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Innovative data gathering and assessment approaches to support future management of multi-sector coastal fisheries

Jim Penn

[Jim Penn is the director of research in the Department of Fisheries, Western Australia, His address is W.A. Marine Laboratories, P.0. Box 20, North Beach, W.A., 6920, Australia]

Abstract

The complexity of multi-sector, multi-species coastal fisheries will limit the ability of researchers to utilise traditional methods and data to assess the status of individual fish stocks for management purposes. For these fisheries, it is likely that a variety of methods will be used to generate an array of assessments and indicators for each stock. Management decisions in these circumstances are likely to be based on an overall 'expert' assessment of the stock supporting each fishery within a risk assessment framework.

Such a multiple assessment and monitoring approach will only succeed if all possible data sources are tapped, and in a cost-effective way.

This report will describe a variety of potential sources of fishery data to support this multiple assessment approach, including commercial, recreational and community volunteers, compliance data and targeted licensing systems. The implications for researchers into multi-sector fisheries in the future are discussed.

Introduction

The complexity of multi-sector, multi-species coastal fisheries will limit the ability of researchers to use traditional data sources and approaches to provide stock assessment information needed by management. Similarly, the management decision-making process will be more complex: it will need to take into account a variety of social and economic factors in each of the sectors (or user groups) in addition to addressing the underlying biological imperative of limiting harvests to sustainable levels. Due to the multi-species nature of the fishing activities, particularly recreational angling, it will not be possible in many cases to harvest every stock at its maximum sustainable level. In these circumstances, management controls will need to be based more on a risk assessment approach, to ensure that all stocks are maintained – even though some will be fished below, while others will above, optimum levels.

To ensure appropriate and cost-effective data are gathered and appropriate analyses are carried out to support management needs, a clear understanding of the overall management framework is first required. This issue has been highlighted by the Ecological Sustainable Development (ESD) reporting and assessment processes now being developed (Fletcher et al. 2002). For example, in the ESD reporting of fisheries of the west coast bio-region of Western Australia, the lack of a recreational management plan to match the long-standing commercial management plans has been noted as a deficiency to be addressed (Figure 1) (Fletcher 2002). Similarly, the lack of legislated links between commercial management plans and marine protected areas (which may in future quarantine significant amounts of some stocks from exploitation) needs to be addressed before attempting to set sustainable harvest limits for key target species in the region.

Figure 1. Summary of the process for completing ESD reports.

Future management frameworks for the coastal fisheries

Before considering the requirements of data for stock assessment, it is useful to consider the management arrangements which are likely to be employed. For practical reasons, in the future there will probably be a series of linked management plans, each dealing with a type of fishing activity or sector to be managed (such as commercial, recreational, charter). Appropriate cross-linkages between plans and setting shares of the overall catch (or fishing effort) compatible with meeting the fundamental requirements of stock sustainability and ecosystem-based management, will form an integral part of the new legislative structure. Against this background or assumed management framework there will clearly need to be data on the catches achieved and effort applied by each sector, as well as information on size composition of the catch relative to each species’ size at maturity. This information is necessary to meet annual assessment and environmental audit processes as required by the current Fish Resources Management Act 1994 in Western Australia and related State and Commonwealth environmental audit arrangements.

In terms of stock management strategies there are two broad approaches available: firstly, ‘output’ controls using methods such as catch quotas (i.e. individually transferable quotas, ITQs) and bag limits to directly control the catch; and secondly, ‘input’ controls in which methods such as individually transferable effort units (ITEs), time limits, spatial closures and gear controls indirectly control the catch by limiting fishing capacity. In Western Australia, where the commercial sector is predominantly managed by input controls (particularly the economically efficient ITEs: Rogers and Penn 2000) it is likely that similar approaches in terms of recreational fishing will be most compatible.

Typical coastal finfish stocks – Western Australian examples

To assess likely future management scenarios and corresponding needs for research information, a series of Western Australian coastal fisheries targeted by both commercial and recreational sectors were examined. These fisheries’ commercial data sets (catch histories) illustrate the basic characteristics of a four commonly fished Western Australian coastal finfish stocks.

