ORCID Profile
0000-0002-4173-3855
Current Organisation
University of Tasmania
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Publisher: Inter-Research Science Center
Date: 30-05-2013
DOI: 10.3354/MEPS10280
Publisher: Springer International Publishing
Date: 2019
Publisher: Wiley
Date: 24-09-2020
Publisher: Wiley
Date: 05-09-2023
DOI: 10.1111/COBI.14177
Publisher: Public Library of Science (PLoS)
Date: 24-03-2022
DOI: 10.1371/JOURNAL.PONE.0265067
Abstract: Predatory fishes on coral reefs continue to decline globally despite playing key roles in ecosystem functioning. Remote atolls and platform reefs provide potential refugia for predator populations, but quantitative information on their spatial distribution is required to establish accurate baselines for ongoing monitoring and conservation management. Current knowledge of predatory fish populations has been derived from targeted shallow er-based surveys ( m). However, the spatial distribution and extent of predatory fishes on outer mesophotic shelf environments has remained under described. Middleton Reef is a remote, high-latitude, oceanic platform reef that is located within a no-take area in the Lord Howe Marine Park off eastern Australia. Here we used baited remote underwater stereo video to s le predatory fishes across lagoon and outer shelf habitats from depths 0–100 m, extending knowledge on use of mesophotic depths and habitats. Many predatory fish demonstrated clear depth and habitat associations over this depth range. Carcharhinid sharks and Carangid fishes were the most abundant predators s led on Middleton Reef, with five predatory fishes accounting for over 90% of the predator fish biomass. Notably, Galapagos shark ( Carcharhinus galapagensis ) and the protected black rockcod ( Epinephelus daemelii ) dominated the predator fish assemblage. A higher richness of predator fish species was s led on reef areas north and south of the lagoon. The more exposed southern aspect of the reef supported a different suite of predator fish across mesophotic habitats relative to the assemblage recorded in the north and lagoonal habitats, a pattern potentially driven by differences in hard coral cover. Biomass of predatory fishes in the more sheltered north habitats was twice that of other areas, predominantly driven by high abundances of Galapagos shark. This work adds to the growing body of literature highlighting the conservation value of isolated oceanic reefs and the need to ensure that lagoon, shallow and mesophotic habitats in these systems are adequately protected, as they support vulnerable ecologically and economically important predator fish assemblages.
Publisher: Elsevier BV
Date: 08-2021
Publisher: CSIRO Publishing
Date: 2020
DOI: 10.1071/MF19207
Abstract: Where several different tools are available for research, the costs and benefits associated with each option become an important part of the selection process. Towed video (ToV) and remotely operated vehicles (ROVs) are both widely used to assess shallow reef benthic habitats and fish assemblages, but quantitative data on their comparative performance is limited. The relative abilities of commercially available ToV and ROV were assessed using two low-cost (less than A$10000), manually deployable systems. These systems were deployed to collect photographs of marine habitats and videos of fish assemblages along six 200-m transects at three separate sites. The time required to operate each system and the specific limitations and advantages of each system were compared. Both systems performed equally in terms of the resolution of data collected on benthic habitats and fish assemblages on shallow reefs. However, ToV required significantly less time (~60% less) to collect data than ROV, and should allow cost savings with no loss in data quality. We recommend ToV as a cost-effective and easily deployable system for assessing rocky reef habitats and fish assemblages.
Publisher: Wiley
Date: 04-2021
DOI: 10.1002/ECS2.3447
Abstract: Worldwide, several countries have established coherent, representative, and large‐scale networks of marine reserves to conserve bio ersity. Very few have, however, published systematic assessments of the ecological responses to this network protection, hindering broad understanding of their generality, utility, and efficacy. We present data collected from systematic s ling of rocky reef fish assemblages at sites across a network of 27 no‐take marine reserve areas (NTMR) and 27 partially protected areas (PPA) nested within multiple marine parks (regional networks) across three Australian bioregions spanning km of coastline (7° latitude) to test the generality of ecological change across this network. We also s led 18 reference areas (outside of the marine parks) to provide an independent assessment of potential NTMR effects and also to assess whole marine park effects. Baited remote underwater video (BRUV) was used to s le fishes between depths of 20–40 m over austral winters in four years (2010, 2011, 2015, and 2016). Despite substantial bioregional differences in fish assemblages, large and consistent effects of NTMR protection were detected across all bioregions for a key commercially and recreationally harvested species, Chrysophrys auratus (pink snapper). There were substantial increases in relative abundance of C. auratus in NTMR compared with fished zones through time (effect sizes %). The wider assemblage of targeted fish (excluding C. auratus ) only showed relatively small effects of protection (~11%) with trends observed for site‐attached wrasses (labrids) and planktivores (e.g., commercially fished Scorpis lineolata ) that are recreationally and commercially harvested. Furthermore, the relative abundance of non‐target or by‐catch species generally did not differ among management zones across the bioregional network. These results highlight how NTMR can be used to assess the ecological effects of fishing and wider environmental management, and can be incorporated into ecosystem‐based management for reef species more generally. Importantly, the provision of robust evidence of the performance and generality of NTMR over large‐spatial scales (e.g., bioregions) provides greater confidence in the expected outcomes from marine reserve networks as a conservation management approach.
