The development of indicators to measure and monitor the performance of fisheries against economic objectives continues to challenge fisheries managers. To date economic metrics have focused on various measures of profitability, and this has been limited to relative few fisheries due to the costs and time involved in collecting the information.
The use of productivity analysis provides an alternative approach to measure and monitor performance in fisheries. It is a broad area of economic analysis that largely estimates how the level and combination of inputs used by fishers affects their level of output, revenue or profitability. From this, the level of efficiency within a fishery can be determined, and how this efficiency level changes over time can be monitored. The role of management in influencing efficiency can also be directly determined. Measures of capacity utilization also provide information on the level (and changes in) excess capacity, which can be used to develop a proxy measure for the optimal fleet size.
Many productivity measures can be derived from available logbook data, while more detailed measures can be obtained from the full economic data (e.g., socio-economics of fishers, vessel characteristics, environmental conditions). These approaches can also provide information about fisher behavior, such as targeting ability in multispecies fisheries, and their response to changes in price and costs, as well as provide information on what is driving changes in profitability (e.g., prices, costs or management). In addition, appropriate measures can be identified to assist managers bridge commercial and other fisheries sectors.
The application of these techniques in Australian fisheries has been limited, and their ability to provide cost-effective information useful for management has not been fully examined. Outside fisheries, productivity has proven to be a useful economic indicator and its potential in Australian fisheries needs to be assessed. This project will meet this need by asking: In what contexts do indicators of productivity and productivity change provide a useful addition to other measures of fisheries economic performance.

Understanding the demographic characteristics, connectivity and stock structure of a fish species is crucial for identifying the appropriate scale and strategy for management.

Black bream is a slow growing and long-lived finfish species with reproduction confined to estuarine habitats. It is distributed in the estuaries and inshore marine waters of southern Australia, from central NSW to central west coast WA, including Tasmania. Throughout its broad distribution, black bream is thought to be composed of a number of isolated spawning stocks, with limited evidence of movements between estuaries.

In SA, black bream supports important commercial fisheries, and is highly sought-after by recreational anglers. Most of the State-wide commercial catch is taken by the Lakes and Coorong Fishery (LCF) in the Coorong estuary, with smaller contributions taken by the Marine Scalefish Fishery. In 2016, the LCF for black bream, which was historically one of Australia’s most productive black bream fisheries, was classified as ‘overfished’. It is unknown whether this status is reflective of the broader population in SA waters, or if current management arrangements for the Coorong population, which are aimed to promote stock recovery, are adequate in terms of the spatial scale that they apply.

There is a need to understand the demography, connectivity and stock structure of black bream populations across southern Australia (SA, VIC and WA). This information will assist in identifying appropriate scales and strategies for management.

‘People development’ is one of several priorities identified in the FRDC’s RD&E Plan 2015-20. The proposed project will be undertaken by a high-performing student as a PhD project. The student will undertake applied research relevant to FRDC stakeholders (scientists, fishery managers, commercial, recreational and indigenous fishers) in SA, and gain industry experience by being co-supervised by scientists from SARDI. The project will increase fisheries science capacity in SA through training of the next generation of researchers.

Globally, aquaculture accounts for over 50% of fish production. However, if poorly planned, rapid expansion to meet the ever increasing demand for seafood brings with it an environmental risk associated with eutrophication and organic enrichment of the seabed, adversely affecting marine coastal ecosystems. Approximately 75-85% of the nitrogen discharged from finfish aquaculture is dissolved and dispersed to nearby habitats. A major spatial constraint on aquaculture in nearshore areas around much of Australia is the potential for these dispersed nutrients to negatively affect seagrasses. Seagrasses can be sensitive to increases in nitrogen, which can lead to habitat loss. This loss can have significant environmental and economic impacts with potential losses of ecosystem services including decreases in commercial and recreational fisheries catches, increases in sand instability and erosion, reduced biodiversity, loss of nitrogen assimilation and cycling, and loss of carbon sequestration.

In other situations, small increases in nutrients may have a positive effect on seagrasses, and thus it is not clear what the consequences of aquaculture derived nutrients will be. Subsequently, we can’t robustly determine the level of finfish aquaculture that can be sustainably supported by seagrass ecosystems. There is therefore a need to develop a process to determine the likelihood of seagrass growth (or loss) due to aquaculture derived nutrient inputs. This work will develop metrics that can be used in other aquaculture developments and in long-term regional monitoring.

Clean Seas Seafood Pty Ltd are developing a new lease for the sea-cage aquaculture of 4500 tonnes of yellowtail kingfish (YTK) in the Fitzgerald Bay region. The nearshore habitats throughout the region are dominated by long-lived Posidonia seagrass. While Fitzgerald Bay was the original focus of YTK aquaculture in SA, it has not been utilised for ~10 years, essentially giving us the potential to study this system prior to the commencement of aquaculture (currently planned for ~ July 2019), as well as while production is increasing, and it thus provides an ideal case study for assessing how to sustainably farm finfish in a seagrass dominated ecosystem.