The West Australian salmon Arripis truttaceus commercial fishery catch data set (Figure 2) shows that the major catches are from the south and west coasts of Western Australia with a smaller, more consistent catch from South Australia (Ayvazian and Nowara 2002a). The major fishery along the south and west coasts targets a spawning migration and is the subject of a commercial beach seine fishery with long-term controls on fishing effort. Nominal effort is effectively constant (although market demand does sometimes limit catch) and as such the catch is a reasonably reliable measure of both abundance and spawning stock size. The stock on the south coast appears to undergo large cyclic variations, which apparently are environmentally driven and independent of fishing pressure. The west coast is even more variable, catches ranging from zero in some years up to 700-1000 tonnes in other years. The variation appears to be caused by effects of the Leeuwin Current on the species' migration around Cape Leeuwin and up the west coast (R. Lenanton, pers. comm.). In the case of Australian salmon the highly variable stock abundance and inability of researchers to forecast regional catches indicate that only an effort-based management system will be effective. Research outputs will need to be tailored to meet this management requirement.

Figure 2. Australian salmon catches for South Australia and Western Australia for the period 1976 to 2000. Catches prior to 1977 for South Australia are unavailable.

A similar situation occurs with the commercial Australian herring Arripis georgianus trap net fishery (Ayvazian and Nowara 2002b) on the south coast (Figure 3). This fishery, also under long-term management controls such that overall nominal effort is effectively constant, shows significant annual variation. As with Australian salmon, the variation is probably related to the environmental effects of the Leeuwin Current (Lenanton et al. 1991). The Australian herring stock supports the largest finfish component of the south and west coast recreational fishery (Ayvazian et al. 2000). The stock's characteristic and significant annual variations in abundance and catch which need to be accounted for when assessing the type of research required for management.

Figure 3. Catches of Australian herring from the south coast and the total Western Australian catch for the period 1976 to 2000.

Estuarine fish resources also make a valuable contribution to the commercial and recreational fisheries along the south coast. Two of the key fish species in these estuaries are black bream Acanthopagrus butcheri and King George whiting Sillaginodes punctata. Data on the commercial catches of these stocks (Figures 4 and 5) indicate that although effort is relatively controlled, the catch (and hence abundance) can be highly variable. In the case of black bream, spawning and recuitment occur essentially within the estuaries, while for King George whiting the catch is based on recruits located inside the estuary prior to their migration offshore to spawn (Ayvazian and Nowara 2002c). The degree of natural variation in abundance of these key angling species suggests that there are few available management options.

Figure 4. The annual catch, effort and catch per unit effort (CPUE) for the black bream (Acanthopagrus butcheri) fishery in south coast estuaries over the period 1980–2000.

Figure 5. The annual catch, effort and catch per unit effort (CPUE) for the King George whiting (Sillaginodes punctata) fishery of Wilson Inlet over the period 1974–2000.

These cases all highlight the variable nature of coastal fish stocks, which are exploited in a multi-species fishery by the recreational sector and a series of commercial fisheries. In this context, the future management arrangements for commercial and recreational fishing are likely to be more appropriately based on input control mechanisms. This type of management generally relies on setting an exploitation rate such that a constant proportion of available stock are taken, rather than on a specific catch for an individual species.

With this background of high stock variability, the questions which are likely to be asked of researchers are:

Fishery assessment and monitoring

To undertake the fishery assessments necessary to address the above questions, the data required are basic. The assessments are likely to support incremental changes to management, particularly where they relate to changes to sectorial catch shares. The data sets needed to answer the questions will be:

The assessment approaches to be adopted for these commercial and recreational fisheries are likely to use yield-per-recruit methods to establish the appropriate size at first capture for each target species. Simple stock production modelling and age-structured models for finfish (where there are sufficient data) are likely to be used to provide basic estimates of sustainable catch ranges. Multiple correlation methods are likely to be used to develop predictive relationships between:

1. spawning stock levels, environmental factors and recruitment to fisheries; and
2. recruitment indices, fishing effort and catch/residual spawning stock levels.

