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5 DATA FOR RESOURCE ASSESSMENT
5.1 Continuous or Project-Based Data
There are two general methods in which data are collected for resource assessment: continuous or project-based. Continuous data are repeatedly collected from a source or sources. The expression “monitoring” is frequently used to describe this type of activity. In contrast, project-based data are obtained for a particular research project and collected to test particular scientific hypotheses. Within resource assessment, continuous data collection methods (for catch, effort, ages and lengths) are frequently used because continuous data contain information about the dynamics18 of a fish population. Dynamic relationships are the basis of assessment models that are required to make quantitative forecasts of managerial decisions. Performance reporting commitments within the FMS are annual. Although there is no stated obligation that the data that are used to compile the reports would be updated every year, there would need to be some system in place that collected up-to-date information for the reports of managerial performance. The continuous data collection programs currently underway (relevant to resource assessment) in the NSW Department of Primary Industries are: the catch-effort reporting system; fishery-independent surveys for abalone; an observer and recruitment index project for rock lobster; the gamefish tournament monitoring program; and, some monitoring of the age and length structure of commercial landings. Project-based data have been collected for particular projects. Once that project is finished and written up, no more data are collected, though the methods are well documented enabling replication of that sampling design. Individual projects can yield information very valuable to resource assessment, particularly biological information such as growth, maturity and vulnerability. Creel surveys are another example of a project that provides a snapshot of recreational harvesting. Project based data are, however, often compromised in their utility within stock assessment because there are no time-series of observations that enable the longer-term dynamics of populations to be measured. Budgetary experience will make public administrators wary of continuous data-collection projects that can develop an expensive life of their own. In contrast, project-based data have clear endpoints and outcomes. Resource assessment requires both types of data. Many of the following types of data for resource assessment could be considered project-based when they are initially planned and researched, but they would become continuous if they were to remain operational in the long term (beyond 5-10 years). The challenge for the NSW Department of Primary Industries is to decide which types of data should be collected continuously and which should be the subject of further research and evaluation.
5.2 The Cost of Data
Dollar costs will be the fundamental constraint on data collection (and the entire assessment process in general) because money is the easiest thing to measure and control. The other fundamental constraint is time. For the FMS to “work”, assessments must be completed within a timeframe appropriate for performance reporting. Although it is easy to argue that other components of this system, such as data being fully representative, should be given priority over time and money, this is not likely to be the reality, at least in the short term. The approach suggested here is to identify what can be done with the time and resources available and then continuously improve the representativeness of data over time. If, however, the data collection is so
18 A dynamic relationship describes the change of system state with time.
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compromised by time and cost constraints that the data are essentially worthless, then alternative methods for managing and assessing these systems will need to be considered. When costing out the collection of data a “life-cycle” approach should be used where the costs include defining/refining sampling protocols, collecting information, data entry/checking and archival costs. The expenditure on data collection and analysis must be consistent with economic principles within ecological sustainability: all users of the resource could be expected to contribute to the costs of monitoring and assessment. It will be impossible to define a “perfect” data-collection strategy for this assessment strategy from the outset, there are simply too many unknowns. Qualitative cost-benefit analyses of various types of information can be completed quickly (such as table of pros and cons), but full quantitative analyses would be complex and time-consuming. It is beyond the scope of this document to provide accurate cost estimates of various data collection programs for resource assessment, but a general sense of the relative costs of various sources will be indicated. A representation of the approximate cost and value for resource assessment is presented in Figure 5. The exact nature of any particular project and species will, of course, determine the cost and likely benefits for resource assessment. Justifications of the approximate positions of data-sources within this plot are given below.
High Fishery Independent Tagging Surveys Programs
Creel Surveys t s
o Observer Data
C (survey-based)
e Logbook v i Programs t a l Tournament
Re Monitoring Observer Data Sampling (risk-based) at Ports
Effort Data Catch Data Low
Low Value Within High Resource Assessment
Figure 5. A representation of the relative costs and value of various sources of data for resource assessment in NSW. These sources of data are discussed in more detail in the text. Many of these sources of data will have values beyond resource assessment that justify their collection. The relative location of any type of data-source on this plot will depend upon the life-history of the species and the scope of the project that collected that information.
