Prediction of fishery year-class-strengths from larval growth and zooplankton size structure. The abundance of young fish produced in the ocean each year is highly variable, and banks or managers need to prepare for these future changes when the fish reach market size. Therefore many nations conduct special trawl surveys of juvenile fish each year, but these are expensive, particularly when Australia has over 200 commercially harvested fish. We propose that the growth of fish larvae, recorded as ....Prediction of fishery year-class-strengths from larval growth and zooplankton size structure. The abundance of young fish produced in the ocean each year is highly variable, and banks or managers need to prepare for these future changes when the fish reach market size. Therefore many nations conduct special trawl surveys of juvenile fish each year, but these are expensive, particularly when Australia has over 200 commercially harvested fish. We propose that the growth of fish larvae, recorded as daily growth rings within the earstone of undersized fish from the fishery, could predict future abundance. We will link growth to a cost-effective assessment of their zooplankton prey in spawning areas that lead to Australia's South East Trawl region.Read moreRead less
Stocking of fish and prawns at ecologically determined densities into Australian estuaries. Increasing numbers of people like to go fishing, and to catch a fish, which translates into tourism income and aquaculture business. Restocking is a fisheries management option when the natural supply or survival of larvae is limited. This study will determine for the first time the ecologically appropriate abundance of small mulloway and prawns that an estuary can sustain. We will assess the extra eff ....Stocking of fish and prawns at ecologically determined densities into Australian estuaries. Increasing numbers of people like to go fishing, and to catch a fish, which translates into tourism income and aquaculture business. Restocking is a fisheries management option when the natural supply or survival of larvae is limited. This study will determine for the first time the ecologically appropriate abundance of small mulloway and prawns that an estuary can sustain. We will assess the extra effort needed to release larvae into particular key habitats, and develop new technologies to identify our larvae from the wild. Our findings will be relevant to restocking of Australia's inland rivers, which at present has little ecological basis.Read moreRead less
Feeding and breeding: Rainfall effects on connectivity and fidelity of iconic coastal fishes. Large predatory fish are of great significance to recreational anglers, not only for their trophy status but also for their disproportional fecundity and contribution to future fishing. Remarkably, the distribution and movements of large estuarine fish in estuaries and the coastal ocean are unknown, despite their importance to the national economy. We will determine the role of freshwater discharge an ....Feeding and breeding: Rainfall effects on connectivity and fidelity of iconic coastal fishes. Large predatory fish are of great significance to recreational anglers, not only for their trophy status but also for their disproportional fecundity and contribution to future fishing. Remarkably, the distribution and movements of large estuarine fish in estuaries and the coastal ocean are unknown, despite their importance to the national economy. We will determine the role of freshwater discharge and oceanography on the coastal and estuarine habitat requirements, movements and home ranges of mulloway, flathead and bream from the scale of hours to years, and extend these findings to evaluate population sub-structuring and connectivity in the context of a changing climate.Read moreRead less
Linkage Infrastructure, Equipment And Facilities - Grant ID: LE100100059
Funder
Australian Research Council
Funding Amount
$100,000.00
Summary
Dual frequency identification SONAR (DIDSON) facility for sampling benthic and pelagic fish populations. Many Australians enjoy marine and freshwater resources, and we are exploiting fisheries and waterways in particular at an increasing rate. Effective management of fisheries requires understanding the abundance and behavior of fish. This facility will provide novel acoustic video technology for researchers to count fishes and sharks near weirs, under wharves or logs, and within seagrass beds. ....Dual frequency identification SONAR (DIDSON) facility for sampling benthic and pelagic fish populations. Many Australians enjoy marine and freshwater resources, and we are exploiting fisheries and waterways in particular at an increasing rate. Effective management of fisheries requires understanding the abundance and behavior of fish. This facility will provide novel acoustic video technology for researchers to count fishes and sharks near weirs, under wharves or logs, and within seagrass beds. The dual frequency identification sonar (DIDSON) will also allow accurate and standardised study of fish movements in response to floods, algal blooms or re-stocking events without disturbing the fish or their habitats. This will enhance our understanding of the top-down control by fish of aquatic ecosystems that are directly adjacent to human activity.Read moreRead less
Trophic cascades in Australian seagrasses: linking nutrients to survival and growth of commercially-important fishes. Despite its high conservation status and importance to commercial and recreational fisheries, seagrass is still declining in Australian waters. By investigating a trophic cascade that links nutrient pollution to the growth and survivorship of seagrass and commercially-important juvenile fishes, our study fills knowledge gaps crucial for improved future management of seagrass hab ....Trophic cascades in Australian seagrasses: linking nutrients to survival and growth of commercially-important fishes. Despite its high conservation status and importance to commercial and recreational fisheries, seagrass is still declining in Australian waters. By investigating a trophic cascade that links nutrient pollution to the growth and survivorship of seagrass and commercially-important juvenile fishes, our study fills knowledge gaps crucial for improved future management of seagrass habitats. The primary outcome of this study will be a model that can predict how changes in nutrient pollution will influence population dynamics of commercially-important fish species supported by seagrass. This information has, therefore, direct relevance to managers of estuarine and coastal environments at all levels of government - local, state and federal.Read moreRead less
