History of Eutrophication Research
Eutrophication
refers to the process of nutrient enrichment and can lead to the
over-enrichment of lakes, rivers and the marine environment to the extent that there are excessive growths
of algae and other aquatic plants. For lakes and rivers, phosphorus is considered to be the limiting
nutrient that determines plant nutrient and algal growth and so is the driver of eutrophication.
Through
its research divisions, the Department of Agriculture and Rural Development (DARD) had a long history
of eutrophication research in Northern Ireland. This began in 1967 when the Government of Northern Ireland
set up the Freshwater Biological Investigation Unit (FBIU) under the Ministry of Agriculture to research
the cause of algal blooms on Lough Neagh. In 1990, the FBIU joined with the Fisheries Laboratory to
form the Aquatic Sciences Research Division (ASRD). In 1995, the ASRD was merged with soils and animal
husbandry sections into the Agricultural and Environmental Sciences Division of DARD. These mergers
reflect the increasingly inter-disciplinary nature of eutrophication
research. Most recently in April 2006 the Science Service of DARD and the Agricultural Research Institute
for Northern Ireland transferred to the new Agri-Food and Biosciences Institute (AFBI) of Northern Ireland.
Lough Neagh
Lough Erne
Enrichment of large lakes
Lough Neagh is the UK’s largest lake and a multi-purpose resource. It is a major source of drinking water and one of the most eutrophic lakes in the world due to high phosphorus (P) inputs. Research at FBIU quantified these P inputs to Lough Neagh and ascribed them to sources.
Phosphorus from sewage works was shown to account for almost half the amount entering the lake. To curtail this source, P reduction treatment was introduced by the Department of the Environment in NI (DoE) in 1981 at the ten major sewage disposal works in the Lough Neagh Catchment. This was the first time P reduction treatment had been employed in the UK and it was followed by a reduction in P loading and improved water quality in the lake.
Lough Neagh and its tributaries have been sampled at least fortnightly since 1969. This unbroken record of nutrient inputs and water quality in the lake is unique within the UK and Ireland. By the early 1990’s, the effects of sewage P reduction had been overtaken by increasing P loads from diffuse sources, most probably from agriculture.
For further details, see the Phosphorous inputs to Lough Neagh PowerPoint presentation below.
Downloading the original PowerPoint presentation and double clicking the graphs will display the respective data
(To download: right mouse click on link > Save Target As > enter filename)
A similar picture has been observed in Lough Erne, a large lake in Co. Fermanagh, which is an outstanding tourist amenity for angling and pleasure boat cruising. Although the Erne catchment is more sparsely populated than the Neagh catchment, P inputs to both lakes are increasing at similar rates.
Other research
Eutrophication research within DARD has embraced lake-, river- and soil-based studies. A survey of 614 small lakes carried out between 1989 and 1991 in conjunction with DoE showed that eutrophication is common throughout Northern Ireland and most lakes in rural catchments contain high P concentrations. Current research has focused on understanding the causes of P loss from agriculture. Northern Ireland agriculture has been running a consistent surplus since the Second World War, with P inputs exceeding P exports. The size of the annual surplus has not greatly changed over that period but the net result has been a steady increase of P in agricultural soils. Many soils have moved from available P deficiency to P surplus. Geographic Information Systems (GIS) technology is being used to map variation in land use and areas of high soil P. Other studies examine factors controlling the soluble P in Irish soils.
Downloading the original PowerPoint presentation and double clicking the graphs will display the respective data
(To download: right mouse click on link > Save Target As > enter filename)
A list of scientific publications on both phosphorus and nitrogen is also available.
Related issues
In recent years the findings of this research has been used to decide how the Nitrates Directive should be applied in Northern Ireland, more information can be found on the
Environment and Heritage Service websiteFor further information on Freshwater Eutrophication contact AFBI:
