Population Structure Of The Patagonian Toothfish, Dissostichus Eleginoides, In Australian Waters
Funder
Fisheries Research and Development Corporation
Funding Amount
$71,219.00
Summary
Resolution of stock structure of toothfish in Australian and other waters is required. Tagging experiments, while important, cannot by themselves give a complete picture of stock structure. If genetic differences between areas are detected, then the amount of gene flow between areas must be minimal and more than one stock can be assumed. However, if differences are not detected, then the hypothesis of a single genetic stock cannot be rejected. This hypothesis may be rejected if there is no evide ....Resolution of stock structure of toothfish in Australian and other waters is required. Tagging experiments, while important, cannot by themselves give a complete picture of stock structure. If genetic differences between areas are detected, then the amount of gene flow between areas must be minimal and more than one stock can be assumed. However, if differences are not detected, then the hypothesis of a single genetic stock cannot be rejected. This hypothesis may be rejected if there is no evidence from tagging experiments of fish movement between areas. Therefore, resolution of stock structure is better managed by a combination of tagging and genetic approaches than by either approach alone. Tagging experiments are under way; we propose to carry out the required genetic analyses, and then consider both sets of data jointly to define likely stock structures.
Genetic evidence already collected (based on small sample sizes from two areas of Macquarie), suggests that the amount of movement between fishing locations might be very limited. If this preliminary conclusion is substantiated by larger sample sizes, then careful management of the fishery will be needed, as depletion of one area is unlikely to be quickly replaced by immigration from another area.
The work proposed here will resolve this issue for Macquarie island, and will also determine whether there are separable substocks of toothfish around HIMI, and whether the HIMI stock(s) are separable from the Macquarie island stock(s). Importantly, if William's Ridge fish are identified as part of a straddling stock extending into Australia's EEZ (Heard Island), then they can be managed as though wholly part of Australia's EEZ (recent UNIA agreement).
These issues have to be resolved for effective and sustainable management of toothfish fisheries by Australian management (AFMA). The information gathered will also be relevant to the management authorities of other nations controlling toothfish fisheries.
Note: Recent meetings of CCAMLR (1998, 1999) have recognised the urgent requirement of further work on stock structure in D. eleginoides , particularly as initial genetic studies in other laboratories using isolectric focussing and allozyme analysis have reported inconsistent results (see Box 1 below). Objectives: 1. To use microsatellite variation to resolve the genetic connectivity of different spatial and temporal toothfish samples collected from Macquarie Island and Heard, McDonald Islands. 2. To compare genetic and tagging data from Macquarie and Heard, McDonald regions to maximise toothfish stock structure knowledge in these regions. 3. To report on the outputs from the research and the resultant management response. Read moreRead less
Mobility Shocks: Understanding disruptions to Australian migration. This Fellowship aims to generate new knowledge about the impacts of the Covid-19 pandemic on human migration and mobility, in order to advance understanding of major disruptive changes to population movement more broadly. Fellowship outcomes will include designing innovative geospatial research methods, linking and analysing cutting-edge datasets, and building cross-sector collaborations, in order to develop a new theory of ‘Mob ....Mobility Shocks: Understanding disruptions to Australian migration. This Fellowship aims to generate new knowledge about the impacts of the Covid-19 pandemic on human migration and mobility, in order to advance understanding of major disruptive changes to population movement more broadly. Fellowship outcomes will include designing innovative geospatial research methods, linking and analysing cutting-edge datasets, and building cross-sector collaborations, in order to develop a new theory of ‘Mobility Shocks’. This will benefit Australia and its migration partners with new ideas, tools, evidence and expertise to help scholars, policy makers and practitioners to understand, anticipate, and manage future disruptive changes to human migration and mobility in the Australian context and beyond.Read moreRead less
A Study Of The Movement And Behaviour Of The Sand Crab (Portunus Pelagicus) Using Ultrasonic Tags
Funder
Fisheries Research and Development Corporation
Summary
Objectives: 1. Develop ultrasonic tags suitable for tracking & monitoring behaviour of sand crabs. 2. Develop simple methods of tracking tagged free-ranging crabs in Moreton Bay. 3. Obtain positional & Behavioural information over 24-hour periods to map movement of individual crabs
The Origin Of Recruits To The East Coast Yellowfin Tuna Fishery And The Delineation Of The Structure Of Yellowfin Stocks In The Western Pacific
Funder
Fisheries Research and Development Corporation
Funding Amount
$549,631.19
Summary
