The catch-effort relationship of the River Nile is Complicated by such factors as changes in water level and hydrology as well as spawning movements of the fish, which result in uneven distribution of the fish and fishing. The effects ofdam construction on the ecology of the fish fauna are considered, with particular reference to the effects of the Faraskour dam on the river fishery.
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.
Details are given of a project undertaken in the central Philippines concerning various factors affecting coral reefsand the protective management of the coral reefs.
Rapid and detailed post-tsunami surveys carried out in the Langkawi archipelago in January 2005 showed that the coral reefs do not suffer any significant structural damage. Nevertheless, there were signs of recent sediment resuspension at the sites studied. The diversity and abundance of coral reef fishes and invertebrates were low. However, this was not attributed to the tsunami effect but rather to the present environmental conditions.
Procedures for impact assessment, including "beyond-BACI" (before-after control-impact) and proportional differences (ratios between impact and control treatments) were used to test population replenishment of marine invertebrates at a marine conservation area (MCA) and three fished (control) areas in the Solomon Islands of the southwestern tropical Pacific. Within shallow reef terrace habitat, the MCA caused abundance and size of the topshell Trochus niloticus to increase but did not affect holothurians (sea cucumbers) or the giant clam Tridacna maxima.
The social and environmental impacts of coastal aquaculture have been widely reported. It is now generally agreed that aquaculture development needs to be better planned and managed if is to achieve its potential and develop in a sustainable manner. The author examines the strengths and weaknesses of different approaches to theenvironmental management of aquaculture development and discusses how they might best be promoted and applied in practice.
Coastal aquaculture is a traditional practice in Southeast Asia. Accelerated development in the last three decades has created negative environmental impacts, such as extensive mangrove conversion to ponds, changes in hydrologic regimes in enclosed waters due to proliferation of aquaculture structures, and discharge of high levels of organic matter into coastal waters. Similarly, the increasing deterioration of coastal water quality resulting from the discharge of domestic, agricultural and industrial wastes into coastal waters has affected aquaculture production and profitability.
The environmental impact of the recent reservoir development in Asia is examined with respect to fishery and aquaculture management.
Tilapias have been introduced as alien species to about 90 tropical or subtropical countries and territories, purposely for aquaculture or fisheries, or accidentally. In Africa, tilapias have been moved, again mainly for aquaculture and fisheries, beyond their natural ranges. Tilapia introductions are increasing as tilapia becomes an internationally traded commodity, and these introductions include not only alien species and subspecies but also genetically modified fish.
This is a compilation of information from tape recording of a discussion on aquaculture and the environment in developing countries.