PROJECT NUMBER
•
2019-014
PROJECT STATUS:
CURRENT
ORGANISATION:
University of Adelaide
7 results
Improving the precision of estimates of egg production and spawning biomass obtained using the Daily Egg Production Method
Project number:
2014-026
Project Status:
Completed
Budget expenditure:
$200,000.00
Principal Investigator:
Timothy M. Ward
Organisation:
SARDI Food Safety and Innovation
Project start/end date:
11 May 2014
-
9 Jan 2016
Contact:
FRDC
SPECIES
A project to refine methods for estimating egg production in application of the DEPM is needed because:
1) spawning biomass estimates obtained using the DEPM are the key biological performance indicators in the SASF and SPF;
2) the DEPM is recognized as being imprecise and the main source of this imprecision is associated with estimation of mean daily egg production;
3) a range of field and statistical methods are used to estimate total daily egg production but there is no consensus about which approach is most appropriate for the range of circumstances that are encountered, with different methods currently used in the Americas, Europe and Australia.
Uncertainty in the method used to estimate the spawning biomass of Jack Mackerel off the east coast of Australia was raised as an issue of particular concern in the recent public debate associated with the introduction of a large factory trawler into the SPF.
That debate undermined public confidence in the stock assessment and management of the SPF and has the potential to undermine other fisheries species of small pelagic fishes.
1. Compare the performance of current and developmental statistical methods for estimating egg production using long-term datasets for several species
2. Conduct simulations to formally evaluate the performance of different approaches to sampling and statistical analysis on estimates of egg production
3. Establish improved methods for estimating daily egg production in applications of the DEPM
Final report
ISBN:
978-1-876007-07-2
Authors:
T.M. Ward
J. Carroll
G.L. Grammer
C. James
R. McGarvey
J. Smart
A. Ivey
Final Report
•
2018-02-22
•
6.96 MB
2014-026-DLD.pdf
This project was undertaken to refine the application of the Daily Egg Production Method to Australia’s largest fishery, the South Australian Sardine Fishery and the Commonwealth Small Pelagic Fishery. Key findings and outcomes from this study include: 1) a new generalised egg staging method that has several advantages over previous egg staging systems; 2) refinements to methods used to identify samples where a zero count should be allocated to one or more egg cohorts; 3) identification of factors that cause the high levels of uncertainty associated with estimates of mean daily egg production (P0) and egg mortality (z); 4) confirmation that the log-linear model is the most precise method currently available for estimating P0 and z for Australian Sardine off South Australia; 5) a simulation model that can be used to evaluate the effects of key processes on the precision of estimates of P0 and z; and 6) recommendations to trial a new oblique plankton sampler that may improve the precision of future estimates of P0. These findings and outcomes will improve the ongoing application of the Daily Egg Production Method to small pelagic species as well as other species to which the method is being applied.
Small Pelagics Research Co-ordination Program
Project number:
2013-064
Project Status:
Completed
Budget expenditure:
$81,800.00
Principal Investigator:
Colin Buxton
Organisation:
Colin Buxton and Associates
Project start/end date:
31 Jan 2014
-
27 Feb 2015
Contact:
FRDC
Several scientific studies have recently examined the effects of fisheries on small pelagic species (also sometimes called forage fish) and how they should be managed so as to avoid undesirable flow-on effects of these fisheries on the food web and ecosystem. There is now clear and widely agreed understanding about how these fisheries should be managed, and this understanding has a strong scientific basis (e.g. Smith et al. 2011). The latest and most comprehensive study and guidance comes from the Lenfest Forage Fish Task Force (Pikitch et al. 2012).
Although methods used to set the TAC in the SPF were consistent with this scientific advice, recent attempts to introduce a factory trawler into the fishery were met with intense public resistance. Much of the concern related to perceived risks of localised depletion and the impact that this would have on fisheries for predator species (eg SBT). Thus the interaction between commercial fisheries for small pelagics and commercial and/or recreational fisheries that target predators is pertinent.
There was also considerable debate over the stock status and assessment method (Daily Egg Production Method – DEPM). This highlighted a significant level of distrust in the science and management of small pelagics, something that is likely to continue unless a concerted effort is made to increase our understanding of small pelagic fisheries and to better communicate this knowledge to the community and other stakeholders.
