Spatial and temporal scales for monitoring coastal aquatic ecosystems

Abstract

1. Coastal ecology is mostly regulated by hydro-meteorological factors and human disturbances. The spatial and temporal scales of variation of the processes associated with these factors may not correlate. 2. Monitoring of water and ecosystem quality in the coastal zone must be performed at spatial and temporal scales that adequately address the objectives. They range between two extreme states, i.e. high water turnover due to surface water exchanges and evaporation driven turnover, and can cover a range of ecological situations depending on hydrological variables. 3. The spatial scale for monitoring coastal aquatic ecosystems may be better related to water masses circulation than to physiographic features. Biologically mediated processes require monitoring taking account of meteorological, seasonal and interannual time scales. 4. Variables to be monitored must be in accordance with objectives. They may range from intra-compartment variables (e.g. demography of a biological population) to inter-zone relationships (e.g. budgets of nutrient exchange with the sea). Larger and longer scales, such as including buffer zones around lagoons and the continental and sea basins, and the consideration of interdecadal and secular time scales are required for wider monitoring perspectives. 5. Monitoring the impacts of global changes (both direct, such as urbanization and eutrophication of the coastal zone, and indirect, through relative sea-level rise due to climate change) requires a wider conceptual scale of approach to coastal zone ecology and even longer monitoring programmes. Copyright © 2004 John Wiley & Sons, Ltd.