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

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.

2017 ◽  
Vol 68 (8) ◽  
pp. 1567 ◽  
Author(s):  
W. M. Koster ◽  
D. A. Crook

As human demands for freshwater resources increase, there is growing concern for the long-term viability of native fish populations globally. Understanding the movements of fish, and how these are influenced by or respond to environmental changes, is a critical knowledge requirement for effective management; however, limited information on the ecological requirements of many fish species currently hinders our ability to sustainably manage fish populations. In this paper, we use four native Australian fish species with contrasting life histories as case studies to demonstrate how data derived from acoustic and radiotelemetry studies can be synthesised into conceptual diagrams to help scientists and managers develop targeted and effective conservation management strategies. Commonalities in the observed movement patterns were observed among the species despite their contrasting life histories, but there were also important differences that need to be recognised in the development of species-specific conservation management strategies. We conclude by discussing how such information has been or could be incorporated into conservation management actions, including the implementation of environmental flow releases and the identification of critical habitats.


2012 ◽  
Vol 21 (3) ◽  
pp. 197 ◽  
Author(s):  
Lucy G. Halliday ◽  
J. Guy Castley ◽  
James A. Fitzsimons ◽  
Cuong Tran ◽  
Jan Warnken

Fire is an important natural disturbance process within the Australian landscape, but the complex and hazardous nature of fire creates a conservation management dilemma. For landholders of private conservation lands, management for conservation of biodiversity and risk reduction is complicated. Private conservation landholders in eastern Australia directed far less effort towards fire management than other conservation management actions, despite clearly acknowledging the risk and associated responsibilities of fire management on their lands. Nonetheless, landholders did undertake actions to reduce fuel hazards and prepare for wildfire events on their land. Despite the established role and benefits of fire to many ecosystems in the region, landholder understanding of the ecological role of fire was generally poor. Few landholders were aware of ecologically appropriate fire regimes for the vegetation types on their property, and few undertook fire management actions to achieve ecological outcomes. Site-specific obstacles, lack of fire management knowledge and experience, and legal and containment concerns contributed to the low level of fire management observed. There is a need for property-specific fire management planning across all private conservation lands, to further integrate ecological fire requirements into biodiversity management, and prioritise actions that aim to improve conservation outcomes while safeguarding life and property.


2018 ◽  
Vol 45 (3) ◽  
pp. 208 ◽  
Author(s):  
Tegan Whitehead ◽  
Karl Vernes ◽  
Miriam Goosem ◽  
Sandra E. Abell

Context Identification of key threats to endangered species is vital for devising effective management strategies, but may be hindered when relevant data is limited. A population viability approach may overcome this problem. Aims We aimed to determine the population viability of endangered northern bettongs (Bettongia tropica) in north-eastern Australia. We also assessed the key threats to the population resilience and how the population viability responds to increases in mortality rates and changes in fire and drought frequency. Methods Using population viability analysis (PVA) we modelled survival probability of B. tropica populations under likely scenarios, including: (1) increased predation; (2) changes in drought and fire frequency predicted with anthropogenic climate change; and (3) synergistic effects of predation, fire and drought. Key results Population viability models suggest that populations are highly vulnerable to increases in predation by feral cats (Felis catus), and potentially red fox (Vulpes vulpes) should they colonise the area, as juvenile mortality is the main age class driving population viability. If B. tropica become more vulnerable to predators during post-fire vegetation recovery, more frequent fires could exacerbate effects of low-level cat predation. In contrast, it was predicted that populations would be resilient to the greater frequency of droughts expected as a result of climate change, with high probabilities of extinctions only predicted under the unprecedented and unlikely scenario of four drought years in 10. However, since drought and fire are interlinked, the impacts of predation could be more severe with climate change should predation and fire interact to increase B. tropica mortality risk. Conclusion Like other Potoroids, B. tropica appear highly vulnerable to predation by introduced mammalian predators such as feral cats. Implications Managers need information allowing them to recognise scenarios when populations are most vulnerable to potential threats, such as drought, fire and predation. PVA modelling can assess scenarios and allow pro-active management based on predicted responses rather than requiring collection of extensive field data before management actions. Our analysis suggests that assessing and controlling predator populations and thereby minimising predation, particularly of juveniles, should assist in maintaining stability of populations of the northern bettong.


