Cumulative effects in marine ecosystems

The material and the geographical designations in this report do not imply the expression of any opinion whatsoever on the part of WWF concerning the legal status of any country, territory, or area, or concerning the delimitation of its frontiers or boundaries. [...] WWF’s mission is to stop the degradation of the planet’s natural environment and to build a future in which humans live in harmony with nature, by: conserving the world’s biological diversity, ensuring that the use of renewable natural resources is sustainable, and promoting the reduction of pollution and wasteful consumption. [...] In order to fully account for the cumulative effects on coastal and marine ecosystems from multiple human activities, scientists and managers must be able to understand: (1) which activities cause which stressors; (2) the magnitude, frequency, and spatial scale at which the activities occur; (3) what the resulting direct and indirect cumulative effects will be on the ecosystem; and (4) how multipl [...] A study of the effects of nutrients and trace elements on estuarine food webs found that the interactions among stressors and background environmental conditions resulted in either increases or reductions in the temporal and spatial variability of species (Breitburg et al., 1999). [...] More often researchers discuss the range of existing activities that are likely to have produced the stressors (Mach et al., submitted), and then assess the cumulative effects of the stressors on a suite of ecological components.