Comparative exploitation exploitation by recreational anglers of brown trout, Salmo trutta L., and rainbow trout, Oncorhynchus mykiss (Walbaum), in Lake Eucumbene, New South Wales

1992 ◽  
Vol 43 (4) ◽  
pp. 835 ◽  
Author(s):  
RA Faragher ◽  
GNG Gordon
Keyword(s):  
Rainbow Trout ◽  
Confidence Interval ◽  
Brown Trout ◽  
New South ◽  
New South Wales ◽  
Likelihood Method ◽  
Linear Regression Method ◽  
Tag Loss ◽  
South Wales ◽  
Significant Difference

Exploitation rates of syrnpatric brown trout and rainbow trout in Lake Eucumbene, New South Wales, were estimated from a tagging study. Tag returns were analysed by applying a non-linear regression method. Tag loss was estimated from a concurrent double tagging study using a maximum likelihood method. No significant difference at the 5% level was found between the rates of tag loss of the two species. The annual exploitation rate for rainbow trout was 26.7% (95% confidence interval 24.2- 29.2%) and was significantly less for brown trout, 8.8% (95% confidence interval 4.2-13.5%).

Repeat Homing of Brown Trout (Salmo trutta) in Lake Eucumbene, New South Wales, Australia

1977 ◽  
Vol 34 (8) ◽  
pp. 1085-1094 ◽  
Author(s):  
R. D. J. Tilzey
Keyword(s):  
Rainbow Trout ◽  
Brown Trout ◽  
Salmo Trutta ◽  
New South ◽  
Tag Loss ◽  
Trout Population ◽  
South Wales ◽  
High Incidence ◽  
Brown Trout Salmo Trutta ◽  
External Form

Spawning runs of lentic-dwelling brown trout (Salmo trutta) and rainbow trout (S. gairdneri) in Swamp Creek, an inlet of Lake Eucumbene, were studied for 4 consecutive yr, and 3517 browns and 415 rainbows were tagged during 1968–70. A further 240 browns and 229 rainbows were marked in other inlets. Recaptures of marked browns in 1969 and 1970 showed a high incidence of repeat homing, up to 25.7 and 10.6% returning after 12 and 24 mo, respectively. Few rainbow trout homed. Tag loss and the mortality and maturation of marked browns were estimated and percentage homing and straying in 1969, 1970 and 1971 was calculated. High percentage homing [Formula: see text] in 1969–70 and the variance in external form in the lentic population suggested some genetic isolation within the brown trout population. Homing ability was not influenced by fish age. Percentage homing fell markedly in 1971 after the removal of nearly all resident brown trout from Swamp Creek and suggested racially distinct stream trout populations to be an important navigational cue to homing brown trout. Key words: repeat homing, Salmo trutta, homing frequency, navigation, racial cue, Australia

Role of the crayfish Cherax destructor clark as food for trout in Lake Eucumbene, New South Wales

1983 ◽  
Vol 34 (3) ◽  
pp. 407 ◽  
Author(s):  
RA Faragher
Keyword(s):  
Rainbow Trout ◽  
Brown Trout ◽  
Salmo Trutta ◽  
New South ◽  
New South Wales ◽  
Water Levels ◽  
Size Analysis ◽  
Fish Length ◽  
Freshwater Crayfish ◽  
South Wales

The freshwater crayfish C. destructor was a major dietary item for brown trout, Salmo trutta L., and rainbow trout, S. gairdneri Richardson, in Lake Eucumbene, New South Wales. The incidence of crayfish in the diet increased, particularly in brown trout, over the period 1972-1977. The proportion of the trout's diet comprising C. destructor increased with length of brown trout but not with length of rainbow trout. The size of crayfish ingested was postively correlated with fish length for both species of trout, although rainbow trout tended to ingest smaller crayfish than brown trout of equivalent size. Analysis of the crayfish's diet revealed predominantly plant material. Spawning by the crayfish was apparently confined to the period December-April. The abundance of C. destructor in Lake Eucumbene was apparently low until about 1970 but increased between 1972-1977. A decline in the average size of brown and rainbow trout in the angler catch occurred from 1959-1960 until 1977-1978. Hypotheses are suggested for the increase of the crayfish population since impoundment of the lake (1957). Factors considered include predation by trout and the biology of the crayfish, particularly related to its occurrence in this lake, which has fluctuating water levels and a short season suitable for growth and spawning.

