Our recent publication, 50 for the Future, lists 50 things that we believe should happen in Scotland over the next 50 years to benefit both people and wildlife. In this week's 50 for the Future article, Jim Densham, the RSPB Scotland's Senior Land Use Policy Officer, explains the importance of removing artificial barriers along our coastlines.
Number 33: Remove artificial barriers along our coastlines to ensure adequate space for wildlife habitats and to help tackle increased flood risk due to climate change.
Sea level rise and its impacts are inevitable. Even with green house gas reduction targets and action to cut emissions, we will still see further sea level rise into the 21st century. Seas as much as half a metre higher are predicted for some areas of Scotland by the end of the century. On top of that, we have the chaos caused by storms. This winter we have already had a battering from nine storms, Storm Imogen being the most recent.
According to SEPA, 26,000 homes and businesses are at risk from coastal flooding in Scotland, many along our soft coasts and firths in the south and east. Nature too is under pressure from sea level rise. Coastal habitats such as saltmarsh are fragmented because much of our historical saltmarsh was reclaimed for agriculture or development. A study of the Forth showed that 50% of saltmarsh was lost in this way. Now, the narrow remnants of these wet, muddy habitats are squeezed between flood embankments and the rising tides, unable to colonise inland as the tides rise.
Ironically, the very habitat under threat can protect us from sea level rise and the risk of flooding. Saltmarsh is a natural buffer around the coast – 50% of wave energy is absorbed by 10-20m of saltmarsh. But squeezed as it is, this protective ability is lessened and the risk of waves overtopping or breaking embankments and the sea flooding inland areas is greater.
Managed coastal realignment is a technique which can reduce the risk of coastal flooding and make space for nature. It involves breaking a hole in the sea wall to allow an inland area to be inundated by the tides in a controlled way, but not before the new tidal area is enclosed by a new flood embankment.
Scotland’s first ever managed realignment project was completed at RSPB Scotland’s Nigg Bay reserve in 2003. A 25ha field, locally called Meddat Marsh, was returned to the tide’s influence, half a century after it had been converted to agricultural use.
More than 10 years on since the old sea wall was broken, there has been a 30% increase in salt marsh in the bay. Four surveyed species of mud-dwelling invertebrates (snails, worms and shrimps) were found on the site in the first winter after the tide flooded back in, much quicker than expected. These are key food for waterbirds, with 25 species now using the site including redshank, bar-tailed godwit and whooper swan. The managed realignment site is one of the last areas in the whole of Nigg Bay to be covered by seawater on the incoming tide. As a consequence it provides valuable extra feeding areas as the tide comes in and safe roosting areas at high tide. During windy conditions and in high spring tides it is an essential refuge for up to 2000 waterbirds (find out more in the monitoring report).
The project has been a resounding success for habitat creation and wildlife. It has shown that this technique works in Scotland – what’s needed now is much more of this type of land use change around the coast. There are many potential areas, principally located in the Solway, Forth, Tay and in the area of the Beauly, Cromarty & Dornoch Firths.
We need to recreate a swathe of lost intertidal habitats along Scotland’s coasts to protect us from flooding and climate change, as well as providing more homes for wildlife. To make this happen, Scotland needs a new blueprint for coastal adaptation and change, one which identifies these areas and prioritises nature-based adaptation. The Scottish Government needs to provide new funding which actively supports managed realignment. At present, Scotland’s Rural Development Programme only funds a small part of the overall cost and this holds back action. Local Authorities also need to be strongly encouraged and empowered to choose sustainable and long-term natural flood management techniques, such as managed realignment, when making plans to protect coastal communities.
Our wet, muddy coastal habitats provide homes for nature and protection for people. If we help nature now, it will help us in the face of a changing climate.
Let us know your thoughts by emailing firstname.lastname@example.org or Tweet @ScotWildlife using #50fortheFuture.
Jim Densham is the Senior Land Use Policy Officer at RSPB Scotland
For further information, read the RSPB report: Glorious Mud
Banner image: © Stephen Middlemiss, Creative Commons