Taking a step back

Article from: A World of Science (Vol. 7 - N°4; October-December 2009)

Malindi Watamu Biosphere Reserve in Kenya and Braunton Burrows–North Devon’s Biosphere Reserve in the UK have a lot in common. They may be thousands of kilometres apart with very different climates but they share similar problems.

[...] Although one coastline is dotted with coral reefs, sandy beaches and mangroves and the other with marshlands, dunes and popular surfing beaches, both are in the frontlines of the battle being waged against the elements. Sea-level rise and erosion are eating into their beautiful coastlines, threatening the economy and people’s livelihoods. The wildlife habitats and beaches that are a draw for tourists are being threatened not only by these natural phenomena but also by unsustainable development. Last year, the communities of Malindi Watamu and North Devon decided to engage in an experiment. By twinning their biosphere reserves, they hope to learn from one another how best to adapt to their changing world.

Sea level is rising around the world. It will be impossible to stop this phenomenon, yet in north Devon in the UK, that is exactly what some residents are still hoping to do. Research done in the UK indicates that there is a risk of losing 20% of important intertidal habitats to sea-level rise over the next 20 years. These salt marshes will need to be replaced because they provide important defences against flooding. If you have a salt marsh in front of a sea wall, the sea wall doesn’t have to be nearly as big or resilient because the salt marsh actually takes the energy out of the waves and the tide, as they beat against those defences. [...]

Getting people to decide with their heads

[...] For many people living in a developed nation, the term ‘climate change’ evokes accelerating desertification in the Sahel or stronger monsoons in India. They perceive the likely severest effects of climate change as being too remote and too slow-moving for there to be any urgency to act closer to home. Getting people to understand that 2.5 mm of sealevel rise per year actually means a lot when you total that up over the years is no easy task, especially when you tell them that it will accelerate over the coming years. People often react with their hearts rather than their heads when it comes to making difficult decisions like whether or not to abandon land to the sea. Placing the time horizon for the impact just beyond the life expectancy of the current community depersonalises the issues and can give people the space they need to develop an adaptation policy that their children or grandchildren might appreciate.

Trouble in paradise 

Meanwhile, in tropical Malindi Watamu Biosphere Reserve on the Kenyan coast, all eyes are turned towards the mangroves and beaches. In the reserve, embayments with large mangrove forests provide the same functions as the temperate salt marshes in north Devon: fish nurseries and the dissipation of wave energy. The Sabaki River discharges into this part of the coast but carries with it sediment from the soils eroding in the catchment behind, stifling the corals. This source of stress comes on top of a rise in sea temperature and the threat of acidifying oceans. Sea-level rise combined with possible over-abstraction of freshwater along the coast has also led to reports that some of these wells are increasingly saline due to seepage of the sea through the permeable limestone. [...]

 

Full story in:
:: A World of Science, Vol. 7, N°4, October-December 2009. page 20-23 [.pdf]

• Source:from... A World of Science (Vol. 7 - N°4; October-December 2009)
• 04-12-2009

• © Andrew Bell -