These analyses are likely to be based on selected commercial fisheries data sets as they are more consistent than data sets from other fishery sectors and contain data from a longer time series.

Existing data sources in Western Australia

In Western Australia three basic fishery data categories are available: records supplied by commercial fishers; data obtained by surveying recreational fishers; and fishery-independent research data.

Commercial fishers provide monthly catch and effort records required as a condition of fishery licences, and voluntary research logbooks are completed by dedicated commercial skippers. Landings records provided by fish receival companies are also a statutory requirement, and some information they contain validates commercial fishers’ catch estimates. These vessel data sets, supported by an annual database on vessel sizes, gear and equipment, are supplied directly by the commercial sector at relatively low collection cost, and generally provide a consistent year-round data series capable of reflecting seasonal and inter-annual stock abundance. These commercial vessel data sets do, however, require research validation, particularly the effort measures, which also need to be standardised to account for technology changes. The distribution of fishing effort also needs to be recorded at a reasonably fine scale to allow effective effort to be calculated (Hall and Penn 1979). Once the calibrations have been added, these data sets are a particularly valuable resource for fisheries monitoring and stock assessment for management.

For the recreational fishery, Western Australia has established a series of ‘creel’ or catch surveys of recreational fishers in each of its four marine bioregions: north coast, gascoyne coast, west coast and south coast. These large field surveys, each involving 12 months of field data collection and six months of analysis and reporting, are presently undertaken on a rotational basis, which means that each bioregion is surveyed approximately every six years. The surveys provide detailed information on recreational fishing effort, catches and size composition – for example, see Sumner and Williamson (1999). In addition, annual telephone and mail surveys to gather estimates of recreational catch, participation rates and effort, are carried out on high-value, specifically licensed recreational fisheries for rock lobster Panulirus spp., abalone Haliotis spp., marron Cherax tenuimanus and trout Oncorhynchus mykiss and Salmo trutta (reported in Penn 2002). Some recreational fishers also keep logbooks in which all their fishing activities are recorded, and most fishing clubs record competition catch in a series of recreational databases. Both of these record sets are volunteered to fishery managers and scientists. In both of these cases, the data collected are relatively inconsistent, reflecting varying effort levels which are not as directly related to fish abundance as is generally the case with commercial catch data. Overall these voluntary recreational data sets are relatively inexpensive to collect but do not provide a reliable basis to assess within-year changes in abundance or stock status. They can, however, be useful in assessing long-term trends in recreational catch rates and fish sizes.

The third category of data available in Western Australia is from fishery-independent research. This research provides more reliable data on matters such as general biology and size composition but is also very expensive to collect. However, reliable measures of abundance cannot usually be gathered from fishery-independent surveys as they cannot provide adequate levels or distribution of effort. Collection of such 'independent' data through direct collaboration with commercial fishing activities (i.e. on-board catch sampling, commercial vessel surveys and market sampling of catches) has generally proven in Western Australia to be the most cost-effective method of data gathering for fishery assessment. This approach of sampling on commercial vessels or from independent research vessels is most effective when used to calibrate the commercial fisheries data sets.

For environmental parameters, Western Australia is fortunate in having a very long time series of sea level data. This data provides a good indication of the strength of the Leeuwin Current, the most dominant oceanographic variable for Western Australian coastal waters. In addition, the State has the usual climatic data series for rainfall, evaporation, wind, and cyclonic activity, which is a key environmental factor in the north-west of the State. More recently, sea surface temperatures and ocean colour data sets have become available from satellite recordings.

For Western Australian fisheries management purposes, all of the above conventional categories of fisheries data, together with environmental/oceanographic data series, are utilised in the assessment process. For the major Western Australian commercial fisheries where extensive time series of data are available and major research projects are supportable, these data sources are clearly sufficient for management purposes. In contrast, for the smaller coastal fish stocks, which support relatively small-scale commercial fisheries and are also fished extensively by the recreational sector, these traditional sources of data do not provide sufficient coverage to support management decision-making needs.

