Downstream spawning migration by the amphidromous Australian grayling (Prototroctes maraena) in a coastal river in south-eastern Australia

2013 ◽  
Vol 64 (1) ◽  
pp. 31 ◽  
Author(s):  
W. M. Koster ◽  
D. R. Dawson ◽  
D. A. Crook
Keyword(s):  
Management Strategies ◽  
River Estuary ◽  
Adult Fish ◽  
Spawning Period ◽  
Tag Retention ◽  
Eastern Australia ◽  
Coastal River ◽  
Australian Grayling ◽  
Effective Conservation ◽  
Egg Abundance

Understanding the reasons and cues for migration is crucial for developing effective conservation and management strategies of diadromous fishes. Spawning and movement patterns of the threatened diadromous Australian grayling (Prototroctes maraena) were investigated in the Bunyip River, Victoria, using drift sampling (2008–2011) and acoustic telemetry (2009–2010) during the autumn–winter spawning period of each year. Fifty-five adult fish (2009: n = 21; 2010: n = 34) were tagged and released in February ~15–30 km upstream of the Bunyip River estuary. Thirteen fish (2009: n = 7; 2010: n = 6) undertook rapid downstream migrations from March to April to reaches immediately upstream of the estuary. Drifting eggs were detected at multiple sites between April and July; however, the majority (78.8%) were collected in the lower reaches within ~0.5 km of the estuary in early–mid-May. Tagged adult fish arrived in this area 1–4 weeks before eggs were detected and usually moved back upstream within 2 weeks following the peak egg abundance. Downstream migration and peak egg abundance were associated with increased river flows. Although the proportion of fish that undertook migrations was low, low rates of tag retention in this species likely account for the failure to detect migration by many of the tagged individuals.

Black Bass Diversity: Multidisciplinary Science for Conservation

2015 ◽  
Keyword(s):  
Population Dynamics ◽  
Management Strategies ◽  
Smallmouth Bass ◽  
Micropterus Dolomieu ◽  
Spawning Period ◽  
Sampling Gear ◽  
Gray Literature ◽  
Black Bass ◽  
Effective Conservation ◽  
Conservation And Management

<em>Abstract</em>.—We reviewed the published and gray literature associated with Neosho Smallmouth Bass <em>Micropterus dolomieu velox</em> and the genetically distinct Ouachita lineage. Substantial interstream variation appears to occur among these populations, particularly related to age. The Neosho subspecies is more abundant, grows faster, and lives longer than the genetically distinct Ouachita lineage. Recruitment is highly variable among streams for both populations and appears to be related to some undescribed aspects of hydrology but also likely reflect bias due to sampling gear. Information on annual and seasonal trends is lacking for the Neosho subspecies and the Ouachita lineages, particularly as related to the spawning period. Conservation efforts for these lineages might benefit from agencies partnering to achieve goals that extend beyond a particular agency’s responsibilities and state boundaries. Recognition of spatial and temporal considerations, combined with a better understanding of the population dynamics as related to abundance, growth, mortality and reproduction, would benefit the creation of more effective conservation and management strategies for genetically distinct populations of Smallmouth Bass <em>M. dolomieu</em>.

Habitat use and movements of Australian grayling (Prototroctes maraena) in a Victorian coastal stream

2018 ◽  
Vol 69 (8) ◽  
pp. 1259 ◽  
Author(s):  
D. R. Dawson ◽  
W. M. Koster
Keyword(s):  
Habitat Use ◽  
Conservation Management ◽  
Radio Telemetry ◽  
Management Strategies ◽  
Movement Ecology ◽  
Ecological Requirements ◽  
Management Actions ◽  
Eastern Australia ◽  
The World ◽  
Australian Grayling

Riverine fishes are among the most imperilled fauna in the world; however, for many species, there is little or no understanding of their ecological requirements. The Australian grayling (Prototroctes maraena) is a small diadromous fish endemic to rivers in south-eastern Australia that has declined considerably in range and abundance and is listed as threatened nationally. To improve understanding of the species’ movement ecology and to inform the development of conservation management actions, we examined the day-to-day movements and habitat use of Australian grayling (n=7) over 8 weeks by using radio-telemetry. Tagged individuals of Australian grayling typically occupied restricted (i.e. tens to hundreds of metres) reaches of stream, and were mostly located in moderate- to fast-flowing habitats (i.e. glide or run), although, at night, use of slower-flowing habitats (i.e. pools) increased. They also undertook longer-distance downstream movements during a period of increased streamflow. Incorporation of such information into management strategies has the potential to improve our capacity to maintain or re-instate the conditions required to conserve and restore Australian grayling populations.

