Growth of four species of juvenile fish associated with the Seagrass Zostera capricorni, in Botany Bay, NSW

1992 ◽  
Vol 43 (5) ◽  
pp. 1189 ◽  
Author(s):  
DG Worthington ◽  
DJ Ferrell ◽  
SE NcNeill ◽  
JD Bell
Keyword(s):  
Sea Water ◽  
New South ◽  
Juvenile Fish ◽  
Natural Populations ◽  
Length Frequency ◽  
Frequency Distributions ◽  
South Wales ◽  
Time Period ◽  
Flow Through ◽  
Sampling Programme

Populations of four species of juvenile fish- Rhabdosargus sarba, Acanthopagrus australis, Achoerodus viridis and Girella tricuspidata-were sampled from a seagrass bed in Botany Bay, New South Wales. Fish were collected eight times between 22 March 1990 and 22 February 1991, using a small seine-net. Growth rates were calculated from the progression of cohorts in length-frequency distributions. Cohorts of R. sarba, A. australis and A. viridis grew most slowly during winter (0.02, 0.04 and 0.21 mm day-1, respectively); growth then increased, peaking just prior to the loss of the cohort from the habitat (0.3 1, 0.24 and 0.39 mm day-1). Populations of R. sarba, A. australis and A. viridis were comprised of one or two cohorts that remained in the habitat for at least 3-4 months. Conversely, up to seven cohorts of G. tricuspidata were found between October and February, and most cohorts did not remain in the habitat for more than 2 months. As a result, there were only two confident estimates of growth for G. tricuspidata: 0.23 mm day-1 between October and November, and 0.34 mm day-1 between January and February. Individuals of each species were also kept in a flow-through 4000-L tank of sea water. Growth of cohorts of fish kept in the tank was very similar to that found in natural populations during the same time period. The rates of recruitment and loss of cohorts from seagrass can be rapid and these factors must be considered in designing a sampling programme to assess growth by analysis of length-frequency distributions.

Sydney rock oyster farming in Australia.

2020 ◽  
Author(s):  
John Nell
Keyword(s):  
New South ◽  
Quality Assurance Program ◽  
First Year ◽  
Water Sampling ◽  
Time To Market ◽  
Profit Margins ◽  
Rock Oyster ◽  
South Wales ◽  
Sampling Programme

Abstract The 120-year-old Sydney rock oyster industry in New South Wales (NSW) and southern Queensland is one of the oldest aquaculture industries in Australia. The industry has been forced to adapt to competition from other species, tighter harvesting and oyster storage and handling requirements as well as eroding profit margins. Recent changes in farming practices include the move away from stick culture to single seed culture, as the half-shell market demands a more uniformly shaped oyster. When selective breeding demonstrated that it could reduce time to market (50 g whole weight) by nearly a year out of an industry average of 3.5 years, the industry wanted to try hatchery technology. Although the industry had never used hatchery technology before, it purchased 10 million spat or 8% of its annual spat requirement from hatcheries in 2003-2004, the first year that they were made available to farmers. The industry also embraced the Australian Shellfish Quality Assurance Program, which requires that shellfish harvest areas be classified on the basis of a sanitary survey and the results of an ongoing strategic water-sampling programme. This programme ensures product safety for the consumers and helps to provide the industry with a long-term future.

Repeatability and frequency of in-paddock sheep walk-over weights: implications for flock-based management

2014 ◽  
Vol 54 (5) ◽  
pp. 582 ◽  
Author(s):  
D. J. Brown ◽  
D. B. Savage ◽  
G. N. Hinch
Keyword(s):  
Radio Frequency ◽  
New South ◽  
Management Decision ◽  
Data Filtering ◽  
Sheep Flock ◽  
Average Reference ◽  
South Wales ◽  
Time Period ◽  
Management Decision Making ◽  
Reference Weight

The ability to monitor average liveweight of a sheep flock provides livestock managers the opportunity to nutritionally manage their flock for higher productivity. Mob-based walk-over weighing (MBWOW) is a remote weighing concept for sheep flocks whereby liveweights are collected as the animals pass freely over a strategically placed weighing platform. We tested the hypothesis that the repeatability and frequency of MBWOW data are sufficient to generate sheep flock average liveweight estimates with a 95% confidence interval (CI) of <2 kg over a 5-day time period. These criteria were considered reasonable, in terms of accuracy and timeliness, for application in a commercial context. Radio frequency-identified WOW data were obtained from four sheep flocks in south-eastern New South Wales, representing a mix of age and breeds, as sheep traversed a remote weighing platform to and from some form of incentive. The repeatability and frequency of three forms of radio frequency-identified WOW data, being raw (unfiltered), course-filtered (filtered to remove all sheep weights outside the flock weight range) and fine-filtered (filtered to remove all sheep weights outside a 25% range of a recent flock average reference weight), were used in a simulation to test the 95% CI of 1- and 5-day MBWOW liveweight capture periods (samples). All data-filtering approaches over a 5-day sample generated flock average liveweight estimates with 95% CI of <2 kg, thus meeting the hypothesis criteria. One-day samples generated flock average liveweight estimates with 95% CI of >2 kg and data filtering, although reducing the 95% CI, did not bring it below the hypothesis criteria. Thus, when the appropriate data handling technique is used, MBWOW may provide information suitable for sheep management decision-making in a commercial context.