New data opportunities

For the coastal multi-sector fisheries, new approaches to obtaining improved management data are emerging from the collaboration between fishers (both commercial and recreational) and fisheries researchers. They are:

1. Biological sampling by commercial fishers

Commercial fishers are often willing to collect detailed data on fishing effort/location, species caught, size and sex composition on either a voluntary or a limited payment basis. Examples of this activity include Western Australian rock lobster fishers who voluntarily provide to the Department of Fisheries detailed data on the catch taken by the last ten pots pulled each day. In the Northern Prawn Fishery, crew members have collected detailed species and size composition samples from across the fishery for the Commonwealth Scientific and Industrial Research Organisation in return for a small payment per sample collected. In all of these cases, specific training for vessel crews and regular feedback is necessary to ensure consistency and reliability of the data collected.

2. Environmental recording by commercial fishers

In addition to direct fisheries assessment data, the operators in two small-scale fisheries, the Coorong fishery in South Australia (ABC Landline 2000) and the Bribie Island fishery in Queensland (Bribie Island Commercial Fishers Association Inc. 2001), have actively involved themselves in environmental monitoring of their fishery areas. As regular and expert observers of their environment, and as fishers, they have a direct interest in the relationship between environmental factors and fish abundance and recruitment.

Monitoring costs to record basic parameters – such as temperature, salinity– are minimal, and increasingly, these data are being recorded by skippers on a voluntary basis. With collaboration between researchers and such expert fishing groups, standardised and reliable environmental databases can be developed for regional coastal areas. Observations on relative fish abundance linked to environmental conditions can also be obtained from this collaboration, providing environmental data on a more local scale than is available from the more large-scale, regional oceanographic and weather data series.

3. Research surveys linked to commercial access

Commercial fishing is currently being phased out of many coastal and estuarine areas around Australia as a result of Government buy-back schemes. The absence of commercial fishing is leading to significant gaps in data availability for stock management. An opportunity exists for restricted commercial fishing surveys in these and other closed areas to be carried out under special licence conditions so that samples for research can be obtained. Sampling costs would be offset by returns from catches taken, as occurs in major Western Australian prawn fisheries (E. Sporer, pers. comm.). Similarly, in areas where commercial fishing is still permitted, specific research sampling could be undertaken, perhaps funded by licence fee discounts supplemented by the value of the catch.

4. Short-term recreational licensing systems

The current focus of most Western Australian recreational licence systems, and of those in other States, is to provide revenue for managing the fisheries resources. These licensing systems also have some limited research benefits in providing an identified group of people for catch survey purposes (Molony and Bird 2002). It is possible, however, and at minimal cost, to utilise the licensing systems themselves to directly obtain data on fishery-specific and regional recreational effort, and in some cases, catch. For example, daily or weekly licences sold through a regional network would provide direct measures of fishing effort and its distribution. For fisheries such as abalone where there is a high degree of certainty that the bag limit will be obtained, a short-term licence for a single bag limit would also give a direct measure of catch by region and time. It would also generate a fishery database for low-cost follow-up data gathering by targeted telephone interview.

While there would be an operational cost for licence sales and the recording and processing of the data from such a licensing arrangement, the current survey costs would be lowered, a more comprehensive data set would be created, and funding generated for general management purposes. Validation of such data would be provided by the regular compliance activities undertaken by the management agency in each case.

5. Indicator creel surveys

While comprehensive on-ground creel surveys are required, particularly for the management of resource-sharing, they cannot generally be economically undertaken on an annual basis. An opportunity exists for use of both compliance activities and recreational fishery volunteers to undertake short, low-cost surveys at peak periods identified by the results from full-scale 12-month creel surveys. These standardised ‘indicator surveys’ should be able to provide an assessment of annual variations in catch and effort, which would lead to an index of stock abundance from year to year. Such surveys, linking the larger creel surveys carried out at intervals of five years or more, have the potential to be a cost-effective means of monitoring catch and effort and thus provide indices of stock abundance, particularly if undertaken as part of a voluntary program.

