Testable models of aquatic systems: A NERC special topic for integrating experiments and modelling

A major part of the support for fundamental research on aquatic ecosystems continues to be provided by the Natural Environment Research Council (NERC). Funds are released for ”thematic” studies in a selected special topic or programme. ”Testable Models of Aquatic Ecosystems” was a Special Topic of the NERC, initiated in 1995, the aim of which was to promote ecological modelling by making new links between experimental aquatic biologists and state-of-the-art modellers. The Topic covered both marine and freshwater systems. This paper summarises projects on aspects of the responses of individual organisms to the effects of environmental variability, on the assembly, permanence and resilience of communities, and on aspects of spatial models. The authors conclude that the NERC Special Topic has been highly successful in promoting the development and application of models, most particularly through the interplay between experimental ecologists and formal modellers.

Human Resources Development for Sustainable Aquaculture in Bangladesh

The ennoblement of human resources has become a prime issue in the philosophy of sustainable aquaculture development in the new millennium.Being the planners, designers, conductors and philosophers of sustainable aquaculture, human beings always demand their further improvement at level best from their current positions to bring supreme success in the sector. As sustainable aquaculture is socio-economic –cum-environmental in concept, its operation and management requires constant interplay of various human knowledge for ensuring its smooth direction and for achieving its goal. So, the arrangement of different types and levels of training and education are the great need for the development of personnel involved in sustainable aquaculture route and also for growing awareness of environmental issues. The modus operandi of training and education has to be changed systematically to answer the calls of the needs of the new millennium. In the developing and developed countries where aquaculture plays a vital role in promoting production of aquatic organisms, alleviating of poverty, ensuring environmental compatibility, replenishing and improving the natural stocks, increasing socio-economic upliftment through integrated development approach, developing and managing the aquatic resources, maintaining gene banks and preserving the diversity of fish stocks, it has been already proved that Human resources development (HRD) is inevitable to bring sustainable aquaculture and plays a great role in the flourishment of the system . Different types and levels of training of personnel required for sustainable aquaculture in the new millennium are brought forward in the study. The importance of human resources development (HRD) through specialized training to the personnel is also depicted.

The influence of North Pacific atmospheric circulation on streamflow in the West [abstract]

EXTRACT (SEE PDF FOR FULL ABSTRACT): The annual cycle and non-seasonal variability of streamflow over a network of stations in western North America and Hawaii is studied in terms of atmospheric forcing elements. The phase lag between the annual cycle of streamflow and precipitation varies considerably over this network, as does the persistence of monthly streamflow anomalies. This lag effect appears to be largely a function of the relative amount of snow laid down in a particular basin. In addition to the rather strong annual cycle that exists in mean streamflow and its variance at most of the stations, there is also a distinct annual cycle in the autocorrelation of streamflow anomalies that is related to the interplay between the temperature and precipitation annual cycles; of particular importance is the existence of stored water in the form of a snow pack.

Demersal groundfish densities in trawlable and untrawlable habitats off Washington: implications for the estimation of habitat bias in trawl surveys

Demersal groundfish densities were estimated by conducting a visual strip-transect survey via manned submersible on the continental shelf off Cape Flattery, Washington. The purpose of this study was to evaluate the statistical sampling power of the submersible survey as a tool to discriminate density differences between trawlable and untrawlable habitats. A geophysical map of the study area was prepared with side-scan sonar imagery, multibeam bathymetry data, and known locations of historical NMFS trawl survey events. Submersible transects were completed at randomly selected dive sites located in each habitat type. Significant differences in density between habitats were observed for lingcod (Ophiodon elongatus), yelloweye rockfish (Sebastes ruberrimus), and tiger rockfish (S. nigrocinctus) individually, and for “all rockfish” and “all flatfish” in the aggregate. Flatfish were more than ten times as abundant in the trawlable habitat samples than in the untrawlable samples, whereas rockfish as a group were over three times as abundant in the untrawlable habitat samples. Guidelines for sample sizes and implications for the estimation of the continental shelf trawl-survey habitat-bias are considered. We demonstrate an approach that can be used to establish sample size guidelines for future work by illustrating the interplay between statistical sampling power and 1) habitat specific-density differences, 2) variance of density differences, and 3) the proportion of untrawlable area in a habitat.