2020 ◽  
Author(s):  
Sarah L. Heidmann ◽  
Jonathan Jossart ◽  
Richard S. Nemeth

Abstract Background: The movement ecology of mutton snapper Lutjanus analis is poorly understood despite their ecological and economic importance in the Caribbean. Passive acoustic telemetry was used to determine home ranges of six adult L. analis, including diel patterns, in Brewers Bay, St. Thomas, US Virgin Islands. Understanding long-term space use, including site fidelity and habitat usage, is necessary to implement effective and appropriate management actions for a species with extensive space and resource needs.Results: Individual L. analis were tracked over an average period of 316 days (range 125 - 509 days) and showed high site fidelity to relatively small home ranges (mean ± SD: 0.103 ± 0.028 km2, range 0.019 - 0.190 km2) and core use areas with low overlap among individuals. Most home ranges had a habitat composition dominated by seagrass and to a lesser degree, coral reef and/or pavement. Nighttime activity spaces were distinct from but contained within daytime areas.Conclusions: Mutton snapper showed strong site fidelity to home ranges in Brewers Bay. Two individuals that were absent from the array for more than a few hours were detected at separate arrays at spawning aggregation sites. This study expands upon knowledge of mutton snapper home range characteristics, highlights the importance of maintaining adjacent high-quality habitat types in any spatial management plan, and encourages the adoption of other types of management strategies, particularly for transient-aggregating species.


2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Sarah L. Heidmann ◽  
Jonathan Jossart ◽  
Melissa Kimble ◽  
Richard S. Nemeth

Abstract Background The movement ecology of mutton snapper Lutjanus analis is poorly understood despite their ecological and economic importance in the Caribbean. Passive acoustic telemetry was used to determine home ranges of six adult L. analis, including diel patterns, in Brewers Bay, St. Thomas, US Virgin Islands. Understanding long-term space use, including site fidelity and habitat usage, is necessary to implement effective and appropriate management actions for a species with extensive space and resource needs. Results Individual L. analis were tracked over an average period of 316 days (range 125–509 days) and showed high site fidelity to relatively small home ranges (mean ± SD: 0.103 ± 0.028 km2, range 0.019–0.190 km2) and core use areas with low overlap among individuals. Most home ranges had a habitat composition dominated by seagrass and to a lesser degree, coral reef and/or pavement. Nighttime activity spaces were distinct from but contained within daytime areas. Conclusions Mutton snapper showed strong site fidelity to home ranges in Brewers Bay. Two individuals that were absent from the array for more than a few hours were detected at separate arrays at spawning aggregation sites. This study expands upon knowledge of mutton snapper home range characteristics, highlights the importance of maintaining adjacent high-quality habitat types in any spatial management plan, and encourages the adoption of other types of management strategies, particularly for transient-aggregating species.


2013 ◽  
Vol 64 (1) ◽  
pp. 31 ◽  
Author(s):  
W. M. Koster ◽  
D. R. Dawson ◽  
D. A. Crook

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.


2014 ◽  
Vol 56 (3) ◽  
pp. 121-134 ◽  
Author(s):  
Mehdi Heydari ◽  
Hassan Poorbabaei ◽  
Masoud Bazgir ◽  
Ali Salehi ◽  
Javad Eshaghirad

Abstract There has been observed widespread destruction of natural ecosystems around the world due to population growth, land use change and clear cutting which have affected soil properties. Different management strategies have been so far implemented to reduce this crisis in various regions of the world, such as e.g. short-term and long-term conservation management in the Zagros region. However, any management approach should be evaluated with appropriate measures to determine how managed areas respond. The main objective of the present study was to evaluate the potential of earthworms as an indicator for different forest management strategies and human disturbances in Zagros oak (Quercus persica Jaub. and Spach) forest. The sites selected included undisturbed one as the control (Un), the sites under five-year conservation management (FCM) and twenty-year conservation management (TCM) as well as the disturbed site (D). The results of principal component analysis (PCA) showed that different regions separated into the components: PC1 and PC2. Un and TCM sites gathered together and represented higher values of the factors such as pH, Kavailable, OC, clay content, Pavailable, CEC, overstory tree canopy, Ntot, biomass and abundance of earthworms. The positive direction of the first axis reflected a gradient of EC, BD and Ptot. According to the logistic model, NH4-N and EC played the most important role in earthworm presence and absence in Zagros forest ecosystem. Earthworm abundance and biomass could be a good indicator to evaluate different forest management strategies in the study area.


