Bioeconomics of the Philippine small pelagics fishery
Abstract
Time series analysis of catch and effort data in the Philippines small pelagics fishery resulted in a level of biological and economic overexploitation. Open-access equilibrium has been reached at 410,000 hp representing a catch level of 465,000 tonnes. Present levels of effort would have to be reduced by 40% to attain maximum economic yield. An analysis of producer surplus showed that municipal aand commercial fishers were sustaining pure losses amounting to P9.4 billion indicating misallocation of labor and capital in an already overexploited fishery. Solutions to fisheries management problems are shown to emanate not just from the fishery, but more importantly, from the broader macroeconomic environment.
... The biomass 1967 1969 1971 1973 1975 1977 1979 1981 1983 1985 1987 1989 1991 1993 1995 1997 YEAR Exports Imports of fished stocks declined in the mid-1980s to about 30% of levels in the late 1940s, resulting in an annual rent dissipation of about US$130 million per year, due to over-fishing of demersal stocks ) estimated MSY for small pelagics at 550 000 t, the Maximum Economic Yield (MEY) for fish and invertebrates in the exploited fishing grounds at around 250 000 t and the Maximum Economic Rent (MER) for the latter at US$290 million. Subsequent refinements of this assessment have yielded similar results (Trinidad et al. 1993). The 550 000 t MSY for small pelagics when combined with the MSY estimates of 250 000 t for lightly fished small pelagic resources in waters off Palawan, parts of the country's Pacific coasts and some parts of Mindanao, is within the consensual earlier MSY estimate for small pelagics of 800 thousand t noted above. ...
... Among the few socioeconomic studies on the commercial sector is the bioeconomic analysis of the Philippine small pelagic fishery by Trinidad et al (1993). Twenty-two commercial vessels were monitored in Regions IV, VII, IX and NCR for the period March -April 1988. ...
... The crews of trawlers and purse seiners were given a fixed salary while crews of bag-netters, ring-netters, beach seiners and encircling gill netters were each given a fixed minimum plus a share of the catch (Trinidad et al. 1993). The frequency of payment varied from per trip, weekly, monthly to a combination of these. ...
Marine fisheries are an important source of protein, livelihood and export earnings for the Philippines. In 1994, total marine fisheries catch was 1.67 million t (62% of total fisheries production) valued at about US$ 1.65 billion. Of this total, 277 thousand t were demersal fisheries, 885 thousand t small pelagics, 305 thousand t tunas, and 203 thousand t other species or groups. Current catches have leveled of since 1991 (at a level near estimated maximum sustainable yield) and existing fishing effort is too high. This paper reviews the status of marine fisheries and the development of trawl fisheries in the Philippines. The combined effects of excessive fishing effort and environmental degradation have contributed to the depletion of fishery resources, particularly coastal demersal and small pelagics.
... The biomass 1967 1969 1971 1973 1975 1977 1979 1981 1983 1985 1987 1989 1991 1993 1995 1997 YEAR Exports Imports of fished stocks declined in the mid-1980s to about 30% of levels in the late 1940s, resulting in an annual rent dissipation of about US$130 million per year, due to over-fishing of demersal stocks ) estimated MSY for small pelagics at 550 000 t, the Maximum Economic Yield (MEY) for fish and invertebrates in the exploited fishing grounds at around 250 000 t and the Maximum Economic Rent (MER) for the latter at US$290 million. Subsequent refinements of this assessment have yielded similar results (Trinidad et al. 1993). The 550 000 t MSY for small pelagics when combined with the MSY estimates of 250 000 t for lightly fished small pelagic resources in waters off Palawan, parts of the country's Pacific coasts and some parts of Mindanao, is within the consensual earlier MSY estimate for small pelagics of 800 thousand t noted above. ...
... Among the few socioeconomic studies on the commercial sector is the bioeconomic analysis of the Philippine small pelagic fishery by Trinidad et al (1993). Twenty-two commercial vessels were monitored in Regions IV, VII, IX and NCR for the period March -April 1988. ...
... The crews of trawlers and purse seiners were given a fixed salary while crews of bag-netters, ring-netters, beach seiners and encircling gill netters were each given a fixed minimum plus a share of the catch (Trinidad et al. 1993). The frequency of payment varied from per trip, weekly, monthly to a combination of these. ...