The aim of this project is to build confidence in the science underpinning the sustainability of small pelagic fisheries in Australia.
Pikitch, E., et al. (2012) Little Fish, Big Impact: Managing a Crucial Link in Ocean Food Webs. Lenfest Ocean Program. Washington, DC. 108 pp. http://www.oceanconservationscience.org/foragefish/
Smith, A.D.M., et al. (2011) Impacts of fishing low-trophic level species on marine ecosystems. Science, 333: 1147-1150
1. To administer and co-ordinate the activities of FRDC funded small pelagics (SP) research
2. To review project proposals to ensure stakeholder relevance
3. To review milestone reports and final reports
4. To facilitate and chair meetings of the SP Technical Committee
5. To ensure appropriate liaison between beneficiaries and research providers
6. To provide advice to FRDC, DAFF, AFMA and other stakeholders on SP research
7. To communicate findings of SP research through: a) Research meetings (possibly held in conjunction with a major conference such as ASFB or Seafood Directions) b) Specialist workshops aimed at stakeholders on topics identified through the course of the program
and c) Relevant articles in the media and Fish magazine
Final report
Author:
Colin David Buxton
Review and update harvest strategy settings for the Commonwealth small pelagic fishery
Project number:
2013-028
Project Status:
Completed
Budget expenditure:
$122,741.00
Principal Investigator:
Tony D. Smith
Organisation:
CSIRO Oceans and Atmosphere Hobart
Project start/end date:
31 Jul 2013
-
28 Jul 2014
Contact:
FRDC
SPECIES
The SPF has been the focus of considerable stakeholder scrutiny in 2012. Part of this focus has been on the harvest strategy, which has been in place since 2009. Two questions have arisen about the current harvest strategy: 1) What reference points for exploitation rates are appropriate for the species exploited in this fishery, taking into account their ecological role in the food chain? 2) Is the maximum exploitation rate specified in the strategy appropriate for all the target species, given their different productivities, life histories and trophic importance? Questions have also been raised about the possibility and impacts of localised depletion in this fishery, but these will not be dealt with in this proposal.
There is an urgent need to review and if necessary update the harvest strategy settings for the SPF. Specifically, there is a need to answer the two questions outlined above, both of which involve settings in the current harvest strategy. One concerns appropriate choice of target (and limit) reference points, while the other concerns selecting individual harvest rates for each of the target species in the fishery, appropriate to its life history and productivity.
Notwithstanding that the vessel which caused the high level of scrutiny on the fishery has departed Australian waters, answering the two questions remains fundamental to proper implementation of the Commonwealth Harvest Strategy Policy for this fishery. The need for a review of the harvest strategy settings had been flagged by SPF RAG ahead of the contorversy with the "super trawler".
1. Provide advice on best practice reference points for the four main target species in the SPF
2. Provide advice on suitable exploitation rates to achieve management targets for the four main target species in the SPF
Final report
ISBN:
978-1-4863-0513-1
Authors:
Anthony D.M. Smith
T.M. Ward
F. Hurtado
N. Klaer
E. Fulton
A.E. Punt
Final Report
•
2015-01-30
•
3.63 MB
2013-028-DLD.pdf
This study undertook ecosystem and population modelling to evaluate and provide advice on the reference points (e.g. biomass depletion levels) and settings (e.g. exploitation rates) for the four main target species in the harvest strategy of the Commonwealth Small Pelagic Fishery (SPF) – Jack Mackerel, Trachurus declivis, Redbait Emmelichthys nitidus, Blue Mackerel Scomber australasicus and Australian Sardine Sardinops sagax.
The study used a new variant of the Atlantis ecosystem model (Atlantis-SPF). The model found that both singly and in combination, depleting these target species has only minor impacts on other parts of the ecosystem. Unlike some other regions which show higher levels of dependence on similar species, such as in Peru and the Benguela systems (Smith et al., 2011), the food web in southern and eastern Australia does not appear to be highly dependent on SPF target species. None of the key higher trophic level predators in SE Australia, such as seals, penguins and tunas, have a high dietary dependence on these species. Studies using other ecosystem models such as Ecosim in the same region have reached similar conclusions (Goldsworthy et al., 2013; Bulman et al., 2011).