scholarly journals Leopard Density Estimation within an Enclosed Reserve, Namibia Using Spatially Explicit Capture-Recapture Models

Animals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 724
Author(s):  
Noack ◽  
Heyns ◽  
Rodenwoldt ◽  
Edwards
Keyword(s):  
Management Strategies ◽  
Camera Traps ◽  
Spatially Explicit ◽  
Conservation Areas ◽  
Term Survival ◽  
New Class ◽  
Capture Recapture ◽  
Wildlife Populations ◽  
Effective Conservation

The establishment of enclosed conservation areas are claimed to be the driving force for the long-term survival of wildlife populations. Whilst fencing provides an important tool in conservation, it simultaneously represents a controversial matter as it stops natural migration processes, which could ultimately lead to inbreeding, a decline in genetic diversity and local extinction if not managed correctly. Thus, wildlife residing in enclosed reserves requires effective conservation and management strategies, which are strongly reliant on robust population estimates. Here, we used camera traps combined with the relatively new class of spatially explicit capture-recaptured models (SECR) to produce the first reliable leopard population estimate for an enclosed reserve in Namibia. Leopard density was estimated at 14.51 leopards/100 km2, the highest recorded density in Namibia to date. A combination of high prey abundance, the absence of human persecution and a lack of top-down control are believed to be the main drivers of the recorded high leopard population. Our results add to the growing body of literature which suggests enclosed reserves have the potential to harbour high densities and highlight the importance of such reserves for the survival of threatened species in the future.

scholarly journals Response of the Snowy River Estuary to two environmental flows

2015 ◽  
Vol 127 (2) ◽  
pp. 28
Author(s):  
Errol J. McLean ◽  
Jon B. Hinwood
Keyword(s):  
Fresh Water ◽  
Peak Flow ◽  
Environmental Flows ◽  
River Estuary ◽  
Environmental Flow ◽  
River Channel ◽  
Salinity Gradients ◽  
Tasman Sea ◽  
Eastern Australia ◽  
Major River

The Snowy River is a major river in south-eastern Australia, discharging to the Tasman Sea via a barrier estuary, with its entrance constricted by marine sands. Since the construction of the Snowy Mountains Scheme, river flows have not been sufficient to maintain the river channel. A program of environmental flow releases (EFR) is returning water to the river to restore the fluvial reaches and is now trialling flow regimes that may also benefit the estuarine reaches. This paper documents the response of the estuarine segments of the Snowy River to two EFRs; the release in 2010 was designed to scour the upper reaches of the Snowy River while the larger 2011 release was intended to extend the scouring downstream. For each release, the effects on the entrance morphology, tides and salinity through the flow peak and recovery are described. Each EFR caused minor increases in depth and very minor longshore movement of the entrance channel, although each EFR had been preceded by a larger fresh flow that would have scoured the channels. The small increase in fresh water inflow in the 2010 EFR pushed salinity contours seawards and steepened vertical salinity gradients. The larger inflow in the 2011 EFR purged the upper estuary of saltwater. After the peak flow, salinity recovery was rapid in the principal estuarine channels but took weeks where poorly connected wetlands could store fresh flood waters. Critical flows for scouring the entrance and purging salinity are estimated.

Seven new species of Graphidaceae (Lichenized Ascomycetes) from the Coastal Plain of southeastern North America

Phytotaxa ◽  
2014 ◽  
Vol 189 (1) ◽  
pp. 153 ◽  
Author(s):  
James C. Lendemer ◽  
Richard C. Harris
Keyword(s):  
North Carolina ◽  
New Species ◽  
North America ◽  
Coastal Plain ◽  
Management Strategies ◽  
Lichenized Ascomycetes ◽  
North America North ◽  
Effective Conservation ◽  
Conservation And Management

Seven new species of Graphidaceae are described from the Coastal Plain of southeastern North America: Acanthothecis floridana (Florida, USA), A. leucoxanthoides (North Carolina, USA), A. paucispora (North Carolina, USA), Fissurina alligatorensis (Florida and North Carolina, USA), F. americana (Florida and Georgia, USA), F. ilicicola (Florida and Georgia, USA), and Phaeographis oricola (North Carolina, USA). The ecology and distribution of each species is discussed in the broader context of the imminent need for effective conservation and management strategies to maintain the lichen biodiversity in the region. Color illustrations of all species are provided, as are keys to the genera Acanthothecis and Fissurina in North America north of Mexico.