Objectives: 1. To develop the use of microsatellites for the genetic analysis of yellowfin tuna 2. To determine the genetic relationships of yellowfin tuna form the Coral Sea To those from the east coat of Australia and to those from other Western Pacific fisheries 3. To develop techniques for estimation of oxygen 18/16 isotopic ratios in otoliths using SIMS microprobe 4. Using analysis of otolith chemistry and isotopic ratios examine the hypothesis that all recruits to th ....Objectives: 1. To develop the use of microsatellites for the genetic analysis of yellowfin tuna 2. To determine the genetic relationships of yellowfin tuna form the Coral Sea To those from the east coat of Australia and to those from other Western Pacific fisheries 3. To develop techniques for estimation of oxygen 18/16 isotopic ratios in otoliths using SIMS microprobe 4. Using analysis of otolith chemistry and isotopic ratios examine the hypothesis that all recruits to the ECTUNA fishery are derived from spawning grounds in the Coral Sea 5. In the event of rejection of the null hypothesis that there is a single panmictic WP stock, use otolith chemical data collected from yellowfin collected throughout WP to estimate the proportion of immigrant recruits and determine their most likely origin Read moreRead less
Assessment Of Juvenile Eel Resources In South-east Australia
Funder
Fisheries Research and Development Corporation
Funding Amount
$279,545.00
Summary
Objectives: 1. To characterise and qualitatively assess A. australis glass eel migration into coastal catchments of southern NSW, Victoria and Tasmania for the purpose of investigating potential for commercial exploitation of glass eels on an ecologically sustainable basis. 2. To adapt intensive/semi-intensive, pond/tank culture technology for the purpose of enhancing survival and viability of translocated juvenile eels, including glass eels, to be used in restocking/extensive producti ....Objectives: 1. To characterise and qualitatively assess A. australis glass eel migration into coastal catchments of southern NSW, Victoria and Tasmania for the purpose of investigating potential for commercial exploitation of glass eels on an ecologically sustainable basis. 2. To adapt intensive/semi-intensive, pond/tank culture technology for the purpose of enhancing survival and viability of translocated juvenile eels, including glass eels, to be used in restocking/extensive production and/or intensive production to market size. Read moreRead less
Assessment Of The Impacts Of Hydro-electric Dams On Eel Stocks In Tasmania And An Evaluation And Assessment Of Mitigation Strategies
Funder
Fisheries Research and Development Corporation
Funding Amount
$282,684.00
Summary
Stock enhancement strategies can be a cost-effective means of restoring or maintaining fisheries, and have proven essential in catchments with barriers to migration (Knights and White 1998). Regulation of natural river systems has obstructed eel migration in many catchments, and with the implementation of appropriate management tools such as fish passes / ladders and translocation through trapping / netting programs, restoration of stocks can be achieved. Such strategies have not only proven s ....Stock enhancement strategies can be a cost-effective means of restoring or maintaining fisheries, and have proven essential in catchments with barriers to migration (Knights and White 1998). Regulation of natural river systems has obstructed eel migration in many catchments, and with the implementation of appropriate management tools such as fish passes / ladders and translocation through trapping / netting programs, restoration of stocks can be achieved. Such strategies have not only proven successful in increasing commercial fishery yields, but also contribute to enhanced spawning stocks and increased silver eel escapements.
Hydro electric operations (dams and power generating turbines) reduce the chance of successful emigration of silver eel, especially for larger female eel (Dekker 1999), and, depending on flow and turbine type and number, may represent a major source of mortality to pre-spawning adults (Ritter et al 1997).The design of downstream passage ways and the use of non-generating periods to reduce mortality have been trialled and implemented in New Zealand, the USA and Europe, but have yet to be adopted or investigated in Australia.
The sustainability of the eel resource in Tasmania and of existing (and potentially new) commercial eel fisheries in hydro-impounded catchments will ultimately depend on the implementation of appropriate and effective mitigation strategies (passage and/or translocations) specific to both upstream and downstream migrations.
This proposed program addresses the issue of sustainability by assessing both cause and effect of impacts and various mitigation options. It is envisaged that the results and recommendations arising from this proposed study will underpin the development of an integrated management strategy for managing eel fisheries in hydro-impacted catchments with direct benefits to managers and industry alike. Results from this study could be readily transferred to other States, with coordination and dissemination through the existing Australian and New Zealand Eel Reference Group (ANZERG).
REFERENCES
Dekker, W. 1999. Effects of Transfers and Restocking of Eel. Report of the EIFAC Working Group on Eels - Denmark, September 1999. Pp13-17.
Knights, B. and E. White, 1998. An appraisal of stocking strategies for the European eel, Anguilla anguilla - In Cowx, I.G. (ed): Stocking and Introduction of Fish. Fishing News Books. Pp 121-140.