5.3 Role of “Basic Biological” Information in Resource Assessment
Basic biological information such as information on growth, maturity, selectivity, movement and mortality is valuable and sometimes crucial when applying input controls such as minimum legal lengths, closed seasons and closed areas. That said, these controls are always somewhat “blunt” and the marginal value of more detailed information may be small.
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Understanding growth, maturity, selectivity, movement and mortality will also improve our interpretation of indicators. For example, understanding variability of length at age improves our interpretation of length data. Knowledge of length and, to a lesser extent, age at maturity is a critical factor in specifying a minimum legal length. Understanding the growth of individuals is crucial when estimating mortality rates from length data. Any system to prioritise species for stock assessment needs to consider the basic life history of the animal. Low growth rate species must be given higher assessment priority than high growth rate species of similar commercial/recreational value, as they are simply higher managerial risk. Such comments are supported by the risk assessments being undertaken in the EIS. There will be some species in NSW where there is insufficient biological information to make such judgments in regard to growth, maturity and mortality. These species have or will be identified and given a high priority for such studies. Obtaining such information is relatively inexpensive.
5.4 Sources of Data for Resource Assessment
5.4.1 Commercial Catch and Effort Data
Use of fishery-dependent CPUE data could not be described as international best-practice in higher valued fisheries but would probably be considered acceptable for the lower valued stocks that occur in NSW. There are examples of fisheries that have been well managed with fishery- dependent CPUE data and others that have been badly managed with expensive survey data. An understanding of the behaviour of the fish and the fleet can dramatically improve our ability to understand the relative value and usefulness of CPUE data. Records of commercial landings from LCatch/ComCatch exist for many species but these records do not account for: pre-1984 data; recreational harvesting; discard mortality; or illegal harvesting. There exists within the NSW Department of Primary Industries enough expertise to identify the strengths and weaknesses of this database quite quickly. Pre-1984 data is available in other databases for some species (but not generally at the level of individual fisher activity) and relevant catch-effort information is held by Commonwealth agencies (e.g. AFZIS). As assessment priorities are determined, there will need to be an identification of a credible time- series of effort from 1984-199719 (e.g. mesh netting in the EG fishery) or an acknowledgement that such a time-series is not useful. Similar steps will have to be taken for the post 1997 data, but this should be more straightforward as there was more satisfactory recording of effort data. This latter window will have to be the baseline for many species. If adding effort information degrades the robustness of the indicator of abundance (from the default of using landings data alone) then it will not be used. This degradation will occur if there are systematic biases in the effort data. The catch records database is currently subject to a significant time lag (~6-12 months). Consideration needs to be given to developing mechanisms to update this database more rapidly including the timely arrival of records from fishers. Catch records were an integral part of the value of the property right in these fisheries. Measures should be imposed if individual fishers do not take their responsibility in maintaining accurate records of landings seriously20. It is far more practical to check upon the quality of the catch data than the effort data. The Fish Receiver’s program (ss 117-120) could be used to validate that the total local purchases of a Receiver corroborate with the landings reported by fishers. Efficiencies in the recording of catch data could be found by developing automated systems for recording catch data. Such systems are presently being investigated in the Clarence River Fisherman’s Co-operative.
19 Restricted fisheries started on the 1-Jul-1997. Substantial and important revisions to catch and effort forms were undertaken at this time. These revisions significantly improved the interpretability of effort data. 20 Section 122 of the FMA (Commercial fishers to furnish records to Director) provides for this.
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Changes to the commercial catch and effort record system need to be considered seriously but undertaken cautiously. There are some fundamental issues about commercial catch and effort data that will always constrain the application of these data and it is critical to understand the different source and roles played by catch and CPUE (the index of abundance) data. The costs and benefits of alternative mechanisms to record and/or validate total commercial landings need to be investigated. Alternative methods to obtain an index of abundance were summarised in Table 3 and all of these methods need robust debate in due course. An appropriate framework for comparing these sources of data is cost-benefit analysis. Commercial catch data are essential and valuable for the NSW Department of Primary Industries and commercial fishers. The value of these data must be recognized and appropriate investments made. A census of commercial fishing effort is less valuable and a sample of higher quality effort information would be beneficial. Indicators of abundance must be specified for the primary/target species and should be specified for key-secondary species where possible. In the short-term, this will inevitably be done with commercial CPUE data. The data collection program for commercial catch and effort data should continue in the present, or an improved, form. Without this historical catch and effort data, any type of statewide resource assessment in NSW would be seriously compromised. The cost of this program is extremely small compared to the benefit.