The effect of Noisy Miners on small bush birds: an unofficial cull and its outcome

2008 ◽  
Vol 14 (3) ◽  
pp. 185 ◽  
Author(s):  
S. J. S. Debus
Keyword(s):  
New South ◽  
Bird Species ◽  
Bird Community ◽  
Major Contributor ◽  
Bird Species Richness ◽  
Woodland Birds ◽  
South Wales ◽  
Time Period ◽  
Manorina Melanocephala ◽  
Time Periods

This paper documents the bird community in a small (~15 ha) patch of remnant woodland New South Wales sheep? wheat belt (i) before Noisy Miners Manorina melanocephala were abundant in the patch (1972-79), (ii) after a dense miner colony became established (1980-1990), (iii) after the miners were removed (1991?92) and, subsequently, (iv) while extensive, dense plantings of native trees became established (1992-2006). Bird species richness in the patch was, respectively, 64, 18, 45 and 83 species in each time period. Totals for small (<120 g) bush birds, mostly insectivorous passerines, were 26, 0, 22 and 46 species in the respective time periods. Although this was an unofficial, unreplicated and uncontrolled activity, the results support those of previous similar studies that indicate that Noisy Miners are a major contributor to the local decline of many woodland birds. The results also affirm the value of a shrub layer to small birds.

Life history, food and habitat of southern pygmy perch, Nannoperca australis, in the Macquarie River, Tasmania

1995 ◽  
Vol 46 (8) ◽  
pp. 1159 ◽  
Author(s):  
P Humphries
Keyword(s):  
Benthic Invertebrates ◽  
Aquatic Macrophytes ◽  
New South ◽  
Gonadosomatic Index ◽  
First Year ◽  
Small Fish ◽  
Prey Fish ◽  
Length Frequency ◽  
South Wales ◽  
Fish Spawning

The reproductive biology, age, growth, food and habitat of Nannoperca australis are described from samples collected from fringing macrophyte beds of the Macquarie River, Tasmania. Comparisons are made with the same species at Narrandera in New South Wales and other nannopercids, mainly in south-western Australia. Nannoperca australis spawned at the end of its first year, predominantly between October and December, inclusive. The peak mean gonadosomatic index of males occurred in August at 8.0 and that of females two months later at 11.5. The largest oocytes, of running-ripe females collected in October and December, were 1.15 mm in diameter. Fecundities ranged from 78 for a 1-year-old 37-mm fish to 679 for a 2-year-old 63-mm fish. Spawning is presumed to occur in the macrophyte habitat, since adults did not emigrate from these areas at this time. Otoliths and length-frequency histograms indicated that populations were dominated by 0+ fish. Amphipods and ostracods predominated in the guts of N. australis and prey items were mostly either benthic invertebrates or plant epifauna. Plankton was consumed by small fish in greater quantities than by larger fish, whereas the opposite was true for benthic and epifaunal prey. Fish were virtually always associated with aquatic macrophytes and almost always with shallow, still water.

Genetic diversity in natural populations of Acacia mearnsii

2000 ◽  
Vol 48 (2) ◽  
pp. 279 ◽  
Author(s):  
S. D. Searle ◽  
J. C. Bell ◽  
G. F. Moran
Keyword(s):  
Genetic Diversity ◽  
Gene Diversity ◽  
New South ◽  
Natural Populations ◽  
South Australia ◽  
Population Diversity ◽  
Regional Level ◽  
Acacia Mearnsii ◽  
South Wales ◽  
Isozyme Loci

Twenty-three isozyme loci were used to examine genetic diversity within and between 19 natural populations of Acacia mearnsii De Wild. selected to represent its entire geographic range. Acacia mearnsii was found to have moderate genetic diversity (species level gene diversity HT = 0.201) with the majority (89.2%) of variation occurring within populations. All measures of population diversity were higher in the northern (New South Wales) than the southern (Victoria, South Australia, Tasmania) populations. There was some evidence of differentiation between populations but no strong clustering at a regional level.

