The Canary Islands are particularly important to Mirlo. Not only because this is where we launched our first ever project, the Corona Forestal, or because it’s where the mirlo capiblanco migrates to – the little bird known in English as the Ring Ouzel whose story is the inspiration behind all that we are doing today. There’s so much more because the Canary Islands are a veritable treasure trove of biodiversity full of spectacular phenomena such as the horizontal rain we want to tell you about today.
The trade winds blow and blow, clouds billow across the sea and the Canary Islands bask in an exceptionally benign climate. Put together, all this makes it possible for a phenomenon known as “horizontal rain” to exist and in fact this little-known form of rainfall has an incalculable ecological value particularly because at certain times of the year it outdoes conventional rainfall in both quantity and quality.
Fog is a vital source of water for the Canary Island’s laurel forests and the island that most benefits from this peculiar form of rainfall is El Hierro. In fact, the island’s mythical and holy Garoé tree, is the best possible demonstration of how effective horizontal rainfall actually us and how it is in fact a phenomenon that had already been observed and exploited by our ancestors.
In order to take greater advantage of this highly peculiar phenomenon, a number of instruments referred to as fog collectors or fog catchers have been set up in recent years in Tenerife — and not long ago in El Hierro also. As we’re sure you can imagine, what these devices do is capture and make use of the water that is present in the fog and mist. Fog collectors were first used in the 1960s in Atacama (Chile), the world’s driest desert where the idea was to capture the water from the morning mist known by the charming name of camanchacas in those parts. The fog collectors used in Tenerife imitate the treetop effect and feature a mesh of raffia which is laid out perpendicular to the wind – which of course is full of little drops of water. When the wind passes through this mesh, the drops are deposited onto it and are then captured in containers. In this Canary Island, some 700 litres are collected on average each month per square metre.
(Photos: Jessica Hernández Torres)