Microprocessor Controlled Passive Sonar For Fisheries Studies
Funder
Fisheries Research and Development Corporation
Summary
Objectives: 1. Demonstrate feasibility of underwater data acquisition by diver positioned omnidirectional active sonar source and three fixed passive hydrophones. 2. Test the data acquisition system on different fisheries (crayfish and abalone)
The Application Of Industry Acoustic Techniques To The Surveying Of NSW Redfish Stocks: A Feasibility Study
Funder
Fisheries Research and Development Corporation
Funding Amount
$44,780.00
Summary
Considered a low priority species the SEF for many years the importance of redfish research has greatly increased over the last few years because of a contentious review of the existing stock assessment.
Over the last 20 years redfish catches have varied between 900 and 4000t. In 1997 the redfish catch, including estimated discards, was around 2000t. Standardised catch rates of commercial trawlers reported in SEF1 returns have varied without trend between 115 - 240kg/h since ....
Considered a low priority species the SEF for many years the importance of redfish research has greatly increased over the last few years because of a contentious review of the existing stock assessment.
Over the last 20 years redfish catches have varied between 900 and 4000t. In 1997 the redfish catch, including estimated discards, was around 2000t. Standardised catch rates of commercial trawlers reported in SEF1 returns have varied without trend between 115 - 240kg/h since 1986.
In 1993 the redfish stock was estimated by SEFAG on the basis of commercial catch rate trends and the changing size structure of the catch to be around 10 - 20,000t.
A Redfish Assessment Group (RAG) was established in 1998 to refine and update the redfish assessment. The RAG reviewed for the 1998 SEFAG plenary a highly contentious preliminary assessment which estimated that the redfish biomass was only 3-4,000t, and likely to decline rapidly even without further fishing. The RAG's cohort analysis also suggested that over the last five years recruitment rates have first spiked up to several times historic levels, but have then declined to virtually nothing in the last two years of the analysis.
These estimates are extremely contentious with industry in NSW who fiercely dispute them. On the basis of the size of acoustic marks they see, and the size of their own shots, they believe the biomass to be considerably higher. Fishers claim that catch rate trends reflect changing fishing patterns. That quota management has lead to them optimising the species composition of catches which has lead to decreased targeting of single species aggregations and a decline in catch rates (FRDC 97/114). They claim that changing catchability is producing a misleading stock assessment.
There was some support for this industry view amongst the scientific members of the 1998 SEFAG plenary. The plenary was also aware that cohort analyses are prone to producing unrealistic estimates in the final years of the modelled time series. SEFAG Plenary considered that the model provided unrealistic estimates of recruitment and stock biomass and decided that it could not endorse the preliminary assessment. Instead they have prescribed a series of diagnostic analyses which should be carried out on the cohort analysis during 1998/99 and placed a high prioirity on this research proposal. It is hoped that the diagnostic test, which include applying alternative assessment models to the same data, will indicate whether or not the RAG's preliminary assessment is reliable and so suggest an appropriate reaction to the new draft assessment for redfish.
However the essential problem remains that assessment will continue to be based upon questionable fishery dependent trends unless quantitative techniques are developed for surveying these stocks independently to evolving fishing practices.
The aim of this proposal is to demonstrate the feasibility of acoustically surveying an area of the SEF containing redfish aggregations during the winter of 1999.
It should be noted that the scope of this current proposal is only to prove the feasibility of the industry acoustic survey technique. It does not extend to conducting a full scale survey of redfish stocks in 1999. Should the feasibility of producing fishery independent indices of redfish abundance be demonstrated by this feasibility study it is anticipated that the proven techniques would be scaled up by future projects to provide full stock surveys for redfish, and then potentially for other amenable SEF species.
In the long term RAG and SEFAG need reliable indices of stock abundance if they are to provide meaningful assessments of the status of redfish stocks. This project aims to prove the feasibility of the industry acoustic technique for providing fishery independent estimates of trends in redfish biomass. Information flowing from this project should in the long term improve the quality of the stock assessment which is vital to ensuring effective TAC setting.
In the short term the project will also provide some subsidiary benefits that may help resolve the issues raised by the RAG's revised assessment of redfish stocks.
The project will involve Dr Jeremy Prince becoming involved in RAG meetings allowing this project to be co-ordinated with the RAG's research plan. In addition to conducting this project Dr Prince has agreed to develop an alternative synthesis assessment of redfish using an assessment framework developed by Prof. Ray Hilborn of the University of Washington. This will go some way to responding to SEFAG's call for conducting diagnostic tests during 1999 on the new cohort assessment.
In addition the data collected by this feasibility study may allow some minimum estimates of absolute redfish biomass (actual tonnage) to be made for the selected survey area (see methods). While it is acknowledged that absolute estimates of biomass will be highly imprecise because of the number of assumptions that will be required to produce the estimates; making uniformily conservative assumptions will allow some minimum level of biomass to be proved. Such minimum proven estimates may still prove useful to the RAG by allowing the stock assessment to be bounded by some scientifically proven extremes.
