MSc. Thesis Submitted in Partial Fulfilment of the Requirements for the Master of Science in International Fisheries Management ___________________________________________________________ BIOECONOMIC ANALYSIS OF ARTISANAL MARINE FISHERIES OF TANZANIA (Mainland) By Isaac G. Berachi Department of Economics Norwegian College of Fishery Science University of Tromsø, Norway Tromsø, May 2003 1 ACKNOWLEDGMENTS First and foremost I would like to thank the Almighty God for making my academic aspirations and accomplishments a reality. Then my sincere and utmost gratitude goes to my supervisor Ass. Prof Arne Aide for his invaluable support and patient guidance during the course of this thesis. I am highly indebted to NORAD for offering me the scholarship to pursue MSc at this esteemed college, and to the Centre for Environment and Development Studies (SEMUT) for its financial support to undertake the fieldwork. In deed, I have benefited a lot from the program to transfer knowledge to home country. I would also like to extend my heartfelt thanks to the program co-ordinators (Anne-Marie Hektoen, Arne Eide and Jorge Santos) due to whom our stay was both academically and socially successful. I dearly thank my family for their never-ending love and moral support. Special gratitude goes to the Fisheries Division officials of the Tanzanian Ministry of Natural Resources and Tourism for their permission to carry out the study, and to Yahya Mgawe for his kind assistance during the data collection. Paul, you took your time reading manuscript of this paper that is worth mentioning. Last but not least, I thank all my NFH classmates, UiTØ friends and all Eritrean and Norwegian folks who have been part of my stay in Tromsø, it was a pleasure and experience to have acquainted with you all. 2 ABSTRACT Artisanal marine fisheries of Tanzania involve the majority of the coastal population whose survival is entirely dependent on the coastal fishery resources. In this paper the artisanal sector of the marine fisheries for the period 1987 -2000 is analysed by applying Gordon-Schaefer Surplus Production Model on time series of total catch and standardised effort. Static reference points such as open access equilibrium, maximum economic yield and maximum sustainable yield are established in addition to the more dynamic optimal yield solution. The results show that the fishery has expanded beyond the economically optimum point where the current level of effort is further beyond that of maximum sustainable yield resulting in suboptimal yield, i.e. it has been evident that there is already overfishing in the inshore waters where majority of artisan fishermen concentrate. The major constraint is assumed to be the inadequate institution and legal framework for fisheries management. Also social and equity considerations have been the bottlenecks for the implementation of regulatory measures which would cause further unemployment. Thus, the present study calls for policy intervention to rescue the stock from the existing high fishing pressure that would lead to depletion. KEYWORDS: artisanal fisheries, efficiency, optimality, sustainable fishing, overfishing, bioeconomic model, maximum economic yield, optimal sustainable yield, maximum sustainable yield, open access equilibrium, catch per unit effort. 3 TABLE OF CONTENTS 1. INTRODUCTION.………………………………………………………………...1 1.0 Introduction …………………………………………………………………….1 1.1 Rationale of the Study ………………………………………………………….2 1.2 Objectives of the Study ………………………………………………………...3 1.3 Significance of the Study ………………………………………………………4 2. BACKGROUND …………………………………………………………………..5 2.1 Marine Fisheries of Tanzania …………………………………………………..5 2.1.1 Economic Contribution of the Fishery Sector ……………………………5 2.1.2 Natural Environmental Variables…………………………………………6 2.1.3 Technical Characteristics of the Fishery …………………………………7 2.2 Artisanal Marine Fisheries ……………………………………………………..8 2.2.1 Artisanal Fishing Community ……………………………………………8 2.2.2 Fishing Craft and Gear …………………………………………………...9 2.2.3 Species Caught ………………………………………………………….10 2.2.4 Productivity in the Artisanal Fisheries ………………………………….10 2.2.5 Markets and Distribution ………………………………………………..11 2.2.6 Fishery Management Practice …………………………………………..11 3. MODEL …………………………………………………………………………..13 3.1 Need and Importance of Models ……………………………………………...13 3.2 Choice of Model ………………………………………………………………13 3.2.1 Biological Model ………………………………………………………..14 3.2.2 Economic Model ………………………………………………………..16 3.2.3 Bioeconomic Dynamic Model and the Price of Time ………………….17 3.3 Limitation of the Model ………………………………………………………19 4. DATA AND PARAMETER ESTIMATES ……………………………………20 4.1 Fishing Effort Data ……………………………………………………………20 4.2 Trends in Real Effort ………………………………………………………….21 4.3 Standardized Effort Data and Parameter Estimates …………………………..22 4.4 Catch Trends ………………………………………………………………….23 4 4.5 Price of Fish and Cost of Effort ………………………………………………24 5. RESULTS ………………………………………………………………………...25 5.1 Estimated Total Standardized Effort and Corresponding CPUE.