Grow-out culture of the Asian catfish Clarias macrocephalus (Gunther)

Asian catfish Clarias macrocephalus is an esteemed food fish especially in Southeast Asia due to its tender and delicious meat. This commodity constitutes a valuable fishery for small-scale fishers in the region and has a great potential for aquaculture. The important considerations in the grow-out culture of catfish are reliable water supply, soil with good compaction properties for dike construction, supply of fingerlings, feeds, labor, pond supplies and technology assistance. The farm must also be accessible by road, near to market facilities and has a peaceful environment. Rearing catfish in ponds is the most popular and commonly practiced. The pen culture is a system fully enclosed by nets on all sides but utilizes the dug-out pond, dam or lake bed as bottom enclosure. Tanks in abandoned old hatcheries with freshwater source can be used for catfish culture. In the cage culture system the stock is fully enclosed by nylon nets on all sides and bottom similar to an inverted mosquito net installed in suitable areas like reservoirs, dams, lakes and dug-out ponds. The rice-fish (catfish) culture is also practiced where the rice pond canals are utilized to retain water at 1-2 m depth to provide shelter to the fish while the rice plot maintains 10-20 cm water depth. For the stock, select fingerlings that are active, healthy and uniform in size. Handling of fish stock is important to avoid mortality due to stress during harvest, sorting, counting and transport. Furthermore, stocking of fish is recommended during the cooler part of the day. Catfish fingerlings stocking density is about 5 to 20 pcs/m2 depending on the water supply and support facilities of the farm. The catfish, C. macrocephalus, requires a substantial amount of dietary protein for growth. For this species a formulated diet with crude protein (CP) of 34%, moist diet (trash fish or blanched chicken entrails plus rice bran or cooked broken rice), and a combination of pellet feeds (50%) and moist diet (50%) have been tested and acceptable for the grow-out culture. Economic evaluation based on a grow-out culture in pond with an area of 1,000 m2 showed that feeds and fingerlings are the major variable costs. The net income, return on investments and payback period, respectively range from PhP22,972-PhP35,741, 80-122% and 0.8-1.2 years when using pellet, moist feed or a combination of these feeds. Feeding using formulated diet has an advantage of convenience, quality and quantity over moist diet which has issues such as inconsistent supply, storage requirement and fouling the rearing water

Chapter: Landcare on the Poverty-Protection Interface in an Asian Watershed

Serious methodological and policy hurdles constrain effective natural resource management that alleviates poverty while protecting environmental services in tropical watersheds. We review the development of an approach to integrate biodiversity conservation and agroforestry development through the active involvement of communities and their local governments near the Kitanglad Range Natural Park in the Manupali watershed, central Mindanao, the Philippines. Agroforestry innovations were developed to suit the biophysical and socioeconomic conditions of the buffer zone. These included practices for tree farming, and conservation farming for annual cropping on slopes. Institutional innovations improved resource management, resulting in an effective social contract to protect the natural biodiversity o f the park. Fruit and timber tree production dramatically increased, re-establishing tree cover in the buffer zone. Natural vegetative contour strips were installed on several hundred sloping farms. Soil erosion and runoff declined, while the buffer strips increased maize yields by an average of 0.5 t/ha on hill-slope farms. The scientific knowledge base guided the development and implementation of a natural resource management plan for the municipality of Lantapan. A dynamic grassroots movement o f farmer-led Landcare groups evolved in the villages near the park boundary, which had significant impact on conservation in both the natural and managed ecosystems. Encroachment in the natural park was reduced 95% in three years. The local Landcare groups also restored stream corridor vegetation. This integrated approach has been recognized as a national model for local natural resource and watershed management in the Philippines. Currently, the collaborating institutions are evolving a negotiation support system to resolve the interactions between the three management domains: the park, the ancestral domain claim, and the municipalities. This integrated systems approach operated effectively with highly constrained funding, suggesting that commitment and impact may best be stimulated by a “drip-feed” approach rather than by large, externally funded efforts

