Category: Research

Here’s the fifth of our series of blogposts by Mary Morrison, in which she reflects on the Aire Air Sunnd project led by Comann Eachdraidh Uibhist a Tuath. As with her previous posts, comments are welcome!

Drawing by John from the AAS Caraidean Uibhist workshops

Mary writes:

Professor Stewart Angus.  ‘Coastal Changes on North Uist.’  

‘You might be able to do more than I can’.

On the evening of July 10^th, as part of our Heritage, Gaelic and Wellbeing project, ‘Aire Air Sunnd’, a packed room of members of Comann Eachdraidh Uibhist a Tuath were privileged to have an evening visit from Professor Stewart Angus. He gave us an impressive talk about his extensive, longitudinal research into ‘Coastal Changes in North Uist’, using a comprehensive array of historical sources, photographs, maps and diagrams to illustrate his points. Since he has worked across the Long Island, comparisons were offered to his own and others’ collections of data from along the Hebridean coasts, including references to Lewis, Harris, Benbecula and South Uist.

Professor Angus encouraged the audience to use research findings and make their community voices heard in governmental and environmental circles. He seemed to feel that, as a community, we have a significant role to play here, both alongside the scientific data, as well as in the promotion of the research recommendations these have generated. He reiterated throughout the evening that he felt the community voice might persuade those in power to listen to and to pay attention to the scientific data?

(One of the most strongly voiced concerns the ‘AAS’ project’s community members’ survey in 2023 had raised was that local voices were not being heard at local or national levels.) We think, as a project, and as a seemingly small band of electors, these findings will need to be central to our project on-line conference early in October, ‘Making our Voices Heard’.

Professor Angus stressed the importance of ‘lived’ local knowledge, such as the finds of saddle querns amongst the shingle banks made by lobster fishermen, the relevance of coastal or rock placenames, some even referring to attempts in the past to build sluice gates to prevent the sea waters entering the freshwater lochs. One reef, Sgeir Husabost, is all that remains today of an ancient township, mentioned in The Charter of Inchaffrey, but lost to the sea. This lay close to Baleshare, or Baile Sear, (Eastern Township), whose name itself implies that maybe it was once two, separated townships.

Some of the key points Professor Angus made are summarised as follows, (with my apologies as a mere citizen scientist for any misinterpretations):

• Global warming does not always mean the same as local warming.
• Uist has the highest rate of relative sea level rise in relation to land in Scotland.
• Winter rain is predicted to rise by 45%. Even the levels of low tides are rising.
• The land is also rising, although, because of rainfall here, and our topology, the mainland of Scotland is sinking faster, by 6mm a year.
• Moving dunes have a key role to play in adaptation to these rising sea levels; preserving the integrity of their ridges and the breadth of these are very important.
• The coast and dunes move on every tide; they provide a natural structure for warding off the ocean. Evidence shows the dunes work better than any built structure in dampening the effects of high tides and storms – not losing sand but redepositing it, often in useful ways, since sand absorbs wave energy well.
• The wider the dune structure, the more protection it provides. The scale of the impact is determined by the height of the waves, which in turn is the result of atmospheric pressure, astronomical pressure, the nature of the weather and the tide.
• Built structures, such as walls, tend to be less useful: it may be better to work with respect for the ways the environment works itself and avoid building walls?
• It may also be important that no rubbish of any kind should be buried within the dunes. Whatever is buried will be released back onto the shore at some stage – there is some alarming evidence that this is still happening today.
• It is also important that we try to avoid saltwater getting into the freshwater lochs through breaches in the dunes. In two lochs, North Uist has the highest national score for protected organisms, (such as a very rare kind of cockle or the birds nest stonewort), boasting seven out of the eight rarest species.
• There are other important ways of dampening wave energy, such as North Uist’s extensive kelp fields, our extended shallow horizontal seabed, our shingle bank deposits and seaweed on the shore.
• Those who collect our ‘truly wonderful’ seaweed are advised to take this from as low down the beach as possible. Leaving a ridge of seaweed high on the shore encourages the very fertile insect and beetle life to propagate rapidly in the heat of its decay, providing essential food for wading birds.
• The seeds within the tangle higher up the beach will also be nurtured, having time to bed themselves into the sand, thus trapping it and preventing it from blowing. This ridge of seaweed should be allowed to rest, ideally, for at least two years.

The talk then followed the North Uist coastline in considerable detail revealing how differently the shorelines were responding to local wave energy and tidal forces, such as refraction, accretion and storms. There are some puzzling results here, especially at Sollas, where the sand appears to be moving west and at Griminish, where the movement appears to be to the east! Although Baleshare has the highest ground elevation on North Uist, it lacks a dune ridge, making it more susceptible to flooding.

(Once we have transcribed the talk in full, we hope to profile more of the individual detail alongside the talk’s valuable slides on the CEUT website.)

Professor Angus also referred to the importance of a wide range of local historical written resources, some reaching back to mediaeval times; these can provide critical evidence for the shifts in our North Uist coastline over time. One of the earliest Gaelic sources he mentioned was John MacCodrum, born in Ard na Runair, and Alaistair mac Mhaighstir Alasdair, https://en.wikipedia.org/wiki/Alasdair_mac_Mhaighstir_Alasdair both writing eloquently about the machair, although, in the case of MacCodrum, as an official bard, he may have been susceptible to poetic licence and the need to please Sir James Macdonald of Sleat.

A recent paper by himself and Dr Hanson was referred to, and the recommendations in this are probably those we should be using to inform ourselves when we raise our concerns more widely in Aire air Sunnd’s final on-line conference early in October. Professor Stewart’s final message reiterated

• Respect the ability of the dunes to move freely
• Protect the vast kelp bed lying west of North Uist
• Encourage the height of the dunes – maximise the natural function of the coast
• Try to keep the grazing animals away from the edges of the dunes.