……………..25 5.2 Trends in Total Standardized Effort …………………………………………..25 5.3 Total Standard CPUE Trends …………………………………………………25 5.4 Yield – Effort Curve …………………………………………………………..27 5.5 Calculated MSY, MEY, OSY and OAY and Corresponding Effort Levels and Economic Rent ………………………………………………………………..27 6. DISCUSSION ……………………………………………………………………30 6.1 Is There Overfishing in Tanzania’s Marine Waters …………………………..30 6.2 Major Factors Accounting for the Overfishing …...…………………………..31 6.3 Sustainability, Efficiency and Optimality……………………………………..32 6.4 Required Reduction of Effort …………………………………………………33 6.5 Employment Impacts of Effort Reduction ……………………………………34 6.6 Limitations of the Study ………………………………………………………34 7. SUMMARY AND POLICY RECOMMENDATIONS ……………………… 35 8. REFERENCES …………………………………………………………………..37 5 LIST OF FIGURES Figure 2.1 Map of Tanzania showing the coastline …………………………………..8 Figure 4.1 Trends in the main fishing gears ………………………………………...21 Figure 4.2 Artisanal catches over time ……………………………………………...24 Figure 5.1 Total standardised effort 1987 – 2000 …………………………………..26 Figure 5.2 Trend in total standardised CPUE ………………………………………26 Figure 5.3 Gordon-Schaefer Yield curve for the fishery 1987 – 2000 ……………..27 Figure 5.4 Revenue and Cost curves as function of effort ………………………….29 LIST OF TABLES Table 4.1 Fishing gears by type and number ………………………………………..20 Table 4.2 Estimated Parameters …………………………………………………….22 Table 4.3 Standardising Weights …………………………………………………...23 Table 4.4 Standardised Effort and Catch data ………………………………………23 Table 4.5 Economic data ……………………………………………………………24 Table 5.1 Calculated Total standardised effort and total standard CPUE ………….25 Table 5.2 Key Indicators based on Gordon-Schaefer Model ………………………27 Table 5.3 Optimal biomass, catch and effort estimates …………………………….28 6 CHAPTER ONE 1.0 Introduction Worldwide fishery is of immense importance and most of the coastal people depend on fisheries for their livelihood. It is historically known that artisanal fisheries have provided the economic foundation for most countries of the Southwest Indian Ocean region (Mapunda, 1993). The artisanal fisheries are by far the most important fisheries in the marine sector of Tanzania. According to MNRT report, they contribute for over 95% of the total marine catch (Anon., 2000a). The waters of the Southwest Indian Ocean region possess few rich fishing grounds, both in terms of total size of biomass of commercial species like tuna and in terms of density (Sharp, 1982). While it is true that fish qualifies as a renewable resource, it is not necessarily an inexhaustible one (Hartwick and Olewiler, 1998). Annual catch can be sustained indefinitely as long as it equals annual net growth. As such, Maximum Sustainable Yield (MSY1) can be achieved. Another aspect of fish resource utilization going to be considered here is the maximization of economic rent. That refers to attaining the economic equilibrium, which is referred to as the Maximum Economic Yield (MEY2). Conrad and Clark (1987) stated that the relative economic efficiency of the fishing industry has significantly declined in many countries in recent years partly due to overexploitation and the consequent reduced yield from many fish stocks. Overfishing and waste of resource rent in fisheries are caused by free and open access to the resource exploitation. In reality, open access is common in Tanzania’s marine artisanal fisheries (Keen, 1991). Tanzanian marine artisanal fishery is characterized by conditions of crowding where the available coastal resources are exploited by a large number of fishermen (Tarbit, 1 MSY refers to the catch level, which if maintained perpetually would produce the largest annual harvest or net benefit. 2 MEY is the sustainable level of catch that produces the greatest economic profits. 