The fisheries sector in the Philippines provides a significant contribution to the na-tional economy in terms of income, foreign exchange and employment. In 2000, total fish production was estimated at 2.94 million t, 84% of which was derived from marine capture fisheries. The export of fish and related fishery products amounted to about US$400 million in the same year. Between 1984 and 1997, the fisheries sector contributed between 3.8% to 5.0% of the national GDP and 18.4% to 20.6% of the agricultural GDP in the same period. The fisheries sector also provided employment to about 1 million people in 1997. This paper reviews the Philippine coastal fisheries situation in terms of the status of the marine/coastal environment, resource potential, socioeconomic aspects of the fisheries and management measures to sustain the fishery. It also presents the prob-lems, opportunities and recommendations for sustainable exploitation of coastal fish stocks based on a multi-sectoral workshop under the “Sustainable Management of Coastal Fish Stocks in Asia” Project in September 2000. We highlighted the following areas that should be addressed in attaining improved fisheries management in the context of the Philippines: (1) maintaining integrity of coastal stocks and habitats; (2) maintaining the integrity of shared stocks; (3) maximizing economic benefits from utilization of resources; (4) promotion of equity in sharing benefits from the utilization of the resources; (5) minimizing conflicts among resource users; and (6) minimizing poverty among small scale fishers.
... While it is economically significant, the fisheries sector currently faces a serious problem that threatens its viability as economic base-overfishing ( Dalzell et al. 1987; Trinidad et al. 1993Figure 1). Thus, within the fisheries sector, the municipal marine and commercial fisheries are the most important sub-sectors in terms of employment. ...
... Thus, within the fisheries sector, the municipal marine and commercial fisheries are the most important sub-sectors in terms of employment. In addition, when all backward and forward linkages are considered, about 12 percent of the general population of the country were in one way or another dependent on fisheries-related activities for their livelihood (Trinidad et al. 1993). This highlights the importance to the national economy of fisheries as employment base. ...
... Once the engine horsepower for the catch fleet was accounted for, the labor horsepower was computed. As there were no available data which could be used to directly measure labor horsepower, it was estimated by taking it as ratio of engine horsepower using data from Trinidad et al. (1993) and Karim (1985). In the case of the commercial carrier fleet, engine horsepower data for earlier years were directly generated from Dalzell et al. (1987). ...
The objective of this paper is to address this research gap by looking into the issue of overfishing using a sectoral approach (i.e., in terms of commercial fisheries, municipal fisheries and total marine fisheries). It is hoped that the results will help show whether or not overfishing indeed exists as sectoral problem. This paper also attempts to provide, given limited data, some preliminary estimation of the likely employment impacts that may result from future reductions in fishing effort intended to control overfishing. This exercise is aimed to provide a rough picture of the social cost, albeit partial, of possible effort reduction within the marine fisheries.
... While the fisheries sector is economically significant, it is currently facing a serious problem that threatens k viability as economic base. Specifically, empirical studies indicate that marine fishery stocks are already overfished (e.g Dalzell et al. 1987; Trinidad et al. 1993; Padilla and De Guzman 1994). It has been argued that if the current rate of overfishingcontinues unabated, the marine fisheries may collapse as important edible fish species are driven to virtual extinction. ...
... In In addition,when all backward and forward linkages are considered, about 12 percent of the general population were in one way or another dependent on fisheries related activities for their livelihood (e.g. Trinidad et al. 1993). This again highlights the importance of fisheries as a source of employmentto the national economy. ...
... The Once the engine horsepower for the catch fleet was accounted for, the labor horsepower was computed. As there were no available data which can be used to directly measure it labor horsepower, it was estimatedby taking it as ratio of engine horsepower by using data from Trinidad et al. (1993) and Karim (1985). In the case of the commercial cartier fleet, engine horsepower data for e_lier years were directly generated from DalzeUet al. (1987). ...
This paper examines the recent decentralization of governance in Indonesia and its impact on local infrastructure provision. The decentralization of decisionmaking power to local jurisdictions in Indonesia may have improved the matching of public infrastructures provision with local preferences. However, decentralization has made local public infrastructures depend on local resources. Due to differences in initial endowments, this may result in the divergence of local public infrastructures in rich and poor jurisdictions. Using data from village-level panel surveys conducted in 1996, 2000, and 2006, this paper finds that (1) local public infrastructures depend on local resources, (2) decentralization has improved the availability of local public infrastructures, (3) local jurisdictions are converging to a similar level of local public infrastructure, and (4) to some extent, decentralized public infrastructures' provision reflects local preferences.
... For the climatology runs, we generated time-series averaged rasters for all six dynamic predictors (i.e., except bathymetry) from 2013 to 2016. Under this set, models were run with and without bathymetry as a predictor and accounting for possible effects of monsoons which have been known to affect small pelagic fish production in the Philippines [63]. ...
... A search in Fishbase (www.fishbase.org) on depth information for the dominant small pelagic fishes caught in Philippines waters shows that commonly targeted small pelagic fishes by the Philippine fishing fleet are often found in depths of less than 200 m [63]. In addition, CFAs most likely have a large mix of different fishing gears that target various species of small pelagic fishes. ...
