David Milton

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Alex Mauricio Jimenez-Ortega

Universidad Tecnológica del Chocó

Marta Diaz-Guardamino

Durham University

Armando Marques-Guedes

UNL - New University of Lisbon

Stefano R L Campana

University of Siena / Università di Siena

Barry Molloy

University College Dublin

José F. González-Maya

Universidad Autónoma Metropolitana-Lerma

Diego F Cisneros-Heredia

Universidad San Francisco de Quito

DanielJ Klionsky

University of Michigan

Pedro M S Nunes

Universidade Federal de Pernambuco

Dr. Eluvathingal Antony Jayson

Kerala Forest Research Institute

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Papers by David Milton

Continental-scale decreases in shorebird populations in Australia

by Robert Clemens, B. Hansen, Eric Woehler, David Milton, Dan Weller, Kimberly Onton, and Ashley Herrod

Decreases in shorebird populations are increasingly evident worldwide, especially in the East Asi... more Decreases in shorebird populations are increasingly evident worldwide, especially in the East Asian–Australasian Flyway (EAAF). To arrest these declines, it is important to understand the scale of both the problem and the solutions. We analysed an expansive Australian citizen-science dataset, spanning the period 1973 to 2014, to explore factors related to differences in trends among shorebird populations in wetlands throughout Australia. Of seven resident Australian shorebird species, the four inland species exhibited continental decreases, whereas the three coastal species did not. Decreases in inland resident shorebirds were related to changes in availability of water at non-tidal wetlands, suggesting that degradation of wetlands in Australia’s interior is playing a role in these declines. For migratory shorebirds, the analyses revealed continental decreases in abundance in 12 of 19 species, and decreases in 17 of 19 in the southern half of Australia over the past 15 years. Many trends were strongly associated with continental gradients in latitude or longitude, suggesting some large-scale patterns in the decreases, with steeper declines often evident in southern Australia. After accounting for this effect, local variables did not explain variation in migratory shorebird trends between sites. Our results are consistent with other studies indicating that decreases in migratory shorebird populations in the EAAF are most likely being driven primarily by factors outside Australia. This reinforces the need for urgent overseas conservation actions. However, substantially heterogeneous trends within Australia, combined with declines of inland resident shorebirds indicate effective management of Australian shorebird habitat remains important.

A Population Monitoring Program for Shorebirds in Australia

by David Milton, Robert Clemens, Mike Bamford, Danny Rogers, and Michael Weston

Selectivity for barramundi (Lates calcarifer) in the Fly River, Papua New Guinea: implications for managing gill-net fisheries on protandrous fishes

Marine and Freshwater Research, 1998

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Validating ecological risk assessments for fisheries: assessing the impacts of turtle excluder devices on elasmobranch bycatch populations in an Australian trawl fishery

Marine and Freshwater Research, 2006

Demonstrating ecological sustainability is a challenge for fisheries worldwide, and few methods c... more Demonstrating ecological sustainability is a challenge for fisheries worldwide, and few methods can quantify fishing impacts on diverse, low value or rare species. The current study employed a widely used ecological risk assessment method and incorporated new data to assess the change in sustainability of species following the introduction of Turtle Excluder Devices (TEDs) in Australia's Northern Prawn Fishery (NPF). Population recovery ranks changed for 19 of the 56 elasmobranch species after the introduction of TEDs, with nine species showing an increase in sustainability. Unexpectedly, ten species showed a decrease in sustainability. This was due to TEDs successfully excluding large animals from the catch, resulting in a lower mean length at capture, which reduced the recovery ranks for two criteria relying on length data. This falsely indicates that TEDs increase the impact on pre-breeding animals, thus reducing the recovery potential of these species. The results demonstrate that existing attribute-based risk assessment methods may be inadequate for reflecting even the most obvious changes in fishing impacts on bycatch species. Industry and management can benefit greatly from an approach that more accurately estimates absolute risk. The development and requirements of a new quantitative risk assessment method to be developed for the NPF, and applicable to fisheries worldwide, are discussed.

