Decadal trends in shark catches and effort from the New South Wales, Australia, Shark Meshing Program 1950 - 2010

2011 ◽  
Vol 62 (6) ◽  
pp. 676 ◽  
Author(s):  
D. D. Reid ◽  
W. D. Robbins ◽  
V. M. Peddemors

The New South Wales (NSW) government has operated a program of netting beaches for the protection of swimmers and surfers against shark attack since 1937 in Sydney, and since 1949 in Newcastle and Wollongong. The scope and directives of the Shark Meshing Program have remained constant since its inception, with operational modifications in net specifications in 1972, changes in spatial deployment in 1972, 1987 and 1992, and the elimination of winter netting since 1989. This markedly increased meshing effort in 1972, and again in 1987. In the present study, we examine the trends in catch and effort for the period from 1950–1951 to 2009–2010 over this 200-km section of the NSW coast. Significant temporal trends in species, size and sex composition are described herein. Catches were consistently dominated by three shark taxa, hammerhead sharks (Sphyrna spp.), whaler sharks (Carcharhinus spp.) and Australian angel sharks (Squatina australis), although their relative contributions to catches varied over time. Catch per unit effort has significantly declined for five of the most abundant shark taxa over the study period, increasing only for a single taxon, the sevengill shark (Notorynchus cepedianus). Catches of larger, potentially dangerous white sharks (Carcharodon carcharias) and tiger sharks (Galeocerdo cuvier) saw fewer large animals being caught over time. This pattern was not observed across other taxa. Four different monthly trends were observed in landings of the most abundant eight taxa, reflecting differences in the biology of the catch species. The current study also provides useful information on catches and sizes of grey nurse (Carcharias taurus) and white sharks before and after their protection in NSW waters in 1984 and 1998, respectively.

Lung Cancer ◽  
2017 ◽  
Vol 108 ◽  
pp. 55-61 ◽  
Author(s):  
Xue Qin Yu ◽  
Qingwei Luo ◽  
Clare Kahn ◽  
Paul Grogan ◽  
Dianne L. O’Connell ◽  
...  

1986 ◽  
Vol 26 (3) ◽  
pp. 331 ◽  
Author(s):  
MH Campbell ◽  
MJ Keys ◽  
RD Murison ◽  
JJ Dellow

The effects of time and rate of application of glyphosate, 2,2-DPA and tetrapion on Poa labillardieri and Themeda australis were measured in seven experiments carried out 55 km south of Braidwood, on the southern tablelands of New South Wales between 1980 and 1982. In an eighth experiment (1981) and in a 35-ha demonstration (1983), at the same site, the effects of applying herbicides (before and after the autumn break) and surface-sowing Phalaris aquatica, Festuca arundinacea and Trifiolium repens with fertiliser on the control of P. labillardieri were ascertained. All three herbicides proved effective in reducing the ground cover of P. labillardieri from applications at any time of the year. For T. australis, tetrapion proved effective when applied at any time of the year, while glyphosate and 2,2-DPA were effective in all seasons except winter. Glyphosate at rates between 0.72 and 1.44 kg/ha a.i. was more cost effective than 2,2-DPA (11.1 kg/ha a.i.) and tetrapion (3.75 kg/ha a.i.). Best establishment and development of sown grasses and legumes was attained by applying herbicides after the autumn break but before heavy frosts, and then surface-sowing 1-3 months later. Control of P. labillardieri was best where P. aquatica and F. arundinacea established most densely.


2000 ◽  
Vol 6 (1) ◽  
pp. 18 ◽  
Author(s):  
Rodney P. Kavanagh ◽  
Rodney P. Kavanagh

Populations of arboreal marsupials were assessed in forests before and after logging at different levels of logging intensity to determine the sensitivity of these species to habitat disturbance. The logging treatments imposed were unlogged controls and two intensities of integrated logging for sawlogs and woodchips. The mean basal area of trees retained in logged blocks ranged from 83% to 35% of pre-logging levels. The objective of the study was to develop better methods for managing arboreal marsupials within the wood production forests of southeastern New South Wales. Seven species of arboreal marsupials were recorded during the study, but the Greater Glider Petauroides volans was the only species recorded in sufficient numbers for analysis (86% of all records). No significant differences were observed between the treatments in counts of the Greater Glider before and after logging. However, given the observed trend and an a priori expectation of a decline in numbers of this species following intensive logging, a one-tailed statistical test was applied which resulted in a significant difference at P = 0.08 for the contrast between the unlogged controls and the most intensively logged treatment. The existence of a threshold in logging intensity within the range of 21 % to 39% retention of tree basal area, below which numbers of the Greater Glider suffer a marked decline, was inferred on the basis of comparisons with the results of other studies. Factors other than logging were important in determining the distribution of the Greater Glider. Elevation, in particular, was a significant environmental variable, with Greater Gliders more likely to occur in forests above 845 m a.s.1. The presence and absence of particular tree species also influenced the distribution of the Greater Glider. Forests containing Manna Gum E. viminalis and Mountain Gum E. dalrympleana were highly preferred compared to forests with a high proportion of E. obliqua. The presence of E. cypellocarpa appeared to improve the quality of habitat for the Greater Glider in forests dominated by E. obliqua. This study has shown that Greater Glider populations can be maintained at or near pre-logging levels when at least 40% of the original tree basal area is retained thoughout logged areas and when the usual practice of retaining unlogged forest in riparian strips is applied.


2000 ◽  
Vol 60 (4) ◽  
pp. 1088-1119
Author(s):  
B. Zorina Khan

I examine the evolution of conflict and cooperation during economic growth by analyzing civil disputes in New South Wales between 1860 and 1900. Disputes per capita fell over time and the proportion of cases settled before trial increased, but patterns varied across locations and types of disputes. Economic conflicts were likelier to be settled than personal disputes, and the fraction of cases settled was significantly lower in frontier areas and in districts without access to transportation. The results suggest that increased market exchange facilitates the development of informal rules and encourages transactors to find cooperative solutions through private bargaining.


2021 ◽  
Author(s):  
Alicia Arnott ◽  
Jenny Draper ◽  
Rebecca J Rockett ◽  
Connie Lam ◽  
Rosemarie Sadsad ◽  
...  

Abstract Objective: To adapt ‘fishplots’ to describe SARS-CoV-2 genomic cluster evolution. Results: This novel analysis adapted the fishplot to depict the size and duration of circulating genomic clusters over time in New South Wales, Australia. It illuminated the effectiveness of interventions on the emergence, spread and eventual elimination of clusters and distilled genomic data into clear information to inform public health action.


Author(s):  
J.V. Nolan ◽  
J.A. Thomas ◽  
M.K. Hill

Protein-rich supplements often enhance production of ruminants grazing native pastures during the winter on the northern tablelands of New South Wales. However, graziers report that animals offered supplements often do not consume them; there is also experimental evidence, obtained using tritiated supplements, that intake of supplements by individuals within a flock may exhibit wide variation. The objectives of this study were first, to evaluate a commercial protein-rich supplement when given to winter-grazed weaners, by determining the effect of supplementation on liveweight gain, wool production and fibre diameter, and second, to estimate the changes in patterns of intake of supplement by individual animals over time during a 12 week supplementation period.


Agronomy ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 460
Author(s):  
Yashvir S. Chauhan ◽  
Merrill Ryan

Post-flowering frosts cause appreciable losses to the Australian chickpea industry. The Northern Grains Region (NGR) of Australia, which accounts for nearly 95% of chickpea production in Australia, is frequently subjected to such events. The objective of this study was to map frost risk in chickpea in the NGR and develop strategies to minimise the impacts of such risk. The Agricultural Production System Simulator (APSIM) modelling framework was used to determine spatial and temporal trends in post-flowering frost risk. The NGR could be divided into six broad sub-regions, each delineating locations with similar frost risk. The risk was nearly two to three times greater in the Southern Downs and Darling Downs sub-regions as compared to the Central Queensland Highlands, Dawson Callide, New South Wales, and Northern New South Wales–Western Downs sub-regions. There was an increasing trend in the frequency of frost events in the Southern Downs and New South Wales sub-regions, and a decreasing trend in the Central Queensland Highlands and Dawson Callide sub-regions, consistent with the changing climate of the NGR. In each sub-region, frost risk declined with delayed sowings, but such sowings resulted in simulation of reduced water limited yield potential (unfrosted) as well. The model output was also used to compute 10, 30, 50, and 70% probabilities of the last day of experiencing −3 to 2 °C minimum temperatures and identify the earliest possible sowings that would avoid such temperatures after flowering. Choosing the earliest sowing times with a 30% frost risk could help increase overall yields in environments with high frost risk. Simulations involving genotype x environment x management interactions suggested additional opportunities to minimise frost losses through the adoption of particular cultivars of differing phenology and the use of different agronomy in various environments of the NGR. The study indicates that there is considerable variation in frost risk across the NGR and that manipulating flowering times either through time of sowing or cultivar choice could assist in minimising yield losses in chickpea due to frost.


2005 ◽  
Vol 18 (2) ◽  
Author(s):  
B. VAN DER WALT ◽  
R. A. FARAGHER ◽  
J. HARRIS

A joint program between New South Wales Fisheries and three fishing clubs was initiated in 1988 with the aim of collecting standardised catch and effort data during biannual fishing competitions on three major rivers in New South Wales. This paper examines the data to determine trends in the catch of the target species, Australian bass (Macquaria novemaculeata) and to evaluate whether the data can be used to assess Australian bass populations over time. Distinct trends in Australian bass mean length in each river system were evident but catch rates were more variable. Median catch per unit effort was similar (mostly between 0.5 and 1.5 Australian bass·h-1 ) in the Nepean and Williams Rivers although catch rates in the Manning River were nearly always zero. There was an increasing trend in the mean length of Australian bass in all three rivers, possibly representing a recovery in fish populations following severe drought from 1979 to 1983. Low or zero catch rates were continually recorded in the Manning River and size composition data indicated a lack of recruitment through most of the study period. The standardised format of the data collection program provided qualitative and reliable time series data allowing the determination of long-term trends in the population structure of Australian bass which can be used for monitoring and management purposes.


2021 ◽  
Vol 12 ◽  
Author(s):  
Yumi Tomari Kashida ◽  
Carlos Garcia-Esperon ◽  
Thomas Lillicrap ◽  
Ferdinand Miteff ◽  
Pablo Garcia-Bermejo ◽  
...  

Introduction: A telestroke network in Northern New South Wales, Australia has been developed since 2017. We theorized that the telestroke network development would drive a progressive improvement in stroke care metrics over time.Aim: This study aimed to describe changes in acute stroke workflow metrics over time to determine whether they improved with network experience.Methods: We prospectively collected data of patients assessed by telestroke who received multimodal computed tomography (mCT) and were diagnosed with ischemic stroke or transient ischemic attack from January 2017 to July 2019. The period was divided into two phases (phase 1: January 2017 – October 2018 and phase 2: November 2018 – July 2019). We compared median door-to-call, door-to-image, and door-to-decision time between the two phases.Results: We included 433 patients (243 in phase 1 and 190 in phase 2). Each spoke site treated 1.5–5.2 patients per month. There were Door-to-call time (median 39 in phase 1, 35 min in phase 2, p = 0.18), and door-to-decision time (median 81.5 vs. 83 min, p = 0.31) were not improved significantly. Similarly, in the reperfusion therapy subgroup, door-to-call time (median 29 vs. 24.5 min, p = 0.12) and door-to-decision time (median 70.5 vs. 67.5 min, p = 0.75) remained substantially unchanged. Regression analysis showed no association between time in the network and door-to-decision time (coefficient 1.5, p = 0.32).Conclusion: In our telestroke network, acute stroke timing metrics did not improve over time. There is the need for targeted education and training focusing on both stroke reperfusion competencies and the technical aspects of telestroke in areas with limited workforce and high turnover.


Soil Research ◽  
1977 ◽  
Vol 15 (2) ◽  
pp. 159 ◽  
Author(s):  
GJ Osborne

The nitrogen in six surface soils from southern New South Wales was chemically fractionated into the mineral nitrogen; hydrolysed ammonium + amino sugar; hydrolysed non-distillable acid soluble nitrogen; intercalary ammonium and insoluble humin nitrogen fractions. These fractions were determined before and after a glasshouse study in which ryegrass (Lolium perenne) was grown. There was no significant relationship between any of the fractions and the dry matter producion of ryegrass at three harvest dates. The levels of each fraction varied between the soils ; however, each fraction as a percentage of the total nitrogen showed little variation, either before or after plant growth. In four soils the hydrolysed ammonium + amino sugar fraction was increased during the glasshouse study, while the hydrolysed non-distillable acid soluble fraction was decreased on three soils, increased on two, and was unchanged in the remaining soil. Two methods of hydrolysis were compared and found to give significantly different results for some soils. On the basis of the data presented, the chemical fractionation of soil nitrogen following acid hydrolysis was of no practical value as a predictor of plant yield.


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