Egg distribution, reproductive parameters and spawning biomass of Blue Mackerel, Australian Sardine and Tailor off the East Coast during late winter and early spring
Knowledge of the winter/spring spawning patterns of Blue Mackerel and Australian Sardine is needed to underpin future assessment of these stocks and to underpin the ecologically sustainable development of pelagic fish resources off the East Coast of Australia.
Recent and robust estimates the population size of Blue Mackerel and Australian Sardine off the East Coast are needed to address community concerns regarding the potential ecological impacts of large scale fishing for small pelagic fishes off the East Coast.
Information on the egg distribution, reproductive parameters and spawning biomass of Tailor is needed to inform future management of this iconic recreational fishing species.
Final report
Improving the precision of estimates of egg production and spawning biomass obtained using the Daily Egg Production Method
Seafood CRC: optimising the size and quality of sardines through real-time harvest monitoring
Understanding the combined roles of fishing effort and environmental factors in determining the distribution and abundance of target-sized sardines is essential to the sustainable, ecological and economical, development of the fishery.
In response to recent fluctuations in fish size and quality, the SASF seeks to increase the productivity and profitability of the fishery through the development and implementation of an industry-led, real-time monitoring system for optimising the size, quality and quantity of sardines harvested.
To address these needs industry must: 1) establish the skills and systems required to conduct real-time monitoring of fish harvesting, 2) obtain advice on the key oceanographic factors affecting sardine size distributions, 3) gain ongoing access to information on oceanographic conditions in near real-time and, 4) develop systems for linking spatial fishery performance with oceanographic conditions to optimize the size and quality of fish harvested.
Final report
In order to improve the commercial profitability and sustainability of the South Australian Sardine Fishery (SASF) there was a need to establish improved monitoring and harvest management practices based on an understanding of Sardine habitat preferences. In this project, the South Australian Sardine Industry Association Inc. (SASIA) was empowered with the resources to autonomously implement near real-time monitoring of fish movement in relation to changes in environmental conditions. As a part of the harvest management optimisation, an understanding of the environmental conditions which characterise the habitat preferences of juvenile, adult and spawning Sardines was investigated.
This project was developed at the request of SASIA and comprises two inter-related components with the common objectives of improving the economic value and ecological sustainability of the fishery.
Firstly, the SASIA was assisted in developing and implementing an autonomous near real-time harvest management system. The system is composed of three inter-connected components; fish measurement, data storage and spatial mapping. SASIA collected data on fish length (caudal- fork length) are efficiently measured and stored directly into a database using an electronic fish measurement board. The database has been designed to store and present information related to the location and size of the commercial catch from which sample measures of fish length are collected. Finally, GIS spatial mapping software is linked with the database to provide maps showing the spatial distribution of target and non-target sized fish. Maps detailing changes in the spatial distribution of target and non-target size are updated fortnightly and used by the SASIA to optimise the size of fish harvested.
Secondly, to augment the adopted real-time harvest management system, habitat suitability studies using generalised additive models (GAMs) were undertaken to understand the environmental conditions that explain the habitat preferences of juvenile and adult Sardines, as well as the summer-time spawning habitat. Historical datasets used in the modelling studies included 1) Sardine egg densities and coincident oceanographic measurements made during Daily Egg Production Method (DEPM) surveys conducted since 2004, and 2) fish length measurements made by independent observers aboard commercial vessels since 2004 and corresponding satellite measures of sea surface temperature and surface chlorophyll a concentrations.
Summer spawning patterns and preliminary Daily Egg Production Method survey of Jack Mackerel and Sardine off the East Coast
Knowledge of the summer spawning patterns of Jack Mackerel and Australian Sardine is needed to underpin future assessment of these stocks and to underpin the ecologically sustainable development of pelagic fish resources off the East Coast of Australia.
Methods for estimating the population size of Jack Mackerel and Australian Sardine need be established to address community concerns regarding the potential ecological and social impacts of large scale fishing for small pelagic fishes off the East Coast.
Final report
This study was undertaken collaboratively by fisheries scientists from the South Australian Research and Development Institute (SARDI) and the University of Tasmania. It was the first dedicated application of the Daily Egg Production Method (DEPM) to Jack Mackerel, Trachurus declivis. It successfully collected large numbers of samples of eggs and adults concurrently from the key spawning area off eastern Australia during what has been previously identified as the main spawning period. The study established an effective method for sampling adult Jack Mackerel and provides the first estimates for this species of the adult reproductive parameters required for application of the DEPM. The spawning biomass of Jack Mackerel off eastern Australia during January 2014 was estimated to be approximately 157,805 t (95% CI = 59,570 358,731). Most of the estimates of spawning biomass obtained in sensitivity analyses were between approximately 95,000 t and 215,000 t. Plausible values for only two parameters provide estimates of spawning biomass that were outside that range; both of these parameters were estimated with a high degree of confidence in the present study.