Fisheries surveys over broad spatial areas are crucial in defining and delineating appropriate fisheries management areas. Yet accurate mapping and tracking of fishing activities remain largely restricted to developed countries with sufficient resources to use automated identification systems and vessel monitoring systems. For many countries, the spatial extent and boundaries of fishing grounds are not completely known. We used satellite images at night to detect fishing grounds in the Philippines for fishing gears that use powerful lights to attract coastal pelagic fishes. We used nightly boat detection data, extracted by U.S. NOAA from the Visible Infrared Imaging Radiometer Suite (VIIRS), for the Philippines from 2012 to 2016, covering 1713 nights, to examine spatio-temporal patterns of fishing activities in the country. Using density-based clustering, we identified 134 core fishing areas (CFAs) ranging in size from 6 to 23,215 km 2 within the Philippines' contiguous maritime zone. The CFAs had different seasonal patterns and range of intensities in total light output, possibly reflecting differences in multi-gear and multi-species signatures of fishing activities in each fishing ground. Using maximum entropy modeling, we identified bathymetry and chlorophyll as the main environmental predictors of spatial occurrence of these CFAs when analyzed together, highlighting the multi-gear nature of the CFAs. Applications of the model to specific CFAs identified different environmental drivers of fishing distribution, coinciding with known oceanographic associations for a CFA's dominant target species. This case study highlights nighttime satellite images as a useful source of spatial fishing effort information for fisheries, especially in Southeast Asia.
... The mean monthly catch started to increase in January with a pronounced peak in February followed by a minor peak in May (Fig. 9). On the contrary Trinidad et al. (1993) have reported that the highest production of its congeners in the Philippines happened between March and June ensuing the end of northeast monsoon and the beginning of southwest monsoon. ...
... Disparity in the sizes may affect the production between these months. Furthermore, the slight deviation of the production peak of roughear scad from other members of the genus Decapterus as reported by Trinidad et al. (1993) may suggest some form of migratory behaviour of this species. ...
... Catching efficiency (CE), which is usually expressed as the ratio of catch to fishing effort (Trinidad et al., 1993), was calculated using the total fishers/day indicator, by multiplying the crew size (CS) by the number of days per fishing trip: ...
... Catching efficiency parameters provide an overview of fishing performance taking account of different gear and technology (Trinidad et al., 1993). Purse-seiners appear to be more technically efficient (CE = 0.55) than other fleets, even with the lowest EE values. ...
One of the problems in an ecosystem approach to fisheries management is the lack of economic analyses which clearly define the performance of different fishing fleets within the system. We describe a comparative multi-fleet analysis of socio-economic indicators applicable for inclusion into ecosystem modeling and management. Based on a survey of different industrial fishing fleets in São Paulo, Southeastern Brazil, an inter-fleet comparison of economic attributes such as investment, fixed costs, effort, labour, sailing-related costs and profits, as well as a set of performance indicators, was conducted. Costs varied between fleets with fuel being the largest component on average, representing almost 37% of total costs. Similarities between fleets were driven by fuel costs, gross incomes and profits. In general, the best economic performance was associated with indicators of profitability and economic efficiency. Bottom-longliners and both surface and bottom-gillnet fleets showed the best economic performance per fishing trip due to their low percentage of variable costs. Purse-seiners and pink-shrimp trawlers had the lowest average rate of return and economic efficiency because of their high variable costs and relatively low catch values, and were considered economically net losers. However, in terms of jobs generated, purse-seiners had the greatest value creating about 49% of total jobs by all fleets. The sea-bob-shrimp fleet had the lowest crew size per vessel but generated the second highest total number of direct jobs (23%), with high economic viability as a whole. The inter-fleet cost and socio-economic performance analysis revealed that additional attention should be given to the poor profitability and overcapacity of fleets, fishing impacts, and open-access related issues, while social indicators may also be considered. This study provides information useful for evaluating different fisheries management scenarios and fleet size optimization in the South Brazil Bight, for ecosystem modeling policy optimization routines, and for a pragmatic ecosystem approach to fisheries management.
... H MeanCPUE e n Where Trinidad et al. 1993, fixed costs incurred by the fishing boat owners include tax and insurance, the costs of repairing and maintaining the boat, engines and other equipment, and depreciation. Fixed costs are often only paid for once or twice a year or even less. ...
... Investment costs include capital costs of the boat, engine, and gears, winch and mechanical equipments, electronic equipments, storage equipment (boxes, containers, etc) (Trinidad et al. 1993). Investment cost was collected under the categorized fishing fleet. ...
