Agriculture in Northern Ireland depends on grass-based production, but since
1980, expansion of output has been effectively constrained by production
limits set by the European Union agricultural policy. Despite this, long-term
monitoring over several decades has shown significant degradation of water
quality in Lough Neagh, with persistent high biomass of blue-green algae.
Similar long-term studies have revealed a marked decline in the freshwater
survival of salmon in the nearby River Bush. These changes may be related and
reflect the impact of farming on water quality and salmonid production.
Regular sampling of the inflowing rivers to Lough Neagh has shown that
continued increase in lake phosphorus concentration has been primarily due to
an increase in the soluble reactive phosphorus loading from agricultural
diffuse sources. Similar diffuse inputs of agriculturally derived nutrients to
the River Bush, leading to increased plant growth together with the
accumulation of fine sediment in salmon spawning redds, are considered to be
important in the decline of freshwater survival of salmon from egg to smolt.
The impact of farming practices on lakes and rivers is considered in relation
to understanding of the complex and interacting factors that link land use to
water quality.
Monodiamesa ekmani(Diptera: Choronomidae) in Lough Neagh, Northern Ireland