This paper reviews freshwater use in inland and coastal pond aquaculture, and focuses on options to increase productivity while reducing water use. Total freshwater use depends on system-associated and feed-associated water losses. System-associated water losses depend on total area, evaporation, infiltration and water replacement. About 8,750,000 ha freshwater and 2,333,000 ha brackish water ponds are in use today. Total water withdrawal in freshwater aquaculture is estimated at 16.9 m3/kg production, representing 429 km3/yr, which is 3.6% of flowing water globally. Infiltration and replacement water recharges aquifers; if these losses are clean, their re-use decreases aquaculture-related water withdrawal by nearly 60%. A further reduction in freshwater use in aquaculture can come from intensification and aquafeed development. The goal should be to feed the pond, not the fish. A tripling of average pond production should be possible, without increasing total freshwater use. Such improvements will also benefit brackish water aquaculture, which could in turn further reduce freshwater use by increasing the productivity of saline systems.
The use of serious games in the governance of natural resources and the environment is progressively increasing and includes games used for research and data collection, teaching and training, and fostering a change of practices. However, this diversity remains underexplored and underreported. In view of a growing interest in the use of serious games in natural resource and environmental governance, the absence of discussions about how differences in intended use and delivery influence the performance, assessment, and outcomes of games is problematic. Here we present an inventory, and a description, of such different uses then, by focusing on serious games used as interventions, we discuss when, and how, games could be used to generate learning and social learning. To that end we use a narrative review of selected literature, and insight from research on social learning, to develop an inventory of game use, and within that inventory we conceptualize the use of serious games as a social learning intervention. Also, by means of an illustrative case of a serious game (developed as part of the Assessing the Learning Effects of Games on Attitude of Stakeholders toward Sustainable Shrimp Farming – ALEGAMS research project) we reflect on a few key aspects of game use. We suggest that developing a serious game needs several iterations and, although the learning outcomes can be assessed, the impact of games aiming at changes in current practice and policy will likely fall beyond the timespan of usual project periods. This is something future research should consider as it has implications for the research design and methodology.
Intensive striped catfish production in the Mekong Delta has, in recent years, raised environmental concerns. We conducted a stakeholder-based screening life cycle assessment (LCA) of the intensive farming system to determine the critical environmental impact and their causative processes in producing striped catfish. Additional to the LCA, we assessed water use and flooding hazards in the Mekong Delta. The goal and scope of the LCA were defined in a stakeholder workshop. It was decided there to include all processes up to the exit-gate of the fish farm in the inventory and to focus life cycle impact assessment on global warming, acidification, eutrophication, human toxicity, and marine (MAET) and freshwater aquatic ecotoxicity (FWET). A survey was used to collect primary inventory data from 28 farms on fish grow-out, and from seven feed mills. Hatching and nursing of striped catfish fingerlings were not included in the assessment due to limited data availability and low estimated impact. Average feed composition for all farms had to be applied due to limitation of budget and data availability. Feed ingredient production, transport and milling dominated most of the impact categories in the LCA except for eutrophication and FWET. Most feed ingredients were produced outside Vietnam, and the impact of transport was important. Because of the screening character of this LCA, generic instead of specific inventory data were used for modelling feed ingredient production. However, the use of generic data is unlikely to have affected the main findings, given the dominance of feed production in all impact categories. Of the feed ingredients, rice bran contributed the most to global warming and acidification, while wheat bran contributed the most to eutrophication. The dominance of both was mainly due to the amounts used. Fishmeal production, transport and energy contributed the most to MAET. The biggest impacts of grow-out farming in Vietnam are on eutrophication and FWET. Water nutrient discharge from grow-out farming was high but negligible compared with the natural nutrient content of the Mekong River. The discharge from all grow-out farms together hardly modified river water quality compared with that before sector expansion. Feed production, i.e. ingredient production and transport and milling, remains the main contributor to most impact categories. It contributes indirectly to eutrophication and FWET through the pond effluents. The environmental impact of Pangasius grow-out farming can be reduced by effectively managing sludge and by using feeds with lower feed conversion ratio and lower content of fishery products in the feed. To consider farm variability, a next LCA of aquaculture should enlist closer collaboration from several feed-milling companies and sample farms using their feeds. Future LCAs should also preferably collect specific instead of generic inventory data for feed ingredient production, and include biodiversity and primary production as impact categories.
18 January 2012 in Wetlands Ecology and Management
Around 1990, when in other countries mangrove protection took off, massive conversion of mangrove forest into shrimp ponds started in the Mahakam delta. To identify constraints to and options for sustainable management we analysed institutions and constraints with stakeholders. In 3 sites we used participatory tools and a complementary survey to assess the livelihood framework. Since 1970, ponds for shrimp farming gradually replaced 75% of mangrove forested area. After 2004, recovery of mangrove took off, as, mainly due to low shrimp yields, ponds were abandoned. In 2008, 54% of the delta was dedicated to ponds for shrimp production. Around 80% of livelihood activities of pond-farmers, pond caretakers, and fishermen was related to mangroves. The involvement of men and women in these activities varied between sites and types. Poor households depended more on mangroves. Most activities resulted in seasonal income peaks; only a few activities resulted in a full daily livelihood. Ponds, on the other hand, provide 50% of households’ livelihood, but this remains vulnerable in the context of the risky shrimp production. Skewed land holding, unequal sharing of benefits, competing claims and vested interests of stakeholders pose a great challenge to a transition to a more sustainable use of the mangrove area. In particular, ponds located on peat soils are non-sustainable and would require full restoration into mangrove; ponds on other soils could best be transformed into a mixed mangrove-pond system using a ‘green-water’ technology.