Developing An Independent Shallow-water Survey For The Western Rock Lobster Fishery: Tracking Pre-recruitment Abundance And Habitat Change
Funder
Fisheries Research and Development Corporation
Funding Amount
$445,500.00
Summary
The current method of measuring undersize lobster abundance (PRA) is based on catch data adjusted for multiple biases inherent in commercial monitoring, namely: water depth, water temperature, swell, fisher experience, pot type, escape gaps, pot pulling time, month and location. Biases are exacerbated by recent poor sample sizes, as many fishers choose not to fish in shallow-water areas. Developing a standardized, repeatable survey in shallow areas will provide an improved index of PRA that ca ....The current method of measuring undersize lobster abundance (PRA) is based on catch data adjusted for multiple biases inherent in commercial monitoring, namely: water depth, water temperature, swell, fisher experience, pot type, escape gaps, pot pulling time, month and location. Biases are exacerbated by recent poor sample sizes, as many fishers choose not to fish in shallow-water areas. Developing a standardized, repeatable survey in shallow areas will provide an improved index of PRA that can be incorporated into the stock modelling: this would improve the overall assessment. Currently fishery-independent survey data collection requires a minimum of two staff to process the catch and record information. Data entry is conducted by a third staff member. To increase cost effectiveness (for this and other lobster surveys), a more efficient data collection system is needed. Initial scoping has identified a number of possible solutions (e.g. app-based entry). This project will expand on this original scoping work to develop a solution. This will also benefit commercial lobster monitoring work conducted by DPIRD as well as a range of other surveys in similar pot based fisheries. This survey will also provide a platform for monitoring inshore WRL habitats. This will establish a baseline against which further research into the relationships between WRL and their near shore habitats can be undertaken. This will assist with detecting and quantifying habitat shifts that may impact the fishery. For example, there is anecdotal evidence that the heatwave temporarily modified some of these near shore habitats, leading to the altered relationship between puerulus and lobster recruitment. Long-term monitoring of juvenile habitats will likely provide a useful indicator of one of the factors affecting recruitment to the fishery. Objectives: 1. Produce accurate measures of pre-recruit abundance throughout the West Coast Rock Lobster Managed Fishery. Compare with commercial monitoring undersize lobster abundance and puerulus settlement data. 2. Design and construct a more efficient data recording tool to increase the accuracy and speed of data collection. 3. Develop base-line habitat descriptions at all potting locations throughout the shallow water survey. 4. Determine the relationship between sampling rate required to detect different magnitudes of marine habitat change at these survey locations Read moreRead less
Climate Driven Shifts In Benthic Habitat Composition As A Potential Demographic Bottleneck For Western Rocklobster: Understanding The Role Of Recruitment Habitats To Better Predict The Under-size Lobster Population For Fishery Sustainability
Funder
Fisheries Research and Development Corporation
Funding Amount
$433,791.00
Summary
The marine heat waves (MHW) of 2010/11, 2011/12 and 2012/13 provide a benchmark with which to investigate changes in habitat composition and potential flow on effects to the fishery.
A 2018 independent review of the science used for stock assessment of the fishery recommended that studies should be undertaken to
a) investigate the impacts of the previous MHW on juvenile recruitment to the fishery and,
b) to better understand the role of habitat composition in recruitme ....The marine heat waves (MHW) of 2010/11, 2011/12 and 2012/13 provide a benchmark with which to investigate changes in habitat composition and potential flow on effects to the fishery.
A 2018 independent review of the science used for stock assessment of the fishery recommended that studies should be undertaken to
a) investigate the impacts of the previous MHW on juvenile recruitment to the fishery and,
b) to better understand the role of habitat composition in recruitment
To understand the impact of habitat change on the fishery, either through warming events or changes in coastal processes, we need an increased understanding of the role of habitat on the survivorship and growth of puerulus, post-puerulus, juvenile and adult life stages of lobster.
In the 40 year time-series of puerulus settlement index a very strong relationship has persisted between puerulus abundance and commercial lobster catches 3 - 4 years larter (de lestang et al., 2010). An undersize catch rate index, based on historical (1985 - present) catch-rate records, evidenced the existence of a strong correlation between puerulus and undersize catch rate (de Lestang pers. com.). However, two-four years after the MHW of 2010/11, this relationship degraded, with the observed catch rate of lobsters being far less than expected at northern locations of the fishery. Although the relationship has now started to return to its historical form, the severity and longevity of its departure are cause for concern and highlight the marked impact future MHW or changes in coastal processes could have on the fishery.
