Scottish Fishing Industry
The Scottish fishing industry relies on invertebrates like shrimps, prawns, crabs, lobsters and other shellfish such as mussels and oysters which make an important contribution to the economy of coastal communities. Catches of Langoustine (Norway Lobster or Scampi) contribute £89.3 million to the Scottish economy each year – more than the combined catches of Cod, Haddock and Monkfish. In the pelagic fisheries our important stocks of cod, herring and haddock depend on invertebrates such as krill and copepods for their food.
Freshwater fisheries for game fish contribute over £112 million annually to the Scottish economy. Aquatic invertebrates like stoneflies and mayflies are an essential source of food for such fish.
|Northern February red stonefly (Brachyptera putata) © Mike Hammett|
Invertebrates provide a number of important 'ecological services'. These services are often overlooked until they are damaged or lost. They are usually impossible to replace. One example is crop pollination. Insects are responsible for the pollination of a variety of crops in Scotland. The most significant is the soft fruit industry with the raspberry crop in Scotland worth £52 million annually. The blackcurrant crop is valued at £8 million; however, the associated processing industry is worth an additional £200 million.
Invertebrates play an important role in sewage treatment. One of the simplest but most effective treatments for sewage involves passing the effluent over a bed of stones on which a biofilm of bacteria, fungi and algae grow and process the waste. The biofilm attracts, and is ingested by invertebrates including non-biting midges, moth-flies and worms. Altogether these organisms turn the sewage into clean water and an organic sludge that can be used as fertiliser or fuel.
Earthworms and other soil invertebrates like springtails benefit agriculture by maintaining and improving the structure and aeration of soil by their constant feeding and burrowing. They breakdown organic matter such as dead leaves and return essential minerals and organic matter to the soil so enabling renewed crop growth.
Tourism - especially ‘eco-tourism' constitutes an important and increasing element of economic activity in Scotland. Much of this is about history and landscape but it is also about wildlife. Indirectly, invertebrates are important in underpinning the survival of popular plants and animals such as Ospreys and Otters. But there is also an increasing interest in Scotland’s special invertebrate fauna. Certain iconic species such as the Kentish glory moth (Endromis versicolora), Chequered skipper (Carterocephalus palaemon) and Mountain ringlet (Erebia epiphron) butterfly as well as the many striking dragonflies, beetles and flies of our boreal woodlands increasingly attract visitors not just from within Scotland but also from other parts of the UK and Europe.
Negative economic impacts
Some invertebrates have a negative economic impact. For example certain aphids cause damage to crops, the heather beetle (Lochmaea suturalis) can affect areas of moorland and the pine looper moth (Bupalus piniarius) can have an impact on Scots Pine forests. In general however these outbreaks are short lived and populations return to a normal level within a season or two. A more difficult issue are biting midges (Culicoides species) which, at high densities, can contribute to the loss of work-days and potentially a loss of tourism revenue.