Planning, implementing and managing MPA not only requires attentions to biological issues which influence the performance of MPA but also to social and economic aspects that can greatly affect the outcome of MPA implementation. This study used data from logbook program over 4 years and face-to-face interview to explore the effectiveness of Cu Lao Cham MPA which is one of 4 MPAs in Vietnam through the performance of ecological (CPUE), economic (income from fishing) and social (perception to the MPA objectives) indicators. Result of study has indicated linkages between ecological, socio and economic issues which often give an insight to direct and immediate feedbacks to MPA and despite the various of problems in management of Cu Lao Cham MPA such as poaching, poor and ineffective enforcement, sustainability…., the performance of ecological, economic and social indicators in this study showed that Cu Lao Cham MPA has achieved a significant amount of success and is one of the few well-managed marine protected areas in Vietnam. This study has also identified a number of indications that the coastal fishery of Cu Lao Cham could be on a transition towards becoming a viable, sustainable characteristic of better-established tropical marine protected areas. Nå
... The operation of the ring net, which was introduced in the 1970s, also increased, and there were >500 ring netters in 1995. Nevertheless, the landings of small pelagics from offshore vessels doubled during 1984-1995, forming 70% of the total landings of small pelagics in 1995 [44,45]. The increasing trend of ring net operation in the country in the subsequent years resulted in the decline of the CPUE especially small pelagic fishes [23]. ...
Romblon Passage is part of Sulu-Sulawesi eco-region which is considered the global center of marine biodiversity. This area between the major basins provides an important route for migratory species including commercially important marine species. Because of the rich marine resource of this area, it serves as an important fishing ground for the fishermen of Romblon. Despite this, no study had been conducted on the species composition, abundance, size structure, and Length-Weight Relationship of common caught by ring net in Romblon Passage, Philippines. Thus, this study was realized. From July 2017 to January 2018. Six species were identified and Selar crumenophthalmus was the dominant species in the area. The majority of this species were in the 93 immature stage. An increasing trend of growth of S. crumenophthalmus was observed during the survey. The growth of this species is said to be isometric. Catch Per Unit Effort (CPUE) varied in every month. Sample sizes were ranging from 3 to 155 grams with an average weight of 59.24 grams. Based on the findings of this study, a whole year duration of sampling should be conducted. The reproductive biology of S. crumenophthalmus such as the gonadosomatic index, hepatosomatic index, and fecundity of this species should be done. In addition, a comprehensive whole-year study of the catch rate of ring net fishing in Romblon Pass should be conducted in order determines the population status of the small and big pelagic fishes in the area.
... This region is among the best studied in Southeast Asia where several fisheries models have been used for management and policy formulation such as the estimation of sustainable and economic yields in the 1980's (Silvestre and Pauly 1987;Dalzel et al. 1987;Trinidad et al. 1993). Modeling of multispecies dynamic fisheries had also been derived using static trophic interactions of coastal fisheries ecosystems in the 1990's (Aliñ o et al. 1993;Campos 2003). ...
The impact of trawlers on the fisheries ecosystem was investigated using the distribution of trawl fisheries catch in Ragay Gulf, the degree of overlap of species caught with those from other coastal fisheries and the trophic flow structure of the components of the system. Multivariate analysis of the exploratory trawl-fishing survey revealed northern and southern species clusters associated with prevailing circulation patterns and phytoplankton density in the gulf. Further analysis of the trawl catch composition showed two more clusters which indicate spatial distribution and intensity of the trawl fishery. These areas were differentiated as "highly fished" and "less fished." More than 50% overlap in species from these different habitats (coral reef, seagrass, mangrove and soft bottom) caught in the multispecies fisheries has implications on municipal water jurisdictions, especially on coastal communities where trawling is a source of living and food. The 45-yr historical reconstruction of trawl fisheries in the gulf using ECOSIM showed a significant decrease in the biomass of large, high-value fish groups and also an increase in small reef-associated carnivores and cephalopod biomass, because of ecosystem overfishing. The subsequent 100-yr simulation showed a shift to small reef-associated species as an effect of trawling activity. Minimal change on the small reef-associated species is noted when there is a complete ban on trawl fishing in the gulf but shows an increase in large carnivores. Coastal zoning schemes should consider the benefits derived from the ban on trawl fishing as also affirmed by anecdotal fisher accounts. In addition, the implications of the effects of trophic interaction and ontogenetic habitat connectedness have a profound influence on the overall dynamics of the fisheries ecosystem.
... In order to get a more conservative estimate of reef fish contribution to food supply and fisheries value, we separated "small pelagics," as defined in Trinidad et al. (1993) and Dalzell and Lewis (1989), from the reef-associated and oceanodramous fish classifications used by Geronimo and Cabral (2013). The remaining reef fish group was called as "inshore reef fish." ...