Change in the extent and configurations of coastal habitats is already occurring in response to natural physical forcing (coastal processes) and accelerated by climate change related stressors. It is crucial to have a detailed knowledge of how habitat change affects survival and recruitment key life-stages of the western rock lobster, so these can be taken into consideration for management practices that ensure the sustainability of the fishery. Such information is currently lacking. Objectives: 1. The overall objective is to evaluate the implications of habitat change for the western rock lobster fishery, by determining the relative importance of habitat for the survivorship and growth of critical western rock lobster life stages, to inform the interpretation of existing settlement and recruitment metrics where and when habitat change also occurs. This will be examined via four linked objectives: 2. Synthesise evidence of habitat change: use novel and historical habitat imagery and other remote sensing datasets to determine the spatial extent of habitat loss and recovery, either attributed to 2011/2012 marine heat wave or changes in coastal processes. 3. Investigate fine-scale correlations in anomalies between predicted and observed undersize catch rate index and areas of habitat loss and recovery, either attributed to 2011/2012 marine heat waves or changes in coastal processes. 4. Evaluate evidence of essential benthic habitat for juvenile lobster, by measuring how habitat quality (cover and composition) influences lobster survival. 5. Create a spatial index of essential habitats to inform the interpretation of existing settlement and recruitment metrics. Read moreRead less
Assessing The Biology And Connectivity Of Deep-water Finfish On Australia’s East Coast And The Impact Of Fleet Dynamics
Funder
Fisheries Research and Development Corporation
Funding Amount
$433,228.00
Summary
Deep-water finfish are an increasingly important fisheries resource on Australia's east coast that has been subjected to recent and rapid growth in fishing pressure across commercial, recreational, and charter sectors. Drivers of increased targeting of deep-water species likely include depletion of inshore stocks leading to effort shifts to deeper areas, advances in technology facilitating more effective targeting of deep-water species and changing market dynamics leading to increased profitabil ....Deep-water finfish are an increasingly important fisheries resource on Australia's east coast that has been subjected to recent and rapid growth in fishing pressure across commercial, recreational, and charter sectors. Drivers of increased targeting of deep-water species likely include depletion of inshore stocks leading to effort shifts to deeper areas, advances in technology facilitating more effective targeting of deep-water species and changing market dynamics leading to increased profitability. However, sustainable management of deep-water finfish stocks requires species-specific information on fundamental life history characteristics and stock structure to inform evidence-based management that is currently lacking.
Deep-water species are often characterised by slow growth, late maturity, and clustered distributions around pockets of suitable habitat that leave them vulnerable to overfishing. It is necessary to determine how such traits and connectivity among populations affect the sustainability of fisheries for key deep-water species on Australia's east coast. Management of deep-water species is also complicated by cross-jurisdictional distributions including Queensland, New South Wales, and Commonwealth managed fisheries.
Currently, due to the lack of fundamental biological information, key deep-water species are managed using basic harvest strategies set to trigger enhanced management and scientific focus when such need arises, which is now occurring. For example, the 2021 commercial harvest of Bar Cod (Epinephelus ergastularius) in Queensland exceeded double the mean harvest from 2011-2015, triggering a requirement for the first stock assessment of this species. Anecdotally, recreational catches in Queensland of other key species including Flametail Snapper (Etelis coruscans) and Goldband Snapper (Pristipomoides multidens) have substantially increased in recent years, with the latter given priority status for future stock assessment. New South Wales DPI has indicated a particular need for research focus on Bass groper (Polyprion americanus) and Hapuku (Polyprion oxygeneios) due to the complete lack of biological information required for fisheries management of these species, both of which are now quota managed. Recreational fishing effort is important to quantify because this sector has come to dominate the deep-water fishery in some areas where commercial fishing effort is sparse. Changing fleet dynamics and the uptake of technological advances in fishing gear have also increased fishing power for deep-water species in ways that are poorly understood.
This project aims to address these issues with a cross-jurisdictional collaboration between Qld DAF, NSW DPI, and AFMA supported by the University of Queensland providing fundamental information on the biology and population connectivity of key deep-water species. Project staff are well placed to leverage their existing networks and will also build new relationships with stakeholders throughout the deep-water fishery to pursue sample collection from all available sources including commercial fishers, processors, and recreational and charter fishers. Archived samples and targeted fishery-independent sampling will also be employed to secure sufficient samples to provide confident estimates on life history parameters and population connectivity to inform stock assessment. Additionally, we aim to develop novel methods to improve recreational reporting of deep-water catches and improve estimates of fishing power effects on catches of deep-water finfish.
