Shark Conference 2000
Honolulu, Hawaii February 21-24
|FAO TECHNICAL WORKING GROUP ON THE CONSERVATION AND MANAGEMENT OF SHARKS|
Tokyo, Japan, 23-27 April 1998
FAO. 1999. Report of the FAO Technical Working Group on the Conservation and Management of Sharks. Tokyo, Japan, 23-27 April 1998. FAO Fisheries Report. No. 583. Rome, FAO. 28p.
The FAO Technical Group (TWG) on the Conservation and Management of Sharks reviewed available information pertinent to the subject, including draft documents on the status of sharks species, an overview of shark fisheries by region, case studies in management of elasmobranch fisheries, a shark species catalogue, on shark utilization, marketing and trade and a review of data needs for management of shark fisheries. It considered preliminary drafts of guidelines and a plan of action for the conservation and management of shark fisheries and discussed specific issues in two working groups on management and on data needs. On the basis of the discussion of the TWG Technical Guidelines for the Implementation of National Plans of Action for the Conservation and Management of Sharks (FAO Fish. Circ. No. 939) were elaborated for the FAO Consultation held in October 1998.
The proposal of the Working Group for the guidelines is to have a general introduction on fisheries management, and then to focus on those particular aspects of management that are unique to shark fisheries, using the draft guidelines provided by the FAO Secretariat as a starting point. Although it was realized that each management situation will be different according to area, species and type of fishery, a number of generalisations were made.
Reporting and recording of data
Collection and collation of data on sharks has a low priority in many cases. The biological characteristics of most sharks means that they cannot withstand consistently high rates of exploitation. Often fisheries lead to a local depletion of numbers and it is unknown if this is a local or a regional effect. In order to determine if the harvesting of sharks is sustainable the stocks must be monitored and the reporting and recording of data must be improved. Many shark species are caught in a multispecies fishery and landings data are often lumped under one heading. Due to the high variation in reproductive and life history parameters, some species are more in need of management than others. We should recognize that all fisheries management tools (e.g. TACs, effort control, closed areas, closed seasons, size-selective harvesting) can be used to reduce total fishing mortality (F) on sharks, taking their specific biology into account, although new methods may be necessary. Sharks are utilized for a wide range of products and trade data may only be noted as export, so improved tariff codes should be considered to improve recording of (species) data. Data on discards should also be improved, so captures (catch + discards) should be recorded. Fishermen should not be relied upon alone to provide detailed species data and observer programs and (fisheries independent) surveys should be initiated. Practical systems to facilitate accurì.
measures and the precautionary approach
A discussion arose concerning two points, the first being what to do ian, 23-27 April 1998
PRIVATE ion on stock status and the second being how to manage a multispecies fishery in which there is one or more relatively lesser productive species. Fishing mortality should be sustainable for all the species involved and we should strive for long-term ecosystem stability, within the concept of the precautionary approach. A conclusion was reached that management of a multispecies fishery should take into account the specific biological and ecological characteristics of all species. There should be provisions to allow for the management of the least productive species. Technological improvements, or management measures, such as area or seasonal closures or live release policies, could be used as management tools to mitigate the impacts on both the shark populations and the fishers themselves.
Following a discussion on the different meanings attached to the word 'bycatch', it was decided to adopt the terms target and non-target, with individuals being retained or discarded. If sharks can be returned to sea alive then their chances of survival may be quite high - this should be considered as a management measure and recorded as such. Research to estimate and increase survival should be carried out. This measure was considered a difficult one to persuade fishermen to carry out, but this brought up the topic of enforcement and compliance. The FAO Code of Conduct (Paragraph 8.5.1) indicates that 'states should require that fishing gear, methods and practices, to the extent practicable, are sufficiently selective so as to minimize waste, discards and catch of non-target species'. Although regional management is essential for many shark species, there must be national bodies able to deal with management issues. The interaction and commitment of national and regional bodies is vital for the success of regional management. The WG suggested that there should be an Appendix of the various regional management initiatives taken.
The fisheries for those species which are subject to finning should be managed with the aim to maintain a level of fishing mortality compatible with adequate recruitment and survival of the stocks. Priority should be given to the measurement of catch and effort and to identify the species in the landings of fins.
The exposure of elasmobranchs to fishing activities has increased significantly during the past 30 years throughout the world's oceans. They are caught as the target of fishing that has developed specifically to increase their utilization and also caught during fishing directed at other species in which they are caught unintentionally. It was once acceptable to consider all sources of fishing mortality as insignificant because elasmobranchs were mostly taken as non-targets and there was virtually no targeted fishing. The increased demand for and harvest of elasmobranchs in directed fisheries has elevated the need to include the impacts of all sources of fishing mortality on each species. Even if the unintentional mortality remains very low, the additive effect it has on each species in today's management of elasmobranch fisheries becomes extremely important. Our management efforts should include the recognition and regulation of all sources of fishing mortality, whether or not that mortality was intended to occur, if we are to prevent the depletion of these resources.
There is unanimity among fisheries biologists and managers assembled in Tokyo, Japan, during April 23-27, 1998, that at a minimum, it is unacceptable to allow the combined effects of target and non-target fishing mortality to reduce elasmobranch stocks below a level of sustainability. In addition, there is agreement among the world's nations that long-term sustainable use of fisheries resources is the overriding objective of conservation and management. Article 7 of the FAO Code of Conduct for Responsible Fisheries states that management measures be designed to maintain or restore stocks at levels capable of producing maximum sustainable yield (MSY), as qualified by relevant environmental and economic factors, including the special requirements of developing countries. It appears possible that short-term economic factors could conceivably be used to adjust management measures such that stocks could be maintained at levels far below that capable of producing MSY, even to levels that would lead to extirpation of a species or stock. It should be made clear that total fishing mortality of elasmobranchs, regardless of intent to capture, location of capture, gear used, species caught, use or disposition of capture, or any other factor, should be no greater than that which is sustainable. In other words, total fishing mortality must be kept sufficiently low to allow each elasmobranch species or stock to maintain itself through reproduction.
Established regional bodies should be encouraged to lead coordinated efforts to: (1) standardize data collection for (trans-boundary) elasmobranchs; (2) facilitate cooperative research; and (3) develop appropriate comprehensive management measures. These measures can then be implemented by national organizations. Those countries which contribute to the total fishing mortality on a species should participate in management, where appropriate and possible.
There should be adequate enforcement of whatever management measure is adopted to ensure sustainable F. Methods of obtaining compliance with management measures should be studied and encouraged at the national and regional levels.
If sharks are released alive as a management measure the possibility of them surviving should be maximized and experiments on survival of returned sharks should be carried out.
Management of a multispecies fishery should take into account the specific biological and ecological characteristics of all species. There should be provisions to allow for the management of the least productive species. Technological improvements, or management measures, such as area or seasonal closures or live release policies, could be used as management tools to mitigate the impacts on both the shark populations and the fishers themselves.
Compliance with international guidelines
It is not the task of the TWG to recommend that anyone comply with the guidelines or voluntary international agreements. However it should be pointed out that the FAO Code of Conduct has a provision encouraging countries to implement the Code as law and that the FAO Conference, when it adopted the Code of conduct also noted that Code contains various provisions which could be made compulsory.
The points in the draft guidelines (revenues, costs, fishing activities, employment, development of fisheries) cover this issue and were dealt with by the other WG. Moreover, the precautionary approach includes socio-economic issues and the issue has been well-documented in other international agreements (Kyoto Declaration, Declaration of Rome World Food Summit).
An extensive discussion took place on the ethical and moral issues of finning of sharks and discarding of carcasses. Although several issues were identified, the group could not reach a consensus as to how to word a guideline concerning finning and the ethical and moral issues involved and considered such a guideline to be outside the remit of the group.
Management guidelines may be directed at one of three levels. At one level, policy and senior decision makers will be concerned with strategic implications of management, at another, biologists and economists will be concerned with the collection of fisheries-related data and its interpretation. Between these two levels will be the 'operational' managers, those with the mandate to implement plans aimed at achieving management objectives using the information supplied by the resource biologists and fisheries economists. It is at this middle level that these guidelines are directed. These guidelines are intended to supplement those described in the FAO "Code of Conduct for Responsible Fisheries" (FAO 1995), and elaborated in the FAO Technical Guidelines for Responsible Fisheries, Volume 4 (FAO 1997). In this document, an attempt is made to provide general guidelines that consider the particular characteristics of elasmobranch resources and their fisheries. Although some directed and bycatch fisheries for elasmobranchs might require fundamentally different management responses depending on the respective management objectives, an attempt is made to address these possible differences as required under each specific heading while presenting one single comprehensive document. This might be more appropriate given (a) the poor knowledge about elasmobranch resources and the limited experience for their fisheries management globally, and (b) the inter-changeable nature of elasmobranch fisheries that may rapidly move from one to the other depending on economic and resource considerations.
Fisheries for elasmobranchs (1) may be the object of a specific directed management plan, (2) their management may be implicit within a general national approach, or (3) the fisheries may be prosecuted outside any planning context at all. A common objective of management plans is to achieve a desirable level of fishing mortality in the fishery. This may be done by limiting fishery inputs (i.e., the amount of fishing gear or fishing effort that may be used) in relation to the fishing mortality it generates. The plan may aim to regulate the catch that can be taken from the fishery by setting total allowable catches (TACs), either for the fishery as a whole or broken down by the different gear sectors. Other plans aim to maintain a minimum level of biomass often expressed in relation to its spawning capability.
As apex predators, elasmobranchs have an important role in ocean ecosystems in maintaining the ecological balance. Further, they represent a valuable resource but little attention has been paid to their management.
This report focuses on resource and fishery management issues relevant to preparation of a shark fishery management plan. This part of the recommended guidelines is not concerned with issues of monitoring, control and enforcement (MCS) though obviously without enforcement the success of any management plan is endangered. The report does not deal in detail with issues such as means of ensuring effective stakeholder consultation, despite the importance of such activity to successful implementation of management plans.
In many elasmobranch fisheries, achieving a specific singular elasmobranch management goal is, if not difficult, impossible, because of the multispecies nature of the fisheries. An example is demersal trawl fisheries that catch batoids. Successful conservation of batoid populations in these cases may require restrictions on the activities of the trawl fishery, and consequential under-utilisation of more important target fish resources of the trawl fishery that it is impossible to gain agreement for their implementation.
2. The Information Base
The aim of this section is to provide general guidelines for the data needs for elasmobranchs fisheries management, whether these fisheries are industrial, artisanal or recreational in nature, and whether they target elasmobranchs or take them incidentally. Necessarily, most of the data requirements outlined here are no different for those needed for managing fisheries for almost any other type of marine group. However, knowing the lack of experience in the implementation of management programmes for elasmobranchs and associated data gathering systems in the large majority of fishing countries we feel it would be useful to provide guidelines that were as comprehensive as possible. The layout of this section tries to prioritise by differentiating the types of data that are essential and those that, although important for better fisheries management, might be very difficult to obtain. Undoubtedly, in an ideal situation all the types of information listed here should be available if good management is to be achieved, but considering the different economic, cultural and social realities of each fishing nation, we should be realistic and hope that where ideal conditions do not exist, the available resources are used in gathering the most relevant data. If funding and human resources become more available, managers can tackle lower priority data collection activities. In all cases, a thorough understanding by fishermen of the conservation needs and management system envisioned is recommended for successful gathering of accurate data. This can be achieved by using social scientists together with the biologists for design and implementation of the overall sampling programme.
The proper design of fishery data collection schemes first requires a good understanding and thorough description of the fishery or fisheries acting upon the resource concerned. This includes (i) determination of the structure of each fleet by vessel size and power, gear characteristics, knowledge of their operations and landing sites, and (ii) collation of the information on the distribution and composition of the stocks.
Trends in catch, fishing effort and CPUE are usually critical elements in fishery management decisions. These data can be used for simple stock assessment of shark species by the application of biomass dynamics models. Life history information on reproduction, longevity and growth enable the use of methods such as life tables. More sophisticated methods such as length or age-structured simulation models require, in addition to the above, additional information such as mortality, length and/or age composition, and fishing gear selectivity parameters. These models can be improved by making use of additional information such as time series data on mean size of fish in the catch, and tag release-recapture data. For highly mobile species, uncertainty can be further reduced by using spatially-structured models. In all cases, time series of fishery independent abundance indices can greatly reduce uncertainty in the estimations of any fishery model.
2.2 Estimation of Catches and Effort
These data are the most fundamental and thus their collection should be the first objective of information gathering programmes. Various levels of data collection may be attempted depending on the availability of resources and the management demands.
Accurate estimation of fishery statistics requires sampling programmes based on rigorous probabilistic survey designs for the selection of vessels and fish to be sampled. Methods of design of such sampling programmes have been described in many reports, e.g., Beverton and Holt (1956), Caddy and Bazigos (1985) and Lagler (1968).
Methods that are appropriate for collection of data at-sea are (Note that more than one approach should ideally be used to corroborate and improve the quality of the data):
The following approaches - as needed - are recommended to successfully obtain this information:
2.3 Stock Structure and Migration
Given the mobility of many shark species and the large distribution ranges occupied by some. This additional information will permit improved management advice.
This information is essential in the case of migratory or transboundary stocks, and is usually obtained through carefully designed tag and release programmes and by studies of population genetics. Additional techniques are analyses of: catch distribution and timing, morphometrics, life history parameters, and parasitic fauna. Tagging can be done in conjunction with the research surveys and will depend strongly on good reporting rates of recovered tags from the fishermen. A careful analysis of available biochemical techniques should be performed before choosing one for the population genetics studies in order to assure as far as possible the level of resolution needed to differentiate a particular stock (see Carvalho and Hauser 1995).
2.4 Fishery independent abundance indices
Catch-per-unit-effort (CPUE) may not reflect the abundance of the stocks as the dynamics of fishermen's behaviour and the movements of the fish stocks may bias or invalidate estimates of CPUE (e.g., see Hilborn and Walters 1992). Research surveys based on statistically sound designs may provide accurate measures of stock abundance. If the CPUE of the fishery does measure resource abundance accurately, survey-based abundance indices can still be important in reducing uncertainty during fitting of stock assessment models to fishery data. Chartering of fishing vessels may provide a cost-effective means of undertaking resource surveys if research vessels are unavailable.
2.5 Biological Information
Resource management advice may be improved if the following biological information is obtained:
Monitoring of Catch Composition
Life History Information
Research surveys can be used to gather additional information. If on-board observers are available, they are also a means of data gathering. Well-designed tagging studies can be used to provide information on rates of mortality and growth.
2.6 Economics of the Fishery
Management of elasmobranch fisheries may involve economic considerations both at the level of the firm or the vessel, and at the level of the industry, or higher macro-economic level. In this case, consideration such as those of opportunity costs of capital will be of concern. For analysis of vessel or sector profitability, knowledge of costs and revenues of fishing can be determined through appropriate sample surveys. Respondents should be selected on a probabilistic basis according to an appropriate survey design.
2.7 Social Aspects of the Fishery
Fisheries for elasmobranchs take place within a wide range of social and economic circumstances from industrial fisheries with formal access rights, through open access situations to artisanal fisheries or primarily subsistence fisheries. To successfully take this into consideration, it will be necessary for appropriate social and economic analysis to be carried out. Accurate socio-economic information helps managers determine optimum resource allocation, economic benefit and economic evaluation of various management alternatives. Where appropriate, as central stakeholders, fishermen should be involved in data collection programmes and decisions relating to data collection programmes, using, e.g., log book programmes. Further, usually fishermen's support is essential for the success of management initiatives.
Decisions relating to socio-economic objectives may require information on:
2.8 Trade and Market Data
Trade in shark products has been an important factor in accentuating problems of conservation. Thus, trade data can be important in assisting to characterise management problems. The following data are relevant and should be collected:
3. Literature Cited
Beverton, R.J.H. & S. J. Holt, 1956. A Review of Methods for Estimating Mortality Rates in Exploited Fish Populations with Special Reference to Sources of Bias in Catch Sampling. J. Rapp. Cons. explor. Mer. 140(1):67-83.
Caddy, J.F. and G.P. Bazigos 1985. Practical Guidelines for Statistical Monitoring of Fisheries in Manpower Limited Situations. FAO Tech. Report No. 257. 86pp.
Carvalho, G., and L. Hauser. 1995. Fish population genetics. Rev. Fish Biol. Fish. (5?): xxpp
FAO 1995. Code of Conduct for Responsible Fisheries. Rome. 41pp.
FAO 1996. Precautionary Approach to Capture Fisheries and Species Introductions. FAO Technical Guidelines for Responsible Fisheries. No.2. 54pp.
FAO 1997. Fisheries Management. FAO Technical Guildlines for Resonsible Fisheries. No. 4. Rome. 82pp.
Hilborn, R, and C. J. Walters. 1992. Fisheries Stock Assessment: objectives and uncertainty. Chapman and Hall. London, xxx pp
Lagler, K.F., 1968. Capture, Sampling an Biological Sampling Methods and Procedures. In Fish Production in Freshwater. Ed. W.E. Ricker
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