This was also the first study to investigate the spawning habitat of Australian Sardine Sardinops sagax off eastern Australia during summer. It showed that during January 2014 spawning occurred between northern Tasmania and southern Victoria. The spawning biomass at this location during this period was approximately 10,962 t. This estimate should be treated with caution as adult samples were not collected during the study. It also is important to note that this not an estimate of the total adult biomass of Australian Sardine off eastern Australia. It is only an estimate of the portion of the population that was spawning in this southern part of the range during that period. The main spawning area of Australian Sardine off eastern Australia occurs off southern Queensland and northern NSW during late winter and early spring.
Keywords: Jack Mackerel, Trachurus declivis, Australian Sardine, Sardinops sagax, Daily Egg Production Method, Spawning Biomass, Small Pelagic Fishery, eastern Australia, Tasmania, Bass Strait.
Seafood CRC: successful sardines - post-harvest optimisation and new product development for human consumption
Sardines are an undervalued species in South Australia, with the majority of the catch going for tuna feed for an average price of $0.72/kg. The industry has recognised the need to increase the value of the fishery, and that more of the catch has to be turned into value-added products for human consumption. In order to achieve this aim, it has targeted to use at least 10% of the TACC for value-adding.
Three of the licence holders have invested in equipment and processes to produce value-added products. However, individually these businesses are having limited success, struggling to adopt the technical and operational practices that are required to deliver safe, profitable products for human consumption markets both domestically and abroad. This project will provide technical expertise and experimental support to assist them in optimising raw materials, labour and equipment and to develop new products specifically for these markets.
There has been limited success in value-adding sardine products for human consumption in sardine fisheries in Australia. As a result, research has focussed on increasing the value of sardines but has not resulted in products being successfully test marketed/commercialised and evaluated. This is perhaps due to a disconnect in the supply chain between consumers, markets, distribution and processing. We now have the consumer/market intelligence to understand the barriers to sardine acceptability. We can develop products that will overcome these barriers and with the businesses already supplying into the human consumption markets, we have an identified route to market to commercialise and evaluate the success of these new products.
The project offers the opportunity for the three businesses to work together to achieve more than could be individually. They will benefit from the economies of scale that business partnerships have to ultimately deliver safe, profitable products to market for human consumption.
Movement patterns and stock structure of Australian sardine (Sardinops sagax) off South Australia and the East Coast: implications for future stock assessment and management
This project is needed to assess the potential for increasing catches of sardine in the fisheries off SA (i.e. SASF) and the East Coast (i.e. NSW Ocean Haul Fishery and SPF).
For the SASF, information on the patterns and rates of movement of sardines between the Great Australian Bight (where the majority of the spawning biomass is located) and southern Spencer Gulf (where most fishing is conducted) is needed to determine whether (or not) future potential increases in the TAC should be accompanied by the establishment of zones within the fishery.
For the NSW Ocean Haul Fishery and SPF, information on the patterns and rates of movement of sardines along the East Coast is needed to assess the extent to which estimates of spawning biomass from northern NSW and southern Qld waters reflect the size of the entire sardine stock off eastern Australia.
Final report
Seafood CRC: improving quality of Australian Sardines through utilization of flow-ice technology
This project will contribute toward Seafood CRC Program 1B:
Output 1.7 "Smart processing technologies and practices"
Milestone 1.7.2
Application of innovative technologies for controlling spoilage to enhance shelf-life and marketability
Milestone 1.7.6
Harvest, post-harvest and processing practices evaluated and enhanced to maximise and protect quality attributes
Milestone 1.7.8.
Technology and capability to support innovation of new seafood products developed
This project fits into the CRC “smart processing” theme
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Global economic factors and market forces warrant the need for a significant portion of the SASF harvest to diversify from the domestic tuna feed market into higher value markets. This need is in part driven by the strength of the Australian dollar. Over the last 24 months the volume of relatively cheap imported feed has forced a significant decrease in the beach price of locally caught sardines, necessary so local catch can maintain market share. The strength of the dollar is forecast to remain high.
The South Australian Sardine Industry needs to diversify its market base and increase the portion of the annual catch that is value-added to offset the issues described above, and the associated risks of sustained low returns.
The marketability of South Australian sardines is negatively affected by high volume of the nightly catch and the limited capacity of most sardine vessels to adequately chill fish on board. There is a need to trial technology that will remove heat from fish immediately postharvest more efficiently than current practices. This will reduce spoilage and extend the shelf-life for value-added grade fish.
The implementation of post-harvest technologies such as flow-ice at the point of capture will assist the production of a higher quality product which, in turn, should increase the GVP of the SASF.
Final report
This project assessed the utility of flow-ice in preserving the freshness of Australian Sardines from the point of harvest to processing, and wholesale and retail supply chains. Trials were carried out on the Gemma Marie (White Fisheries) based at Port Lincoln, South Australia. Experiments involved comparisons between flow ice (FI), ice slurry (IS) and refrigerated seawater (RSW) at a fish:cooling medium ratio of 1:1. Core temperatures were recorded from fish stored in FI and IS for up to two days; with associated shelf-life trials running up to six days. Fish were also sent to markets (SAFCOL, Angelakis and Cappo Bros in Adelaide, and Sydney Fish Market) for appraisal and sale.
