Science and management in four U.S. coastal ecossytems dominated by land-ocean interactions

The influence of science in the recognition of the effects of landscape changes on coastal ecosystems and in the development of effective policy for managing and restoring these ecosystems is examined through four case studies: Chesapeake Bay, San Francisco Bay, the Mississippi Delta, and Florida Bay. These ecosystems have undergone major alterations as a result of changes in the delivery of water, sediments and nutrients from their watersheds. Both science and management have been challenged by the spatial, functional and temporal scale mismatches inherent in the watershed-coastal ecosystem relationship. Key factors affecting the influence of science on management include (1) sustained scientific investigation, responsive to but not totally defined by managers; (2) clear evidence of change, the scale of the change and the causes of the change; (3) consensus among the scientific communities associated with various interests; (4) the development of models to guide management actions; (5) identification of effective and feasible solutions to the problems.     

“Low-Salt” Shrimp Aquaculture in Thailand: Goodbye Coastline, Hello Khon Kaen!

/ Intensive shrimp culture has been confined to relatively narrow bands of land along the seashores of tropical developing nations due to the need for large volumes of saltwater for water exchange during the culture period. Recent developments in Thailand suggest, however, that this close association could soon be a thing of the past. Large numbers of Thai farmers are adopting low-salinity culture systems that rely upon sea or salt pan water that is trucked inland. This development greatly increases the potential for establishing shrimp cultivation much further from the coast than previously believed possible. The migration of intensive shrimp farming into freshwater environments, however, raises serious concerns over the disposal of pond effluents and the impact of saltwater intrusion on surrounding agricultural activities. In the absence of effective government regulation of the expansion and operation of the shrimp culture industry, supporting local nongovernmental organizations (NGOs) and community initiatives may be the only means of minimizing the negative impacts of shrimp farming on rural communities.KEY WORDS: Aquaculture; Shrimp; Salinity; Thailand     

Sensor design for saltwater ingress detection in high reliable all-electric deep sea actuators

Subsea oil and gas production relies on Xmas Trees which are mounted on boreholes. Xmas Trees are an arrangement of different valve types and sizes actuated by hydraulic, electro-mechanic or all-electric actuators. All these actuators sharing problems with saltwater ingress and the re-sulting increased wear. This paper investigates potential effects which can be measured after saltwater ingress. Extensive testing is executed and the investigated effects are used for novel sensor designs. These designs are evaluated regarding certain requirements and a resulting sen-sor design is proposed for industrialization. The resulting sensor can then be used to collect new important data to support optimal maintenance in the subsea industry.