Objectives: 1. Describe the life history characteristics of key deep-water species, e.g., Bar Cod, Flametail Snapper, and Goldband Snapper 2. Understand the stock structure and connectivity of deep-water species in Queensland and New South Wales 3. Investigate and implement novel methods for improving recreational catch reporting of deep-water species 4. Improve estimates of fishing power in the deep-water line fishery by reviewing (as opposed to trialling) historic and current fishing technologies Read moreRead less
Developing A Cost-effective Monitoring Regime And Stock Assessment For Sand Flathead In Tasmania
Funder
Fisheries Research and Development Corporation
Funding Amount
$703,700.00
Summary
Sand Flathead account for well over half of the total catch (by numbers) taken by marine recreational fishers in Tasmania and represent the mainstay of Tasmania's recreational fishery. Furthermore, since the recreational catch of sand flathead is more than 20 times the commercial catch, trends in commercial catch and catch rates are of little value in inferring changes in stock status. This has meant that fishery independent or novel assessment methods are required. To date, IMAS has implemente ....Sand Flathead account for well over half of the total catch (by numbers) taken by marine recreational fishers in Tasmania and represent the mainstay of Tasmania's recreational fishery. Furthermore, since the recreational catch of sand flathead is more than 20 times the commercial catch, trends in commercial catch and catch rates are of little value in inferring changes in stock status. This has meant that fishery independent or novel assessment methods are required. To date, IMAS has implemented a research program focused on sand flathead in the south-east of the state that provides a spatially restricted, perspective and semi-quantitative evaluation of stock condition. Given the significance of the species and a status of 'depleting' in the latest stock assessment report, there is a need to implement a more comprehensive stock monitoring approach throughout the state that can support the development of a spatially explicit quantitative stock assessment model. There is also a need to determine the appropriate spatial resolution to apply to the stock assessment model. As such, there is a need to understand the extent of adult movement and ontogenetic connectivity of regional sub-populations of sand flathead throughout Tasmania. In addition, by collation of biological data sets from historical studies and surveys conducted around Tasmania the extent and direction of potential changes in population size structures, and life history characteristics will be investigated. Where possible collated biological data will be used to assess spatial and temporal changes in life history characteristics to assess the implications of selective excessive fishing pressure and/or past and future climate change effects for this species. Objectives: 1. Review and collate available biological and fishery data collected on sand flathead within Tasmanian waters 2. Design, implement and assess the effectiveness of fishery dependent and fishery independent biological sample collection techniques for sand flathead 3. Determine the spatial and temporal variability of key life history characteristics and population structures of sand flathead 4. Investigate movement and connectivity of sand flathead within Tasmania 5. Develop a quantitative region-age-sex structured fishery assessment model for sand flathead 6. Identify management scenarios for consideration Read moreRead less
Examining The Potential Impacts Of Seismic Surveys On Octopus And Larval Stages Of Southern Rock Lobster
Funder
Fisheries Research and Development Corporation
Funding Amount
$669,770.00
Summary
CGG has NOPSEMA approval for a 3D seismic survey in the Gippsland Basin to commence in early 2020. This survey overlaps the Victorian shelter-pot octopus fishery off Lakes Entrance. This overlap has raised concerns from the fishing industry about the potential impacts to octopus and the fishers. Tank-based experiments simulating seismic exposure have resulted in high levels of damage in several species of octopus, however, it is unclear how experiments conducted in tanks translate into the field ....CGG has NOPSEMA approval for a 3D seismic survey in the Gippsland Basin to commence in early 2020. This survey overlaps the Victorian shelter-pot octopus fishery off Lakes Entrance. This overlap has raised concerns from the fishing industry about the potential impacts to octopus and the fishers. Tank-based experiments simulating seismic exposure have resulted in high levels of damage in several species of octopus, however, it is unclear how experiments conducted in tanks translate into the field. Field-based seismic experiments have rarely been conducted on invertebrates, with no such studies conducted on octopus. However, the benthic and relatively sessile habit of octopus leaves them potentially vulnerable to impacts, as they have limited capacity to avoid the waterborne and ground-borne energy of seismic signals. CCG has agreed to provide funds to fill the knowledge gap surrounding the potential impact of seismic surveying on octopus and to do this in conjunction with a commercial scale seismic