Fisheries Research 78 (2006) 130–142 Decline of demersal coastal fisheries resources in three developing Asian countries I.C. Stobutzki a,∗, G.T. Silvestre a,1, A. Abu Talib b, A. Krongprom c, M. Supongpan d, P. Khemakorn c, N. Armada e, L.R. Garces a a WorldFish Center, P.O. Box 500 GPO, 10670 Penang, Malaysia b Fisheries Research Institute, Department of Fisheries, 11960 Batu Maung, Penang, Malaysia c Southern Marine Fisheries Research and Development Center, 79/1 Wichaenchom Rd., Muang, Songkla 9000, Thailand d Marine Fisheries Development Center, Bangkok, Thailand e College of Fisheries, University of the Philippines, Visayas, Miag-ao, Iloilo 5023, Philippines Abstract Worldwide, there is serious concern about the state of fisheries; yet for Asia, which accounts for half of the global fisheries production, information on the state of fisheries in order to guide management is sparse. In this paper we review the results of a regional study that examined the state of demersal fisheries resources in the coastal areas of Malaysia, the Philippines and Thailand. In each country time series of scientific trawl survey data (spanning 12–49 years, depending on the area) were used to assess changes in the total biomass of demersal species over time. All countries showed substantial declines in the total biomass. In Malaysia, the declines were greatest in the shallow depths (<50 m) where the biomass declined to 4–20% of the original estimates. In the Gulf of Thailand, by 1995 the total biomass estimates had declined to less than 8% of the 1965 estimates. In the Philippines, changes in the biomass were examined in different bays and fishing areas and the recent estimates of the biomass were 12–64% of the original estimates. These severe declines in the total biomass are thought to be due to over-fishing, compounded by environmental degradation. While over- fishing has been previously documented for selected species or fisheries in these countries, the fishery-independent data analysed here provide the first multi-country evidence of the widespread degradation of demersal coastal resources. Exploitation ratios (fishing mortality:total mortality), calculated from length frequency data, were on average >0.5, suggesting over-fishing. In Thailand a time series of exploitation ratios for 17 species showed increasing fishing pressure over time. Environmental degradation, in terms of changes in water quality and habitat modification and loss, has been documented in all countries and this is likely to be a contributing factor for the declines. The serious declines observed in these three countries are illustrative of a regional trend and highlight the urgent need for countries to reduce and manage their fishing capacity. This regional study also identified a requirement for key interventions, such as strengthening licensing systems, limiting entry to fisheries and increasing gear selectivity. It also highlighted the fact that the strategies developed must take into account the context of the developing countries and the broader socioeconomic role of fisheries. © 2006 Elsevier B.V. All rights reserved. Keywords: Asian fisheries; Exploitation ratios; Demersal fisheries resources; Fisheries biomass declines; Over-fishing 1. Introduction due to the levelling off or possible decrease in the total fish- eries landings since the 1980s (Watson and Pauly, 2001), the Worldwide, there is increasing awareness and concern public collapse of major fisheries (e.g. North Atlantic cod; regarding the state of fisheries resources. This concern is Myers et al., 1996, 1997), the depleted state of many fish- eries (FAO, 2002) and the broader ecological changes that ∗ Corresponding author. Current address: Bureau of Rural Sciences, GPO have been observed (e.g. changes in the structure of kelp for- Box 858, Canberra ACT 2601, Australia. Tel.: +61 2 6272 4781; est and coral reef systems; Jackson et al., 2001). For marine fax: +61 2 6272 3882. E-mail address: [email protected] (I.C. Stobutzki). fisheries where assessments are available, FAO estimates that 1 Current address: Tetra Tech EM Inc., 18th Floor, OMM-CITRA Bld., 75% are fully exploited, overexploited, severely depleted or San Miguel Avenue, Ortigas Center, Pasig City 1605, Philippines. in recovery (FAO, 2002). Most of the examples documented 0165-7836/$ – see front matter © 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.fishres.2006.02.004 I.C. Stobutzki et al. / Fisheries Research 78 (2006) 130–142 131 in the international scientific literature, regarding the depleted growing population and development (Delgado et al., 2003). state of fisheries and the urgent need for action, originate Fish are a vital source of animal protein in many devel- from developed countries (e.g. Myers et al., 1996; Cook et oping countries. In countries, such as the Philippines and al., 1997). This bias is probably driven by numerous factors, Malaysia, over 60% of the animal protein comes from particularly the availability and quality of data. Developed fish (Barut et al., 2003; Abu Talib et al., 2003b). How- countries in general