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In search of climate and wildlife stories…by bike

Machair under threat — August 24, 2012

Machair under threat

On the ferry crossing from Coll to Tiree I saw basking sharks and a pod of dolphins – amazing. Basking sharks are the second largest fish in the ocean, second only to the whale shark. They are slow moving filter feeders, opening their huge mouths to take in gallons of water and filter out the nutritious tiny plankton. I saw them some way off so just the dark dorsal fin above the water – but it was my first ever sighting. John Bowler, my RSPB colleague on Tiree, said he counted 250 off the west cost of the island on one occasion this year and that it has been a good year for them because the sea has stayed relatively cool through the summer and this has been good for plankton.

John showed me ‘The Reef’, a large flat Machair plain to the east and south of the airport, almost bisecting the island, land that he looks after and manages. It’s a sensitive spot so not a reserve that the RSPB advertises. In April and May there are large numbers of lapwing nesting and in the winter rain flood the lowest point before draining to the sea. Whooper swans, geese and other water birds use this area. Whooper swans migrate to Tiree from Greenland and stay for the winter but in the past 10-15 years their arrival date has got later and later. They used to arrive in September or October but nowadays they delay until November because Greenland is getting warmer.

Between The Reef and the sea is a stretch of sand dunes. John showed me that these are eroding and I could easily see the steep seaward edge in many places. This might be due to the storms which seem to come in a more southerly direction these days. This winter was the wettest ever winter and very windy, often force 8, 9 and 10. The storms have battered the beachhead in places on the island and roads have to be repaired after each. At The Reef the sand isn’t blowing inland to create new dunes but rather washing away at a rate of approximately half a metre per year and in some places the dunes are now very low and narrow. If the sea did wash through the dunes it is hard to say how long any inundation might last or how nature would respond and adapt. Some Machair would be lost as the saltwater wouldn’t be favourable to it, instead saltmarsh might take hold permanently.

Machair is under threat throughout the Hebrides because of climate change causing sea level rise and extreme weather. Machair is unique, delicate and vulnerable, and we can’t create lots more in other places in Scotland. All we can do is manage the Machair that we have so that it is in the best condition possible for the wildlife that depends on it and for us to enjoy. The best thing to avoistop the erosion of Machair is to cut our carbon emissions and put a halt to climate change as soon as we can.

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