5.4.2 Monitoring of Commercial Landings at Ports
Collecting information on the length and age structure of commercial landings is a cost effective method of monitoring the structure of harvested stocks. Such methods may have technical disadvantages over independent surveys of the fish population, but can be undertaken at a fraction of the cost. These data are an important low-cost complement to the use of commercial CPUE as an index of abundance. Issues such as grading of sizes and direct sales to retailers must be considered in the design and execution of sampling programs. Information from Sydney Fish Markets will be logistically simpler to obtain and the sampling protocols are well documented and repeatable. Information from regional co-ops could be logistically more expensive to obtain but should better represent regional stocks. Documented and repeatable sampling protocols also need to prepared and used, particularly when non-departmental staff are involved. Approximate costs of a program to monitor the lengths and ages of the catch of primary/target and key secondary species across NSW (at ports) would be in the order of hundreds of thousands of dollars per year. This is inexpensive in comparison to any alternative method to measure the structure of commercially exploited stocks. The structure of a port-sampling program should be based upon a consideration of the risk of the current management strategy and the currency of existing data. A system based upon multi- criterion decision analysis has been proposed (see “Proposed Prioritisation System”, page 20) which would provide guidance into the long-term structure of such a sampling program.
5.4.3 Commercial Logbook Programs
There are various types of logbook programs, but the general concept is that all or some commercial fishers within a fishery keep more detailed records of their fishing activity. Ideally, these fishers would have superior skills in species identification and record keeping. This information, which is more reliable than that provided on the standard catch and effort returns, could be used as a sample, rather than a census of commercial fishing activity. The most common application of a logbook program would be to provide superior records of commercial CPUE. All fishers within a fishery could, of course, be involved in such a program. Pease and Walford included a summary of a logbook program for the Estuary General Fishery in Gray et al. (2000). The most difficult aspect of logbook programs is that they are, from the perspective of the NSW Department of Primary Industries, very labour intensive. Staff will need to be in constant
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communication with fishers to resolve any issues within the program. This in itself is not a bad thing, but it could be expensive and frustrating. Equity issues could constrain any regulatory enforcement of logbook programs and some type of contractual arrangement may have to be considered if all participants within a fishery do not use logbooks. Some of the benefits of a logbook program for resource assessment may only be realised after several years.
5.4.4 Observer Programs
These programs are not completely within the scope of the “assessment strategy” as such but there are important issues of overlap. Observer programs have roles that are far broader than those described here; particularly with issues associated bycatch, discarding and threatened species. It is unlikely that data from this program could, or should, be used as an index of abundance or recruitment because these outcomes are not usually within the goals of an observer program. Rather, the opportunity to collect more extensive and detailed samples of the catch will provide the following opportunities (in order of importance): • Estimation of non-landed catch of primary/target and key-secondary/byproduct species. This is an important source of fishing mortality that should be included in resource assessments. • Estimates of discards, or species caught but not landed. • Information to help quantify the landings of difficult-to-identify species complexes (such as octopus or sharks) and provide relevant biological data for these species. • Analysis of multi-species or population structure changes due to season, gear and location. • Measurement of the effects of changes to fishing gear or other regulations. • Collection of sub-legal fish for growth and maturity studies. The type of information from the observer program is, in some respects, similar to the type of information that will be collected from fishery independent surveys. The important difference is that observer data aim to be representative of the catch (including bycatches) of the fishery, whilst independent surveys aim to be representative of the underlying fish population. There are two alternative approaches to designing an observer program: a survey approach or a risk-based approach. A survey approach would apply a systematic sampling design across fisheries and methods each year. Data from such a program would be extremely valuable to resource assessment and could, if adequately funded, replace sampling of catches at ports. Such a program would also be required for ongoing monitoring of bycatches. Preliminary estimates of the cost of such a program across all fisheries in NSW is in the millions of dollars per year. An alternative approach is risk-based prioritisation. This approach would only observe fisheries and methods where bycatches were either known or likely to be a significant problem or that existing data were out-of-date (see “Proposed Prioritisation System”, page 20). The costs of this approach will be much lower but could not replace port sampling of catches and would not offer insight into population processes.
