Serrano E.,CSIC - Center for Advanced Studies of Blanes |
Coma R.,CSIC - Center for Advanced Studies of Blanes |
Inostroza K.,BMT Oceanica Pty Ltd |
Serrano O.,Edith Cowan University
Marine Biodiversity | Year: 2017
Knowledge of reproductive biology is essential for ecological studies on coral population dynamics. The azooxanthellate colonial coral Astroides calycularis is endemic to the western Mediterranean Sea and adjacent Atlantic coasts. Specimens of this species in artificial conditions, an aquarium with enclosed seawater and low food availability, appeared to show an asexual dispersal mechanism. This mechanism consisted of the detachment and release of single, skeletonless polyps from the underlying colony skeleton (i.e., polyp bail-out). While the released free-living polyps regularly showed extended tentacles and most of them survived, they did not show re-attachment to the substrate or any skeleton formation until the end of the experiment, ∼2–3 months after bail-out. Formation of new reproductive colonies, thereby the eventual completion of asexual reproduction through polyp bail-out in A. calycularis, still needs to be confirmed. In addition to sexual reproduction, polyp bail-out may constitute an alternative propagation mechanism during periods of environmental stress, thereby potentially increasing the survival rate of the parental genotype and the dispersal by drifting soft polyps. © 2017 Senckenberg Gesellschaft für Naturforschung and Springer-Verlag Berlin Heidelberg
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.
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.
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.
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.
Ridgway T.,BMT Oceanica Pty Ltd |
Ridgway T.,University of Western Australia |
Ridgway T.,University of Georgia |
Ridgway T.,University of Queensland |
And 5 more authors.
Marine Biology | Year: 2016
Patterns of hard coral cover and benthic composition were assessed at seven sites around Barrow Island in the Pilbara region of Western Australia between 2008 and 2013. While the per cent hard coral cover around Barrow Island was relatively stable between 2009 and 2012, there was a 69.3 % proportional change in hard coral cover between 2012 and 2013. Concomitant with this decline, Principle Coordinates Analysis showed a shift towards turf/coralline algae and there was a reduction in the proportion of the Acroporidae and a relative increase in the proportion of the Poritidae at most sites. During early 2013, sea surface temperatures around Barrow Island rose above seasonal averages, reaching 7.4 °C-weeks (degree heating weeks) from late February 2013 to mid-April 2013, and the decline in hard coral cover and shifts in benthic composition appear to be related to mortality associated with a coral bleaching event in early 2013. © 2016, Springer-Verlag Berlin Heidelberg.