Maintaining ecosystem services of coral reefs, sustainable fishing, and improved food security are the three higher level outcomes of the Coral Triangle Initiative on Coral Reefs, Fisheries and Food Security (CTI-CFF). Food security is an obvious concern of the CTI-CFF because of 130 million people dependent on fish resources for food, income, and livelihoods, and also because it provides 11.3% (19.1 million tons) to global fisheries production from capture fisheries and aquaculture. Yet, anthropogenic stressors, especially overfishing, threaten the ecosystems that support food production. Fish supply deficits and undernourishment are observed in varying degrees across the CTI-CFF countries to be further exacerbated by increasing populations, increasing demand for fish from developed economies, unabated coastal development, and climate change. Short-term and urgent strategies to improve food security focus on arresting continued deterioration of coral reefs and fisheries to improve availability of fish, stabilize ecosystem services, and improve incomes at the local level. Wealth-focused and welfare-based approaches to achieve food security at various governance levels are proposed.
... Longhurst and Pauly (1987) have documented the occurrence of overfishing in east Malaysia, the Philippines, Vietnam and southern China. Reports show that the maximum sustainable yield (MSY), the limit reference point beyond which immediate and substantial action should be taken to protect harvested stock (Caddy and Csirke 1983), has already been exceeded for demersal (Silvestre et al. 1987), pelagic (Dalzell and Ganaden 1987; Trinidad et al. 1993) and reef fisheries (McManus and Meñez 1997) Aside from being unsustainable, overfishing in the region has implications for species diversity and abundance for both pelagic (Christensen 1998) and reef fisheries (McManus 1992). Biodiversity loss due to harvest is apparent in the local-scale extinctions of reef-associated species such as the sea urchin Tripneustes gratilla (McManus and Kesner 1995) and the giant clams Tridacna derasa and Tridacna gigas (). ...
Local communities and local government units are recognized as the primary stakeholders and participants in the management of coral reef resources and the primary beneficiaries of small-scale fishing activities in the nearshore areas of the coastal zone. The issues relating to the management of the coastal zone are multi-faceted and some issues are largely intertwined with national policy and development goals. Thus, national governments have jurisdiction over these nearshore coastal resources to harmonize policies, monitor resource use and provide incentives for sustainable use. However, the natural boundaries of these reef resources, the processes that support reef ecosystems, and the local or national affiliation of the people who benefit from them may transcend the boundaries of the local and national management units. Therefore, efforts to arrest the decline in fish catch and loss of biodiversity for reefs require management interventions and assessment activities to be carried out at varying scales. In Southeast Asia, some aspects of reef and reef resources management — particularly in deciding the allocation of catch among competing fisheries, development of sustainable harvest strategies, use of broodstock for restocking or stock enhancement programs, protection of nursery and spawning areas, designation of systems of marine protected areas, and the identification of representative, adequate and comprehensive areas for biodiversity conservation in the region — may require the definition of larger management units. At the regional level, multi-country initiatives will need to define units for the transboundary management of resources. The use of large marine ecosystems (LMEs) to identify and manage fisheries resources may be a starting point; however, given the relatively sedentary nature of coral reef-dwelling and reef-associated organisms compared with other pelagic and demersal species, meso-scale transboundary units within the LMEs have to be defined. This paper provides suggestions for transboundary management units for coral reef and reef-associated resources in Southeast Asia based on information from genetic structures of model organisms in the region. In addition, specific reef areas are identified, which may be important beyond their national boundaries, as potential sources of recruits.
... Again, it will be tedious to measure exactly how many individuals belong to these industries but some rough figures can be utilized for estimation. For instance, it has been assumed that 12 percent of the national population are in one way or another dependent on fisheries for their livelihood (Trinidad et al. 1993). Taking the current national population of about 70 million people, this means that 8.4 million individuals generate their livelihood from fisheries and fisheries-related activities. ...
This paper looks into the national R&D program for the production of hatchery-bred milkfish fry and the fledgling industry it has spawned with the end purpose of recommending courses of actions that the national government can pursue for their furtherance. The study concludes that hatchery-bred fry is necessary for milkfish culture to attain sustainable growth and international competitiveness in the coming years. Therefore, the government should continue to strongly support the R&D program and industry by exerting concrete measures to address the various technical, market, institutional and other problems which hinder them from fully becoming a vehicle of growth in the fisheries sector.
... Dalzell et al. (1987) compute a maximum sustainable yield (MSY) of 544,000 t for small pelagic fishes, an output level reached back in 1975. Foregone economic rent is estimated at US$500 million/yr (Trinidad et al. 1993). Similar figures for MSY are obtained for the same fishery by Padilla and de Guzman (1994), with foregone rent computed at about 7 billion pesos. ...
The fishery sector has become a large and dynamic contributor to Philippine agriculture. However, the sector confronts the problem of high poverty and alarming threats to its resource base. Policy responses to these problems have been implemented in recent years, but serious gaps remain. Addressing these policy gaps requires reforms that would lead to aquaculture development, bureaucratic rationalization and decentralization, the protection of aquatic habitats, the implementation of a science-based regime of fisheries management, and the promotion of diversified livelihoods among poor fishing communities. A concerted effort to address poverty and resource degradation may incur considerable short-run costs, but would likely yield larger long-term social payoffs.
