines from damage from storms. Coastal areas are culturally importantly hubs for recreation and tourism. Habitat mapping demonstrates diverse habitats throughout temperate Australia, but a formal investigation of services provided by these habitats has been lacking. This review of ecosystem services provided by coast and marine environments throughout temperate Australia reveals vast and productive ecosystems that provide multiple ecosystem services, substantial value to the Australian economy and contribute to the health and well-being of people who live in, visit of benefit from services or products from these regions. Some of these are considered within traditional economic metrics such as provision of wild catch fisheries, but this review demonstrates that regulation and maintenance services including waste treatment and protecting shorelines from extreme events are under recognized, and their value is substantial. However, consistent with many locations globally, coast and marine habitats are under threat from increasing development, sewage, agricultural, industrial discharges, urban runoff and climate change. Resultantly, temperate Australian coast and marine habitat extent and condition is generally declining in many regions, putting the provision of services and benefits to the community at risk. Continued degraded or lost habitats indicate current management frameworks are not capturing the full risk from development and there are winners and losers in trade off decision making. Incorporating ecosystem services in decision making may allow an integrated approach to management, and acknowledgment of services provided could prevent habitats from being undervalued against economic and social interests, a practice that often results in environmental degradation

Recovery from the impact of light reduction on the seagrass Amphibolis griffithii, insights for dredging management

A large-scale, manipulative experiment was conducted to examine the extent and rate of recovery of meadows of the temperate Australian seagrass, Amphibolis griffithii to different light-reduction scenarios typical of dredging operations, and to identify potential indicators of recovery from light reduction stress. Shade cloth was used to mimic different intensities, durations and start times of light reduction, and then was removed to assess the recovery. The meadow could recover from 3 months of light stress (5–18% ambient) following 10 months re-exposure to ambient light, even when up to 72% of leaf biomass was lost, much faster recovery rates than has previously been observed for large seagrasses. However, when the meadow had been shaded for 6–9 months and more than 82% of leaf biomass was lost, no recovery was detected up to 23 months after the light stress had ceased, consistent with other studies. Five potential indicators of recovery were recommended

Essays on private equity buyouts

This thesis consists of three independent essays on the consequences of and market for private equity buyouts. The introduction provides a brief outline of the growth of buyout markets in recent decades and the conclusion summarises the main findings. The first essay examines the exporting behaviour of buyout target firms relative to control firms. We build a data set of over 1,400 buyouts in the UK from 2004 to 2017 and using a difference-in-differences approach, estimate the effect of private equity ownership on target firms' exporting activities at the extensive and intensive margin, relative to a sample of carefully matched control firms. The results show that: (a) private equity ownership increases the probability of firms exporting (the extensive margin of trade); (b) private equity ownership increases the value of firms exports (the intensive margin of trade); (c) private equity ownership increases the exporting intensity of firms (the ratio of export sales-to-total sales). Our consequent findings indicate private equity investors' ability to alleviate financing constraints of companies, as our results are amplified where the target company is more likely to be in a constrained position. Along similar lines, target firms' exporting is found to have been more resilient during the global financial crisis. To explain our findings, we postulate that improvements to target firms' working capital management allows them to overcome the associated costs of exporting. Our results support this hypothesis: the working capital of buyout targets improves significantly relative to control firms. In an attempt to better understand how banking sector shocks can be transmitted onto the real economy, the second essay examines bank-affiliated private equity buyouts and studies how portfolio companies respond to external shocks affecting their parent banks. In particular, we assess how the 2011 European Banking Authority (hereafter EBA) Capital Exercise impacted the portfolio companies of the private equity arms of affected and unaffected banks. Our results imply that the shock came with associated real effects: the portfolio companies associated with the private equity arms of affected banks experienced weaker investment and financing at the onset of the shock. These companies were consequently found to under-perform the portfolio companies of unaffected banks. The effects are heterogeneous in two ways: first, the negative effect on portfolio company performance is stronger for companies which were more likely to be constrained at the onset of the shock. Second, the effect is found to be stronger on portfolio companies whose private equity owner is less experienced. The last essay investigates the importance of capital market development for international buyout activity. Given the evidence of the diverse range of industry- and firm-level benefits of buyout investment, studying the stimulants of an active buyout market merits attention. Robust to a battery of checks, our findings strongly suggest that well-developed stock and credit markets are an important driver of buyout activity. We show that that capital market development is more important to buyout investment relative to other types of international investment flows. Lastly, we underline the importance of countries' institutional environments for their buyout market activity. The positive effect of capital market development on buyout capital is significantly stronger in country-years with lower legal and political risk

Accounting for the influence of temperature and location when predicting seagrass (halophila ovalis) photosynthetic performance

We show that the effect of temperature on photosynthesis of a widely distributed and ecological important seagrass species was not consistent among locations, with some evidence of acclimation to the local temperature range. This has important implications for modelling seagrass productivity and the impacts of light reduction on seagrass ecosystems. Reduced light availability is one of the main pressures negatively impacting on seagrass meadows worldwide. Our knowledge of seagrass photosynthetic characteristics is critical to predicting and managing impacts of light reducing activities but suffers from two critical information gaps: first, data is overwhelmingly derived from studies of leaf tissue and not for whole plants, and is unlikely to reflect whole plant performance under light reduction stress; and second, few studies have looked at spatial and temporal variability in photosynthetic performance of whole seagrasses. We investigated temporal and spatial variation at a range of temperatures for whole plants of Halophila ovalis, a widely distributed species, by measuring oxygen exchange of intact plants collected from four locations across a latitudinal gradient (10°) at three temperatures (17 °C, 23 °C, 28 °C). For all locations, temperature affected all photosynthetic parameters, with some parameters (NPmax, R, Ik) showing a distinct difference between tropical and temperate locations. For example, NPmax ranged from 1.35 ± 0.12 to 5 ± 0.16 mg O₂. g DW−1. hr−1 in temperate locations and from 4 ± 0.3 to 12 ± 0.68 mg O₂. g DW−1. hr−1 in the tropical location. However, the effect of temperature on photosynthesis was not consistent among locations, and often the rate of photosynthesis was greatest at temperatures approaching the mean month maximum temperature for the location, suggestive of acclimation. Time of year also affected photosynthetic rates and how temperature influenced those rates. We conclude that the application of P–I parameters to model, predict or manage the effect of light reduction of H. ovalis, and likely other seagrass species, may require site- and time-specific knowledge of P–I relationships

Material residence time in marine canopies under wave-driven flows

© Copyright © 2020 Abdolahpour, Ghisalberti, McMahon and Lavery. Coastal canopies (e.g., seagrasses, coral reefs, and kelp forests) are vitally important ecosystems that provide a range of ecological services (e.g., oxygen production, sediment stabilization and trapping, and recycling of nutrients). The long-term health, productivity, and survival of these canopies rely heavily on the residence time of ecologically-significant materials in these environments. Recent studies have shown that submerged canopies induce a strong mean current over the canopy top, even in purely wave-dominated environments. Thus, in addition to vertical mixing, the horizontal flushing of materials (resulting from these canopy-induced currents) will dictate rates of water renewal and, therefore, residence time in wave-dominated flows over submerged canopies. Building on this recently-improved understanding, this paper provides (for the first time) a framework for estimation of material residence time (Tres) and its variation with core system parameters, including both canopy and wave characteristics. This is done through consideration of a Péclet number (Pe) which is the ratio of mixing to advective time scales. Prediction of residence time for a wide and realistic range of marine canopies (and a correspondingly wide range of Pe) reveals that while Tres decreases with wave height and increases with water depth, it has a complex relationship with canopy density and height. Importantly, residence time can vary from orders of seconds to hours, depending on wave and canopy properties. This has considerable ecological implications for marine canopies through the direct impact on a range of chemical and biogeochemical processes within the canopy. The framework presented here represents a critical step forward in being able to predict residence time in coastal canopies and test the interacting set of factors that influence the residence time in real, complex systems

Organic chemistry insights for the exceptional soil carbon storage of the seagrass Posidonia australis

The high organic carbon (OC) stores in seagrass meadows have led to their recognition as significant Blue Carbon sinks, though the diagenetic conditions that enable OC retention in seagrass soils remain poorly understood. In this study, seagrass soils were sampled from a Posidonia australis meadow in Oyster Harbour (Albany; south-western Australia) to investigate the preservation of sedimentary OC. We analysed soil characteristics (colour, grain size and redox potential), radiocarbon age, and characterised the soil organic matter (OM) using solid state CP/MAS 13C NMR spectroscopy to examine the preservation of OM down the soil profile. There was minimal change in organic composition over 1,700 years of accumulation, indicating long-term OM preservation. Primarily, this preservation appears to be driven by the recalcitrance of seagrass detritus buried in anoxic soils. The majority (70–83%) of total sedimentary OM comprised components directly attributable to seagrass origins (lignin, carbohydrate and black carbon-like matter), while the remainder consisted mostly of protein, some of which may have been present in seagrass biomass, along with likely contributions from algae and microbes. Although black carbon originates from organic matter combustion, here we provide evidence that the 13C NMR signal identified as black carbon-like matter in our soils is possibly associated with seagrass-derived organic matter consisting of degraded lignin products or other non-pyrogenic aromatics. The increase in the relative abundance of this black carbon-like matter with aging suggests its selective preservation. The relative abundances of carbohydrates significantly decreased with age down core (i.e. they appeared to be selectively decomposed), while lignin and protein did not show any quantitative changes in relative abundance (non-selective preservation). These findings demonstrate the exceptional preservation of P. australis derived OC, which contributes to our understanding of the higher OC storage capacity of Posidonia compared to other seagrass species. © 2020 Elsevier Lt

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

Changes to the amount of light and burial by the deposition of suspended sediments are presumed to be major mechanisms by which dredging can impact seagrasses. This report presents findings from a controlled burial experiment that aimed to determine the effects of burial by sediments on the growth of two seagrass species found in the northwest of Western Australia (NW WA). The report provides guidance and protocols for the application of the research outputs (e.g. seagrass burial stress:response relationships, sub-lethal and lethal bio-indicators and thresholds) to the prediction, assessment, monitoring and management of dredging programs in NW WA..