Development of techniques for the large-scale rearing of the larvae of the Australian freshwater fish golden perch, Macquaria ambigua (Richardson, 1845)

1996 ◽  
Vol 47 (2) ◽  
pp. 233 ◽  
Author(s):  
SJ Rowland
Keyword(s):  
Large Scale ◽  
Poultry Manure ◽  
Stocking Density ◽  
Crustacean Zooplankton ◽  
Positive Linear Relationship ◽  
Zooplankton Density ◽  
Eastern Australia ◽  
Earthen Ponds ◽  
Breeding Seasons ◽  
Australian Freshwater

Experiments were conducted over four consecutive breeding seasons. Golden perch, Macquaria ambigua, larvae (total length, 5.0 mm) held at 23� to 25�C, commenced feeding on crustacean zooplankton (<350 pm in length) five days after hatching, at age D6 (D1 = day of hatch). Zooplankton density had a significant effect (P < 0.01) on the survival of larvae in 70-L aquaria. A delay of only two days to age D8 in initial feeding significantly reduced (P < 0.01) survival, and larvae not offered zooplankton until D10 did not commence feeding. There was a positive linear relationship (r2 = 0.98) between survival in earthen ponds (0-57.6%) and the volume of small zooplankton sampled from the ponds at stocking, but survival was not affected by larval stocking density (32-365 m-2) or length of the culture period (28-53 days). A mean survival of 44.6% in ponds that were left dry over winter and then stocked 10-14 days after filling, was significantly higher (P < 0.01) than survival in ponds stocked only 2-5 days after filling or in ponds inundated during winter. Survival, growth and production were not significantly different among ponds fertilized with inorganic fertilizer (NPK) alone or in combination with lucerne hay or poultry manure. Larvae grew at rates of 0.5-1.1 mm day-1, production rates were up to 153 kg ha-1 and a maximum number of 271 000 juveniles were reared in a 0.3 ha pond. Approximately 3 × 106 golden perch are produced annually at hatcheries in eastern Australia using techniques developed during this study.

Ecological effects of common carp (Cyprinus carpio) in a semi-arid floodplain wetland

2014 ◽  
Vol 65 (9) ◽  
pp. 802 ◽  
Author(s):  
Lorenzo Vilizzi ◽  
Leigh A. Thwaites ◽  
Benjamin B. Smith ◽  
Jason M. Nicol ◽  
Chris P. Madden
Keyword(s):  
Common Carp ◽  
Cyprinus Carpio ◽  
Large Scale ◽  
Experimental Studies ◽  
Benthic Invertebrate ◽  
Common Carp Cyprinus Carpio ◽  
Zooplankton Density ◽  
Eastern Australia ◽  
Carp Cyprinus Carpio ◽  
Semi Arid

Common carp, Cyprinus carpio, is a highly invasive fish species across freshwater systems of south-eastern Australia, and especially in semi-arid floodplain wetlands. However, multi-component, large-scale experimental studies on carp effects on such ecosystems are scarce. This is in spite of demands to prioritise management and control of carp for the rehabilitation of habitats across the Murray–Darling Basin. A 2-year, large-scale field experiment in a terminal wetland of the lower River Murray (South Australia) evaluated the effects of free-ranging carp on water transparency, aquatic macrophytes (biomass and cover), zooplankton density, benthic invertebrates (density, richness and diversity) as well as native fish. Within 1 year since artificial inundation, transparency sharply decreased and this was accompanied by a decrease in aquatic macrophyte biomass and cover, a fluctuation in zooplankton density, and a decrease in benthic invertebrate richness and diversity. Also, the decreases in transparency and benthic invertebrate richness were significantly related to carp biomass, which averaged 68.0 kg ha–1 and induced a shift from clear- to turbid-water state. Following a flood event, increased connectivity caused carp to further access the newly inundated areas.

Influence of rainfall on population dynamics and survival of a threatened rodent (Pseudomys novaehollandiae) under a drying climate in coastal woodlands of south-eastern Australia

2017 ◽  
Vol 65 (1) ◽  
pp. 60 ◽  
Author(s):  
Mandy Lock ◽  
Barbara A. Wilson
Keyword(s):  
Population Dynamics ◽  
Population Decline ◽  
Resource Depletion ◽  
Mammal Species ◽  
Eastern Australia ◽  
Apparent Decrease ◽  
Mediterranean Systems ◽  
Precipitous Decline ◽  
Breeding Seasons ◽  
Successional Vegetation