The findings have implications for the target and limit reference points that should be selected for the main commercial species in the SPF. Equilibrium BMSY for these species ranged from about 30 to 35% of unfished levels. However, these levels are uncertain and it may be more appropriate to use the default values from the HSP with BMSY set at B40 (40% of unfished levels) and the default BMEY set at 1.2 times this level, close to B50. This study suggests that the target reference point for these SPF target species should be set at B50 and the limit reference point at B20, in line with the HSP default settings. The results presented in this report, combined with evidence from other studies, suggest that these levels are safe from an ecosystem perspective and provide reasonable levels of yield relative to MSY.
Population modelling suggests that target exploitation rates (ERs) for the SPF should be species-specific and possibly even stock-specific. The current average Tier 1 harvest rate of 15% appears to be too high for eastern Redbait. Taking account of some of the sensitivity scenarios, the report states that it may also be too high for western Redbait and Jack Mackerel.
The results help inform the choice of suitable ERs for each of the species and stocks. For Tier 1, the analyses focus on achieving the reference points recommended by the ecosystem modelling, that it is to achieve a median depletion of 0.5 or B50, while maintaining less than a 10% chance of falling below the suggested limit reference point of B20. The base case exploitation rates that achieve this target, assuming surveys every five years, are as follows:
- Eastern Redbait 9%
- Western Redbait 10%
- Jack Mackerel 12%
- Eastern Blue Mackerel 23%
- Western Blue Mackerel 23%
- Eastern Sardine 33%
- Western Sardine 33%
In the current harvest strategy Tier 2 rates are set at half the Tier 1 rate. It was assumed that the Tier 2 rate would only be applied after 5 years of exploitation at Tier 1, and that no further surveys would take place. The report summises that it is generally not safe to apply Tier 2 for long periods of time unchecked. Particularly for the shorter lived species (Blue Mackerel and Sardine), this can result in unacceptable probabilities of depletion in quite short periods of time (5 or 6 years), while the period is on the order of 20 years for the other two species. The study found that an alternative approach would be to make the Tier 2 rate more precautionary (i.e. less than half the Tier 1 rate) and/or reduce the period over which it is applied (e.g. not more than 5 years).
Tactical Research Fund: Management Strategy Evaluation (MSE) of the harvest strategy for the Small Pelagic Fishery
Project number:
2008-064
Project Status:
Completed
Budget expenditure:
$85,897.00
Principal Investigator:
Patty Hobsbawn
Organisation:
Department of Agriculture, Fisheries and Forestry (DAFF) ABARES
Project start/end date:
30 Nov 2008
-
30 Mar 2009
Contact:
FRDC
SPECIES
Commonwealth fisheries have been required to implement harvest strategies in accordance with the recently released Commonwealth Harvest Strategy Policy. The policy specifically requires that a MSE be conducted to demonstrate that each harvest strategy is robust to the uncertainty inherent in the assessment and management of the respective fishery.
In June 2008, the AFMA Board approved a harvest strategy for the SPF, which will be reviewed during 2008/09. In 2007, the SPFRAG and SPFMAC engaged a consultant to review the draft harvest strategy that had been developed for the fishery. Based on the outcomes of that review, which included a quantitative evaluation, SPFRAG and SPFMAC agreed to a harvest strategy. During 2008/09, further testing of the harvest strategy will be undertaken and various scenarios investigated. There is an urgent need to investigate the robustness of the harvest strategy under a range of harvest scenarios and to determine the implications of these harvest scenarios on the wider trophodynamic relationships (through linkages with the CSIRO project). The proposed project will develop an interactive tool that SPFRAG and SPFMAC can use to explore the robustness of the harvest strategy now and in the future.