Changes in Drug Eluting Stent Usage During a Four-Year Time Period in a Regional Cath Lab in New South Wales

2016 ◽  
Vol 25 ◽  
pp. S167-S168
Author(s):  
C. Itty ◽  
A. Blenkhorn ◽  
D. Mumford ◽  
P. Kwan
Keyword(s):  
New South ◽  
New South Wales ◽  
Drug Eluting Stent ◽  
South Wales ◽  
Time Period ◽  
Drug Eluting

Reproduction of the turban shell Turbo torquatus Gmelin 1791 (Mollusca : Gastropoda), in New South Wales, Australia

2002 ◽  
Vol 53 (1) ◽  
pp. 85 ◽  
Author(s):  
D. W. Ward ◽  
A. R. Davis
Keyword(s):  
Reproductive Cycle ◽  
Developmental Stages ◽  
New South ◽  
Gonadosomatic Index ◽  
New South Wales ◽  
Gonad Development ◽  
Gonadal Development ◽  
Small Scale ◽  
Frequency Distributions ◽  
South Wales

The Sydney turban shell Turbo torquatus is the focus of a small-scale commercial fishery in New South Wales. Effective management requires knowledge of the reproductive biology, yet this is lacking for NSW waters. The reproductive cycle was investigated at three localities on the southern New South Wales coast. Samples of T. torquatus were collected monthly at Wollongong, Ulladulla and Eden from February 1996 until August or December 1997. The reproductive cycle was investigated by three methods: monthly determination of a gonadosomatic index, estimation of oocyte size-frequency distributions and classification of female gonads into developmental stages following histological sectioning. Males and females within a population underwent synchronous gonad development and spawning. Spawning events were often protracted over a period of several months with females in various stages of gonadal development. Two spawning events occurred each year, with a spawning event in autumn–winter and another in spring–summer. These events were asynchronous among the three localities, and partial spawning appeared to be a common occurrence. Owing to variation in the timing of spawning between populations separated by a distance as small as 15 km, seasonal closures to protect spawning stocks are unlikely to be effective.

scholarly journals Genetic Structure of Natural Populations of Wild Sunflowers (Helianthus annuus L.) in Australia

1986 ◽  
Vol 39 (3) ◽  
pp. 255 ◽  
Author(s):  
PJ Dry ◽  
JJ Burdon
Keyword(s):  
Genetic Structure ◽  
Gene Diversity ◽  
New South ◽  
Geographic Distance ◽  
Natural Populations ◽  
Wild Populations ◽  
South Wales ◽  
Fixation Indices ◽  
O 19 ◽  
Isozyme Diversity

The genetic structure of 11 wild populations of H. annuus occurring in New South Wales and Queensland was determined by isozyme analysis. Considerable isozyme diversity was found among loci within and between populations, with three to five alleles being identified at each of 10 loci. Mean levels of heterozygosity ranged from o� 19 to O� 38 and gene diversity values from 0�29 to O� 52. In all populations Wright's fixation indices were positive (0�09-0� 51) suggesting a degree of inbreeding. Differences in the level of genetic differentiation between populations were not correlated with geographic distance. Indeed, notable genetic diversity was detected between six sites occurring within a 2-km radius of Gunnedah, N.S.W., where the genetic distance relationships were D = 0�13 � 0'08, the same as those between popUlations throughout the region.

Reproduction and Growth of The Bandicoot Isoodon macrourus At Four Sites in Rockhampton, Queensland.

1998 ◽  
Vol 20 (3) ◽  
pp. 411
Author(s):  
S.M. Attard ◽  
S.C. Mckillup
Keyword(s):  
Growth And Development ◽  
New South ◽  
Reproductive Ecology ◽  
New South Wales ◽  
Natural Populations ◽  
Northern Territory ◽  
Coastal Areas ◽  
South Wales ◽  
Cape York ◽  
The Tropics

Within Australia the northern short-nosed bandicoot, Isoodon macrourus, occurs in coastal areas from the Kimberleys to the monsoonal tropics of the Northern Territory and from Cape York Peninsula to the Hawkesbury River, New South Wales (Gordon 1983). The reproductive ecology of I. macrourus has been studied in two captive (Hall 1983; Gemmell 1988) and five natural populations (Gordon 1971, 1974; Gemmell 1982; Hall 1983; Friend 1990; Kem- per et al. 1990; Budiawan 1993). Three of the latter (Darwin, the Mitchell Plateau and Townsville) were in the tropics; breeding at these sites occurred dur- ing the wetter months of the year but not during the summer of 1982/3 in Darwin when the monsoon failed (Friend 1990) or during the relatively dry winter/spring of 1991 in Townsville (Budiawan 1993), suggesting a dependence on rainfall (Friend 1990; Budiawan 1993). We report on differences in the reproduction, growth and development of I. macrourus in Rockhampton, Queensland, from March - October 1993 at four adjacent sites which received different amounts of artificial watering.

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