... The Philippine coastal zone, however, is confronted with numerous challenges like overexploitation of resources, degradation of coastal habitats and poverty of the fisherfolk. With regard to the production from marine capture fisheries, empirical studies have shown evidence of biological and economic overfishing in both pelagic and demersal fish stocks (Dalzell et al, 1987; Trinidad et al, 1993; Barut et al, 2003; Barut et al, 2004). The degradation of coastal habitats has been documented for coral reefs where more than 70% of the reefs have been subjected to damage (Gomez et al, 1994) while the forested mangrove area has decreased from 450,000 ha in 1918 to 120,000 ha in the late 1990s (DENR, 1988; as cited in DENR et al, 2001a). ...
The Food and Agriculture Organization of the United Nations provided funding in support of the development of micro-enterprises in Banate Bay, Iloilo and Southern Iloilo. This project was implemented by the University of the Philippines in the Visayas in coordination with the Banate Bay Resource Management Council, Inc. and the Southern Iloilo Coastal Resource Management Council. The following micro-enterprises were developed in the various municipalities of Banate Bay and Southern Iloilo: Anilao - fish balls production; Banate - fish vending; Barotac Nuevo - shrimp paste production; Barotac Viejo - oyster and mussel culture; Guimbal - fish vending; Miagao – salt iodization; Oton - fish vending; San Joaquin - fish sauce production; Tigbauan - shrimp paste production.
Inspired by the work of the renowned fisheries scientist Daniel Pauly, this book provides a detailed overview of ecosystem-based management of fisheries. It explores the complex and interdisciplinary nature of the subject by bringing together contributions from some of the world's leading fisheries scientists, managers and conservationists. Combining both research reviews and opinion pieces, and reflecting the breadth of Pauly's influence within the field, the book illustrates the range of issues associated with the implementation of the ecosystem approach and the challenge of long-term sustainability. Topics covered include global biodiversity, the impact of human actions on marine life, the implications for economic and social systems and the role of science in communicating and shaping ocean policy to preserve resources for the future. This book provides a complete and essential overview for advanced researchers and those just entering the field.
The year-class success of small pelagic fish is strongly modulated by the growth and survival of early life stages. Determining how environments control growth is critical to understanding processes influencing annual production. We provide the first measurements of larval growth in Sardinella lemuru, the most abundant and exploited tropical sardine species in the Philippines. Growth rates of larvae were examined across a 2 yr period (2011-2012 and 2012-2013 spawning seasons) using otolith microstructure analysis. Transition to the juvenile stage occurred within 25 to 37 d. Mean growth rate of the 2011 year-class was significantly lower than the 2012 year-class despite significant intra-annual (batch) differences in growth trajectories. In both years, larvae that hatched and developed in the cooler yet prey-rich period in the middle of the spawning season (January) displayed the fastest growth, while those spawned early (September-October 2012) and late (February-March 2012) showed the slowest growth rates. Peak hatch-months (December 2011 and October 2012) were just prior to periods of upwelling, with mean prey concentrations of 0.24 ± 0.13 mg m-3 at 26.35 ± 2.56°C sea surface temperature (SST) and 0.23 ± 0.15 mg m-3 at 26.26 ± 1.79°C, respectively. The SST during upwelling was 0.01 to 1.23°C cooler accompanied by a 0.07 to 0.45 mg m-3 increase in prey concentration. In both years, differences in growth rate were strongly linked to oceanographic conditions. Moderate winds during a ‘neutral’ El Niño-Southern Oscillation year resulted in upwelling conditions favoring faster overall growth in larvae which was associated with stronger recruitment. In contrast, slower growth and weaker recruitment were associated with weak upwelling conditions in the 2011-2012 La Niña year. While temperature may be important, larval growth rates appear to be driven more by prey abundance.
This report is an account of a cross-country study that covered Vietnam, Indonesia and the Philippines. Covering four sites (one each in Indonesia and Vietnam) and two sites in the Philippines, the study documented the impacts of three climate hazards affecting coastal communities, namely typhoon/flooding, coastal erosion and saltwater intrusion. It also analyzed planned adaptation options, which communities and local governments can implement, as well as autonomous responses of households to protect and insure themselves from these hazards. It employed a variety of techniques, ranging from participatory based approaches such as community hazard mapping and Focus Group Discussions (FGDs) to regression techniques, to analyze the impact of climate change and the behavior of affected communities and households.
Results show that households in coastal communities face a confluence of risks and often adapt simultaneously to these risks. These risks have the most impact on the sources and types of livelihoods of households. Foregone income due to these risks was in fact found to be higher than the value of damages from loss of assets including damage to houses. Foregone income in the end affected consumption patterns. Using the Vulnerability as Expected Poverty (VEP) as a measure, it was found that the incidence of vulnerable households is highest in Palawan, Philippines (56%), followed by Vietnam (46%), Batangas, Philippines (42%) and then Indonesia (35%). The mean vulnerability estimate for Palawan is 0.51, which means that on average the probability that households will fall below the minimum consumption level (at which they will be considered poor) is 51%. For Vietnam, the mean vulnerability is 0.43, while Batangas and Indonesia have mean estimates of 0.38 and 0.37, respectively.
Various planned adaptation options, which communities and local governments can implement, were studied using cost effectiveness analysis. A consistent and common result across three sites is that ecosystem-based approaches (or natural barriers such as mangroves) are more cost effective than hard infrastructure investments. There also seem to be a preponderance of protective measures when, in fact, the main impact or risk from these hazards is really on the livelihoods of coastal-based communities. In Batangas, for example, it was found that livelihood diversification is a viable planned adaptation measure.
Factors that determine autonomous or private responses to climate hazards were also assessed. It was found that there are geographical and spatial differences in adaptation patterns, suggesting that households react rationally to the degree of threats from the hazards. For instance, households near riverbanks are more likely to employ autonomous adaptation strategies against flooding. Evidence was also found that planned adaptation “crowds out” private or autonomous adaptation. Presence of natural barriers such as mangroves and riverbank rehabilitation schemes result in less likelihood of autonomous adaptation to flooding and saltwater intrusion being pursued. Income from external sources, such as disaster relief, also tends to crowd out autonomous adaptation. Social capital, which was represented by the number of people from whom the respondents can turn to for loans with some level of certainty, had a positive effect on the likelihood of autonomous adaptation. There was also some gender dimension in adaptation. In particular, households with more female members have lower likelihood of pursuing autonomous adaptation to flooding and typhoon, but higher
adaptation to saltwater intrusion. Unfortunately the study did not assess the reasons for this behavior in more detail, as this was not part of the original design.
Scombrids (tunas, bonitos, Spanish mackerels and mackerels) support important fisheries in tropical, subtropical and temperate waters around the world, being one of the most economically- and socially-important marine species globally. Their sustainable exploitation, management and conservation depend on accurate life history information for the development of quantitative fisheries stock assessments, and in the fishery data-poor situations for the identification of vulnerable species. Here, we assemble life history traits (maximum size, growth, longevity, maturity, fecundity, spawning duration and spawning interval) for the 51 species of scombrids globally. We identify major biological gaps in knowledge and prioritize life history research needs in scombrids based on their biological gaps in knowledge, the importance of their fisheries and their current conservation status according to the International Union for Conservation of Nature Red List. We find that the growth and reproductive biology of tunas and mackerel species have been more extensively studied than for Spanish mackerels and bonitos, although there are notable exceptions in all groups. We also reveal that reproductive biology of species, particular fecundity, is the least studied biological aspect in scombrids. We identify two priority groups, including 32 species of scombrids, and several populations of principal market tunas, for which life history research should be prioritized following the species-specific life history gaps identified in this study in the coming decades. By highlighting the important gaps in biological knowledge and providing a priority setting for life history research in scombrid species this study provides guidance for management and conservation and serves as a guide for biologists and resource managers interested in the biology, ecology, and management of scombrid species.
Experimental estimates of gear selectivity by age used for estimating stock size and measuring fishing impact have been scarcely documented in small-scale fisheries from Latin-America and the Caribbean. In order to improve stock assessment and fisheries management in such fisheries, an experimental approach was designed to estimate the selective performance of the encircling gillnet “boliche” used in the tropical small-scale fishery of the Ciénaga Grande de Santa Marta, Colombia. Similar to covered cod-end hauls, an experimental net was enclosed by a control small-mesh net in 70 hauls. Both contact and available-selection processes affecting the selectivity of the “boliche” were modelled by fitting two selection curves: the logistic (a retention curve) and the encounter-probability (probability that a fish contacts the net) models. The encounter-probability model gave the most appropriate results in terms of the deviance statistic and the lowest Akaike's Information Criterion. Selectivity parameters were estimated for the main targeted fish species, highlighting differential avoidance reactions to the “boliche” for Eugerres plumieri (0.28), Diapterus rhombeus (0.24), Elops saurus (0.22), Micropogonias furnieri (0.13) and Cathorops spixii (0.16), but not Mugil incilis (all fish retained). To provide an overall (aggregated) effect of the “boliche” on the fish assemblage, the multi-species selection curve showed 61% retention at 15cm, indicating that 39% of the multi-specific component may avoid the “boliche”.
Philippines coastal fisheries research started during the colonization period in the 1800s with the basic taxonomic identification
of the countries aquatic resources and a description of their distribution in national waters. Research further evolved with
the change from localized fisheries governance to a centralized one, presently, with a combination of both. The dramatic postwar
expansion of Philippine fisheries in the mid 1940s led to the need for sustainable resources management. In the mid-1970s,
single-species fisheries approaches (i.e. specifically surplus production models) indicated the overfished state of the Philippine
coastal fisheries resources. These early models together with additional ecological and socioeconomic studies, served as inputs
to coastal resources management initiatives, in the context of an ecosystem approach. The implementation of further management
schemes such as marine reserves and fish sanctuaries also resulted from these initiatives. The decentralization of governance
of coastal resources in the 1990s led to participatory or co-management approaches for the local governance of coastal resources.
The development and great improvement of ecosystem-based models in fisheries science (such as Ecopath with Ecosim [EwE]) during
this period allowed for investigations into the interactions of the multispecies and multigear fisheries dynamics. Complementary
models derived from single-species such as Yield per Recruit and Surplus production in conjunction with ecosystem-based (EwE-type)
approaches are both needed in Philippine fisheries research. An emerging framework for sustainable Philippine fisheries management
system requires mainstreaming of coastal governance with science based adaptive management for Philippine aquatic resources
governance.
This report provides information on the environmental and economic impact of a marine protected area in Danao Bay, in the Philippines. It looks at how the biodiversity in the reserve has improved thanks to the protection it has been given. It also investigates how much of this biodiversity 'spills out' into surrounding waters and whether this has benefited local fishermen, in terms of improved catches. The research involved a combination of underwater biodiversity surveys, community interviews and secondary research on historical trends in fishery production in the area. The report finds that the establishment of the MPA has had a significant positive effect on the overall ecological condition of both the protected reserve area and of some of the reefs outside it. There is also strong evidence to suggest that the sanctuary had helped protect spawning fish and so helped boost catches. This impact has not, however, been large enough to create a truly sustainable and economically viable fishery area. The author therefore recommends that other policy instruments and fishery management strategies are needed in the bay to reduce overall fishing levels. She concludes that if these are put in place, the reserve could act as the centrepiece of a sustainable fisheries area- a model for other regions where fishing is in crisis.
A sampling survey of Philippine small pelagic fisheries was undertaken between 1987 and 1988 at eight sites in the Philippines. A description is given of the different fishing methods and estimates are made of catch per unit of effort and catch composition. Catches of sardines and anchovies dominated the landings of small-scale small pelagic gears whilst roundscads were an important catch component of large-scale fishing vessels. A first attempt to describe the overall species composition of the Philippine small pelagic landings was made using the sampling data and annual fisheries statistics for the years 1982-1986. Ten species of scad, mackerel and anchovy comprised 75% of the Philippine small pelagic landings. These results are discussed with respect to improving monitoring and sampling programmes designed to provide management-related information.
A surplus-yield model of fishery dynamics which assumes the Gompertz growth function is developed, resulting in an implied exponential relationship between catch per unit effort and fishing effort, and in an asymmetrical yield curve. A maximum sustainable yield, predicted by the exponential model, is obtained from a population size which is about 37% of the environmentally limited maximum size. Three methods for estimating the parameters of the exponential model, adapted from those used for the linear model of Schaefer (1954, 1957), are presented. The exponential model is compared with the linear model using examples of the fisheries for the California sardine, Sardinops caerulea (Girard), and yellowfin tuna, Thunnus albacares (Bonnaterre) of the eastern tropical Pacific and western Atlantic Oceans. Management implications are discussed.
Following a brief presentation of marine catch trends in Southeast Asia, some biological peculiarities of the stocks upon which these fisheries rely are discussed. Two empirical log- linear models are presented allowing rough estimation of potential yield of small pelagic fishes fish from primary production, and of demersal fish from mean water depth and primary production. These models are applied to the Banda and Arafura Seas, and the results compared with yield estimates from similar ecological areas, the Sulu Sea (Philippines) and Gulf of Papua. The standing stock and ecological production of mesopelagic fishes in the Banda Sea are also estimated. The implications for management of these findings are discussed, with emphasis on the strong east to west human population gradient of Indonesia.
Over the last three decades, the demand for fish in the Amazon basin has greatly increased due to population growth in the main cities of the region. While technological improvements in commercial fishing methods have made it possible to meet this growing demand, they have led to concerns about the possible extinction of certain fish species and to conflicts over the resource between commercial fishermen and rural communities. This study reviews the current state of inland fisheries in the Amazon in order to analyse policy options for fisheries management, and identifies key gaps in information on the economic, social and biological aspects of fisheries which constrain policymakers.