Public health decision-makers in Ontario have very positive perceptions of the usefulness of systematic reviews in policy development. Therefore, ongoing efforts to promote the usefulness and relevance of systematic reviews to public health decision-makers should remain a priority for health services researchers.

The ecological effect of prawn trawling on the benthos of the Gulf of Carpentaria, northern Australia, was investigated by examining stomach contents of common demersal fishes incidentally caught as by-catch in the fishery. Fishes were collected from high and low fishing intensity sites in three regions based on vessel monitoring system data. The diets of eight species of benthic fish predators were compared between regions and fishing intensities. A regional effect on diet was evident for seven species. Only one generalist species had no significant difference in diet among the three regions. For the comparisons within each region, five predator species had significantly different diet between high and low fishing intensities in at least one region. Across the three regions, high fishing intensity sites had predators that consumed a greater biomass of crustaceans, molluscs and echinoderms. At low fishing intensity sites, predators had diets comprising a greater biomass of cnidarians and teleosts, and a different assemblage of molluscs, crustaceans and fishes. These changes in diet suggest that there may have been a shift in the structure of the benthic community following intensive fishing. Analysis of predator diets is a useful tool to help identify changes in the benthic community composition after exposure to fishing. This study also provided valuable diet information on a range of abundant generalist benthic predators to improve the ecosystem modelling tools needed to support ecosystem-based fisheries management.

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Freshwater flow into estuaries during periods of high rainfall is considered to enhance the biomass of primary producers, with positive effects propagating to higher trophic groups. We examined the effect of flow on chlorophyll a (chl a) concentrations and meiofaunal abundance on the intertidal mudflats in a wet-dry tropical estuary in the Norman River, northern Australia. Meiofaunal density and sediment chl a concentrations (microphytobenthos) were signifi cantly reduced during 2 consecutive wet season floods (the first, a major flood; the second, minor). Additionally, a short-term study of primary productivity on the mudflats during the minor flood measured rates below detection limits. The effects of salinity and burial by sediment on chl a concentrations and meiofaunal abundance were examined experimentally. Both the sudden and prolonged changes in salinity and sediment movement, and subsequent sedimentation as a result of wet season floods were the likely causes of the reduced meiofaunal density, chl a concentrations and benthic primary production. In the short term, large floods in the wet-dry tropics appear to act more as a disturbance event than a subsidy for benthic estuarine biota, and any positive effects of the flood may not occur until flooding eases. Additionally, we propose that there is a transitional period between the typical wet and dry seasons in the wet-dry tropics, during which flood waters are dissipating and the initial impact of the flood has abated, and there are positive effects on meiofauna and microphytobenthos biomass.