The data collected indicated the greater cooling effectiveness of flow ice and its beneficial effect on fish quality (through lower Quality Index Method (QIM) scores). Sardines in FI reached 2°C after approximately nine minutes and O°C within 11 minutes. Fish in IS took 30 minutes to reach 2°C and few cooled beyond this point. All batches of fish chilled with FI that were sent to market as part of this study were better than average, and, in one case, the best they had seen in a long time. However, there was no difference in price between sardines chilled in flow ice and those chilled in ice slurry. The study was terminated due to persistent mechanical failures of the leased flow ice machine. Thus, further work is necessary to explore the potential of flow ice, particularly at higher fish:cooling medium ratios. It may be that auction market price is not the best indicator of product quality and it is therefore suggested that QIM and other tests such as further storage, and filleting and cooking trials be carried out using sardines treated with the technology.
Effects of environmental variability on recruitment to fisheries in South Australia
Fisheries recruitment is generally variable and seldom related to spawning stock size, except in the case of salmonid fishes. Environmental variability has a large effect on recruitment that can be stronger than the effect of stock size. It is difficult to understand whether fishing pressure is affecting stock sizes unless we have some understanding of how the environment affects the populations of exploited species. While the environment is known to significantly affect recruitment, the relationship is complex and multivariate. To gain insight into the relationship, we need to assemble a range of environmental variables for appropriate statistical analyses. These data are often scattered, and have varying spatial and temporal resolutions and quality. An important step along the way to elucidating relationships between environment and recruitment is to compile the datasets into a form that can be spatially matched, appropriately averaged and statistically scaled to extract the environmental signal from the background noise that could otherwise obscure a relationship with recruitment.
If environmental indices are related to fisheries recruitment of specific species (e.g. marine scale fish, rock lobsters and prawns) then management can use the indices (1) to understand the physical processes that account for variability in recruitment and fishery productivity, (2) possibly predict recruitment a year or two in advance, and (3) to speculate about the effects of global warming on our fisheries.
Pearce et al. (FRDC 94/032) compiled time series of environmental variables in Western Australia, and found that variations in the strength and path of the Leeuwin Current affected mainly the larval stages of commercial species. The magnitude and sign (positive or negative) of the effect differed by species. We will build on this study, incorporating some of their recommendations, to gain insight into the processes affecting recruitment.
Final report
Establishing ecosystem-based management for the South Australian sardine fishery: developing ecological performance indicators and reference points to assess the need for ecological allocations
Provisions of the Commonwealth Environment and Biodiversity Conservation Act require strategic assessment and, if necessary, mitigation of the ecological effects of fishing, including trophic impacts.
The strategic assessment of the South Australian pilchard fishery identified the need to measure and minimize the impacts of the fishery
on the “broader ecosystem” and “to review the current ecological management objectives, management strategies and performance indicators”.
However, operational ecological performance indicators and mitigating strategies have not yet been established for any pelagic fishery in Australia, and there is no agreed scientific framework for establishing these tools.
In recognition of -
1) the high profile of the SA pilchard fishery (as Australia’s largest pelagic fishery);
2) the important ecological role of pilchards in the Flinders Current Ecosystem;
3) the high economic value and conservation significance of the region’s marine predators;
4) and the sophisticated (single-species) stock assessment procedures and management arrangements that have been established,
members of the South Australian pilchard fishery have identified the need to establish “world’s best practices” for managing the potential ecological impacts of the fishery. In response to this need, fishers have invested $620K to assess the role of pilchards in the Flinders Current Ecosystem and to begin to develop ecological performance indicators and reference points for their fishery.
Currently, there is no scientific framework to assess whether the management arrangements that have been established for the SA Pilchard Fishery are sufficiently conservative to ensure that fishery is managed according to the principles of ESD (i.e. that fishing does not significantly affect the status of other components of the ecosystem, Fletcher et al. 2002).
In recognition of the large data sets and extended timeframes that are needed to establish and assess ecological performance indicators and reference points for pelagic fisheries, members of the South Australian pilchard fishery have also agreed to invest a further $310K (cash) to support the additional ecological research that is outlined in this proposal.
This project addresses the pressing need to develop a scientific framework for establishing ecological performance indicators and reference points for pelagic fisheries. The focus on the SA pilchard fishery is necessary, as such a large and complex undertaking could only be contemplated in large and valuable fishery that has sophisticated stock assessment procedures and management arrangements in place, and can thus afford to allocate significant resources to support the establishment of an ecosystem-based management system.
This project is needed to refine the management plan for Australia’s largest fishery to include ecological perfomance indicators and reference points and to ensure that research and management systems for the fishery correspond with, or exceed, world’s best practice by incorporating scientifically-based approaches for assessing and, if necessary, mitigating, the fishery's potential trophic impacts.
Projects such as this are needed to maintain Australia’s position as the world leader in the ecosystem-based management of fisheries.