5.4.5 Fishery Independent Surveys
Fishery independent surveys are designed to sample the underlying fish population rather than commercial or recreational fishing activity. The representativeness of such samples will depend upon many factors including: replication and stratification; spatial and temporal variation of fish populations; and the efficiency of the sampling gear. Saturation of fishing gear with increasing effort can bias the results of surveys. Data from such surveys should be less biased than data from fisher-dependent sources, but might not be that precise, particularly if few samples can be afforded.
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The ecological sustainability of fishery independent surveys for commercial and recreational fisheries management is a complex and fascinating issue but is beyond the scope of this document. The NSW Department of Primary Industries has a project (partly funded by FRDC) that will study fishery independent sampling in estuaries; this project will provide sufficient information to design a (continuous or operational) sampling program for estuaries in NSW. During this project, resources will be allocated to estimate the power of a design to detect changes to stock status. This is a complex problem because the sampling regime will have varying power depending upon life history of species being sampled. This project should also take the opportunity to consider multi- species, biodiversity and ecosystem issues. Data from gear with wide selectivity could be very valuable for “ecosystem” indicators. Another potential outcome of this approach is to use information about sub-legal fish as an indicator of recruitment. Fishery independent surveys also have the potential to use non-destructive sampling methods such as hydro-acoustic signals to measure the distribution, abundance and size-structure of live, undisturbed fish populations. The EPT FMS states that fishery independent surveys will be used as the core data collection method for stock assessment (EPT at 49) “.. stock assessments for the Estuary Prawn Trawl Fishery will be based upon fishery independent methods involving stratified randomised surveys of relative abundances and size and age structures of wild populations. Such data will provide more robust and rigorous assessments of natural populations than that solely relying on data from the fishery.”. Similar suggestions were not made for the EG or OH fishery. Determining the robustness of an indicator derived from a fishery-independent survey will be a complex analysis. If an indicator is unbiased but highly variable (because of the bias-variance tradeoff) then it may have less power to detect significant system change than an indicator that is biased but quite precise. The analysis completed by Scandol (submitted) considered some of these issues but, in general, it should not simply be assumed that unbiased indicators are always superior for monitoring. The most important advantage of independent surveys is that any biases present should stay constant with time. When these statistical issues are combined with cost-benefit arguments, independent surveys may most easily be justified in areas where commercial fishing is not feasible. Such areas include Recreational Fishing Havens or marine parks. A complete costing of fishery-independent surveys for all marine waters under NSW jurisdiction has not been completed, but it would likely cost in the order of several millions of dollars per year.
5.4.6 National/Statewide Telephone Surveys of Recreational Fishing
The recently released report on the National Recreational and Indigenous Fishing Survey (Henry and Lyle, 2003) has provided the best estimates to date of the magnitude and distribution of recreational fishing in NSW. The aims of this survey were to: obtain estimates of the level of participation, fishing effort and catch by recreational fishers; obtain information on the economic activity associated with fishing and the attitude of recreational fishers to prominent fisheries issues. The cost-effectiveness of such a survey design for the ongoing monitoring of recreational fishing in NSW requires additional deliberation. Not all aspects of the survey have been interpreted with the same degree of credibility. In particular, estimates of magnitude and distribution of recreational effort have been far less controversial than estimates of recreational catch and economic value. The sparse spatial sampling required for the national survey has also resulted in limited resolution of recreational catch and effort estimates at the smaller spatial scales frequently used in management. Recreational fishing is, however, a significant source of mortality of many species in NSW. Estimation of this mortality should be undertaken with a commitment that reflects the socio- economic value of recreational fishing in NSW. Credible estimates of total recreational catch are required for any biomass estimate of stocks.
