Southern Bluefin Tuna: Changing The Trajectory
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
Beyond GVP: The value of inshore commercial fisheries to fishers and consumers in regional communities on Queensland’s east coast
There are multiple threats to ongoing access/operation of commercial inshore fisheries (finfish and crab) along Queensland’s east coast. These include port developments and expansions, coastal development, public perception (which influences management) and competition between fishing sectors (which also influences management). These threats to access could adversely affect not only commercial fishers themselves, but also secondary industries as well as the availability of seafood to local communities. It is now well documented that consumers prefer local seafood products, and are willing to pay more for seafood labelled ‘local’ (Tobin et al. 2010; Calogeras et al. 2011).
It could be assumed that reducing these threats and ensuring ongoing operation of commercial fisheries and local seafood supply is desirable, for many social and economic reasons. Yet there is little information about the value inshore commercial fisheries and fishing businesses provide to communities (aside from the much used GVP, which has long been recognised as a nonsensical measure of value (e.g. Edwards 1991, McPhee & Hundloe 2004)), or the relative value of local seafood compared to non-local seafood for consumers.
Without knowing the real economic value of commercial fisheries and local seafood for regional communities, decisions regarding management of, and access to, resources are likely to be ill informed. Real value information can be used to ensure appropriate access of fishers and consumers to fisheries resources, better assess the economic impacts of other coastal activities that negatively affect fishing, or better inform reallocation processes where necessary.
Final report
Small Pelagics Research Co-ordination Program
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
Final report
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.