Publisher: Springer Science and Business Media LLC
Date: 10-03-2022
Publisher: Elsevier BV
Date: 11-2020
Publisher: Public Library of Science (PLoS)
Date: 15-03-2019
Publisher: MDPI AG
Date: 12-10-2022
Abstract: Seaborne movement underpins frontier research in prehistoric archaeology, including water-crossings in the context of human dispersals, and island colonisation. Yet, it also controls the degree of interaction between locations, which in turn is essential for investigating the properties of maritime networks. The onset of the Holocene (circa 12,000 years ago) is a critical period for understanding the origins of early visitors/inhabitants to the island of Cyprus in the Eastern Mediterranean in connection with the spread of Neolithic cultures in the region. The research undertaken in this work exemplifies the synergies between archaeology, physical sciences and geomatics, towards providing novel insights on the feasibility of drift-induced seaborne movement and the corresponding trip duration between Cyprus and coastal regions on the surrounding mainland. The overarching objective is to support archaeological inquiry regarding the possible origins of these visitors/inhabitants—Anatolia and/or the Levant being two suggested origins.
Publisher: Wiley
Date: 18-04-2012
DOI: 10.1111/J.1095-8649.2012.03283.X
Abstract: This study tested the hypothesis that variable freshwater flow in the Gippsland Lakes, Australia, influences the location and extent of environmental conditions suitable for spawning and larval development of black bream, Acanthopagrus butcheri. Freshwater flow had a large influence on the salinity and level of stratification (difference between bottom and surface salinity) in the Gippsland Lakes. Freshwater flows throughout this study varied from no or low flows through to major flooding in 2007. Eggs of A. butcheri were found in similar concentrations throughout the lakes and rivers. More than 99% of larvae, however, were collected from within rivers, with very few larvae being collected from the lakes. A comparison of two spawning seasons revealed that the year with higher freshwater flows also had greater spawning activity and higher concentrations of larvae. Interestingly, there was a significant relationship between the distribution of eggs and larvae with the level of stratification. The highest concentrations of larvae occurred at sites with a difference in bottom and surface salinities of 15-20. This study demonstrates that despite A. butcheri spawning in the lakes and rivers, it is only locations with a halocline that function as larval nursery habitat.
Publisher: Oxford University Press (OUP)
Date: 10-06-2019
Abstract: Recreational fishing is popular in Australia and is managed by in idual states in consultation with the Commonwealth for those fisheries that they regulate and also for Australian Marine Parks (AMPs). Fishers regularly access both state and offshore Commonwealth waters but this offshore component of the recreational fishery is poorly understood. Our study tested the functionality of existing state-based surveys in Western Australia (WA) and New South Wales (NSW) to better inform Commonwealth fisheries and AMP managers about recreational fishing in their jurisdictions. Catch estimates for nine species of interest to the Commonwealth were developed and two case study AMPs [Ningaloo (WA) and The Hunter (NSW)] were also chosen to test the ability of the state survey data to be disaggregated to the park scale. As each state’s fishery survey designs were contextual to their own management needs, the application of the data to Commonwealth jurisdictions were limited by their statistical power, however aspects of each states surveys still provided useful information. Continued evolution of state-wide survey methods, including collection of precise spatial data, and regional over-s ling would be beneficial, particularly where there are multiple stakeholder and jurisdictional interests. National coordination, to temporally align state surveys, would also add value to the existing approaches.
Publisher: Frontiers Media SA
Date: 11-04-2023
DOI: 10.3389/FMARS.2023.1173075
Abstract: Since 2012, there has been a surge in the numbers of marine science publications that use the term ‘best practice’, yet the term is not often defined, nor is the process behind the best practice development described. Importantly a ‘best practice’ is more than a documented practice that an in idual or institution uses and considers good. This article describes a rigorous process to develop an ocean best practice using ex les from a case study from Australia in which a suite of nine standard operating procedures were released in 2018 and have since become national best practices. The process to develop a best practice includes three phases 1) scope and recruit, 2) develop and release, 3) revise and ratify. Each phase includes 2-3 steps and associated actions that are supported by the Ocean Best Practices System ( www.oceanbestpractices.org ). The Australian case study differs from many other practices, which only use the second phase (develop and release). In this article, we emphasize the value of the other phases to ensure a practice is truly a ‘best practice’. These phases also have other benefits, including higher uptake of a practice stemming from a sense of shared ownership (from scope and recruit phase) and currency and accuracy (from revise and ratify phase). Although the process described in this paper may be challenging and time-consuming, it optimizes the chance to develop a true best practice that is a) fit-for-purpose with clearly defined scope b) representative and inclusive of potential users c) accurate and effective, reflecting emerging technologies and programs and d) supported and adopted by users.
Publisher: Wiley
Date: 20-07-2017
DOI: 10.1002/LNO.10627
Publisher: Springer Science and Business Media LLC
Date: 22-06-2017
Publisher: Elsevier BV
Date: 11-2018
Publisher: Elsevier BV
Date: 08-2020
Publisher: Elsevier BV
Date: 10-2018
Publisher: Frontiers Media SA
Date: 13-06-2018
Publisher: Wiley
Date: 25-06-2018
DOI: 10.1002/ECE3.4236
No related grants have been discovered for Joel Williams.