In Mediterranean systems, such as south-east Australia, predictions of climate change including lower rainfall and extended drought, threaten vulnerable mammal species. We investigated the relationship between rainfall and population dynamics for a native rodent at risk of extinction, the New Holland mouse (Pseudomys novaehollandiae). In the eastern Otways, the species was significantly influenced by rainfall, exhibiting a population irruption (15–20 individuals ha–1) following six years of above-average rainfall and a precipitous decline to site extinction during subsequent drought. The decline was predominantly related to loss of adults before and during breeding seasons, together with an apparent decrease in juvenile survival. Population abundance was positively correlated with a rainfall lag of 0–9 months. We propose that the response of this omnivore to high rainfall was mediated through increased productivity and that rainfall decline resulted in resource depletion and population decline. Under a drying climate the direct impacts of rainfall decline will continue. However management of other threats may increase the species’ resilience. Burning to provide optimal successional vegetation, protection of refugia, and predator control are priorities. However, burning should be avoided during drought, as the likelihood of local extinctions is substantial.

Large-scale patterns in species richness and composition of temperate riverine fish communities, south-eastern Australia

2000 ◽  
Vol 51 (2) ◽  
pp. 165 ◽  
Author(s):  
Peter C. Gehrke ◽  
John H. Harris
Keyword(s):  
Species Richness ◽  
Large Scale ◽  
Fish Communities ◽  
Fish Fauna ◽  
South Coast ◽  
North Coast ◽  
Large Spatial Scale ◽  
River Types ◽  
Eastern Australia ◽  
Riverine Fish

Riverine fish in New South Wales were studied to examine longitudinal trends in species richness and to identify fish communities on a large spatial scale. Five replicate rivers of four types (montane, slopes, regulated lowland and unregulated lowland) were selected from North Coast, South Coast, Murray and Darling regions. Fishwere sampled during summer and winter in two consecutive years with standardized gear that maximized the range of species caught. The composition of fish communities varied among regions and river types, with little temporal variation. Distinct regional communities converged in montane reaches and diverged downstream. The fish fauna can be classified into North Coast, South Coast, Murray and Darling communities, with a distinct montane community at high elevations irrespective of the drainage division. Species richness increased downstream in both North Coast and South Coast regions by both replacement and the addition of new species. In contrast, species richness in the Darling and Murray regions reached a maximum in the slopes reaches and then declined, reflecting a loss of species in lowland reaches. The small number of species is typical of the freshwater fish faunas of similar climatic regions world-wide. Fish communities identified in this study form logical entities for fisheries management consistent with the ecosystem-focused, catchment-based approach to river management and water reform being adopted in Australia.

Out in the wash: spatial ecology of a temperate marine shallow rocky-reef species derived using acoustic telemetry

2015 ◽  
Vol 66 (6) ◽  
pp. 559 ◽  
Author(s):  
Jerom R. Stocks ◽  
Charles A. Gray ◽  
Matthew D. Taylor
Keyword(s):  
Spatial Ecology ◽  
Large Scale ◽  
Spatial Information ◽  
Activity Space ◽  
Rocky Reef ◽  
Temperate Reef ◽  
Detection Frequency ◽  
Detection Depth ◽  
Eastern Australia ◽  
Temperate Reef Fish

Characterising the movement and habitat affinities of fish is a fundamental component in understanding the functioning of marine ecosystems. A comprehensive array of acoustic receivers was deployed at two near-shore coastal sites in south-eastern Australia, to examine the movements, activity-space size and residency of a temperate rocky-reef, herbivorous species Girella elevata. Twenty-four G. elevata individuals were internally tagged with pressure-sensing acoustic transmitters across these two arrays and monitored for up to 550 days. An existing network of coastal receivers was used to examine large-scale movement patterns. Individuals exhibited varying residency, but all had small activity-space sizes within the arrays. The species utilised shallow rocky-reef habitat, displaying unimodal or bimodal patterns in depth use. A positive correlation was observed between wind speed and the detection depth of fish, with fish being likely to move to deeper water to escape periods of adverse conditions. Detection frequency data, corrected using sentinel tags, generally illustrated diurnal behaviour. Patterns of habitat usage, residency and spatial utilisation highlighted the susceptibility of G. elevata to recreational fishing pressure. The results from the present study will further contribute to the spatial information required in the zoning of effective marine protected areas, and our understanding of temperate reef fish ecology.

