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Current Position of High-Status River Sites

A 2009 EPA Report, Water Quality in Ireland 2007-2008: Key Indicators of the Aquatic Environment , points to a dramatic loss in the percentage of high ecological river sites over the last 20 years. 30% of our rivers sampled were of high ecological status in 1987. By 2008 this had dropped to 17%, located in less densely populated, less developed and less intensively farmed areas. While serious pollution has decreased significantly in this period and the rate of increase in the channel length classified as being in moderate and poor status has been reduced there has been a dramatic loss of the best quality High-Status sites. Rivers best illustrate this but there is no reason to suppose that lakes in such catchments are not also impacted by many of the same pressures.

Causes of the decline in High-Status sites

In order to protect the remaining High-Status sites, and to reverse the trend of decline outlined above it is important to tackle the principal pressures causing the ecological damage. Apart from obvious point source pollution or accidental releases of pollutants relatively low intensity activities are important in this context including, e.g., land use changes such as field drainage and fertilisation, one-off housing, forestry drainage or clear-felling, road building, wind farms are important. Animal access to waters and sheep dip pesticides are also important pressures on High-Status waters. It is important to note that the smallest pressure can impact on high status. The input of a few grams of phosphorus will have a much more damaging impact on the ecology of a High-Status sensitive system than the same addition to an already eutrophic system. Similarly, small increases in silt inputs, hydromorphological pressure or priority substances will have an apparently disproportionate impact on a High-Status systems relative to the impact of the same input to an already degraded system.

It has therefore become critical to develop and implement measures to protect High-Status water bodies from becoming degraded.

Aims & Objectives

The project being undertaken is a Desk-Study. The Overall Aims are as follows:

1) to review existing legislation relevant to the protection & management of High-Status freshwater sites (rivers and lakes) and its interaction with other

legislation (e.g. planning);

2) to review best practices on protecting High-Status sites, in other European states; and

3) to suggest new approaches to ensuring that High-Status water bodies remain at high status.

The Main Objectives are to:

Review existing outputs of recent scientific research with a clear emphasis on knowledge gaps;

Review practices in other EU countries;

Review the interactions between water & non-water related legislation and highlight where new legislation may be required;

Provide guidance for local authorities (LAs) (and other public bodies) on how to handle the protection of High-Status water bodies in their day to day work;

Suggest management strategies to ensuring that High-Status water bodies remain at high status, e.g.: internal systems to throw up alerts and linking in with River Basin Plans Management Systems;

routine investigative monitoring of catchments to ensure that poor land use practices are eliminated;

better interaction between Planning, Environment and Sanitary Services within LAs;

better awareness of RBMP Programmes of Measures); and

Make recommendations towards future research needed to address this issue.

High Ecological Quality River Sites

Source: Water Quality in Ireland 2007-2008 Key Indicators of the Aquatic Environment. EPA 2009.

High ecological quality at river sites is an indicator of largely undisturbed conditions and reflects the natural background status or only minor distortion by anthropogenic influences. Such sites are used as reference from which deviation in quality is measured. Sites of high ecological quality are important for supporting aquatic species sensitive to enrichment or siltation such as the protected, but declining, freshwater pearl mussel (Margaritifera margaritifera) and juvenile salmon (Salmo salar). The presence of high status sites along a river system can contribute significantly to the overall species diversity and recolonisation of species to rehabilitated stretches. These sites play an important part in conserving individual species and overall catchment biodiversity. The Water Framework Directive (WFD) requires Member States to protect and maintain high and good status water bodies.

The ecological quality of Irish rivers has been assessed, using a biotic index scheme, developed by the EPA and its predecessor organisations, An Foras Forbartha and the Environmental Research Unit, since 1971. In 2006 this scheme, known as the Quality Rating System (Q-value), was intercalibrated and is applied as the metric for ascribing Ecological Quality Ratios (EQRs) for the benthic invertebrate fauna element in the Operational river-monitoring programme under the Water Framework Directive* (WFD). When the EQRis derived from the Q-value the site is assigned to one of five ecological status classes ranging from High to Bad.

The percentage number of high quality sites (Figure 2a) has almost halved in the 21 years between 1987 and 2008 and what is more striking is the seven-fold decrease of those attaining Reference Condition (Q5); the latter fraction, less than two per cent in the current period, being the same as for the 2004-2006 period. In each survey period the decline in high status sites has continued, from almost 30 per cent of the total sampled in the 1987-1990 period to less than 17 per cent in 2006-2008 (Figure 2a). A further analysis revealed that only 153 of the 427 sites assessed as being of high status for the period 2006-2008 could be considered long-term high status sites, i.e. continuously assessed as high status since sampling commenced at the sites between 1971 and 1998 (Figure 2b).**

*The Directive requires that the results of the biological monitoring systems operated by each Member State be expressed as ecological quality ratios (EQRs). These ratios represent the relationship between the values of the biological parameters observed for the body of surface water being assessed and the value for those parameters in the reference or undisturbed conditions applicable to that body. The ratio is expressed as a numerical value between zero and one, with high ecological status represented by values close to one and bad ecological status by values close to zero. To ensure comparability across the European Union, the classification systems were compared through an intercalibration network comprised of sites in each Member State and in each Ecoregion and boundaries were set for the status classes high and good.

**Comprising only sites that were high status (Q5 or Q4-5) on all sampling occasions (≥4) and have been sampled in the 2004-2006 period and/or 2007-2008 period.

A decline in the percentage number of high status sites was noted in all river basin districts between 1987 and 2008. The largest percentage number of high status sites continues to be located in the less densely populated and less developed, as well as less intensively farmed regions (South Western and Western RBDs). The greatest decline in the percentage number of high status sites was noted in the North Western, Neagh Bann and Shannon regions.

One of the aims of the Water Framework Directive (WFD) is to maintain high status of water where it exists but where practicable the River Basin Districts (RBDs) should, in addition, strive to restore former high quality sites as well.

Source

EPA (C. Bradley, K. Clabby, J. Lucey and M. McGarrigle)