7 1986). Fishermen and fishing effort increased in number so long as fish catches commanded high prices in the market due to high demand that exists for both fish and fish products (Bagachwa and Maliyamkono, 1994). Artisanal fishing intensity has been increasing in the inshore waters due to the limitation of the range of fishing vessels and lack of proper management practices, resulting in excessive effort (Jiddawi, 2001). However, as Linden and Lundin (1996) pointed out that, during the course of time high levels of fishing effort cause a serious reduction in the size of the fish stock and consequently the rate of catch per unit of effort is reduced. In other words, as will be argued in this paper, overfishing and resource rent dissipation are the likely outcomes. Mapunda (1993) already found out that while the marine fishery has not been able to fully exploit its annual potential, there are ample signs of overfishing in the coastal waters. Also a decline in catches of certain commercial species mainly reef fishes has been reported by Anon. (2001a). This suggests that the fishery is being over-fished, and that better fishery management needs to be imposed in order to maintain productivity of the fishery resource on a sustainable basis. This study, therefore, tries to show whether or not overfishing indeed exists. A literature review of the Tanzanian marine fisheries with particular emphasis on the artisanal sector is presented in chapter 2. Chapter 3 summarizes the basic theory and model of fishery resource exploitation applied for the study. The data used in the study is outlined in chapter 4 while chapter 5 presents the results of the study. Finally, chapter 6 presents discussion based on the results while chapter 7 provides summary and policy recommendations. 1.1 Rationale of the Study Tanzanian marine artisanal fishery is the main economic activity of the coastal people due to the lack of alternative sources of subsistence. This sector is characterized by open access where there is crowding of effort in the coastal waters, which is attributed to the lack of technical skills and capital on the fishermen side to go further beyond the inshore waters. Besides, the overall picture of relative fish prices is that they have risen significantly faster than the prices of other goods, which attracted more efforts. Fishermen like any other economic agents are driven by the profit maximization 8 objective at least in the short run (Conrad and Clark, 1987). Therefore, it is true to believe that fishermen and fishing efforts increased in the inshore reefs in response to the cost limitations and the high prices in the market. This problem coupled with lack of enforcement of existing management measures would possibly lead to overfishing. Therefore it is now timely to know whether the fisheries can be sustained at the current exploitation level and whether society could gain from a reduction in fishing effort. 1.2 Objectives of the Study The present study was undertaken with such objectives as: - Analyzing the artisanal marine fishery of Tanzania using historical data; - Examining the gear composition of the fishery with respect to relative catch contribution; - Determining the different key reference points like MEY, MSY, OSY3 and OAY4 and their corresponding effort levels by applying theoretical bioeconomic model. The study is based on empirical investigations that has provided insight into such questions as: - Are the present fish harvesting levels in the marine waters sustainable? - If fish harvesting is at levels that are unsustainable, what management measures could be drawn to ensure sustainability in the long run? Specifically, this paper tries to identify the main causes influencing decline in catches, change in catch/size composition, changes in gear composition, and disturbance of the marine ecology. 3 OSY (Optimum Sustainable Yield) refers to the catch level which maximizes social welfare. 4 OAY (Open Access Yield) refers to the catch level where total revenues are equal to fishing costs. 9 1.3 Significance of the Study The importance of fishery resources to the economy of Tanzania cannot be understated. These resources make a significant contribution to the Gross Domestic Product (GDP), foreign exchange earnings, provide both direct and indirect employment and supply relative cheap protein to the population. The findings of this study will fill the existing gap of empirical studies that focus on the bioeconomic analysis of sustainable use of fishery resources in Tanzania. The information is also expected to assist policy makers and interested parties to make informed decisions about the management of fisheries. The experience can be extended to similar situations of overexploitation with regards to other marine resources and other renewable resources in general. 10