have more robust fishery statistics, longer ever, with rising prices, fish are potentially becoming less historical time series and greater research effort focused on available to the poor (Ahmed et al., 1999; Delgado et al., evaluating the state of their fisheries. While assessments of 2003). fisheries in developing countries have been undertaken, they Given the importance of fish resources to developing coun- are often published in “grey literature” and so not widely tries and particularly to poor communities, it is imperative available. that they are managed for sustainability. A key to this is An exception, however, is the case of the Gulf of Thai- to have an understanding of the state of fisheries resources. land, which is one of the most well-documented examples However, this is often difficult due to the nature of the fish- of fisheries depletion. The Gulf of Thailand has been fished eries. In developing countries, fisheries are predominantly heavily since the introduction of industrial trawling in the of a tropical and multi-species nature. They are exploited 1960s, and the resulting depletion of fish stocks by the by numerous gear types, often in both a small-scale (tra- 1980s and the “fishing down the food web” phenomenon ditional, artisanal or subsistence) sector and a large-scale have been documented (e.g. Ritragsa, 1976; Pauly, 1979; or industrialized sector (Silvestre and Pauly, 1987; Charles, Beddington and May, 1982; Chanprasertporn and Lamsa- 2001). The species caught often overlap between gears and ard, 1987; Phasuk, 1987; Christensen, 1998). The state of sectors. In some cases the same species may be target- fisheries resources in select areas in the Philippines has also ted at multiple life history stages by different sectors, e.g. been documented (e.g. Pauly and Mines, 1982; Silvestre and shrimp in many countries are targetted as juveniles by stake Pauly, 1987). In general, information on the state of fish- nets and push nets while the adults are targetted offshore eries resources in developing countries is limited and not by trawlers. Developing country fisheries also tend to have widely available, even though the need to understand the state numerous and scattered landing sites, as well as complex of fisheries resources and implement effective governance and variable market chains. These characteristics limit the and management is arguably more critical in developing collection of robust data from fisheries, particularly on fish- countries. ing effort, landings and catch composition. While many Developing countries rely heavily on fish and fisheries, countries collect and publish fisheries statistics, their accu- particularly in the poorer sections of their population. Fish- racy varies considerably (e.g. China; Watson and Pauly, eries contribute significantly to developing countries at the 2001). national and local levels. Since 1973, the global production Given this situation, Pauly (1996) highlighted the potential from fisheries has increased from 44 to over 82 million tonnes of historical scientific trawl survey data to assess the status by 2001 (FAO, 2002). Since the 1980s, developing countries of coastal demersal fisheries resources. In some developing have led in capture fisheries production and they now con- countries, research surveys, primarily trawling, have been tribute over 65%. Fish are a major agricultural commodity for carried out since the early 1900s. These fishery-independent many developing countries; global fish trade currently earns data provide a measure of the resource status and a historical developing countries an estimated US$ 18 billion annually baseline for establishing restoration targets. A key reason why (Delgado et al., 2003). These export earnings can contribute the state of fisheries in the Gulf of Thailand is widely known to lowering international debt and paying for rising food is that Thailand has conducted annual scientific surveys of import bills (Kurien, 2004). the demersal resources since the 1960s (see Garces et al., this Fisheries are an important source of income and means of issue, pp. 143–157). livelihood in developing countries, particularly in rural areas. This paper reviews a regional project in which, for the It is estimated that capture fisheries employ over 27 million first time, Asian countries used similar approaches to col- people worldwide, of which 85% live in Asia (FAO, 2002). late and analyse their scientific trawl survey data to provide a Small-scale fisheries and related industries are estimated to fishery-independent assessment of the state of coastal demer- provide an income to 22 million people living on < US$ 1 sal resources. We review the results from Malaysia (Abu Talib per day (FAO, 2002). The open access nature of many fish- et al., 2003a), the Philippines (Barut et al., 2003) and Thailand eries also means that they can act as a “safety net” for the (Krongprom et al., 2003). The analysis provides critical infor- landless poor or when other sources of income fail (Bene, mation on the degraded nature of coastal fisheries resources 2003).