Dynamics of Cadmium-Stressed Plankton Communities

1980 ◽  
Vol 37 (3) ◽  
pp. 403-414 ◽  
Author(s):  
J. S. Marshall ◽  
D. L. Mellinger
Keyword(s):  
Dissolved Oxygen ◽  
Lake Michigan ◽  
Zooplankton Community ◽  
Cadmium Stress ◽  
Crustacean Zooplankton ◽  
Functional Responses ◽  
Experimental Lakes Area ◽  
Individual Values ◽  
Zooplankton Density ◽  
Plankton Communities

Structural and functional responses of plankton communities to cadmium stress were studied during 1977 in Lake Michigan using small-volume (8 L) completely sealed enclosures, and in Canada's Experimental Lakes Area (ELA) Lake 223 using large-volume (1.5 × 105 L) open-surface enclosures. In Lake Michigan, reductions of the average abundance of micro-crustaceans by cadmium were significantly greater in "light" or shallow epilimnetic incubations than they were in "dark" or deep epilimnetic incubations. Measurements of dissolved oxygen indicated that this interaction with light (depth) was an indirect effect due to a reduction of photosynthesis and primary production. Zooplankton density and species diversity were not significantly affected within 21 d by cadmium concentrations [Formula: see text] and [Formula: see text] Cd/L, respectively, whereas final dissolved oxygen concentration and percentage similarity (PS) of the crustacean zooplankton community were significantly reduced by [Formula: see text] Cd/L. In the ELA Lake 223 experiment, the reducing effect of cadmium on zooplankton density increased up to 31 d after Cd enrichment and then decreased, probably due to decreasing Cd concentrations in the water. Values of PS on day 24 for the ELA enclosures enriched with 1 and 3 μg Cd/L were within the 95% confidence limits for individual values predicted from a regression of PS on cadmium for the 21-d Lake Michigan experiments.Key words: plankton communities, zooplankton, phytoplankton, cadmium stress, Lake Michigan, Canadian Shield lakes

Fungi and fire in Australian ecosystems: a review of current knowledge, management implications and future directions

2011 ◽  
Vol 59 (1) ◽  
pp. 70 ◽  
Author(s):  
Sapphire J. M. McMullan-Fisher ◽  
Tom W. May ◽  
Richard M. Robinson ◽  
Tina L. Bell ◽  
Teresa Lebel ◽  
...  
Keyword(s):  
Fungal Community ◽  
Large Scale ◽  
Current Knowledge ◽  
Vegetation Type ◽  
Fire Regimes ◽  
Trophic Group ◽  
Fire Intensity ◽  
Specific Information ◽  
Eastern Australia ◽  
Essential Components

Fungi are essential components of all ecosystems in roles including symbiotic partners, decomposers and nutrient cyclers and as a source of food for vertebrates and invertebrates. Fire changes the environment in which fungi live by affecting soil structure, nutrient availability, organic and inorganic substrates and other biotic components with which fungi interact, particularly mycophagous animals. We review the literature on fire and fungi in Australia, collating studies that include sites with different time since fire or different fire regimes. The studies used a variety of methods for survey and identification of fungi and focussed on different groups of fungi, with an emphasis on fruit-bodies of epigeal macrofungi and a lack of studies on microfungi in soil or plant tissues. There was a lack of replication of fire treatment effects in some studies. Nevertheless, most studies reported some consequence of fire on the fungal community. Studies on fire and fungi were concentrated in eucalypt forest in south-west and south-eastern Australia, and were lacking for ecosystems such as grasslands and tropical savannahs. The effects of fire on fungi are highly variable and depend on factors such as soil and vegetation type and variation in fire intensity and history, including the length of time between fires. There is a post-fire flush of fruit-bodies of pyrophilous macrofungi, but there are also fungi that prefer long unburnt vegetation. The few studies that tested the effect of fire regimes in relation to the intervals between burns did not yield consistent results. The functional roles of fungi in ecosystems and the interactions of fire with these functions are explained and discussed. Responses of fungi to fire are reviewed for each fungal trophic group, and also in relation to interactions between fungi and vertebrates and invertebrates. Recommendations are made to include monitoring of fungi in large-scale fire management research programs and to integrate the use of morphological and molecular methods of identification. Preliminary results suggest that fire mosaics promote heterogeneity in the fungal community. Management of substrates could assist in preserving fungal diversity in the absence of specific information on fungi.

Deep phylogenetic structure has conservation implications for ornate rainbowfish (Melanotaeniidae:Rhadinocentrus ornatus) in Queensland, eastern Australia

2004 ◽  
Vol 55 (2) ◽  
pp. 165 ◽  
Author(s):  
Timothy J. Page ◽  
Suman Sharma ◽  
Jane M. Hughes
Keyword(s):  
Large Scale ◽  
Mitochondrial Atpase ◽  
Isolated Populations ◽  
Exotic Fish ◽  
Phylogenetic Structure ◽  
Bay Area ◽  
Conservation Implications ◽  
South Wales ◽  
Eastern Australia ◽  
Atpase Gene

The freshwater fish, Rhadinocentrus ornatus Regan, 1914, has a patchy distribution through coastal drainages of Queensland and New South Wales, eastern Australia. Isolated populations of R. ornatus are found on several islands, as well as in a disjunct northern population 350 km from its nearest conspecific population. Deoxyribonucleic acid was extracted and sequenced for the mitochondrial ATPase gene to describe the geographic and genetic subdivision within the species. Four major clades were identified. These clades diverged between two and seven million years ago and so represent long-term divisions and possible units of conservation. There are conservation implications in that the narrow and localised distribution of R. ornatus overlaps with an area of large-scale land clearing, high human population and threats from introduced exotic fish. A particularly high centre of Rhadinocentrus diversity in the Tin Can Bay area of Queensland presents some interesting questions about the evolution of the genus Rhadinocentrus.

