Damming a river may bring electric power, but it often comes at the price of high-quality food fisheries, experts say. When dams are proposed for power, flood control or irrigation, the often devastating impacts on fisheries in rivers and lakes are ignored or discounted.

This report by the UN Environment Programme (UNEP) and the World Fish Centre warns that despite over 40 years of steady production globally, rapid environmental changes are occurring which challenge the viability of future fish stocks and a range of internationally- agreed development targets including the Millennium Development Goals.

The report is available online at http://www.unep.org/pdf/Blue_Harvest.pdf

Adaptive management is appraised as a policy implementation approach by examining its conceptual, technical, equity, and practical strengths and limitations. Three conclusions are drawn: (1) Adaptive management has been more influential, so far, as an idea than as a practical means of gaining insight into the behavior of ecosystems utilized and inhabited by humans. (2) Adaptive management should be used only after disputing parties have agreed to an agenda of questions to be answered using the adaptive approach; this is not how the approach has been used. (3) Efficient, effective social learning, of the kind facilitated by adaptive management, is likely to be of strategic importance in governing ecosystems as humanity searches for a sustainable economy.