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Stoddart J.A.,MScience Pty Ltd
AusIMM Bulletin

The pain in port development occurs when port operators attempt to extend overstretched facilities outside of existing footprints and into these relatively undisturbed habitats. Each expansion project must run the course of determining how much it can minimize its impact and still be viable or if it is approvable at all. In the absence of an agreed vision for the environment-development balance, there is rarely any coordination of environmental activities between port users within the same port. While constructing working plans for the future of a port may be problematic, without an agreed plan, each individual development will continue to suffer the pain of debating how much conservation is enough and what parts of the marine habitat may or may not be lost and the significance of such losses. In some Australian states, regulators have attempted to provide an approach to the problem that guides developers as to what may be acceptable in the absence of an understanding of how the system functions. Source

Stoddart C.W.,University of Western Australia | Stoddart J.A.,MScience Pty Ltd | Blakeway D.R.,MScience Pty Ltd
Coral Reefs

Most coral species off Australia's west coast spawn in the austral autumn (March-April), with a few species also spawning in the southern spring or early summer (November-December). This is the reverse timing to spawning recorded off Australia's east coast. Porites lutea, a gonochoric broadcast spawner that is common on Australia's west coast, is shown here to spawn in the months of November or December, as it does on Australia's east coast. Spawning occurred between 2 and 5 nights after full moon, with the majority of spawning activity on night 3. Gametes developed over three to four months with rapid development in the last two weeks before spawning. Zooxanthellae were typically observed in mature oocytes, only a week before spawning so their presence may provide a useful indicator of imminent spawning. © 2012 Springer-Verlag. Source

Hovey R.K.,University of Western Australia | Statton J.,University of Western Australia | Fraser M.W.,University of Western Australia | Ruiz-Montoya L.,University of Western Australia | And 5 more authors.
Marine Pollution Bulletin

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 14. m 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, sedimentary seed banks prevailed, varying spatially at both broad and fine scales, presenting a source of propagules for re-colonisation following the unfavourable growing conditions of the monsoon. Spatial patterns in H. decipiens biomass following monsoon conditions were highly variable within a landscape that largely comprised potential seagrass habitat. Management strategies for H. decipiens and similar transient species must recognise the high temporal and spatial variability of these populations and be underpinned by a framework that emphasises vulnerability assessments of different life stages instead of relying solely on thresholds for standing stock at fixed reference sites. © 2015 Elsevier Ltd. Source

Blakeway D.,MScience Pty Ltd | Byers M.,MScience Pty Ltd | Stoddart J.,MScience Pty Ltd | Rossendell J.,Rio Tinto Alcan

A 0.6 hectare artificial reef of local rock and recycled concrete sleepers was constructed in December 2006 at Parker Point in the industrial port of Dampier, western Australia, with the aim of providing an environmental offset for a nearshore coral community lost to land reclamation. Corals successfully colonised the artificial reef, despite the relatively harsh environmental conditions at the site (annual water temperature range 18-32°C, intermittent high turbidity, frequent cyclones, frequent nearby ship movements). Coral settlement to the artificial reef was examined by terracotta tile deployments, and later stages of coral community development were examined by in-situ visual surveys within fixed 25 x 25 cm quadrats on the rock and concrete substrates. Mean coral density on the tiles varied from 113 ± 17 SE to 909 ± 85 SE per m2 over five deployments, whereas mean coral density in the quadrats was only 6.0 ± 1.0 SE per m2 at eight months post construction, increasing to 24.0 ± 2.1 SE per m2 at 62 months post construction. Coral taxa colonising the artificial reef were a subset of those on the surrounding natural reef, but occurred in different proportions-Pseudosiderastrea tayami, Mycedium elephantotus and Leptastrea purpurea being disproportionately abundant on the artificial reef. Coral cover increased rapidly in the later stages of the study, reaching 2.3 ± 0.7 SE % at 62 months post construction. This study indicates that simple materials of opportunity can provide a suitable substrate for coral recruitment in Dampier Harbour, and that natural colonisation at the study site remains sufficient to initiate a coral community on artificial substrate despite ongoing natural and anthropogenic perturbations. © 2013 Blakeway et al. Source

Welsh J.Q.,MScience Pty Ltd | Welsh J.Q.,James Cook University | Bellwood D.R.,James Cook University

Ecosystem degradation has become common throughout the world. On coral reefs, macroalgal outbreaks are one of the most widely documented signs of degradation. This study simulated local-scale degradation on a healthy coral reef to determine how resident taxa, with the potential to reverse algal outbreaks, respond. We utilized a combination of acoustic and video monitoring to quantify changes in the movements and densities, respectively, of coral reef herbivores following a simulated algal outbreak. We found an unprecedented accumulation of functionally important herbivorous taxa in response to algal increases. Herbivore densities increased by 267% where algae were present. The increase in herbivore densities was driven primarily by an accumulation of the browsing taxa Naso unicornis and Kyphosus vaigiensis, two species which are known to be important in removing macroalgae and which may be capable of reversing algal outbreaks. However, resident individuals at the site of algal increase exhibited no change in their movements. Instead, analysis of the size classes of the responding individuals indicates that large functionally-important non-resident individuals changed their movement patterns to move in and feed on the algae. This suggests that local-scale reef processes may not be sufficient to mitigate the effects of local degradation and highlights the importance of mobile links and cross-scale interactions. © 2015 Welsh, Bellwood. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Source

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