Preliminary Assessment of the Ecological Water Quality in Greece

The environmental quality is a relatively recent term describing the surface water

status, which was introduced into the Greek law in 2003. The ecological quality

concept includes assessing the status of surface water on the basis of the organisms

living in them compared to what would be expected in undisturbed conditions. The

indicator species in this evaluation include phytoplankton, benthic diatoms,

macrophytes, benthic macroinvertebrates and fish. Complementary to the above

biological elements, physicochemical parameters and nutrients should be considered

as well as the condition of the riverine habitats, the riparian vegetation, the water

discharge and links with groundwater.

The Institute of Inland Waters (IIW) of HCMR undertook, by the Ministry of

Environment, the task to design the monitoring network of ecological and chemical

status of rivers in Greece, in accordance with the Article 8 of 2000/60 / EC Directive.

Moreover, IIW had to proceed with the preliminary assessment of the rivers

ecological quality. The relevant project has been implemented from 1/4/2008 until

31/8/2009. The Greek Center for Biotopes and Wetlands as well as other research and

educational institutions contributed to this task.

The assessment of the ecological status occurred mainly by using existing data on

benthic macroinvertebrates, according to the ‘Greek Classification System’

(Artemiadou & Lazaridou, 2005) and the ranking matrix for microhabitats

(Chatzinikolaou et al., 2006). In the water bodies where numerous samples were

available, a weighting process occurred by taking into consideration the geographical

representation, the period of sampling and the updating of data from recent

measurements of IIW. For the fish, the ecological assessment occurred only in basins

where ichthyological indices existed (Evrotas, Alfeios, Acheloos and Aracthos rivers).

In the rivers where biological data was absent, physicochemical and nutrient

concentrations have been used for the assessment by weighting the relevant

qualitative indices with bentic macroinvertebrate data. In those water bodies were no

data were available, the pollution pressures have been identified and used to classify

them only for the poor, bad and good ecological conditions. In all other cases where

the assessment of river water bodies were not reliable due to the lack of data, the

occurrence of seasonally intermittent streams or conflicting information in terms of

pressures, have not been classified.

Of the total 1,011 inland water bodies 66% of them were preliminarily classified. Of

those registered a 7% has a high ecological quality, 41% is considered to be at a good

status, 39% is of moderate status, 13% is classified as poor and 1% as bad (see

following map).

Ecological Quality

High Good Moderate Poor Bad N/A

Legend

Ecological Quality

Assessement of

Greek Water Bodies

High Good Moderate Poor Bad

Percentage of water bodies in different

ecological classes