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5.4.7 Creel Surveys
Creel surveys have been used to estimate recreational catches in NSW (West and Gordon 1994; Steffe et al. 1996; Steffe and Chapman 2003). Creel surveys involve one-to-one interviews with anglers about their catches and the effort applied. Data collected within these surveys are usually of very high quality because trained staff complete interviews and assess the catch. The labour- intensive nature of creel surveys results in such studies being relatively expensive which will usually result in limited replication in space and time. Creel surveys are currently being used to assess the Recreational Fishing Havens in Lake Macquarie and Tuross Lake (that were declared in 2002). This will be done by undertaking creel surveys of anglers in each of these two havens during 2003/04 and comparing the data with similar creel surveys completed in 1999/2000 (before the declaration of Havens). Thus a comprehensive before versus after comparison will be completed. Data collected will include changes in the number of anglers, their catch, catch rate and the size/species composition of their catch.
5.4.8 Charter Boat Logbooks
There is a statutory requirement for the master of a licenced charter fishing boat to keep records of catch and provide this information to the NSW Department of Primary Industries (s127E of the FMA). These data will form a valuable source of information for resource assessment and should be managed with similar standards and protocols as the commercial catch and effort data. The future structure of the charter boat logbook program is under discussion within the FMS planning process, but it is widely acknowledged that these records are a valuable source of information for resource assessment. Data could readily be used to define an index of abundance for recreationally targeted species that is independent of commercial catch records.
5.4.9 Gamefish Tournament Monitoring Data
The gamefish tournament-monitoring program is designed to obtain data on catch, effort, catch per unit effort, and the species/size composition of catches (many species are tagged and then released) from the club component of the east coast recreational gamefish fishery. This fishery is a multi- species, multi-gear fishery that targets billfish, tuna, sharks and other gamefish in coastal waters off NSW, Victoria and Queensland (Lowry and Murphy 2003). These data are valuable because commercial fishers do not target all of the species of shark subject to gamefishing (e.g. tiger sharks), and black, blue and striped marlin are protected from commercial fishing under s 20(1) of the FMA. The gamefish tournament-monitoring program provides an independent source of information and index of abundance on many species where commercial data are scarce. The Commonwealth “Eastern Tuna and Billfish Fishery” manages commercial harvesting of tuna and swordfish. In general, responsibility for the assessment of these species lies with the Australian Fisheries Management Authority.
5.4.10 Tournament Data from Anglers (Freshwater and Saltwater)
The Anglers Catch Research Program21 (ACRP) monitors numerous freshwater fishing events throughout NSW. Freshwater tournaments covered are being refined to those that are regarded as important and cover the diversity of fishing methods, eastern and western drainage systems, the latitudinal spread of river catchment systems and riverine habitats. Anglers contribute directly to the program by reporting their fishing effort, catch by species and size of all fish caught. The existing database contains records from 1993. These data are collected for stock assessment of
21 Based upon text and information provided by Tim Park (Scientific Officer - Angling Research)
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recreationally important freshwater species and to elucidate the effects of fisheries management on freshwater angling.
The success of freshwater ACRP aroused interest from marine angling groups and a pilot program was initiated in 2001 to determine the feasibility of data collection at marine tournaments. The Saltwater Anglers Catch Research Program was initiated in October. As with the freshwater ACRP, anglers provide effort, catch and size data directly for the purposes of measuring the quality of angling. These data will contribute to stock assessment of targeted species as well as providing a measure for the success of saltwater fisheries management initiatives. The saltwater program also has collected spearfishing tournament data and is also involved with the development of the gamefish tournament-monitoring database.
5.4.11 Fish Tagging Programs
There have been a number of fish tagging programs undertaken in NSW (Gillanders et al. 2001) and there is an ongoing gamefish tagging program. Fish tagging programs have the potential to enable estimates of growth (Laslett et al. 2002), movement (Hilborn 1990), mortality (Xiao et al. 1999) and abundance (Seber 1982). Valuable tuna fisheries have adopted the use of tagging programs to enhance their stock assessments, particularly to improve estimates of fishing mortality (Adam et al. 2003). Using tags to obtain estimates of population parameters is much more difficult than obtaining estimates of individual growth or migration (usually because of limits in effort data). Hilborn and Walters (1992 at 164) noted the following important aspect of tagging programs: “Most fish tagging programs concentrate most of their resources on tagging large numbers of fish, and tend to neglect the tag recovery end of the project; putting tags on fish is fun and somewhat glamorous, whereas groveling around on docks, trying to determine if fishermen are missing tags, or throwing them away, is dirty undesirable work.” That said, there is recent (Martell and Walters, in press) recognition that tagging programs can provide timely estimates of fishing mortality (or harvest rate) and be an excellent method to measure and control fisheries. Direct estimates of fishing mortality avoid the issues associated with improving fleet efficiency (catchability). Fishing mortality is the primary indicator of interest in fisheries management. There are ample opportunities to extend the application of tagging methods to improve stock assessments in NSW, but these programs will be time consuming and expensive. The objectives of any tagging program should be carefully evaluated before the fun of tagging begins (Gillanders et al. 2001). A tagging program that could make a significant contribution to the assessment of marine resources in NSW is likely to cost at least one million dollars to initiate and hundreds of thousands of dollars per year to run.
