2.1 Information Required from Resource Assessments
2.2 Mechanisms for Scientific Advice
The general problems of evaluating and assessing resources have been described many times and need not be repeated. For the present purposes two aspects merit attention: the information that needs to be included in a scientific analysis and assessment of a resource if it is to be used in taking management decisions, and the arrangements (especially those that are best done within the framework of CECAF and the project) that will be needed to ensure that the best possible assessments and biological advice on management are made available to CECAF countries.
At the present time, and for the foreseeable future, the available scientific advice will be less accurate, less precise and less detailed than those taking management decisions would like. Although there are scientific investigations of high quality being carried out on the fish stocks of the region, the number of scientists involved, the resources (research vessels, laboratory facilities, etc.) available to them are much less than in many other areas, especially in temperate waters; further, the duration of the investigations, and the series of statistical and other data are much shorter than, for example, in the North Sea. Even in the latter area very much still has to be learnt about the reaction of the resources to exploitation.
Nevertheless, decisions are being taken, almost daily, on the development and management of the fisheries, e.g., on whether to invest in new vessels, or to allow a certain number of foreign vessels to fish in waters under national jurisdiction. These decisions will be taken, correctly or otherwise, whether or not biological advice is available. Clearly any relevant scientific information will improve the chances of the decisions being correct. The scientist should therefore not refuse to give advice on the grounds that the data are, in scientific terms, very far from being conclusive. However, the advice should contain, in addition to the best estimate of say the greatest yield that could be taken, as an average over a period, information on the reliability of this estimate; for example, what might be the minimum level of catch which, on the more pessimistic interpretation of the data, would exceed the capacity of the stock to sustain.
In the past the types of information required by decision-makers from the scientists were few. The decisions being taken mostly concerned whether or not to encourage the construction of new vessels, and if so, of what type. For the first part, the necessary information concerns the capacity of the resource to support extra catches, i.e., whether the resource is lightly or heavily exploited. For the second, information on the distribution and local concentrations of fish is important, but this will as often come from the operations of existing fisheries, or from special survey or pilot scale operations, as from basic scientific research.
Now a much wider range of information is needed. Even in the absence of explicit management schemes, the extension of national jurisdiction is requiring more complex decisions to be taken. For example, the issuance of licences to foreign vessels requires not only decisions on the number and type of vessels that may fish, but also on other matters, such as possible controls on the time and place of fishing, the level of licence fees, etc. Relevant scientific advice must include an assessment of the capacity of the stock concerned to sustain the extra effort. Also information of the possible impact on existing local fisheries must be assessed, whenever they are exploiting the same stock, or other stocks which might be taken incidentally by the foreign vessels; this assessment, and the determination of where and when fishing is allowed may require quite detailed information on the movements and possible stock separation of the species concerned. Assessments of the quantitative effect on the catch per unit effort (CPUE), and thus on the profitability of individual operations and ultimately on the ability to pay different levels of licence fees will also be very desirable.
These assessments of changes in CPUE, stock structures, etc., will become of increasing importance when practical measures are being considered. When a stock occurs in more than one jurisdiction, questions of distribution, of the relative time spent by the fish in each area, are likely to become important when determining matters such as the shares of a total allowable catch that may be taken by each country.
Awareness of the complexity of any natural system is also increasing the range of information required in scientific advice. Often in the past advice has been given under the implicit assumption that the fish stocks concerned are, except for any effects of fishing, in a state of equilibrium. Given sufficient data it would then be possible to determine some unique level of fishing effort or catch that would maintain the stock at the optimum level, however, that level might be defined. In fact it is clear that most stocks undergo considerable natural fluctuations. These may be of short duration, e.g., due to the occurence of a particularly good or bad year-class, or over longer periods of a decade or more. In addition to changes in abundance, there can be changes in distribution. For example, there has been a considerable extension southward of the sardine in the CECAF area. This extension has the practical significance that the sardine resource and its management is no longer purely a Moroccan responsibility, but will require collaboration between Morocco and Mauritania.
In general, the fact of natural fluctuations will require first, that any advice includes some assessment of the likely extent of these fluctuations in abundance or distribution, and second, that arrangements are made to provide up-to-date revisions of estimates of, for example, levels of total allowable catch, to take account of the current situation.
Another factor that is becoming increasingly apparent in relation to pelagic stocks, especially sardines and related species, is that many of them appear to be unstable. That is, beyond some critical level of exploitation, or under some combination of moderate to heavy exploitation and unfavourable natural conditions, that may collapse to a very low level. Such complete or partial collapses have been observed in, for example, the Californian sardine, Norwegian herring and Peruvian anchovy. It is extremely difficult, at our present level of scientific understanding, to determine in advance what level of exploitation will be critical and could cause a collapse. Indeed, in any given situation it has proved difficult even after the event to determine conclusively the relative importance of heavy fishing and natural events in causing the collapse of a particular stock. For example, the importance of the el Niño phenomenon of 1972 in determining the abrupt drop in Peruvian catches, as compared with the effects of heavy fishing, is still not clear. However, the growing number of cases in which collapse and heavy fishing have been associated make it clear that considerable caution needs to be exercised in exploiting these stocks, and the need for such caution should be clearly spelled out in the scientific advice.
The general framework for the provision of scientific advice in the CECAF area is becoming clear. As in most other parts of the world, the need to make the best use of the scientific resources and the fact that many stocks are common to several countries, make a regional approach essential. CECAF and particularly its Working Party on Resource Evaluation provide the basic structure for this regional approach. It is, however, clear that the size and complexities of the CECAF fisheries make it impossible for the Working Party to give proper attention in detail to all the stocks in the course of its sessions. Judging by experience in other areas, especially in the North Atlantic, the regional scientific activities need to be extended in two ways - first, towards the more detailed examination of the state of particular resources in smaller ad hoc working parties, and second, towards the more open discussion of the general topics of scientific interest concerning the resources. Moves in both directions are already taking place.
Through the CECAF Project, meetings of a number of ad hoc groups (on hakes, demersal fish in the southern area, pelagic fish in the northern area, etc.) have been organized. These have been successful in putting together available information, and providing good information on the resources concerned. It is clear, given the changes that are occurring in the fisheries and the relatively short life of most of the fish in the CECAF region, that the work of these ad hoc groups would have to be updated at frequent intervals, preferably each year, if it is to be used in making practical management decisions. It is also clear that in nearly all cases the groups have not had, up to the present moment, as good information available to them as is desirable, and that in many cases it has not been possible, with the time and expertise available, to extract fully all the conclusions that might be obtained from the available information.
The supply of basic information - catch and effort statistics, size composition of the catches, etc. - should be a national responsibility. However, FAO and the project in particular can do much to ensure better collection and reporting of this routine data by countries. This work may include clear specifications of what data are required, how it should be collected, and how it should be reported (this should include the preparation and dissemination of appropriate forms), regular requests to countries to report data, and prompt follow-up if countries fail to report data, or report scanty and inadequate data, and, especially in the case of coastal states, direct assistance in the collection of data (e.g., training in statistical methods, etc.). The present inadequacies in the available data suggest that the volume of possible activity in this field could be very large.
The ability of the working parties to make full use even of whatever data are available has been limited by the restricted number of participants that have expertise in stock assessment and the provision of scientific advice on development and management of resources. A typical working party in the North Atlantic with similar responsibilities for advising on important fish stocks might have a dozen members; half of these would have considerable stock assessment expertise, while the rest would be familiar with the general biology of the fish species concerned, and with the operations of the fishery. Further, most participants are backed up by the resources of large research institutions, and will have been able, in advance of the meeting, to have carried out considerable preliminary analyses of the material. In contrast, most of the participants in the CECAF ad hoc working parties, especially from the coastal states, would not claim great stock assessment expertise; further, most come from small institutions, and have to combine participation in the working parties with a great range of other scientific and also administrative work. Their contribution to the overall activities of the working parties is, therefore, inevitably limited.
The project has attempted to counteract these limitations by arranging for the attendance at the working parties of other scientists, from FAO headquarters or elsewhere outside the region. However, the input of these scientists has also been limited, being mostly restricted so far to attendance at the meetings, plus a small amount of follow-up work. It would, clearly be desirable if the project could arrange for more extensive input, including some preliminary analysis of data in advance of the meeting.
