They were not just religious establishments: they were also economic power-houses, enterprising and creative. The monks were great farmers – Strata Florida grew wheat and oats, and managed huge sheep flocks – and, centuries before the concept became politically-correct, they diversified into activities such as stained-glass production or manuscript illumination.
One diversification seems likely to have increasing relevance today – fish farming. Monasteries built fish ponds, and made use of rivers and natural lakes, stocking the Teifi Pools with trout, for example.
Fish have always been an important food source, and farming them has been long-established in regions such as China and South-East Asia.
European interest in the subject is growing, as it becomes recognised that some ocean species could be wiped out by excessive fishing – already there are serious concerns over cod, for example, and other varieties are threatened.
But while farming has become established with salmon and certain shellfish, the ecosystems are complex, and experience has shown that lessons must be learned if the practice is not to threaten the well-being of wild varieties.
Source: Icwales
Monks show the way to farm fish
UK - Relics of the monastic tradition are to be found throughout Wales. Although nowadays the significance of their ruins lies mainly in their tourist appeal, their extent testifies to the important role they once played.