5.4.12 Notes on Age and Length Data
The importance of age and length datasets for resource assessment cannot be understated. Age composition data provides a unique demographic snapshot of a population and, based upon the relative strength of younger age-classes, is capable of predicting future exploitable biomass. The age-distribution of catch can be used to measure total mortality and thus used to estimate fishing mortality. Fishing mortality can be converted to the harvest rate that, in conjunction with an estimate of total catch, can be used to estimate the biomass of a stock. Furthermore, indicators such as maximum age provide a metric of the suitability of a species for commercial and recreational harvesting. Length-composition data can be used for similar purposes as age-composition data but because of the highly variable and asymptotic relationship between age and length, the demographic
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information content within length-composition data is compromised. Large numbers of fish-age estimates from the catch (or independent surveys) will always be considered international best practice within the assessment and management of higher valued fish stocks. That said, for many/most of the species harvested in NSW there may not be the need for a superior demographic indicator, but simply an indicator that can detect substantial changes to population structure. For this latter purpose, length-based information may be sufficient and will certainty form the basis of a superior stock status indicator in comparison to a questionable indicator of abundance. It is notable that many invertebrate fisheries are equally as well assessed and managed on the basis of length-data as finfish are on age-data. In terms of cost-benefit, lengths are at least 6× cheaper to collect than ages, and initial studies (Scandol 2002b) indicate that they are certainly not 6× inferior for detecting changes to the stock. Pragmatic issues such as costs are likely to dominate the sampling decisions for most species. Interpretation of length data will be dramatically improved if augmented with good quality length- age relationships (including information from sub-legal fish). If resources were constrained, otoliths could be archived and only processed if additional evidence of a trend was required.
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6 REPORTING
6.1 Review of Resource Assessment Reporting in Other Jurisdictions
This section aims to give a brief overview of the reporting approaches to resource assessment undertaken by other Australian and New Zealand jurisdictions. As expected there are a variety of assessment methods and reporting mechanisms in use. Other jurisdictions in Australia publish similar documents to the NSW Status of Fisheries Resources reports, whilst others simply publish stock assessments of particular species or fisheries. The structure of recent and publicly available assessment or status reports are summarised below. Changes to the management of many fisheries to meet the provisions for export approval under the EPBC Act will likely change the nature of stock status reporting in all Australian jurisdictions over the next few years.
6.1.1 Commonwealth
The Bureau of Rural Sciences (BRS), within the Department of Agriculture, Fisheries and Forestry, compiles assessments of Commonwealth fisheries. These Commonwealth Fishery Status Reports (Caton 2002) summarise status of the Commonwealth managed fisheries and classify the status of fisheries as under-fished, fully-fished, over-fished or uncertain. There is also extended discussion of the target and limit reference points that are used to classify stock status. The resource status of each species or species group is classified and indicators of stock status are also summarised (for example catch per unit of effort). For all but the smallest Commonwealth fisheries, the value of fishery landings is in the millions of dollars (though many individual species have landings of much lower value). A range of methods are used to assess the stocks from simple interpretations of CPUE to complex synthetic stock assessment modelling completed by the BRS and CSIRO.
6.1.2 Western Australia
Fisheries Western Australia publishes an annual Status of the Fisheries Report (Penn 2003). Similarly to the Commonwealth document, this report presents the status of fisheries using a range of indicators and methods. Stock assessments are summarised (if completed) and the stock status given as over-exploited, fully-exploited, under-exploited or not available. In multi-species fisheries there is a mixed range of approaches for reporting upon the status of individual species. Assessment methods range from advanced biomass estimation methods for the more valuable stocks to simple catch and effort charts for the low value stocks. WA Status Reports also include a summary of bycatch, habitat, social and economic issues.
