بهبود استفاده از آمار ماهیگیری در ویتنام برای برنامه ریزی تولید، مدیریت ماهیگیری و حفاظت از طبیعت

The organisation of a fisheries statistical system dictates the potential usage of its information output. Information is used for planning of food production (fish as a commodity), for fisheries management (fish as a renewable natural resource), and for nature conservation (fish as an indicator for ecosystem quality). In this sequence, the required temporal, spatial and categorical resolution of data increases, while aggregation into meaningful ecological spaces requires a subtle way of organising the data flow. The effective usage of the present fisheries information of Vietnam is constrained by (1) its low categorical resolution and (2) the non-transparent aggregation of data into mere administrative spaces. Information requirements can be better articulated with the instalment of mandatory evaluation procedures at all levels in the fisheries administration. Our examples range from the national administration of the 4 million ton marine fisheries in Hanoi, to the local administration of a fishing commune in the Red River Delta.

Management of fisheries and marine coastal resources cannot be effective without reliable information on ecosystem changes and the causes of those changes. Robust fisheries and environmental monitoring systems are indispensable to address questions regarding long-term changes in the coastal ecosystem and regarding impacts both of fishing and of other human activities in the coastal zone [1]. Whereas information needs for fisheries management generally dictate short-term annual input of information for decision making, long-term biological information is needed to differentiate between natural and human-induced changes in fish stocks and ecosystems and to take action accordingly [2]. In many parts of the world, the main supply of such information is through monitoring of fisheries input (fishing effort) and output (catch), i.e. through fishery-dependent monitoring. Fishery-independent monitoring through experimental surveys is difficult to maintain by developing nations, as they are expensive and often cannot generate the amount of data needed for the evaluation of states or changes, especially not in the highly diverse tropical coastal and marine environments. Long-term monitoring of fish stocks, therefore, is almost by necessity dependent on information obtained through the fisheries exploiting them and with that on the official fisheries statistical system in use. Fishery-dependent monitoring entails at least the collection of three essential parameters in fisheries statistics: catch (C), fishing effort (f) and catch-rate (C/f) (Appendix A). Catch and Effort Data Collection Systems (CEDRS) maintained to address information needs for fishery management vary in their degree of administrative and statistical sophistication [3]. Over the past few decades, the methodological core of fisheries monitoring programmes—sampling strategies, data collection and in recent times also data storage and handling—has been consistently addressed in institutional assistance and in capacity building in fisheries management by developing nations. Much less attention was given to the better usage of monitoring information by improving the evaluative capacity of the fisheries administration. In capacity building in fisheries management and research so far, the focus was on data-intensive methods for fish stock assessments, using information on stock structure, on age-specific growth and mortality rates and on catch and effort data. For that purpose, time series of high-quality data are needed. Such series are often difficult to maintain because of the high costs involved in data collection procedures, the institutional set-up and in the maintenance of the knowledge base. The required precision in data collection shows the inefficiencies of the present systems more clearly, leading to frustrations over the applicability of knowledge contained in standard but very analytic fisheries science. The answer to such inefficiencies may not be just ‘more data’. Instead, the answer may lie in the development of management practices that maximise the use of the existing data, information and knowledge on catch and fishing effort and in the improvement of the capacity of an administration to evaluate such information. This presumes an organisational set-up in which it is possible to develop the diagnostic powers [1] needed to turn the information contained in the monitoring data into a growing body of knowledge. In this paper, we will categorise the usage of fisheries statistics in the domains of food production, fisheries management and nature conservation. We identify the differences in data resolution and aggregation required in these domains. Next we examine the fisheries data in the statistical system of Vietnam as available at various administrative levels—from landings per harbour to the national production of marine fish—to assess how well the data collected and processed in the system can be turned into information needed for decision making in these domains. After having identified the major constraints in the generation of information, we suggest improvements to be made in the countrywide fisheries administration.