Diet and growth of rainbow trout, Salmo gairdneri Richardson, in two streams on the New England Tableland, New South Wales

1981 ◽  
Vol 32 (6) ◽  
pp. 967 ◽  
Author(s):  
RWJ Pidgeon
Keyword(s):  
Rainbow Trout ◽  
New England ◽  
New South ◽  
New South Wales ◽  
Rank Correlation ◽  
Dry Weight ◽  
Fish Growth ◽  
Salmo Gairdneri ◽  
Fish Size ◽  
South Wales

The diets and growth rates of rainbow trout in the Wollomombi and Guy Fawkes Rivers in northern New South Wales were examined. The growth rate of trout in the Wollomombi River was much higher than that of fish in the Guy Fawkes River. Spearman rank correlation coefficients indicated that stream type was more important than fish size in determining the composition of the diet of the trout. Benthic invertebrates formed the largest component of the diet in both streams: 66.0 and 63.0% of ash-free dry weight (AFDW) in the Wollomombi River and the Guy Fawkes River, respectively. Trout in the Wollomombi River consumed more nektonic prey (33.3% of AFDW) than fish in the Guy Fawkes River (3.7% of AFDW). In contrast, surface food (aquatic imagines and terrestrial insects) made up a much higher proportion of the diet of trout in the Guy Fawkes River (33.9% of AFDW) than in the Wollomombi River (0.6% of AFDW). Crayfish were a major component of the diet (in terms of AFDW) in both streams, their proportions increasing with fish size. The significance of crayfish in relation to fish growth is discussed.

Effects of variable-intensity logging and the influence of habitat variables on the distribution of the Greater Glider Petauroides volans in montane forest, southeastern New South Wales

2000 ◽  
Vol 6 (1) ◽  
pp. 18 ◽  
Author(s):  
Rodney P. Kavanagh ◽  
Rodney P. Kavanagh
Keyword(s):  
New South ◽  
New South Wales ◽  
Basal Area ◽  
Environmental Variable ◽  
Variable Intensity ◽  
Usual Practice ◽  
South Wales ◽  
Arboreal Marsupials ◽  
Significant Difference ◽  
Before And After

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.

57. GENOTYPING OF UROGENITAL CHLAMYDIA TRACHOMATIS IN REGIONAL NEW SOUTH WALES, AUSTRALIA

Sexual Health ◽  
2007 ◽  
Vol 4 (4) ◽  
pp. 306
Author(s):  
D. Mossman ◽  
C. Ooi ◽  
M. Loewenthal ◽  
M. Boyle
Keyword(s):  
Chlamydia Trachomatis ◽  
Older Patients ◽  
New South ◽  
Genotypic Variation ◽  
New South Wales ◽  
Genotype Frequency ◽  
Sexual Networks ◽  
Genotype Analysis ◽  
South Wales ◽  
Significant Difference

Background: Chlamydia Trachomatis is one of the most common sexually transmitted infections in Australia and world wide. This study was undertaken to map the frequency of Chlamydia genotypes in regional New South Wales (NSW), Australia, to explore the potential utility of genotype analysis in defining local sexual networks, and to investigate whether patterns of genotype frequency are correlated with demographic factors, including age and gender. Methods: We studied 204 urine samples infected with Chlamydia trachomatis, as determined by PCR analysis using the COBAS Amplicor system. Samples were collected from wide geographic area of regional New South Wales (Hunter, New England, Northern Rivers, South Eastern New South Wales). Sequencing and genotyping were performed after nested PCR of the omp1 gene. Results: Genotype E was found in 42.6% of infections, with genotypes F (23.5%) and G (16.7%) other common causes of infection. Mixed infection occurred in only 3 cases. There was no significant difference in genotype frequency based on gender or geographic location. There was a significant difference in gender frequency based on patient age, with older patients significantly more likely to demonstrate infection with genotype G (mean age (years) 23.7+/-7.29 sd, E: 21.7 +/-5.7 sd; G: 28.9; sd 10.18; p�=�0.022). Conclusions: There was no significant difference in genotype frequency in the various regions of New South Wales, suggesting genotype analysis is of limited use in defining sexual networks in regional NSW. The finding of a higher frequency of genotype G in older patients raises the possibility that genotypic variation may be driven by immune responses to genotypes that occur more frequently at a younger age. These results may have implications for the future design of a chlamydial vaccine.

Studies of the Ground-dwelling Mammals of Eucalypt Forests in North-eastern New South Wales: the Species, their Abundance and Distribution

1997 ◽  
Vol 24 (1) ◽  
pp. 1 ◽  
Author(s):  
P. C. Catling ◽  
R. J. Burt
Keyword(s):  
Vulpes Vulpes ◽  
New South ◽  
New South Wales ◽  
Felis Catus ◽  
Widespread Distribution ◽  
South Wales ◽  
Significant Difference ◽  
North Eastern ◽  
Eucalypt Forests ◽  
Abundance And Distribution

The distribution and abundance of ground-dwelling mammals in the major vegetation alliances in the eucalypt forests within an area of c. 24000 km2 in north-eastern New South Wales were examined. Data for 33 species of mammal from 21 areas containing 30 vegetation alliances were collected. Four notable aspects of the data were the absence or low abundance of the introduced fox (Vulpes vulpes), the widespread distribution and abundance of the cat (Felis catus), the diversity and abundance of medium-sized native mammals and the diversity of small mammals. Although differences occurred between areas and alliances, there was no significant difference in the number of native and introduced species. The ground-dwelling mammals present in the eucalypt forests of north-eastern New South Wales were more diverse and in greater abundance than those found in forests of south-eastern New South Wales. However, some species, such as the spotted-tailed quoll (Dasyurus maculatus), appear to be in urgent need of protection and management if they are to persist.

Using abattoir surveillance and producer surveys to investigate the prevalence and current preventative management of Caseous lymphadenitis in Merino flocks in Australia

2012 ◽  
Vol 52 (7) ◽  
pp. 675 ◽  
Author(s):  
R. D. Bush ◽  
R. Barnett ◽  
I. J. Links ◽  
P. A. Windsor
Keyword(s):  
Western Australia ◽  
Management Practices ◽  
New South ◽  
Animal Health ◽  
New South Wales ◽  
Surveillance Data ◽  
Caseous Lymphadenitis ◽  
South Wales ◽  
Significant Difference ◽  
Livestock Health

The prevalence of Caseous lymphadenitis (CLA) in Australia was estimated to be 5.2% using 2009 abattoir surveillance data from all States supplied by Animal Health Australia involving 5029 lines comprising 1 339 463 sheep. This is a decrease from the 26% estimated in a similar study in 1995. There was a significant difference (P < 0.001) in CLA prevalence between all states except Tasmania and Victoria (P = 0.75) with prevalences of 12.8 and 12.9%, respectively. Western Australia recorded the lowest prevalence with 1.0%. The average CLA prevalence for New South Wales was 5.3% and within three surveyed Livestock Health and Pest Authority regions (Tablelands, Central North and Central West) was 2.9, 4.9 and 4.4%, respectively. The attitude of the majority of producers surveyed in these three Livestock Health and Pest Authority areas was that CLA was of little or no significance (75%) but were aware of the need for CLA control with ~68% using 6-in-1 vaccine, though only 39.9% as recommended. It appears that the prolonged use of CLA vaccination has been successful in reducing the prevalence of CLA across Australia and particularly in New South Wales. Further improvements in communication of information on preventative management practices associated with lice control, importance of using an approved vaccination program, plus increasing producers’ awareness of the importance of CLA control, are indicated.

Aspects of Lactation in the Platypus, Ornithorhynchus anatinus (Monotremata), in Waters of Eastern New South Wales.

1983 ◽  
Vol 31 (6) ◽  
pp. 881 ◽  
Author(s):  
TR Grant ◽  
M Griffiths ◽  
RMC Leckie
Keyword(s):  
New South ◽  
New South Wales ◽  
Young Leave ◽  
South Wales ◽  
Ornithorhynchus Anatinus ◽  
Significant Difference ◽  
Lactating Females ◽  
One Year ◽  
The One ◽  
First Time

Female platypuses captured in waters of eastern New South Wales were found to be lactating between the months of October and March. Lactating females were most numerous in December, accounting for 64% of females captured. Non-lactating females were taken in all months, indicating that not all females breed successfully every year. There was no significant difference between the fatty acid complement of milk taken from a platypus lactating very late in the season and those of others sampled in December at the peak of the lactation season. Some evidence exists that females do not become reproductive until at least their second year of life. Some females were found lactating in consecutive years, and others lactated one year and not in the one following. Animals of over 9 years of age are known to breed. Most juveniles were captured in February, March and April, and it is suggested that the young leave the breeding burrows for the first time in late January through to March, and become independent from their mothers, who are ceasing lactation at that time.

A survey of free and conjugated deoxynivalenol in the 2009, 2010 and 2011 cereal crops in Australia

2013 ◽  
Vol 53 (5) ◽  
pp. 407 ◽  
Author(s):  
S. T. Tran ◽  
T. K. Smith
Keyword(s):  
Western Australia ◽  
New South ◽  
New South Wales ◽  
South Australia ◽  
Cereal Crops ◽  
South Wales ◽  
Cereal Grain ◽  
Significant Difference ◽  
Current Survey

Free and conjugated deoxynivalenol (DON, vomitoxin) were determined in samples of cereal grain collected from the 2009, 2010 and 2011 crops in the Australian states of New South Wales, Queensland, South Australia, Victoria and Western Australia. Free DON was absent in 53–64% of analysed samples. Levels of free DON ranged from 0.10 to 7.31 µg/g. The highest levels of free DON were found in samples collected from the New South Wales 2010 crop while no samples from South Australia or Western Australia regions contained this compound. Free DON in the samples collected from the 2010 crop was significantly higher compared with those from the 2009 and the 2011 crop. Conjugated DON was detected in 61, 87 and 68% of contaminated grain samples in the 2009, 2010 and 2011 crop, respectively. Conjugated DON was found mainly in the samples collected from the 2009 crop (up to 48%) and the 2011 crop (up to 43%) but no significant difference between free DON and total DON content was observed. The current survey emphasises the frequency of non-detectable, conjugated DON in Australian cereal crops and the potential challenges in understanding the hazard posed by DON-contaminated feedstuffs.

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