6.1.3 Queensland
The Queensland Department of Primary Industries does not publish annual status reports and has a less frequent reporting cycle. The last report, entitled “Queensland’s Fisheries Resources: Current Condition and Recent Trends 1988-2000” (Williams 2002), presents the data available for the targeted species. Most of this information is commercial catch and effort information from the compulsory log-book program. There are no formal summary judgments about stock status (over- fished etc.) and trends in stock status are usually implied from catch rates. There is some discussion in the Introduction about CFISH, the database system used to manage the information from the commercial log-book program. A recreational monitoring program RFISH is used to estimate patterns of recreational catch.
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6.1.4 Northern Territory
The NT Department of Business, Industry and Resource Development published the NT Strategic Plan for Fisheries Research and Development 2002-2006 (Anon 1999). This document examines the outcomes of the Territory’s fisheries management and identifies specific Research and Development outputs to achieve these outcomes. The outcome of “sustainable harvesting” is associated with projects monitoring populations using catch and effort data, size structure (e.g. mud crabs), depletion estimates and tagging programs (e.g. barramundi and Spanish mackerel). Summaries of the major fisheries, including the status and reliability of the stock assessments are also published on the NTBIRD website (www.nt.gov.au/dbird/dpif). These 3-5 page brochures provide an excellent summary of the status of each fishery and would be an appropriate model for the NSW Department of Primary Industries. The NTBIRD also produces status reports that are similar to those prepared by WA and NSW.
6.1.5 South Australia
Primary Industries and Resources SA (PIRSA) sub-contracts resource assessment to SARDI (South Australian Research and Development Institute). Detailed stock assessments have been completed for the States’ valuable fisheries including abalone, rock lobster, King George whiting, pilchards and sardines. For example, for rock lobster (Prescott and Xiao 2001), these assessments are extensive analyses of stock status with an examination of standardized catch rates, mean weight, pre-recruitment abundance, exploitation rate and egg production. Assessments are available from the SARDI web site (www.sardi.sa.gov.au) for abalone (Rodda et al. 2000) and pilchards (Ward et al. 2001).
6.1.6 Tasmania
The Tasmanian Department of Primary Industries, Water and Environment (TDPIWE) contracts the Tasmanian Aquaculture and Fisheries Institute (TAFI) to complete Fishery Assessment Reports. These assessments are detailed and extensive reports for valuable stocks such as rock lobster (Gardner et al. 2001) and abalone (Tarbath et al. 2001). These assessments usually attempted to estimate biomasses of the stock using model-based methods. Less valuable giant crab (Gardner and Mackinnon 2002) and scalefish stocks (Lyle and Hodgson 2002) are assessed with catch and effort data and no biomass estimates are provided. Trigger points (limit reference points) for these stocks are specified as departures from historical catch data, effort data or trends in catch rates. Other general indicators, such as changes to age/length composition and “fish stock stress” are also used. An assessment report on recreational harvesting was also completed (Smith and Heran 2001).
6.1.7 Victoria
The Marine and Freshwater Resources Institute (MAFRI) undertakes stock assessments for the Victorian Department of Primary Industries (VDPI). Detailed annual assessments are undertaken for the abalone and rock lobster fisheries and these assessments are used within processes for setting the total allowable commercial catch in these quota-managed fisheries. Other coastal fisheries are assessed on a less-frequent basis of 3-8 years. Age and length data from commercial catches are monitored for the more valuable species such as snapper, black bream and King George whiting. Summaries of these assessments are available on the VDPI website (www.dpi.vic.gov.au). Effort is currently being directed at developing an index of recruitment for a range of commercially and recreationally valuable species22.
22 This summary was based upon a conversation with Dr Sandy Morison of MAFRI.
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6.1.8 New Zealand
Summaries of stock assessment from New Zealand (NZ) fisheries were published in Annala et al. (2001). This compiled report follows the Fishery Assessment Plenary that presents the summaries of the Fishery Assessment Working Groups. NZ uses assessment methods that are, where possible, based upon the biological reference points MCY (maximum constant yield) and CAY (current annual yield). Various methods for estimating these reference points are provided depending upon the type of fishery being assessed and the type and quality of information available. Given the commitment that NZ has made to quota management systems it is not surprising that most of the assessments are focused upon methods to recommend an appropriate total allowable commercial catch for each fishery.