Formalising evaluation procedures at any administrative level within a fishery information system will enhance the knowledge base for informed decision making. Diagnostic powers developed through regular annual evaluation of fisheries data and information can aid in the development of quantified variables or indicators to address standards or goals to be set in the context of economic planning, fisheries management and nature conservation. Progressive understanding of trends in basic fisheries monitoring indicators will aid in setting standards related to these generalised objectives. Considering the importance of the Vietnamese fishery in the national economy and welfare—the sector provides about half of the annual supply of animal protein in the national human diet, around 10% of the population derives their main income from fisheries, while with over 10% of total export earnings it is the second most important export-oriented sector after crude oil and ahead of rice [12]—it is of vital importance that such diagnostic powers are being developed for a rational exploitation of the fishery resource base. Our presentation makes clear that the extremely low categorical, spatial and temporal resolution and the large biases in basic fisheries data—catch (C), effort (f) and catch rate (C/f)—produced by the present Vietnamese information system will not be conducive to the development of the necessary evaluative power within the present fishery administration. That the Vietnamese fisheries information base is extremely poor can be highlighted by comparing one of its elements, the categorical detail of the report of annual marine catches to the FAO, with surrounding countries such as China, Indonesia, Malaysia or Thailand (Fig. 9). This figure also indicates that the quality of output of the old monitoring system is much lower than the level of development of Vietnam would suggest. This may have to do with the political history of the country. However, it is important here that a new monitoring system should be embedded in the fisheries administration given the potentials of the level of development in Vietnam. Two further constraints—next to the low resolution and the bias of basic fisheries data—will hamper development of evaluative systems, i.e. the development of indicators and the setting of standards such as reference points in the evaluation of fisheries. These are the administrative complexity of present data collection systems and its production planning focus. The first is partly being addressed to the current establishment of a new management information system. The second constraint is more intractable. Vietnam is a signatory to several international agreements relating to sustainable development, precautionary approaches and exchange of fisheries information, which could act as guidelines along which standards of fisheries management and nature conservation could be developed. However, broadly stated as the objectives mentioned in these agreements are it will take time to operationalise the ideas contained in them and incorporate them in fisheries and ecosystem management. The issue here is a governance challenge to absorb the developments around sustainability issues in fisheries and ecosystem management. The development of monitoring systems will aid in this, but only the set-up of protocols and formal procedures for the maintenance and evaluation of this information will generate the knowledge needed to operationalise such goals in quantitative terms. Presently, the Vietnamese fisheries authorities are hardly addressing this issue, which renders the newly developed fisheries monitoring system isolated from the administration and thus extremely fragile. In principle, better usage of information generated can be reached by establishing mandatory evaluation procedures at all levels in the organisation, from the fishing commune in the Red River Delta to the Ministry of Fisheries in Hanoi. Improvements on behalf of the fisheries management can be expected from a thorough analysis of variances in fishing effort and catch rates in space and time: though time series of reliable data that can be related to fishing grounds and which refer to commercially important species are still relatively short (since 1996), the analysis will point at proper indicators for the evaluation of the various management goals. However, reliable information on total fishing effort should be obtained to enable assessments of total resource usage. For environmental impact assessment, the data requirements and sampling efforts are highest. For that purpose, data should be collected and aggregated for relevant ecological spaces, such as river catchments, stretches of coastal area and estuaries. However, it also requires that existing knowledge on coastal ecosystems available in Vietnam should be incorporated in the fisheries information to enable such evaluations. Evaluation of trends in time series of existing monitoring information always leads to useful conclusions if only on the utility of the information, as our examples from the existing fishery information system of Vietnam demonstrate. It appeared that fish production in Nam Dinh Province increased rapidly since 1980, but not as fast as the national fish production. The two southern districts of the province did show relatively a much more rapid increase in production. Most of this increase can be attributed to a fishery expanding to offshore areas since 1990. Inshore fisheries expanded fast during the period of motorisation in the 1970s. Inshore fishermen are probably exploiting stocks beyond maximum sustainable yield, with a complete spatial coverage of the exploitable inshore stocks. Quantification of impacts of large-scale environmental changes, such as effects of the building of the Hoa Binh River dam in the Red River catchment, is impossible. These conclusions refer to information from one province, covering a large spatial area that can be considered a homogeneous ecological space at the centre of the Red River Delta estuary and as such the generalisations are not confounded by information aggregated for highly divergent ecosystems. We do not imply that all existing data should be treated as shown here, given the biases and low reliability of the information present, but examples such as those shown here could be instrumental in developing the necessary procedures of analysis and evaluative skills. The first stage evaluations in this contribution are made with the aid of graphical displays of trends and with textbook assessment tools. Such assessments are feasible at almost every level within a fishery information system or fisheries administration. They provide an insight to the information content of the data despite known biases. With that the diagnostic power of the information can be assessed both at testing hypotheses on causal connections between interventions and effects (fishery developments—catch rate, dam construction—catch or catch rate) and in providing building blocks for constructing scenarios (offshore/inshore fleet—catch rate). Qualitative and quantitative description of variances and biases can qualify the strength and validity of trends perceived. Based on these simple assessments, information that needs to be addressed by a fishery monitoring system can be more clearly formulated. With the present availability of relatively cheap desktop computers doing graphics and assessments to aid in the evaluation of fisheries data are within the reach of every level in a fishery administration.