Crop stubbles are as important for sheep production as annual pastures in the Victorian Mallee

2006 ◽  
Vol 46 (8) ◽  
pp. 993 ◽  
Author(s):  
S. M. Robertson
Keyword(s):  
Plant Density ◽  
Cropping Systems ◽  
Management Strategies ◽  
Simulation Modelling ◽  
Annual Rainfall ◽  
Pasture Management ◽  
Pasture Production ◽  
Eastern Australia ◽  
Sheep Production ◽  
The Impact

The impact of different management strategies on production and profit can be evaluated with knowledge of how sheep production responds to changes in the available feed base and sheep or pasture management. This study aimed to quantify on-farm pasture and sheep production in mixed sheep and cropping systems in the Victorian Mallee of south-eastern Australia (325 ± 50 mm annual rainfall) as a prelude to computer simulation modelling. During 2001 (average rainfall) and 2002 (extreme drought) pasture production, the feed base and sheep production were monitored in 15 paddocks on 5 properties located across the region. Crop stubbles were the major source of feed for 6 months of the year, enabling ewes to maintain liveweight. There was more variation in pasture parameters between paddocks at the 1 location than between locations. The botanical composition, plant density, soil fertility and management were key variables associated with between-paddock variation in pasture production. Variation in pasture production between years was larger than within-year differences. In contrast, stocking rates were not much lower in the drought year of 2002 than in 2001. This study suggests there is potential for management to improve pasture production, and demonstrates the importance of feed sources other than annual pasture for sheep production in environments where the annual pasture growing season is short.

Too close for comfort: a fishway exit and a hydro-power station inlet

2010 ◽  
Vol 61 (1) ◽  
pp. 23 ◽  
Author(s):  
Ivor G. Stuart ◽  
John D. Koehn ◽  
Tim A. O'Brien ◽  
John A. McKenzie ◽  
Gerry P. Quinn
Keyword(s):  
Management Strategies ◽  
Field Testing ◽  
High Water ◽  
Fish Passage ◽  
Native Fish ◽  
Power Station ◽  
Hydro Power ◽  
Murray River ◽  
Eastern Australia ◽  
Radio Transmitters

A major environmental issue for hydro-electric power generation is passage of fish through turbines, or entrainment onto trash racks. At Yarrawonga Weir, on the upper Murray River in south-eastern Australia, the positioning of a fish lock resulted in the potential for upstream migrating fish to be swept back into the adjacent power station by cross flows. In 2004, a 4.5-m long steel extension flume was attached to the exit to alleviate this problem. To determine the fate of native fish after exiting the extension flume, 72 individuals (305–1015 mm long) were implanted with radio-transmitters and released into the fish lock exit channel. In 2004 (power station inflows 10 300 ML day–1), the majority of fish exited successfully (44 of 45) and only a single fish (2%) was entrained into the power station. In 2005 (power station inflows 12 000 ML day–1), fish again exited successfully (26 of 27) but with a higher proportion entrained (5 of 27; 18%). This reduced success appeared to be related to strong transverse flows with high water velocities adjacent to the fish lock exit. The efficiency of fish passage at this site might be improved by altering water management strategies, integrating engineering and fish biology, and through field-testing of proposed solutions.

scholarly journals Annual and Seasonal Variation in Shorebird Abundance in the St. Lawrence River Estuary during Fall Migration

2018 ◽  
Vol 131 (3) ◽  
pp. 203-214 ◽  
Author(s):  
Yves Turcotte ◽  
Jean-Francois Lamarre ◽  
Joel Bety
Keyword(s):  
General Trend ◽  
River Estuary ◽  
Abundant Species ◽  
Western Hemisphere ◽  
Ecological Value ◽  
Reserve Network ◽  
Semipalmated Sandpiper ◽  
Peak Abundance ◽  
Effective Conservation ◽  
St Lawrence River

