chief economic activity, with cattle being raised in the glens and then driven to market. This trade expanded during the early 19th century, due to the demands of the new industrial cities and the British armed forces for cattle for beef. The clan structure began to break down in the 18th century, as clan chiefs came to see themselves as landlords, and the small tenant farmers had no legal answer to a landlord who wished to have them removed. During the late 18th and 19th centuries, the Highland Clearances saw tenants being forcibly moved to become crofters, a system under which their labour would be available when required by their landlords: they would be workers first and farmers second. Crofters were employed in enterprises such as fishing (Ullapool in the north of Wester Ross was built by the British Fishing Society in the 1780-90s) and kelping (the collection and processing of kelp to create products such as soda ash). In the later stages of the clearances the driver ceased to be industrial enterprises, but simply to clear the land for sheep farming, and later deer forests. At this point emigration was often the only option to those removed from their homes. Under pressure from the Highland Land League and public opinion a series of inquiries were held into the situation, leading to the Crofters' Holdings (Scotland) Act 1886 which put an end to the clearances by granting security of tenure to crofters. However the act did not break up large estates, and Wester Ross continues to consist chiefly of large single-owner estates. Environment There are many different habitats in Wester Ross, ranging from the marine and coastal environment to mountain summits over 1000 m above sea level. The area forms one of the Watsonian vice-counties, geographical divisions of the British Isles used for the purposes of biological recording and other scientific data-gathering. The coastline is mostly formed of cliffs and rocky shores covered with barnacles and seaweed. These cliffs are home to large numbers of seabirds such as puffins, fulmars, kittiwakes, razorbills, guillemots, black guillemots, cormorants and shags, whilst the rocky islets and skerries are important for harbour seals. There are also beaches and sand dunes: the dunes at Achnahaird in particular support three plant species (petalworts, dune slack mosses matted bryum and sea bryum) that occur nowhere else in Scotland. There is relatively little machair in Wester Ross compared