survey, with the lack of a full array often a perceived limitation of seismic research. CGG has also agreed to value add to the work around octopus. This opportunity allows for the potential impact of seismic surveying on larval forms to be examined, with some concerns around localised depletion of larvae of commercially and ecologically important species, such as southern rock lobster and commercial scallops. This project will use a field and laboratory experimental approach to provide a thorough assessment of the potential impacts of seismic surveys on octopus pallidus and its catches, along with rock lobster larvae and other important larvae. These approaches may assist fisheries and petroleum regulators to make informed decisions on the timing and manner in which future surveys are performed. Importantly, along with that of CGG, it has the support of the Victorian Fisheries Authority, who have also offered in-kind support, the two octopus fishers in the region, the Lakes Entrance Fishermen’s co-op, the sustainable shark fishing association and Southern Rock Lobster Inc. Objectives: 1. Determine the impact of intense low frequency acoustic signals on adult pale octopus (Octopus pallidus) 2. Determine the impact of intense low frequency acoustic signals on the development of eggs, hatching rates and competency of the resultant hatchlings. 3. Outline threshold distances for potential impacts of seismic surveying 4. Determine the impact of intense low frequency acoustic signals on pale octopus (Octopus pallidus) catch. 5. Determine the impact of intense low frequency seismic signals on the pueruli of southern rock lobsters. 6. Determine the impact of intense low frequency seismic signals on important planktonic larvae, particularly crustaceans and molluscs. Read moreRead less
Investigation Of The Direct And Indirect Role Of Submarine Groundwater Discharge (SGD) On Western Rock Lobster Settlement Processes: With Consideration Of The Potential Role Of Contaminants
Funder
Fisheries Research and Development Corporation
Funding Amount
$237,535.00
Summary
In Western Australia, the positive and negative effects of SGD in marine benthic communities remains unknown. In Marmion Lagoon, SGD is known to supply up to 50% of the nutrients required for the macrophyte growth rates observed (Johannes and Hearn 1985). Freshwater input has been observed to positively impact seagrass germination (Xu et al., 2016), and although no similar studies exist for temperate seagrass species in the southern hemisphere, SGD may have a role in the creation, maintenance an ....In Western Australia, the positive and negative effects of SGD in marine benthic communities remains unknown. In Marmion Lagoon, SGD is known to supply up to 50% of the nutrients required for the macrophyte growth rates observed (Johannes and Hearn 1985). Freshwater input has been observed to positively impact seagrass germination (Xu et al., 2016), and although no similar studies exist for temperate seagrass species in the southern hemisphere, SGD may have a role in the creation, maintenance and augmentation of seagrass beds. The direct influence of SGD on puerulus settlement rates is unknown but freshwater discharge has been shown to be positively correlated with crab larval abundance (Boylan and Wenner, 1993). An ongoing FRDC project (2016-260: Assess causes and implications of anomalous low lobster catch rates) has demonstrated post-puerulus western rock lobster exhibit a strong choice for the chemical signature of seagrass (Brooker et al. in prep). These findings suggest that SGD may affect puerulus settlement rates either directly through chemotaxis or indirectly by impacting the density of seagrass meadows. Hence, there is a need to investigate both the role of SGD and the presence of seagrass on puerulus settlement rates. Land derived contaminants potentially impacting puerulus settlement and survival could include heavy metals and endocrine disrupting chemicals, such as flame-retardants or pesticides targeting insects (McKenney, 1999). Adult lobster have been shown to be repelled by the presence of copper (McLeese, 1975) and both flame-retardants (polybrominated diphenyl ethers - PBDEs) (Davies and Zou, 2012) and various insecticides (Ghekiere et al., 2005) have been shown to disrupt moulting in marine crustacea. Alkylphenol pollution was implicated in a major die-off of the American lobster (Homarus americanus) population that occurred in Long Island Sound in 1999, with acute impact on post-puerulus mortality during moulting (Laufer et al., 2013). There is a need to investigate both the occurrence and concentration of likely contaminants at potential source locations within the Western Rock Lobster fishery and assess their impact on post-puerulus survival.
Objectives: 1. Identify areas of significant submarine groundwater discharge (SGD) nearby established western rock lobster settlement monitoring sites. 2. Investigate the direct role of SGD on western rock lobster settlement rates. 3. Investigate the link between SGD and the extent and condition of important lobster habitat (e.g. seagrass). 4. Identify and map input of contaminants by SGD in key fishery areas. 5. Investigate impact of contaminants on the survival of puerulus and post-puerulus lobster. Read moreRead less