Stand dynamics and species composition control long-term post-fire trends in evapotranspiration and streamflow from South-eastern Australia’s Temperate Eucalyptus forests

2021 ◽  
Author(s):  
Assaf Inbar ◽  
Richard Benyon ◽  
Patrick Lane ◽  
Shyanika Lakmali ◽  
Shane Haydon ◽  
...  
Keyword(s):  
Species Composition ◽  
Forest Dynamics ◽  
Simulation Analysis ◽  
Stocking Density ◽  
Climatic Conditions ◽  
Water Yield ◽  
Multiple Sources ◽  
Acacia Dealbata ◽  
Eastern Australia

&lt;p&gt;Most of the water that ends up in Melbourne&amp;#8217;s water supply catchments originates from wet Eucalyptus forests that are dominated by Eucalyptus regnans, the tallest known angiosperm on earth. Studies had shown that catchments that are dominated by these forests can experience a significant long-term (&gt;100 years) reduction in streamflow after a stand-replacing fire, which was attributed to higher water-use of the dense overstory regrowth. However, despite several lines of evidence, the direction, extent and duration of post-fire hydrological behaviour vary significantly between catchments and between fire events. Here we propose that this variability is caused by initial stocking density and species composition after the fire, and the climatic conditions that prevail during forest regeneration that affect tree growth and mortality rates. In order to test the hypothesis, we formulated an ecohydrological model that simulates hydrology, growth and forest dynamics of E. regnans and Acacia dealbata, which are known to compete for resources during the initial stages of vegetation recovery. The new model shows high skill in predicting long-term streamflow when compared to observations using multiple sources of data. Simulation analysis shows that the direction, extent and duration of post-fire hydrological behaviour are sensitive to initial stocking density and to the relative abundance of species that regenerate after the fire, which influence the rate of self-thinning during stand development. Furthermore, simulation results show that the observed long-term reduction in streamflow is less likely to occur when the forest would have been less dense before the fire, which theoretically could only occur when a high proportion of the short-lived A. Dealbata regenerated after the previous fire. This highlights the importance of including mechanisms that control the effect of species composition on forest dynamics when modelling the effect of possible future climatic scenarios on water yield.&lt;/p&gt;

scholarly journals Production Economics and Determinants of Potato Production in Nuwakot, Nepal

2019 ◽  
Vol 7 (1) ◽  
pp. 62-68 ◽  
Author(s):  
Bhishma Raj Dahal ◽  
Swodesh Rijal
Keyword(s):  
Large Scale ◽  
Poultry Manure ◽  
Potato Production ◽  
Research Area ◽  
Chemical Fertilizer ◽  
Production Economics ◽  
Microsoft Excel ◽  
Rural Municipality ◽  
Face To Face ◽  
Interview Method

A study was conducted for comparative analysis of demographic, production economics and determinants of potato production between Kakani rural municipality and Bidur municipality of Nuwakot district. Altogether 120 potato producers, 56 from Kakani and 64 from Bidur were randomly selected. Pretested semi-structured questionnaire was administered to randomly selected farmers. Potato growers were interviewed using face to face interview method in the month of October 2018. All the data were entered into SPSS and Microsoft excel and analysis was done by using Microsoft excel, STATA and SPSS. Average productivity in the research area was 14.69 ton per hectare. Average cost of production and profit was Rs 8614.61 per ropani and Rs 6083 per ropani respectively. B/C ratio in the research area was 1.71. 10% increase in organic manure (FYM and poultry manure), pesticide and tuber resulted in 1.88%, 1.99% and 0.05% increase in income respectively. 10% increase in labor and chemical fertilizer resulted into 0.1% and 0.5% decrease in output. Labor and chemical fertilizer was over utilized resource for potato production. The probability of cultivation of potato in large scale was found to be 56.92% higher for those with access to extensive service and 47.89% higher for those who have received training.  Most of the farmers don not use improved seed thus distributing improved seed, providing training and extension services help to increase profit of potato production in Nuwakot district. 100% increase in all the factor of production would result in 32.39% increase in potato production. Int. J. Appl. Sci. Biotechnol. Vol 7(1): 62-68

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