A genetic and experimental assessment of the frequency and importance of hybridisation of Black and Yellow Fin Bream. Bream (Acanthopagrus spp.) species underpin several valuable and heavily exploited fisheries in eastern Australia, but the two principal species, yellowfin (A. australis) and black (A, butcheri), interbreed significantly. This hybridisation is poorly documented and, with increasing harvests, could lead to long-term economic impacts and severe repercussions on biodiversity. It cou ....A genetic and experimental assessment of the frequency and importance of hybridisation of Black and Yellow Fin Bream. Bream (Acanthopagrus spp.) species underpin several valuable and heavily exploited fisheries in eastern Australia, but the two principal species, yellowfin (A. australis) and black (A, butcheri), interbreed significantly. This hybridisation is poorly documented and, with increasing harvests, could lead to long-term economic impacts and severe repercussions on biodiversity. It could, for example, increase the risk of localised extinctions and impact on genetic diversity of both species. We will use an innovative combination of molecular genetics and breeding experiments to: (i) determine frequency and direction of hybridisation; (ii) infer strength of genetic connections among estuaries; and, (iii) explore implications for sustainable fisheries management.Read moreRead less
The importance of edge effects in determining the value of seagrass landscapes as fish nurseries. Seagrasses are a conspicuous element of Australian marine environments, and are crucial in the conservation and maintenance of biodiversity. Degradation of seagrass ecosystems from climatic extremes, increased sediment and nutrients in the water, and other pollutants results in loss and fragmentation of meadows. These changes to seagrass are linked with increased coastal erosion, severe loss of bio ....The importance of edge effects in determining the value of seagrass landscapes as fish nurseries. Seagrasses are a conspicuous element of Australian marine environments, and are crucial in the conservation and maintenance of biodiversity. Degradation of seagrass ecosystems from climatic extremes, increased sediment and nutrients in the water, and other pollutants results in loss and fragmentation of meadows. These changes to seagrass are linked with increased coastal erosion, severe loss of biodiversity, and collapse of fisheries. Increased understanding of how biological processes such as predation and food availability influence animal associations with seagrasses, and how these effects change with landscape structure, will have important applications in the sustainable management of Australia's threatened coastal habitats.Read moreRead less
Big squids in Australian waters, insights into their biology, movement and activity, old questions - new technology. This project will assess important biological parameters of shelf and slope ommastrephid squids. Lab based studies will explore age, growth, maturity rates and diet for the deepwater squid Todarodes filippovae. Cutting -edge telemetry technology (manual tracking, listening curtains and satellite pop-up tags) will assess movement, activity, metabolism and vertical migration of bo ....Big squids in Australian waters, insights into their biology, movement and activity, old questions - new technology. This project will assess important biological parameters of shelf and slope ommastrephid squids. Lab based studies will explore age, growth, maturity rates and diet for the deepwater squid Todarodes filippovae. Cutting -edge telemetry technology (manual tracking, listening curtains and satellite pop-up tags) will assess movement, activity, metabolism and vertical migration of both T. filippovae in deep water and arrow squid (Nototodarus gouldi) on the shelf. A comprehensive understanding will be gained of the biology and lifestyle of these two key squid species that will be utilised by implementers of the South-east Regional Marine Plan, ecosystem modelers and resource managers.Read moreRead less
Marine Reserves as Fisheries Management Tools: A Long-term, Experimental Approach. Marine reserves, areas permanently closed to fishing, are potentially valuable fisheries management tools. Reserves may sustain fisheries external to them by containing undisturbed breeding stocks and becoming net exporters of adults and propagules. Our studies in the Philippines suggest that such benefits may only eventuate after 5-15 years of effective protection. This project will continue our long-term (17-25 ....Marine Reserves as Fisheries Management Tools: A Long-term, Experimental Approach. Marine reserves, areas permanently closed to fishing, are potentially valuable fisheries management tools. Reserves may sustain fisheries external to them by containing undisturbed breeding stocks and becoming net exporters of adults and propagules. Our studies in the Philippines suggest that such benefits may only eventuate after 5-15 years of effective protection. This project will continue our long-term (17-25 year) studies of abundance and yield at 3 established reserves, and use a replicated experiment at 3 new reserves, to test if reserves can enhance local fish biomass and catch. We will also compare effects of reserves in Australia and the Philippines.Read moreRead less
Ecological impacts of QX Oyster disease and its management strategies. QX disease is responsible for mass mortality of oysters, and, as a result, economic and job losses. QX disease also threatens ecosystem services provided by wild oysters, such as biodiversity enhancement and fish production. This project will provide estuarine managers with information about how proposed QX management solutions will impact wild oyster populations and vital ecosystem services. It will also contribute to traini ....Ecological impacts of QX Oyster disease and its management strategies. QX disease is responsible for mass mortality of oysters, and, as a result, economic and job losses. QX disease also threatens ecosystem services provided by wild oysters, such as biodiversity enhancement and fish production. This project will provide estuarine managers with information about how proposed QX management solutions will impact wild oyster populations and vital ecosystem services. It will also contribute to training of early career researchers in strategies to ensure the sustainable use of Australia's biodiversity. As QX outbreaks appear to be increasing, this research and training is urgently needed to underpin management to ensure long-term sustainability of valuable estuarine resources.Read moreRead less