Growth And Yield Of Asian Catfish Clarias Macrocephalus (Gunther) Fed Different Growth-Out Diets

Juveniles of the Asian catfish Clarias macrocephalus (3.6±0.17 g; 78.0±0.09 mm) were fed one of four diets: a laboratory-formulated diet of 18.9% (Diet 1) or 34.2% (Diet 2) protein, a com- mercial feed pellet of 28.9% protein (Diet 3) or a diet of 80% blanched chicken entrails and 20% rice bran (31.7% protein; Diet 4). After 120 days of culture, catfish fed Diet 2 grew significantly better (p0.05). Catfish fed Diet 2 had the highest apparent lipid retention (131.7%). The protein efficiency ratio was lowest (1.3) in Diet 2, but did not differ significantly from Diets 1 and 3. Catfish fed Diet 4 were fatty and had a lower crude protein content. Results suggest that C. macrocephalus fed 34.2% crude protein have a significantly higher weight and total yield. Further, a taste test showed that odor, flavor and appearance did not differ amongst the diets

Governing Landscapes for Ecosystem Services: A Participatory Land-Use Scenario Development in the Northwest Montane Region of Vietnam

Land-use planning is an important policy instrument for governing landscapes to achieve multifunctionality in rural areas. This paper presents a case study conducted in Na Nhan commune in the northwest montane region of Vietnam to assess land-use strategies toward multiple ecosystem services, through integrated land-use planning. The assessment employed the Land-Use Planning for Multiple Ecosystem Services (LUMENS) framework and a number of methods and tools, including land-use mapping, GIS-based land-use change analysis, survey questionnaire, rapid carbon-stock appraisal for different land uses, qualitative ecosystem services assessment, and a backcasting technique. Our findings suggest that a lack of participation and acknowledgement of customary land-use practices inhibit successful implementation of current land-use planning and relevant policies such as payment for forest environmental services and the nationally determined contributions. The study also confirmed the contributions of forests and the land-use sector in achieving national emission reduction targets, especially when local stakeholders are involved early in the planning process. Other findings with important policy implications are: (i) tree-based land uses such as agroforestry are key to securing multiple ecosystem services and are highly relevant to local stakeholders, yet their potentials were not made explicit in current debates at the local level; (ii) local stakeholders are highly aware of the co-benefits of ecosystem services to climate-change mitigation and this should be considered in nationally determined contributions; and (iii) an approach for integrated, participatory land-use planning can help catalyze stakeholder engagement, and hence improve governance in rural landscapes

Trees and agroforestry for coping with extreme weather events: experiences from northern and central Viet Nam

Although tree-based farming systems are often assumed to be “resilient” or “climate-smart” options, adoption is limited. It could be that the sensitivity of individual tree species to extreme weather events is poorly documented or new systems include unfamiliar species and technologies. This paper reports on initial results of an evaluation of farmers’ experiences with trees and crops for responding to major climatic exposures in 21 villages in northern and north-central Viet Nam. Our study assessed the suitability and roles of trees by analyzing data gathered through focus group discussions, workshops and a survey of 661 households. The results showed that a majority of households were exposed annually to what they perceived as natural hazards. Experiences with using trees for coping and adaptation depended on household income status, awareness and policies. In particular, farms with trees had shorter recovery time after most types of natural disasters, except for cold spells, demonstrating economic and environmental buffers. Many leaders were unfamiliar with agroforestry and mainly looking for economies of scale, hence oriented to land use rather than landscape planning. This indicates disconnects between farmers’ needs and policymakers’ priorities with respect to climate change adaptation strategies. Existing agroforestry systems reflected a transition from indigenous or current farming systems via changing to either new species or technologies rather than changing both at the same time. Gaps in current adaptation strategies and key areas for policy and research interventions are finally discussed

Landcare - a landscape approach at scale

Not availabl