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Reproductive dynamics and nursery habitat preferences of two commercially important Indo-Pacific red snappers Lutjanus erythropterus and L. malabaricus

Fisheries Science, 2009

Red snappers were examined for reproductive biology and age-0 habitat preferences. Spawning in re... more

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The effect of habitat and environmental history on otolith chemistry of barramundi Lates calcarifer in estuarine populations of a regulated tropical river

by David Milton and Ian Halliday

Estuarine, Coastal and Shelf Science, 2008

We examine the microchemistry of otoliths of cohorts of a fished population of the large catadrom... more We examine the microchemistry of otoliths of cohorts of a fished population of the large catadromous fish, barramundi Lates calcarifer from the estuary of a large tropical river. Barramundi from the estuary of the large, heavily regulated Fitzroy River, north-eastern Australia were analysed by making transects of 87 Sr/ 86 Sr isotope and trace metal/Ca ratios from the core to the outer edge. Firstly, we examined the Sr/Ca, Ba/Ca, Mg/Ca and Mn/Ca and 87 Sr/ 86 Sr isotope ratios in otoliths of barramundi tagged in either freshwater or estuarine habitats that were caught by the commercial fishery in the estuary. We used 87 Sr/ 86 Sr isotope ratios to identify periods of freshwater residency and assess whether trace metal/Ca ratios varied between habitats. Only Sr/Ca consistently varied between known periods of estuarine or freshwater residency. The relationships between trace metal/Ca and river flow, salinity, temperature were examined in fish tagged and recaptured in the estuary. We found weak and inconsistent patterns in relationships between these variables in the majority of fish. These results suggest that both individual movement history within the estuary and the scale of environmental monitoring were reducing our ability to detect any patterns. Finally, we examined fish in the estuary from two dominant age cohorts (4 and 7 year old) before and after a large flood in 2003 to ascertain if the flood had enabled fish from freshwater habitats to migrate to the estuary. There was no difference in the proportion of fish in the estuary that had accessed freshwater after the flood. Instead, we found that larger individuals with of each age cohort were more likely to have spent a period in freshwater. This highlights the need to maintain freshwater flows in rivers. About half the fish examined had accessed freshwater habitats before capture. Of these, all had spent at least their first two months in marine salinity waters before entering freshwater and some did not enter freshwater until four years of age. This contrasts with the results of several previous studies in other parts of the range that found that access to freshwater swamps by larval barramundi was important for enhanced population productivity and recruitment.

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Can vessel monitoring system data also be used to study trawling intensity and population depletion? The example of Australia's northern prawn fishery

Canadian Journal of Fisheries and Aquatic Sciences, 2005

We explore the potential of using data from Australia's northern prawn fishery (NPF) vessel monit... more We explore the potential of using data from Australia's northern prawn fishery (NPF) vessel monitoring system(s) (VMS) to examine trawl track, trawling intensity, and stock depletion due to trawling. We simulate VMS data by subsampling global positioning system (GPS) fixes from the NPF fishing vessels at different polling intervals to examine their accuracy in describing trawl tracks. The results of the simulations suggest that VMS data with polling intervals longer than 30 min cannot accurately estimate trawl tracks. The analysis of high-polling-frequency VMS data collected in four (later reduced to three) 6 nautical mile × 6 nautical mile grids that historically received high levels of fishing effort showed that trawling was not random and some areas were trawled up to 28 times in the tiger prawn fishing season and the impact varied among years. The results of a catch-depletion analysis suggest that fishery catchper-unit-effort and cumulative catch may not be proportional to overall target-species biomass in areas with highly aggregated trawl effort. The VMS data also showed a large number of trawls can occur in productive areas and that trawling impacts on benthos may be quite marked.

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The conservation status of the world’s reptiles

Biological Conservation, 2013

Effective conservation action requires knowledge of the distribution of threatened 19 species and... more Effective conservation action requires knowledge of the distribution of threatened 19 species and the threat processes affecting them. We present the first global assessment 20 of extinction risk for a random representative sample of 1,500 reptile species. We find 21 strong variation in extinction risk by taxonomic groups and geographic regions, with 22 the most threatened reptiles associated with freshwater environments, tropical regions, 23 and oceanic islands. Extinction risk is predominantly associated with habitat loss and 24 over-exploitation. Our results emphasize the need for research attention to be focussed 25 on tropical areas, which are seeing the highest extinction risk, and fossorial reptiles, 26 for which there is a chronic lack of data. 27 28

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Acknowledgments to Reviewers

Evolutionary Computation, 2000

The Editor in Chief and the Associate Editors wish to express their gratitude to the following “a... more The Editor in Chief and the Associate Editors wish to express their gratitude to the following “anonymous” reviewers who gave their time and energy during the last twelve months, ensuring the quality of the published papers. ... Chang Wook Ahn John Holmes Roberto Santana ... Martin Brown Petros Koumoutsakos Peter Stadler Larry Bull Tim Kovacs Wolfgang Stolzmann ... Luis M. de Campos Sushil Louis Dirk Thierens ... Uday Chakraborti Martin C. Martin Marc Toussaint ... Zeke SH Chan Peter Merz Andrew Tuson ... Ying Ping Chen Martin Middendorf ...