6.2 Outline of approaches used in the NSW Department of Primary Industries
Output controlled share-managed fisheries (abalone and rock lobster) require the preparation of an annual assessment report on the state of the stock. The draft version of this report is then given to the TAC Committee for consideration. Other stock assessments were reported upon in the NSW Fisheries Status of Fisheries Resources series, FRDC Reports, the NSW Fisheries Resource Assessment Series or journal articles23. Assessments of other NSW stocks have been completed including: snapper (Ferrell and Sumpton 1997); yellowtail kingfish (Stewart et al. 2001); silver trevally (Rowling and Raines 2000); estuary finfish (Gray et al. 2000); sea mullet (Virgona et al. 1998; Smith and Deguara 2002); spanner crabs (Kennelly and Scandol 1999; Kennelly and Scandol 2002) and gemfish (Rowling 1987; Rowling 1990; Rowling 1997; Rowling and Makin 2001)24. Most of these publications presented analyses of the age-structure and length-structure of these stocks (from samples of the commercial fishery) along with plots of catch rates derived from appropriate sources. There is no lack of technical sophistication in any of these assessments but the emphasis was upon graphical and statistical analysis not model-based estimation of biomass or fishing mortality. Scandol and Forrest (2001b) completed some more technical calculations using the data within Gray et al. (2000) but did not calculate biomass estimates because of limitations of the data. The Status of Fisheries Resources reports (Fletcher and Keech 1998; Fletcher and McVea 2000; Kennelly and McVea 2001) have provided a fishery-based (and sometimes species-based) assessment of fisheries resources in NSW. The species-based assessments are simple summaries of a few pages that provide the most recently available catch and effort data. Age and length structures of the exploitable stock are sometimes provided if the data are available. Recent editions of the Status of Fisheries Resources reports also included brief comments on bycatch issues. Many byproduct species were not reported upon in these documents. The current resource assessment program undertaken by the NSW Department of Primary Industries is uneven. Abalone and rock lobster have substantial resources and expertise directed at stock assessment, for example Chen and Montgomery (1999); Worthington et al. (1998); Liggins et al. (2000). This is a consequence of the relative value of these fisheries, and therefore the resources for research and assessment available and the expectations of the TAC Committee. There is also a regulatory provision for a (model-based) stock assessment within the share management plans of these species (Anon 2000c; Anon 2000a). There are consultative and review processes applied to the stock assessment of abalone and lobster stocks via the TAC Committee and the MAC. Other stock assessment reports are reviewed internally unless they are submitted to a peer-reviewed journal.
23 The nomenclature of these publications will change when NSW Fisheries becomes fully merged within the NSW Department of Primary Industries. 24 This summary is not an exhaustive review of all assessments conducted by NSW Fisheries.
NSW DPI - Fish. Res. Assess. Ser. 15 Resource Assessment Framework 57
6.3 Electronic Reporting Systems
6.3.1 Background
Since the development of the World Wide Web there has been a revolution in reporting and publishing. All major media channels, including scientific journals, have augmented print publications with electronic mechanisms for archival, searching and delivery. The reasons for this shift are clear: greater accessibility; lower cost; and, shorter delays to the delivery of content. At first (10 years ago) most web sites were static, i.e, the content was hard coded into HTML (hyper- text markup language) and then rendered to web browsers. It did not take long for computer scientists and software companies to define and implement systems that delivered dynamic content to web browsers. At present, most significant web sites are not displaying static web pages, but the results of instructions that render text, tables and graphics to web pages based upon information drawn from relational databases. Furthermore, most institutions (including the NSW Department of Primary Industries) have developed and implemented “Intranets” as an efficient approach to deliver internal information. Given that the reporting requirements for resource assessment in NSW require greater accessibility, lower cost and shorter delays to delivery of content, it would be churlish not to consider the potential role of electronic reporting systems. Such considerations took place in early 2004 and it has been decided to invest modest resources into developing an effective intranet portal for Resource Assessment.
6.3.2 Objectives of the Resource Assessment Intranet
The Resource Assessment Intranet will have the following criteria: