Biomass and reproduction of Pacific sardine (Sardinops sagax) off the Pacific northwestern United States, 2003–2005

The Pacific sardine (Sardinops sagax) is distributed along the west coast of North America from Baja California to British Columbia. This article presents estimates of biomass, spawning biomass, and related biological parameters based on four trawl-ichthyoplankton surveys conducted during July 2003 –March 2005 off Oregon and Washington. The trawl-based biomass estimates, serving as relative abundance, were 198,600 t (coefficient of variation [CV] = 0.51) in July 2003, 20,100 t (0.8) in March 2004, 77,900 t (0.34) in July 2004, and 30,100 t (0.72) in March 2005 over an area close to 200,000 km2. The biomass estimates, high in July and low in March, are a strong indication of migration in and out of this area. Sardine spawn in July off the Pacific Northwest (PNW) coast and none of the sampled fish had spawned in March. The estimated spawning biomass for July 2003 and July 2004 was 39,184 t (0.57) and 84,120 t (0.93), respectively. The average active female sardine in the PNW spawned every 20–40 days compared to every 6–8 days off California. The spawning habitat was located in the southeastern area off the PNW coast, a shift from the northwest area off the PNW coast in the 1990s. Egg production in off the PNW for 2003–04 was lower than that off California and that in the 1990s. Because the biomass of Pacific sardine off the PNW appears to be supported heavily by migratory fish from California, the sustainability of the local PNW population relies on the stability of the population off California, and on local oceanographic conditions for local residence.

Analysis of sex-specific spawning biomass per recruit of the sailfish (Istiophorus platypterus) in the waters off eastern Taiwan

Analyses of sex-specific yield per recruit and spawning stock biomass per recruit were conducted to evaluate the current status of the sailfish (Istiophorus platypterus) fishery in the waters off eastern Taiwan. Natural mortality rates estimated from Pauly’s empirical equation were 0.26/yr for females and 0.27/yr for males. The current fishing mortality rates were estimated as 0.24/yr and 0.43/yr for females and males, respectively, which are much lower than the estimated F0 .1 (0.62/yr and 0.79/yr for females and males, respectively) and FSSB40 (0.46/yr for females) which are commonly used as target reference points in fisheries management. The effects of the fishing mortality, natural mortality, and age at first capture on the estimates of biological reference points were evaluated by using the Monte Carlo simulation. The results indicate that failure to consider the uncertainty in parameters such as natural mortality or age at first capture may lead to the improper estimation of biological reference points. This study indicates the possibility of current fishing mortality exceeding the target biological reference points may be negligible for sailfish in the waters off eastern Taiwan. However, in view of the recent rapid increase in fishing effort, it is evident that the stock status and development of the fishery need to be closely monitore

Assessment of the impact of aquatic resources research by ICLARM: scope and methodologies

The importance of quantifying the economic returns to investments in aquatic resources research together with the social, environmental and institutional impacts of such investments is widely recognized among ICLARM's donors, trustees and beneficiaries. As with other Consultative Group on International Agricultural Research (CGIAR) centers, ICLARM is being asked to provide specific accounts of the outputs of its research and their impact on farms and on fisheries, including their socioeconomic impact. Such impact information has become a necessary, though not sufficient, basis for setting priorities and allocating resources for research for the CGIAR centers. This paper discusses the types and methods of impact assessment relevant to ICLARM's work. A three-pronged assessment approach is envisaged to capture the full range of impacts: 1) ex ante assessment for research priority setting; 2) assessment prior to dissemination or adoption along with monitoring and evaluation; and 3) ex post impact assessment. It also discusses the objectives and scope for operational impact assessment of ICLARM's research.

The Marine Fishery Resources Development and Management Department of SEAFDEC

The Marine Fishery Resources Development and Management Department of SEAFDEC (Malaysia), its objectives and activities are briefly presented.

Community management of Mekong River resources in Laos

The Mekong River is one of Asia's greatest rivers. It is the lifeblood of millions of small-scale farmers and fishers in China, Burma, Thailand, Laos, Cambodia and Vietnam. In the Lao People's Democratic Republic (Lao PDR), the river is particularly important because for the landlocked country, the Mekong is the Sea of Laos. In southern Lao PDR, fisheries for native fish species constitute an extremely important source of subsistence protein and income for local people. It has been estimated that wild-caught fish constitute at least 90% of the protein for lowland Laotians living next to the Mekong. Despite the extreme importance of fish to the diets and economics of communities along the Mekong, the resource, and the people who depend upon it, are in danger.

Marine reserves: they enhance fisheries, reduce conflicts, and protect resources

Marine fishery reserves, its fishery and non fishery benefits are discussed. Problems with marine fishery reserves are also pointed out.

Impact pathway analysis for research planning: the case of aquatic resources research in the WorldFish Center

In line with its mandate of poverty reduction and sustainable development, the WorldFish Center is orienting its research towards high impact scientific activity. Identifying such activities is the task of prospective impact assessment, in turn based on impact pathway analysis. The paper describes a framework for analyzing benefits from aquatic resources research, the relevant research categories, pathways to impact by category, and indicators along each pathway that can be estimated in order to quantify probable research impact.

Integrated resources management, integrated agriculture-aquaculture and the African farmer

Despite the expenditure of huge amounts of money and human effort, the Green Revolution has largely failed to benefit the vast majority of the rural poor in Africa: those smallholding farmers who sell little, if any, of what they grow and rely almost entirely upon natural soil fertility, rainfall and traditional broodstock and seed varieties. New approaches on food production and income generation in the rural areas must be found if this sector of agricultural community is to be assisted. Integrated resources management (IRM) in general, and integrated agriculture-aquaculture (IAA) in particular, may offer some solutions in cases where the classical methods of improving farm output have failed and/or been unsustainable.

Community management of coastal resources, southern Thailand

The involvement of communities with the assistance and support of government and non government organizations on the management of the coastal resources in Southern Thailand are discussed. The 3 most important resources, mangrove, seagrass and coral, create a complex coastal ecology. Several man-made activities causing the deterioration of this resources are also presented.

Assessing and managing the resources available to the Senegalese small-scale fisheries

A brief account of the evolution and structure of the marine fisheries of Senegal, West Africa, is presented, with emphasis on the small-scale subsector and on the major recommendations of an international symposium/workshop on this topic, held on February 1993 in Dakar.

Problems for the conservation of freshwater fish genetic resources in India and some possible solutions

Many interconnected problems involved for the conservation of freshwater fish genetic resources of India are enumerated. Some possible solutions to the problems are also discussed.

Consumption to biomass (Q/B) ratio and estimates of Q/B-predictor parameters for Caribbean fishes

Estimates of the Q/B ratio and parameters of equations to 'predict' Q/B values for 116 fish stocks in the Gulf of Salamanca, Colombia are presented. A compilation of these estimates available for Caribbean Sea fishes (264 stocks) is also provided for comparison purposes. General trends in the value of Q/B resulting from differences in the equation and parameter values used are briefly discussed.

Economic seaweed resources and their management in eastern Indonesia

The article focuses on the economic seaweed resources and production in eastern Indonesia and how the fishers in the country adjust their system in managing the resources. Particular attention is given to seaweed which can be used as materials for producing carageenan and agar; most carrageenophyte species explored in eastern Indonesia belong to the genera Kappaphycus and Eucheuma; and seaweeds that produce agar belong to families Gelidiaceae and Gracilariaceae.