Many north American shorebird populations are declining. it is therefore urgent to identify major sites used during their annual cycle to achieve effective conservation measures. our objective was to expand some aspects of the knowledge base needed to assess the ecological value of the St. Lawrence River Estuary for shorebird conservation. Here, we present the results of the most intensive shorebird survey ever conducted in the St. Lawrence River Estuary during fall migration. Surveys were conducted between St-Jean-Port-Joli and St-Simon-sur-Mer, Quebec, Canada, in 2011 and 2012, from late June/early July through late november, corresponding to the migration period of all species potentially present in the study area. The Semipalmated Sandpiper (Calidris pusilla) was one of the two most abundant species during both years of our study (most abundant species, followed by Dunlin [Calidris alpina] and Black-bellied Plover [Pluvialis squatarola] in 2011; second to Blackbellied Plover in 2012). Considering the entire shorebird community, abundance of individuals peaked in early September. Peak abundance occurred earlier for adults than for juveniles. For most species, juveniles largely outnumbered adults. Juveniles were relatively less abundant in 2012 than in 2011. This reflected a general trend observed in northeastern north America between those years, suggesting a lower breeding success in 2012. Given its importance as a staging site for juvenile birds (study area used annually by up to a few hundred thousand shorebirds) and therein, its conservation value, we recommend that the St. Lawrence River Estuary should be included within the Western Hemisphere Shorebird Reserve network.

When will integrated pest management strategies be adopted? Example of the development and implementation of integrated pest management strategies in cropping systems in Victoria

2008 ◽  
Vol 48 (12) ◽  
pp. 1601 ◽  
Author(s):  
Paul A. Horne ◽  
Jessica Page ◽  
Cam Nicholson
Keyword(s):  
Integrated Pest Management ◽  
Pest Management ◽  
Information Transfer ◽  
Cropping Systems ◽  
Management Strategies ◽  
Sufficient Information ◽  
Motivation To Change ◽  
Implementing Change ◽  
Eastern Australia ◽  
Changing Practices

This paper discusses the development and implementation of integrated pest management (IPM) strategies for broadacre cropping in Victoria, Australia, with reference to other crops and also the levels of adoption of IPM in Australia and overseas. Levels and rates of adoption are mostly low but with some exceptions. The reasons for differing levels of adoption include the failure of strategies to successfully deal with all pests, the lack of motivation to change to using IPM given current successful pesticide-based controls, and the poor availability of IPM advisors in the field. This paper outlines how IPM strategies for wheat, barley and canola crops were developed and implemented using a collaborative approach between farmers, agronomists and entomologists. It was found that although there were no existing specific IPM strategies for the crops grown in the region of south-eastern Australia, there was sufficient information for farmers to start using an IPM approach. This paper gives a case study of implementing change to IPM from conventional pesticide spraying, including the development of a course in IPM for growers and agronomists. It focuses on the process of changing practices and information transfer rather than on entomological details.

Studies in Australian Estuarine Hydrology. II. The Swan River

1956 ◽  
Vol 7 (2) ◽  
pp. 193 ◽  
Author(s):  
RS Spencer
Keyword(s):  
Recovery Period ◽  
River Estuary ◽  
Barometric Pressure ◽  
Tidal Mixing ◽  
Lunar Tides ◽  
Eastern Australia ◽  
Mean Water Level ◽  
Tidal Characteristics ◽  
Basin Region ◽  
Swan River

The physiography of the Swan River is described, with particular reference to the drowned valley basin which is connected to the sea across a shallow sill. The climatological features of the region are discussed, together with the tidal characteristics of the basin. Drought conditions prevail during the summer, effective rainfall being confined to the winter months. Density stratification in the basin is intense and prolonged, because of the weakly developed tidal mixing. Changes in the mean water level of the basin are correlated with variations in barometric pressure; the amplitude of these changes sometimes exceeds that of the lunar tides. This fact has a significant bearing on hydrological conditions within the basin. The distribution and the seasonal cycles of temperature, chlorinity, and oxygen saturation are compared with those of a tidal-dominated estuary situated at the same latitude In eastern Australia. Most of the differences in these cycles can be attributed to the tidal regimes of the two systems. Nutrient cycles within the Swan River basin are discussed with particular reference to the recovery period following the development of stratification. In the later stages of the investigation this period was studied intensively, and from the information obtained several theories are advanced to explain the circulatory features of the basin region. An attempt is made to classify the Swan River estuary.

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