1. Develop and implement an appropriate MSE to aid the review of the SPF harvest strategy
2. Use the MSE to investigate the harvest strategy’s performance under a range of plausible scenarios
3. Develop a research plan, including indicative costs, to collect the data required for the harvest strategy (all Tiers) to meet its objectives
Final report
ISBN:
978-1-921192-50-0
Authors:
F. Giannini
P.I. Hobsbawn
G.A. Begg and M. Chambers
Final Report
•
2010-05-04
•
1.80 MB
2008-064-DLD.pdf
In 2008, the Australian Fisheries Management Authority (AFMA) developed a harvest strategy for the Commonwealth’s Small Pelagic Fishery (SPF) (AFMA 2008) in accordance with the Commonwealth Fisheries Harvest Strategy Policy (DAFF 2007). Before its completion, an independent review was conducted (Knuckey et al. 2008), which included a management strategy evaluation (MSE). The equations developed for the MSE were used in this report to establish a new MSE. The new MSE was used to further test the SPF Harvest Strategy and to investigate a range of alternative harvest strategies for consideration by the Small Pelagic Fisheries Resource Assessment Group (SPFRAG).
In this report, the sensitivities of the MSE were tested to determine how the various input parameters influenced the outcomes over a 30 year simulation period. A number of management/harvest scenarios were run through the MSE to explore options addressed in the SPF Harvest Strategy for each stock — redbait (east), redbait (west), blue mackerel (east), blue mackerel (west), jack mackerel (east and west treated the same) and Australian sardine (east). Themodel was found to be most sensitive to the steepness value in the stock recruitment relationship and to the value of the instantaneous natural mortality.
Aquafin CRC - SBT Aquaculture Subprogram: nutritional profiles of baitfish 3: effects of harvest and post-harvest processes on quality of local baitfish for feeding SBT
Project number:
2004-211
Project Status:
Completed
Budget expenditure:
$305,109.00
Principal Investigator:
John Carragher
Organisation:
SARDI Food Safety and Innovation
Project start/end date:
30 May 2005
-
1 Oct 2007
Contact:
FRDC
SPECIES
Evaluation of egg production as a method of estimating spawning biomass of redbait off the east coast of Tasmania
Project number:
2004-039
Project Status:
Completed
Budget expenditure:
$398,417.47
Principal Investigator:
Jeremy Lyle
Organisation:
University of Tasmania (UTAS)
Project start/end date:
30 Aug 2004
-
24 Apr 2008
Contact:
FRDC
SPECIES
Redbait are an important component of the pelagic ecosystem, being a major consumer of zooplankton and a prey species for predators such as tunas, birds and mammals. The introduction of large-scale mid-water trawl operations (2001) to target small pelagics in Zone A of the Small Pelagic Fishery has produced catches of redbait that have no precedent locally and there is real potential for further rapid expansion. Little information is available on the biology or population dynamics of redbait, and there are no assessments of stock size on which to base TACs, currently set at 34,000t (combined species, including management triggers).
The development of a method for estimating redbait biomass is urgently required to support the setting of scientifically defensible TACs. Fishery-dependent methods of assessing fish stocks are generally unsuitable for small pelagic species due to their schooling behaviour and targeted nature of the fishing operations. Furthermore, due to the very recent development of mid-water trawling targeting redbait, no time series of data are available to detect changes in redbait stocks off Tasmania. The daily egg production method (DEPM) has been applied successfully for biomass estimation of a variety of small pelagic species, and is deemed suitable for estimating redbait biomass. There are advantages in generating biomass estimates as early as possible in the development of this fishery, if fishery impacts are to be detected and managed.
FRDC has supported the evaluation of DEPM for blue mackerel (Project 2002/061), a species that co-occurs with redbait. There are considerable efficiencies in establishing linkages with this project in terms of research focus, expertise and resources. However, as redbait have a different spawning season to blue mackerel, the timing of blue mackerel egg surveys are not appropriate and therefore additional research is required to evaluate the feasibility of using DEPM for redbait.
1. To estimate the critical reproductive parameters for redbait along the east coast of Tasmania, particularly spawning fraction and batch fecundity.
2. To develop and validate methods for identifying and staging the eggs and larvae of redbait.
3. To estimate the location and extent of spawning areas of redbait on the east coast of Tasmania, including a quantification of the levels of egg production of this species.
4. To evaluate the use of the daily egg production method for estimating the spawning biomass of redbait on the east coast of Tasmania.
5. To produce a minimum biomass estimate of redbait in the ZASPF.
Final report
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