Freshwater to oceans hotspots

Some especially sensitive coastal areas are more vulnerable to the combined impact of land-based pollution and climate change effects. IPCC has identified some hotspots for vulnerability¹ and potential impacts of climate change considering the characteristics of exposure, sensitivity, and adaptive capacity. Among the hotspot areas assessed by the IPCC, those with clear land-ocean interaction characteristics include

• deltas and estuaries (especially populated megadeltas)
• coral reef areas
• low-lying coastal wetlands
• small islands
• sand/gravel coastlines/beaches.

Also, any type of coastal/marine protected area directly influenced by land-based activities will be impacted, within and outside their boundaries, by changes in water quality, nutrient runoff, and climate change. Management of MPAs should be integrated with land-based planning, especially in those cases with land-ocean dependent interactions. The combined effect of climate change (eg, sea level rise and coastal erosion) and human impact is increasing the vulnerability of all hotspots. Likely impacts include

• shoreline retreat due to coast erosion and sea level rise
• subsidence of deltas due to runoff pattern change (eg, change of precipitation), sediment starvation and river flooding due to human intervention
• increasing salinity in estuaries due to sea level rise, causing productivity and biodiversity changes, and potential eutrophication due to changes in freshwater residence time
• reduction of mangrove areas and salt marshes due to increased frequency and intensity of severe weather events and changes in the hydrological regimes
• water availability and coastal protection in small islands due to coastal perviousness reduction and the reduction of coastal natural coastal buffer areas (human intervention), change in precipitation cycles, and greater frequency of severe weather events
• reduction of coral reef areas due to anthropogenic impact and bleaching associated with climate change.

The sensitive nature of these hotspots to human intervention and the potential effects of climate change require a special and comprehensive protection that requires both an integrated planning system to unify upstream, downstream, and coastal areas and an understanding of the adaptive capacity of humans and natural systems. There is a huge gap between developed and developing nations in capacity for adaptation, especially in those hotspots where a high concentration of human population can be found. Addressing adaptation issues in developing nations and improving the institutional capacity to respond to these issues should be a priority for international cooperation and donors’ agendas.

¹ IPCC, 2007: Summary for policymakers. In: Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the 4th Assessment Report of the IPCC.

Source: 4th Global Conference on Oceans, Coasts and Islands, Hanoi, Vietnam, 7-11 April, 2008
Policy Brief on Freshwater to Oceans, Pgs 2-3 http://www.thew2o.net/goc2008/freshwater.htm