Finally if the industry acoustic techniques is shown to be feasible this pilot scale project should also have been able to document redfish aggregation dynamics during 1999 this will help build a documented basis upon which long term surveys can be designed. Objectives: 1. To conduct four acoustic surveys of redfish aggregations within a selected research area using EchoListener a commercial fishing vessel equipped with EchoListener equipment. 2. Repeatedly map the distribution and acoustic density of marks attributable to redfish and derive a range of biomass estimates based on these data. 3. Analyse and report on the feasibility of estimating redfish biomass using industry acoustics. Read moreRead less
Industry Survey Of The 1997 Eastern Gemfish Season
Funder
Fisheries Research and Development Corporation
Funding Amount
$144,564.00
Summary
In 1997 1,000t will be allocated amongst the South East Trawl fishery, individual allocations will vary from over 100t down to 100s of kg. These allocations will allow some targeted fishing for gemfish but operators will also have to manage their individual allocations to cover their anticipated bycatch of gemfish as they fill quotas for other species. This management of bycatch will bias reported commercial catch rates in 1997 preventing comparison with historic trends and the updating of the ....In 1997 1,000t will be allocated amongst the South East Trawl fishery, individual allocations will vary from over 100t down to 100s of kg. These allocations will allow some targeted fishing for gemfish but operators will also have to manage their individual allocations to cover their anticipated bycatch of gemfish as they fill quotas for other species. This management of bycatch will bias reported commercial catch rates in 1997 preventing comparison with historic trends and the updating of the stock assessment developed by EGAG during 1996.
Consequently EGAG considered that another Industry Survey in 1997 is needed for two principal reasons: 1. To provide catch rate data which is representative of targeted gemfish fishing. 2. To ensure timely provision of high quality data for stock assessment during September and October 1997.
However having decided on the need for the 1997 survey EGAG considered that two other lesser needs could be addressed for little additional expense. These are: A. to understand targeting patterns in the SEF and their impact on stock assessment and B. the influence of oceanographic factors on the South East Fishery. Objectives: 1. Catch and effort and length-frequency data for targeted eastern gemfish fishing during the 1997 season will supplied in Excel spreadsheets will be supplied to EGAG before 1 September 1997. 2. The targeting practices of four survey vessels; Charissa, Marina Star, Illawara Star and Santa Rosa II during the 1997 season will be documented and analysed in relationship to previously reported targeting patterns. 3. The relationship between gemfish aggregations and oceanographic features during 1997 will be documented and analysed. 4. The feasibility of using multi-frequency acoustics to measure the size of gemfish aggregations will be analysed. Read moreRead less
Echo Sounder, Sonar And Radar Operators And Navigation Course
Funder
Fisheries Research and Development Corporation
Summary
Objectives: 1. In conjunction with NSW Fisheries, Sydney Technical College and Australian Maritime College, 2. provide training in principals & operations of echo sounding, netsondes & sonar; interpret echograms & sonargrams; application & operation of radar; elementary navigation
Aquaculture is expanding not only overseas but also in Australia and this has attracted a cadre of young scientists with little experience in aquatic animal health. Although not all “aquatic” techniques are unique there are some aspects that are specific to aquatic technical skills and procedures. In addition, some of these inexperienced scientists/technologists feel that they are on their own and are even intimidated to request assistance. In some instances they don’t know where to go or whom ....Aquaculture is expanding not only overseas but also in Australia and this has attracted a cadre of young scientists with little experience in aquatic animal health. Although not all “aquatic” techniques are unique there are some aspects that are specific to aquatic technical skills and procedures. In addition, some of these inexperienced scientists/technologists feel that they are on their own and are even intimidated to request assistance. In some instances they don’t know where to go or whom to ask for input or direction. The “aquatic animal heath” discipline involves a relatively small number of specialists that do not get the opportunity to convene at meetings/workshops/ conferences as often as those involved in the terrestrial animal health sphere. The forum activities will include; 1) the planning and hosting of annual training workshop
2) further development of the established email discussion group
The forum would be open to all aquatic animal health specialists and industry personnel eg. fish farm staff who will be encouraged to register as a member of the forum. The forum will include annual workshops for participants with a variety of skills and levels of experience and who are resident at government laboratories, universities and colleges. This will build on the previous skills workshops that have been conducted in 2010 and 2011, which has assisted in the development of functional networks for the exchange of information and enhancement of the skills of the aquatic animal health service providers and on farm staff. In addition to developing a valuable national resource - a repository of technical knowledge – the forum provides mentoring to the new generation of laboratory technicians, students and staff at diagnostic laboratories, teaching institutions and aquaculture enterprises.
