Exploratory analysis of resource demand and the environmental footprint of future aquaculture development using Life Cycle Assessment

Increases in fish demand in the coming decades are projected to be largely met by growth of aquaculture. However, increased aquaculture production is linked to higher demand for natural resources and energy as well as emissions to the environment. This paper explores the use of Life Cycle Assessment to improve knowledge of potential environmental impacts of future aquaculture growth. Different scenarios of future aquaculture development are taken into account in calculating the life cycle environmental impacts. The environmental impact assessments were built on Food and Agriculture Organization statistics in terms of production volume of different species, whereas the inputs and outputs associated with aquaculture production systems were sourced from the literature. The matrix of input-output databases was established through the Blue Frontiers study.

Fishery resources and some economic aspects of four fishing villages on Lakes George and Edward in the Queen Elizabeth National Park, Uganda

The fishery resources of Lake George and Ugandan waters of Lake Edward are described. The main fish species currently observed in the commercial catches were determined and the reasons of changes in species composition of the catches. that occurred in the recent years, are explained. The fishing activity and some economic and nutritional aspects of four fishing villages, selected among the ten present within the Queen Elizabeth National Park boundaries, are analyzed, In the end some suggestions are given for management of the fishery resources of these lakes.

The potential for further proliferation of water hyacinth in Lakes Victoria, Kyoga and Kwania and some urgent aspects for research

Shore environments of Lakes Victoria and Kyoga with potential for the establishment and proliferation of water hyacinth were identified. They are characterised by: (i) shelter from violent off-shore and along-the-shore wind and wave action (ii) flat or gentle slope under relatively shallow water, and (iii) a muddy bottom rich in organic matter. Such environments are strongly associated with emergent macrophytes of papyrus, Vossia sp and, at times Typha sp where Pistia stratiotes, species of ceratophyllum, myriophylum and nymphaea also occur. In Lake Kyoga association with Vossia sp facilitated establishment of water hyacinth even along wind-swept shores and promoted extension of mats of the two machrophytes into the open lake. Urgent research on water hyacinth is proposed in the areas of nutrient relations, weed biology and on its impact on the biodiversity resource, with particular emphasis on the fishery component. Findings from the research could facilitate formulation of weed control options and alternative resource management strategies. A regional approach to address the water hyacinth menace is highly recommended.

Changes in the concentrations of size-fractioned iron and related environmental factors in the northeastern part of lake Dianchi (China)

To observe changes in the concentrations of size-fractionated iron and related environmental factors, experiments were conducted in the northeastern part of the shallow eutrophic lake Dianchi (China) from March 2003 to February 2004. Iron concentrations were measured for three size fractions: particulate iron (phi >0.22 mu m), colloidal iron (phi = 0.025-0.22 mu m) and soluble iron (phi < 0.025 mu m), and environmental factors (physicochemical and biological factors) were synchronously analyzed. Results showed that size-fractionated iron and the related environmental factors all varied with season. Colloidal iron accounted for only 5-9% of total iron, while particulate and soluble iron each accounted for 40-50% of total iron. The results suggested that size-fractionated iron can transform into each other, especially the highly reactive colloidal iron. Significant linear correlations were found between iron in different size fractions, and significant correlations were also obtained between chlorophyll a and environmental factors, such as TN, TP and secchi depth. No significant correlation between iron and chlorophyll a was found in this study.