2018 ◽  
Author(s):  
Carla Isobel Elliff

Coral reefs provide important ecosystem services to coastal communities. The Archipelago of Tinhar?e andBoipeba, Bahia, Brazil, are mostly surrounded by fringing reefs, which have undergone several chronichuman impacts. The objective of the present study was to apply an ecosystem-based approach byanalyzing the ecosystem services provided by the coral reefs of the Archipelago of Tinhar?e and Boipeba inorder to support management actions and serve as a tool for coastal management. Ecosystem serviceswere assessed through the observation of environmental indicators of their occurrence and by using asuite of models from the Integrated Valuation of Environmental Services and Tradeoffs (InVEST) softwarecombined with data from the Atlantic and Gulf Rapid Reef Assessment (AGRRA) protocol database. Theservices of greatest occurrence were food provision, habitat maintenance, shoreline protection andrecreation. While the main stressful factors were tourism activities, the absence of a sewage system andfisheries. The coral reefs presented potential for shoreline protection along 50.5% of the islands. Moreover,46.8% of the shoreline would present moderate to high vulnerability in case of coral reef disappearance.The coincidence of areas with high risk of loss in the capacity to provide services and highvulnerability in the scenario of absence of reefs is concerning. Thus, the current model for tourism usedin the area should be altered, as should new management strategies be implemented, which can bringbenefits and avoid reef decline.


2018 ◽  
Vol 54 (3) ◽  
pp. 339-367 ◽  
Author(s):  
Andrew Kwok

This descriptive, mixed methods study of one interim certification program explores first year urban teachers’ classroom management actions. This study investigates what strategies teachers implement to manage the classroom from programmatic surveys of 87 first-year teachers and interviews, field visits, video recordings, and journals of five case participants. Results indicate that teachers used behavioral, academic, and relational strategies to manage the classroom and they tend to refine several of these actions over time. Findings suggest that teacher preparation should promote beginning teachers to implement a range of classroom management strategies and support teachers in how to refine their actions.


2020 ◽  
Author(s):  
Jacopo Cerri ◽  
Ernesto Azzurro

Aquatic Invasive species (AIS) are a growing driver of change across marine and freshwater ecosystems but spatially-explicit information is seldom available for supporting management actions and decision making. Here we conceived and tested a new participatory method to map the distribution of three invasive species (Callinectes sapidus, Procambarus clarkii and Oreochromis niloticus) in the coastal lagoon of Lesina (Italy). Local fishers were asked to draw the distribution of each species on pre-printed maps, indicating districts of the lagoon characterized by different abundance levels. Then, maps were converted to a lattice grid and a Bayesian hierarchical Generalized Additive Modeling was adopted to model species distribution in the lagoon, calculating the coefficient of variation for model fitted values to map fishers agreement about the distribution of each species.The spatial gradient in the abundance of the three species in the lagoon aligned with their ecological requirements. C. sapidus was abundant throughout the whole lagoon, peaking in correspondence of saltmarsh vegetation, while P. clarkii and O. niloticus, were much less abundant and remained distributed near to freshwater inputs. Experts agreed about the spatial distribution of C. sapidus in the lagoon, with a median coefficient of variation in model fitted values of 3.9%. On the other hand, the coefficient of variation was higher for P.clarkii (19.9%) O. niloticus (18.4%), indicating a higher level of uncertainty about their estimated distribution.With this example, we provided new metrics to evaluate the quality of LEK-based participatory mapping in terms of agreement and consistency among experts. The resulting information provides new insights for spatially informed management across aquatic realms in relation to the increasing ecological and socio-economical pressures posed by biological invaders.


Sign in / Sign up

Export Citation Format

Share Document