Abundance, population modelling, and potential biological removal estimates for Common Dolphins in Spencer Gulf: implications for the South Australian Sardine Fishery
This project is needed to assess the impacts of the South Australian Sardine Fishery (SASF) on the common dolphin (Delphinus delphis). The SASF is Australia’s largest volume fishery and is critical to providing a supply of feed for the ranching of southern bluefin tuna. Operational interactions between common dolphins and the SASF have been persistent since the development of the fishery. Common dolphins occasionally become encircled in purse seine nets during fishing operations, which can lead to their injury and death. Observations of high interaction rates from an initial observer program, led to the temporary closure of the fishery in 2005 while an industry Code of Practice (CoP) to reduce dolphin interactions was developed. Since then, the CoP has been reviewed and refined to increase its effectiveness in preventing dolphin interactions, and improve release procedures. An independent on-board observer program has operated in the fishery since July 2006. It collects information on dolphin interaction and mortality rates, as well as data relating to the application of the CoP, and this information is provided in annual assessment reports. Since the introduction of the CoP, dolphin encirclement and mortality rates have declined, however, concerns about the level of interactions and mortality have persisted, with industry facing sustained pressure to demonstrate that steps taken to manage and mitigate dolphin interactions represent World’s best practice, and are sustainable.
This project is needed to address Marine Stewardship Council Fishery Assessment recommendations for the SASF to collect adequate and sufficient quantitative information to assess the consequences of interactions with common dolphins on their populations. This project is needed to provide an important Australian fisheries test-case for meeting new US Government legislation, requiring nations importing seafood to demonstrate that they have a regulatory program for reducing marine mammal bycatch that are comparable in effectiveness to US standards.
eSAMarine – phase 1: the first step towards an operational now-cast/forecast ocean prediction system for Southern Australia
Developing and testing a multi-species, automated fish in-feed system for a production line to add-value and supply large local markets, replacing imports
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
Developing a rapid molecular identification technique to improve egg production based fish biomass assessments
Our ability to assess the status of many important fish species is restricted by the inability to accurately estimate their biomass. In addition, the high costs of such surveys mean that they are not conducted for many species within Australia's Fisheries. Ichthyoplankton surveys to determine egg production and biomass (such as through the daily egg production method (DEPM)) offer an effective means to get this information. However, current techniques cannot be applied broadly because many fish have morphologically identical eggs and molecular sequencing is prohibitively expensive and time consuming. These issues were highlighted in the DEPM assessments for blue mackerel and red bait (FRDC 2002/061 & 2004/39) where there was poor success in morphological identification of fish eggs collected in plankton tows. These projects identified the need to develop an accurate, rapid and inexpensive technique for fish eggs identification. This project will assess the suitability of developing this technique with the ultimate aim of conducting icthyoplankton surveys to inform a DEPM for mackerel species (Qld, NT and WA), pilchard and herring species in the developing tropical small pelagics fishery(NT) and black jewfish (NT, WA, Qld). While the development is focused on tropical species the technique will have application in many southern fisheries.
This project was developed under the steerage of the Northern Research Partnership (NRP) and addresses northern Australia priorities around developing better biomass estimation methods for Spanish/grey mackerel and for the new multi-species small pelagic and Coastal Line Fisheries in the NT.
Final report
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.