TRADE OFF BETWEEN THE ECONOMIC BENEFITS

Trade Off between the Economic Benefits

Trade Off between the Economic Benefits

Introduction

Over the past few decades, over-exploitation of fishery resources has caused depletion, or extirpation in some extreme cases, of marine populations ([Pauly et al., 2002], [Dulvy et al., 2004] and [Hilborn et al., 2004a]). A challenge to managing exploited marine ecosystems is the trade-offs between ecological, social and economic objectives. Here, trade-offs is defined as giving up some of one thing to get more of something else. Given a set of alternative allocations or system configurations, the system is considered to be in Pareto-optimum if improvement of any one individual or objective would reduce the performance of the others.

The Pareto-frontier is the set of system configurations that are all in Pareto-optimum.

The trade-offs between conservation and socio-economic objectives are complex in a multi-species or ecosystem context. Conventional resource management approaches aim to maximize the long-term sustainable yield of the resources being targeted ([Rosenberg et al., 1993] and Pitcher, 1998 T.J. Pitcher, A covery story: fisheries may drive stocks to extinction, Rev. Fish Biol. Fish. 8 (1998), pp. 367-370. [Pitcher, 1998]). However, most fisheries (particularly the tropical multi-species fisheries) catch a mixture of species and stocks with different productivity.

Northern South China Sea

Rapid expansion of fisheries in the region resulted in depletion of most fishery resources and loss of biodiversity. Fishery resources are exploited mainly by trawlers (demersal, pelagic and shrimp), gillnets, hook and line, purse seine and other fishing gears such as traps; many of them are small-scale, family-based fisheries. Since the foundation of the People's Republic of China (PRC) in 1949, there was a rapid growth in marine capture fisheries. The growth slowed down towards the 1970s. From the 1950s to 1970s, the fishing fleets were mostly state-owned. However, since the end of 1978, following economic reform, fishing fleets started to be privatized and investment in fisheries increased (Pang and Pauly, 2001).

This resulted in a large increase in the number of fishing boats and improvement in fishing technology. From 1978 to 2000, the number of mechanized fishing boats from Guangdong, Guangxi and Hainan - the three provinces bordering the coast of the NSCS - increased by almost 10-fold from 8109 to 79,249. Simultaneously, catch-per-unit-effort of bottom trawlers on 17 major commercial species in the region declined by an average of over 70% from mid 1970s to late 1980s (Cheung, 2007). Although the NSCS fisheries appear to have a reasonably comprehensive set of fisheries legislations and regulations, insufficient enforcement and the high level of illegal fishing (e.g., fishing without license) may have driven the stocks to the bionomic equilibrium (BE). Some vulnerable species, such as the Chinese bahaba (Bahaba taipingensis), were nearly extirpated locally while numerous other species were depleted or over-exploited ([Sadovy and Cornish, 2000], [Sadovy and Cheung, 2003] and Cheung and Sadovy, 2004 W.W.L. Cheung and Y. Sadovy, Retrospective evaluation of data-limited fisheries: a case from Hong Kong, Rev. Fish. Biol. Fisher. 14 (2004), ...