6. Nursery area recruitment surveys

Many coastal aquatic species utilise protected coastal or estuarine areas as nurseries. Regular sampling of these areas for juvenile fish can provide an index of recruitment to the fishery independently and in advance of the fishery. Such a survey system is currently being developed for the south and lower west coasts of Western Australia, as a follow-on from sampling as part of a major study on Australian herring in Western Australia and South Australia (Ayvazian et al. 2000). Another example of this has been the successful use of a beach seine survey to measure juvenile tailor Pomatomus salatrix abundance carried out over several years by a high school biology class in Carnarvon, Western Australia (S. Ayvazian, pers. comm.). If similar surveys could be undertaken by student groups supported by trained teachers or volunteers at defined locations and times within a year, costs would be minimal. To ensure consistency in both sampling methods and levels of enthusiasm from year to year however, such activities require a formally trained research coordinator.

7. Compliance interview data

Fisheries enforcement officers on patrol regularly interview recreational fishers and examine their catches for adherence to the fishing regulations. Records of these interviews are being utilised in Western Australia in a Fisheries Research and Development Corporation-funded project designed to improve the targeting of compliance effort and measure trends in levels of compliance (J. McKinlay, pers. comm.). With minor changes, data gathered by fisheries enforcement officers could be used in biological and stock assessment research.

Firstly, by extending the recording to cover both legal and illegal catches, and by standardising the patrol timing from year to year at high recreational activity times, these data could provide ‘indicator’ surveys for abundance and fishing effort, as noted above. Secondly, by incorporating questions in the interview sheet about the frequency of fishing and whether the fisher has been interviewed previously, it would be possible to generate ‘mark recapture’ type estimates of the total number of fishers undertaking the activity. These ‘effort’ data, together with indicator catch rates from the patrols, can potentially provide estimates of total catch of target species, as well as more reliable estimates of levels of compliance with the regulations, which can assist in managing enforcement activities.

8. Recreational research volunteers

Many recreational fishers, with minimal incentives, are prepared to assist in generating research data. Current Western Australian examples include:

• use of volunteers to catch newly recruiting (0+ age) tailor at a key location in the Swan River estuary over an eight-year period. Fishing times and durations (12 days over three months, and two hours per day at sunset) are standardised from year to year. Data generated provide an index of annual recruitment for cross-correlation with commercial catch rates and future correlation with subsequent recreational catches of older fish from adjacent ocean beaches. The financial cost of this work is limited to food (pizzas) and the time of expert research staff who coordinate the fishing and recording of the catch and effort data.
• a group of volunteers, some of whom travel 1000 kilometres to Shark Bay annually, assist researchers in the capture and tag-and-release of mature snapper Pagrus auratus during the spawning season. This work is providing female gonad maturity samples as part of the annual egg and larval survey (Jackson and Cheng 2001) to estimate spawning biomass for the discrete Shark Bay snapper stocks, and tagging to provide second estimates of spawner numbers and sizes based on mark recapture rates. The cost of this work is small subsidies on bait and boat fuel used in Shark Bay by four to six volunteers' vessels (6–7 metres in length) involving about 24 anglers, and training by the research team in tagging and recording methods.

There are significant opportunities to expand on these types of voluntary program for targeted recreational fishing and tagging. The programs can also be used to generate direct information on exploitation and mortality rates and relative catch shares between sectors.

9. Volunteer Fisheries Liaison Officer programs

In Western Australia there are about 250 recreational fishers who take part in fisheries education and compliance activities at times of peak recreational fishing activities. With appropriate training, these volunteers are able to undertake creel surveys as part of their education activities whilst on patrol. At peak fishing times, volunteers can be particularly useful for undertaking ‘indicator’ creel surveys (point 5. above) which measure year-to-year variations in fishing success.

Many of these volunteers also act as volunteer researchers (point 8. above) and are involved in collecting research information, e.g. on catch size composition of abalone and tailor. These volunteers are often recruited as fishing experts to undertake telephone surveys of licensed recreational fishers on a minimum payment basis.

