Dunn R.J.K.,RPS APASA Pty. Ltd. |
Zigic S.,RPS APASA Pty. Ltd. |
Shiell G.R.,BMT Oceanica Pty. Ltd. |
Shiell G.R.,University of Western Australia
Environmental Monitoring and Assessment | Year: 2014
Numerical models are useful for predicting the transport and fate of contaminants in dynamic marine environments, and are increasingly a practical solution to environmental impact assessments. In this study, a three-dimensional hydrodynamic model and field data were used to validate a far-field dispersion model that, in turn, was used to determine the fate of treated wastewater (TWW) discharged to the ocean via a submarine ocean outfall under hypothetical TWW flows. The models were validated with respect to bottom and surface water current speed and direction, and in situ measurements of total nitrogen and faecal coliforms. Variations in surface and bottom currents were accurately predicted by the model as were nutrient and coliform concentrations. Results indicated that the ocean circulation was predominately wind driven, evidenced by relatively small oscillations in the current speeds along the time-scale of the tide, and that dilution mixing zones were orientated in a predominantly north-eastern direction from the outfall and parallel to the coastline. Outputs of the model were used to determine the 'footprint' of the TWW plume under a differing discharge scenario and, particularly, whether the resultant changes in TWW contaminants, total nitrogen and faecal coliforms would meet local environmental quality objectives (EQO) for ecosystem integrity, shellfish harvesting and primary recreation. Modelling provided a practical solution for predicting the dilution of contaminants under a hypothetical discharge scenario and a means for determining the aerial extent of exclusion zones, where the EQOs for shellfish harvesting and primary recreation may not always be met. Results of this study add to the understanding of regional discharge conditions and provide a practical case study for managing impacts to marine environments under a differing TWW discharge scenario, in comparison to an existing scenario. © 2014 Springer International Publishing Switzerland.
Stul T.,Damara WA Pty Ltd |
Eliot M.,Damara WA Pty Ltd |
Bailey J.,BMT JFA Consultants Pty Ltd. |
Marshman S.,BMT Oceanica Pty. Ltd. |
Hill A.,Range to Reef Environmental
Australian Coasts and Ports 2015 Conference | Year: 2015
This study presents a method for assessing the feasibility of using dredged or hauled sand as a renourishment source for estuarine beaches. Three protocols improve the ease of decision-making when considering renourishment, dredging viability and cost-comparison of dredging against hauled sand. The protocols determine: (1) if renourishment is required at a target site; (2) potential sources of renourishment material and their constraints; and (3) life-cycle costs, allowing comparison with alternate management options. Components of each of these protocols were condensed into a field sheet to facilitate an initial 'Go- No Go' assessment. This produces one of four outcomes: do not renourish; consider hauled sand; consider land-based excavation; or consider floating dredge. Short-listed options may then be subject to a cost comparison over the life-cycle based on cost estimates for all project stages.
Liggins L.,Massey University |
Liggins L.,National Evolutionary Synthesis Center |
Liggins L.,University of Queensland |
Booth D.J.,University of Technology, Sydney |
And 10 more authors.
Ecography | Year: 2015
Few studies have examined core-periphery genetic patterns in tropical marine taxa. The core-periphery hypothesis (CPH) predicts that core populations will have higher genetic diversity and lower genetic differentiation than peripheral populations as a consequence of greater population sizes and population connectivity in the core. However, the applicability of the CPH to many tropical marine taxa may be confounded by their complex population histories and/or high (asymmetric) population connectivity. In this study we investigated genetic patterns (based on mtDNA) across the latitudinal range of the neon damselfish Pomacentrus coelestis (36°N, Japan - 37°S, east Australia). We suggest a novel hypothetical framework for core-periphery genetic patterns and extend typical analyses to include genealogical analyses, partitioned β-diversity measures (total βSOR, turnover βSIM, and nestedness-resultant βSNE), and analyses of nestedness. We found that the existence of two divergent lineages of the neon damselfish led levels of genetic diversity to deviate from CPH expectations. When focusing on the widespread lineage (Pacific clade) nucleotide diversity was higher in the core, supporting the CPH. However, genetic patterns differed toward the northern and southern peripheries of the Pacific clade. The turnover of haplotypes (pairwise-βsim) increased over distance in the north, indicative of historical colonization with little contemporary migration. In contrast, although turnover was still dominant in the south (βSIM), there was no relationship to distance (pairwise-βsim), suggesting the influence of more contemporary processes. Moreover, the haplotype compositions of populations in the south were nested according to latitude, indicating immigration from lower latitudes toward the southern periphery. By extending the typical characterizations of core-periphery genetic patterns we were able to identify the effects of lineage sympatry on measures of genetic diversity and contrasting demographic histories toward the latitudinal peripheries of the neon damselfish's range. Ecography © 2015 Nordic Society Oikos.
Kool J.,Geoscience Australia |
Appleyard S.,CSIRO |
Bax N.,Institute for Marine and Antarctic Studies |
Ford J.,University of Melbourne |
And 7 more authors.
Bulletin of Marine Science | Year: 2015
Marine scientists and environmental managers engaged in a roundtable discussion at the Australian Marine Sciences Association conference in July 2014 to identify areas where linkages could be improved between the two groups. Here, we summarize the key themes and outcomes from the discussion, including the need to clearly define management objectives, to identify the scale of the issue, to conduct effective science communication, to address uncertainty, and to perform iterative engagement. We also discuss some of the challenges inherent in establishing new linkages, and provide a set of examples where effective collaborations have been achieved between marine ecologists and environmental managers working in Australia. © 2015 Rosenstiel School of Marine & Atmospheric Science of the University of Miami.