An alert system for triggering different levels of coastal management urgency: Tunisia case study using rapid environmental assessment data

摘要

Rapid environmental assessment (REA) involves scoring abundances of ecosystems/species groups and magnitude of pressures, concurrently, using the same logarithmic (0-6) assessment scale. We demonstrate the utility of REA data for an alert system identifying different levels of coastal management concern. Thresholds set for abundances/magnitudes, when crossed, trigger proposed responses. Kerkennah, Tunisia, our case study, has significant natural assets (e.g. exceptional seagrass and invertebrate abundances), subjected to varying levels of disturbance and management concern. Using REA thresholds set, fishing, green algae/eutrophication and oil occurred at 'low' levels (scores 0-1): management not (currently) necessary. Construction and wood litter prevailed at 'moderate' levels (scores 2-4): management alerted for (further) monitoring. Solid waste densities were 'high' (scores 5-6): management alerted for action; quantities of rubbish were substantial (20-200 items m~(-1) beach) but not unprecedented. REA is considered a robust methodology and complementary to other rapid assessment techniques, environmental frameworks and indicators of ecosystem condition.