In each of these approaches (points 1–9 above), the identified data gathering opportunities can be expected to contribute to the creation of databases on total catches (by species), relative fishing effort applied to each fishery, indices of abundance (particularly recruits) and size composition of the catch each season. Each data set will, however, require validation and cross-referencing to allow compilation of long-term standardised data sets capable of input to the various assessment models. This process will be the major specialised ‘research’ involvement and will require a high level of statistical treatment to integrate the various data and annual indices into reliable long-term databases.

Discussion – future directions

Researchers attempting to monitor and assess multi-sector coastal fisheries are unlikely to have the luxury of sufficiently detailed data and time series of information to undertake sophisticated species-specific stock assessments utilising the classical fisheries models. In many cases, however, there will be sufficient information available if all of the previously described sources are utilised to provide indicators capable of detecting significant changes in the abundance of the key target stocks. These data, together with a good understanding of the basic biology (growth, mortality and reproduction) of the key species being exploited, should as a minimum enable risk assessment modelling to be carried out with the purpose of setting acceptable catch (or effort) ranges for the fishery and the various sectors involved in it. Having generated appropriate (precautionary) ranges and trigger points for fishery management, the main purpose of the research activities becomes the generation of performance measures such as annual or season indices of sector catches and effort, and ideally, specific measures of recruitment and spawning stock levels. These indices can also then be examined for correlations with environmental factors, to detect where influences outside of fisheries management control may be affecting stock abundance independently of the effects of fishing itself.

In examining alternative opportunities for gathering research data for fisheries management purposes, it is also important to consider the whole process and costs involved in management. That is, in addition to the cost of obtaining research information needed for management decisions, the management process also involves stakeholder consultation and compliance monitoring. These all involve significant costs. Stakeholders involved in the research process become better educated about the impacts of fishing on the stocks and are more likely to understand the need for management of the fisheries involved.

The opportunities identified in this paper for gathering data via commercial, recreational and community collaboration can produce valuable data provided adequate resourcing is committed to the training and ‘encouragement’ of the people involved, and to the critically important validation process necessary to ensure the data sets are reliable. More significantly, however, the direct involvement of stakeholders in the research programs has additional benefits in generally educating the fishers and the wider community in fisheries research and stock assessment techniques. This ancillary education/extension process is particularly valuable in gaining the community’s acceptance of the management processes flowing from data and research analysis, and can improve the efficiency and decrease the cost of community consultation normally required in the management process. Similarly, the overall cost of education to ensure compliance with the rules may be substantially reduced if the research program is specifically arranged to create community understanding of the fishery and acceptance that the scientific data supporting management is reliable.

This approach will, however, require the full integration of the research activities within the overall management planning process, and also that research projects are specifically designed to generate both reliable research data and positive education/compliance outcomes with the stakeholder groups. Optimally this approach should enable scarce financial resources to be allocated more efficiently to generate improvements in quality of data and management acceptance.

The major challenge for the fisheries researchers of the future will be to develop the skills needed to ‘manage’ the wider variety of people involved in research, while ensuring that the quality of the scientific information generated is maintained. The adoption of this approach may not substantially decrease the cost of research, but it has the potential to significantly improve the overall management outcome.

Acknowledgments

The Department of Fisheries’ coastal finfish research group led by Dr Suzy Ayvazian and Ms Gabrielle Nowara kindly provided the time series data for a number of their fisheries. Many of the innovative methods and concepts for data gathering described in this paper have been developed from discussions with my colleagues in the Department’s Fisheries Research Division and are now being implemented or are in the process of implementation by researchers at the Western Australian Marine Research Laboratories. Their valuable input to the paper is gratefully acknowledged. I also particularly thank Drs Rod Lenanton, Nick Caputi, Rick Fletcher and Greg Maguire for the many useful discussions we had and their inputs to the paper. Andrew Cribb, manager of the Department’s recreational fisheries program, also contributed significantly to the concepts and ideas contained in the paper.

References

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¹ Standardisation of effort is needed to take into account the impact of technological changes to fishing performance (over time) and hence catches achieved with a given amount of effort.