Objectives: 1. To further develop the email discussion group for the Aquatic animal health technical forum 2. To ensure the continuation of technical information transfer between forum members 3. To organise annual workshops at various institutes that provide specific aquatic animal health services. 4. To open the forum to international participation and thus enhancing the knowledge base of the forum members, for example exotic diseases. 5. To canvass State Departments for potential funding contributions to enable the continuation of the forum beyond 2015. Read moreRead less
Echo Sounder, Sonar, Radar And Marine Radio Transceiver Course
Funder
Fisheries Research and Development Corporation
Summary
Objectives: 1. Provide instruction in principles of echo sounding, netsounder & sonar. Interpretation of echograms & sonargrams in relation to fishing. 2. Application and operation of radar. 3. Proper selection & use of marine radio equipment, incl installation, care & maintenance
Utilising Innovative Technology To Better Understand Spanish Mackerel Spawning Aggregations And The Protection Offered By Marine Protected Areas
Funder
Fisheries Research and Development Corporation
Funding Amount
$307,132.16
Summary
Though Queensland east coast Spanish mackerel spawning aggregations are highly predictable in both space and time, little is known about the impacts of the sustained fishing pressure these aggregations receive annually. Common anecdote from long-term commercial fishers reports a steady contraction of both the spatial and temporal extent of aggregations over the last decade. Further, in response to these concerns, DEWHA recommended that QPI&F consider protecting spawning aggregations of Spanish m ....Though Queensland east coast Spanish mackerel spawning aggregations are highly predictable in both space and time, little is known about the impacts of the sustained fishing pressure these aggregations receive annually. Common anecdote from long-term commercial fishers reports a steady contraction of both the spatial and temporal extent of aggregations over the last decade. Further, in response to these concerns, DEWHA recommended that QPI&F consider protecting spawning aggregations of Spanish mackerel through spatial and/or temporal closures. The need to better understand Spanish mackerel spawning aggregations, and the potential effects of sustained fishing pressure has another two important bases. Firstly, the most recent 2008 fishery assessment reports the fishery is fully exploited at current harvest rates and steps should be taken to re-build stocks; and secondly, the commercial fishing sector (and to a lesser extent the recreational fishing sector) currently incorporates a large component of potential effort and harvest in the form of under utilized quota.
The potential conservation benefits of the recently expanded Marine Protected Area network within Queensland waters to Spanish mackerel spawning aggregations has yet to be quantified. Given the precarious status of this fishery, it is now mandatory to quantitatively assess the efficacy of the current reef zoning that overlay the primary spawning reefs northeast of Townsville in offering protection to vulnerable spawning aggregations. This project will address the need to better understand movement and residency behaviours by providing modeling outputs to measure and predict the benefits that may be derived by the current MPA network. The project will further expand this need by advising on the potential abilities of expanded spatial and / or temporal closures for additional Spanish mackerel protection that may be required for effective management. Objectives: 1. Document and describe temporal and spatial trends of spawning aggregations throughout the recent history of the fishery. 2. Quantify the potential benefits of marine protected areas to spawning aggregations 3. Conduct an MSE to quantify the benefit(s) of spatial and / or temporal closures as management options for Spanish mackerel. Read moreRead less
Research Priorities For Understanding Movements Of Cross-jurisdictional Species
Funder
Fisheries Research and Development Corporation
Funding Amount
$60,000.00
Summary
Around Australia there are many species of sharks and finfish that range widely and even undertake long-distance migrations for spawning or foraging. There is a need to better describe and understand these aspects of the ecology and biology of these species in order to more effectively manage such species across both single and multiple jurisdictions. These species cross various jurisdictional boundaries (State and Commonwealth) and in this process are subject to .... Around Australia there are many species of sharks and finfish that range widely and even undertake long-distance migrations for spawning or foraging. There is a need to better describe and understand these aspects of the ecology and biology of these species in order to more effectively manage such species across both single and multiple jurisdictions. These species cross various jurisdictional boundaries (State and Commonwealth) and in this process are subject to a range of management regulations which may potentially be simplified to best meet the needs of an overall stock management approach. Recent developments in the acoustic tracking of marine species and the deployment of national tracking infrastructure through IMOS/AATAMS* has provided an unprecedented opportunity to provide this information, and to achieve synergies between fisheries research and management organizations across jurisdictions as well as more efficient use of recent marine infrastructure developments. This proposal will facilitate a national-scale coordinated approach among these organizations regarding the key species that should be targeted for this type of research effort based on their biology as well as the potential risks posed by conflicting jurisdictional management approaches.
* Integrated Marine Observing System/ Australian Animal Tracking and Monitoring System
Objectives: 1. Facilitate communication that will enable the development of effective management of shared stocks of highly mobile or migratory species 2. Develop a consensus around knowledge gaps and research priorities in relation to the management of highly mobile or mirgratory species. 3. Determine whether movement data from a national acoustic tracking network would provide the required information in relation to identified knowledge gaps and research priorities Read moreRead less