This record is for Approval for Access product AfA023. The Convention for the Protection of the Marine Environment of the North-East Atlantic known as the OSPAR Convention 1998 (Oslo Convention 1972 & Paris Convention 1974), is an agreement signed by a number of European countries (including the United Kingdom) to protect the quality of the North East Atlantic. The objective of the OSPAR Convention is to take all possible steps to prevent and eliminate pollution entering the sea.
The OSPAR Convention provides standard methods for estimating the inputs of selected pollutants to the sea by using fixed sampling schedule and a standard input calculation.
All principal rivers are sampled monthly (12 times a year) just upstream of their tidal limits. For those rivers carrying the heaviest contaminant loads the sampling frequency maybe increased beyond the minimum of 12. Major trade effluents and sewage effluents to estuaries or coastal waters are also sampled monthly to assess direct discharges to marine waters. Flow values of discharges direct to estuary or sea are sometimes provided by the operators themselves. This is usually part of statutory monitoring arrangements.
The aim of these programmes is to assess the level of contamination entering the sea from England and Wales (the ‘load’) and to chart the progress in the reduction of this load.
The substances controlled under OSPAR are: Mercury, Cadmium, Copper, Zinc, Lead, PCB, gamma-HCH, Orthophosphate, Phosphorous (total), Nitrate, Nitrogen (total) and suspended particulate material. The load of contamination to the sea is measured at over 300 sites around the coast of England and Wales. These sites have been grouped into thirty two coastal zones.
OSPAR data is updated annually approximately 6 months through the year for the previous year. Data held ranges from 1998 to the present. It’s high/low based on twelve annual samples.
This product provides a pair of annual estimates for each sampling point, known as high load, and low load.
The difference between the high and low load estimates is owing to the way in which the samples with results at the 'limit of detection' are treated. The limit of detection is the lowest concentration of a substance that can be reliably measured – any real concentration lower than this level, including zero, is reported as being present at “less than” the limit of detection concentration.
Where the substance has been analysed for but the concentration is below the limit of detection, a calculation can be made assuming that it is not present at all (a low load estimate). Alternatively, a calculation can be made by assuming that the substance is present exactly at the limit of detection (a high load estimate). The low load calculation gives an optimistic estimate of the real load, whereas the high load calculation gives a pessimistic estimate. The real load discharged will be somewhere between these two figures. Attribution statement: © Environment Agency copyright and/or database right 2015. All rights reserved.