Ritter, J.A., Stanfield, M. and Peterson, R.H. 1997. The American Eel in Eastern Canada - Stock Status and Management Strategies. Proceedings of Eel Workshop January 13-14 1997, Quebec City, QC. Can. Tech. Report 2196. 174p. Objectives: 1. To assess the impacts of hydro-electric dams on eel migrations and eel population structure in Tasmania’s lakes and rivers and to assess the impact of past elver restocking practices in hydro-impounded catchments on eel populations within those catchments. 2. To assess the direct impacts of hydro-electric dams and associated operations (turbine intakes and water management practices) on adult ‘silver’ eel survival rates during their downstream spawning migrations 3. To evaluate various management tools (ladders / bypasses and passage; netting / trapping and translocation) to mitigate impacts and provide recommendations for implementation. 4. To review the management of barriers to eel migration, including overseas experience. Read moreRead less
Transition to adulthood in greater Jakarta: A longitudinal perspective. Interviewing 3,000 young adult Indonesians at two points in time, this project examines whether their economic and social outcomes change across time or whether early experience determines longer-term outcomes. What are the factors involved in transition to adulthood among young people in a rapidly developing metropolis of a developing country?
Stock Structure Of Australian Populations Of Orange Roughy Using Microsatellite Analyses
Funder
Fisheries Research and Development Corporation
Funding Amount
$32,100.00
Summary
Despite the past studies, the question of the stock structure of Australian orange roughy remains unresolved. Broadly, the evidence supports the concept of somewhat localised stocks although with some inter-stock migration - it is really the extent of the migration that remains unknown.
Current management plans are largely based on the premise that southern Tasmanian fish are from a distinct stock from St Helens Hill fish, yet evidence in favour or opposing this proposition is weak. .... Despite the past studies, the question of the stock structure of Australian orange roughy remains unresolved. Broadly, the evidence supports the concept of somewhat localised stocks although with some inter-stock migration - it is really the extent of the migration that remains unknown.
Current management plans are largely based on the premise that southern Tasmanian fish are from a distinct stock from St Helens Hill fish, yet evidence in favour or opposing this proposition is weak.
We propose here an analysis of the stock structure of Australian orange roughy based on the examination of DNA microsatellites. DNA microsatellites will enable a more powerful analysis of genetic stock structure than has hitherto been possible. The study will focus on the relationships of fish from eastern Australia (New South Wales, St Helens Hill, southern Tasmania) but will also examine samples from the Tasman Sea (in particular Lord Howe Rise), New Zealand, and, as a presumably reproductively isolated population, the North Atlantic. Objectives: 1. To develop DNA microsatellite genetic markers for orange roughy 2. To use these markers to delineate stocks of orange roughy from Australian waters 3. To use these markers to compare Australian samples with New Zealand samples. 4. To use these markers to compare North Atlantic samples with Australasian samples Read moreRead less
Adult Migration, Population Replenishment And Geographic Structure For Snapper In South Australia
Funder
Fisheries Research and Development Corporation
Funding Amount
$109,089.00
Summary
Management of the snapper fishery of South Australia has recently attained a level of heightened political sensitivity, reflecting the need to optimise the strategic approach. Nevertheless, from relevant discussions it is apparent that our understanding of the life-history is too poor to predict likely outcomes from suggested regional management strategies.
For this snapper fishery there is a need to optimise management based on a better understanding of the life-history and population ....Management of the snapper fishery of South Australia has recently attained a level of heightened political sensitivity, reflecting the need to optimise the strategic approach. Nevertheless, from relevant discussions it is apparent that our understanding of the life-history is too poor to predict likely outcomes from suggested regional management strategies.
For this snapper fishery there is a need to optimise management based on a better understanding of the life-history and population biology, particularly with regard movement patterns of adult fish. It is currently unknown the extent to which fish move between different geographic regions, and thus the extent to which such behaviour contributes to the natural processes of sustaining the different regional populations. Such adult movement will determine the extent to which regional populations are independent, discrete, and separate sub-populations. Adult movement and stock structure are fundamental to identifying the appropriate spatial scale at which the population dynamics work, and thus the appropriate spatial scale at which fishery management should be applied.
Objectives: 1. to determine whether adult fish from Spencer Gulf, Gulf St. Vincent and other regions migrate to the continental shelf, and where such fish then migrate in order to spawn - do they return to their regions of origin or is subsequent movement determined by other exogenous factors ? 2. to determine the stock structure - does the South Australian snapper population constitute a single, large, inter-mixed population or is it divisible into numerous discrete sub-populations ? 3. to determine whether adult fish collected from particular regions originate as juveniles from those regions or whether they constitute a mixture from different regions. 4. to produce a final report that synthesises all information on snapper movement and stock structure in South Australia, including that from this study on otolith microchemistry with that from tagging studies and work on the analysis of genetics. Read moreRead less
Determination Of The Migration Patterns Of Juvenile Southern Bluefin Tuna And Jackass Morwong
Funder
Fisheries Research and Development Corporation
Summary
Objectives: 1. Determine whether or not all juvenile southern bluefin tuna migrate down coast of WA, hence whether Aust fishery based on all or part of each cohort. 2. Validate ageing techniques for adults. 3. Are bays & estuaries in southern Tasmania the sole nursery grounds of jackass morwong?