DOI: 10.5281/zenodo.220944
title: Visbestandopnames In Vlaanderen In Het Kader Van Het Referentiemeetnet-Bemonsteringsresultaten 2015 En Een Overzicht Van De Resultaten 2013-2015

description: This data set provides the data as represented in the corresponding report, presenting the results of fish surveys performed in 2015 in rivers and canals. These surveys were done in the framework of the 'Reference Freshwater Monitoring’. In addition the results provide the biological information (fish) required by the European Water Framework Directive (WFD). The raw data is published on GBIF and can be derived as such, this data set provides the data as provided in the individual and corresponding figure of the report. 

We also provide an overview of the results 2013-2015 as we completed cycle 1 (spread over 3 years) in the framework of WFD.

The 2015 results are displayed per basin and concisely discussed in several chapters.

We surveyed 25 locations in 2015. We used electro fishing, fyke nets, trawl netting or a combination (multi-method) of these methods.

The 25 sites are located in 25 water bodies, of which 13 are Flemish water bodies and 12 local water bodies. There were only three sites without fish.

We discuss the occurrence of the species for the period 2013-2015 survey results. We also compare the EQR values (Ecological Quality Ratio) as these are a measure of the ecological condition of the water body and are therefore important in the context of the Water Framework Directive.

The results are briefly discussed in several chapters, and a comparison was made with earlier EQR scores (period of 2010-2012).

We surveyed 199 locations in the period 2013-2015. We caught 42 fish species. In 96.5% of the sites fish was present. With a presence in 58% of the sites, eel and the three-spined stickleback, were the most frequently caught species, followed by roach in 48% of the sites, then perch (47%) and gudgeon (42%).

167 locations on rivers and streams were sampled. The sites are located in 63 different local water bodies and 68 different Flemish water bodies. Only 8% of the waterbodies were in a ‘good condition’. Most of the sampled water bodies were in a ’moderate condition‘ (44%). 30% of the water bodies were in a 'poor state' and 20% of the water bodies had a 'bad quality’.

The local water bodies have the least locations with a ‘good condition’. Only 3% were in a 'good condition,' while 33% were in a ‘poor state’. For the Flemish water bodies, 12% were in a ‘good condition’ while only 9% were in a state of ‘poor quality’.

If we look at the water bodies in each stratum, we see that water courses of the type "small stream" were in the worst shape. About 35% of these water bodies were in a’ bad state’ and only 4% were in ‘good condition’. The type “big stream and small river” had the best scores. The bulk scored a ‘moderate quality’. This stratum contains water bodies having the largest share of the ‘good quality’class (14%).

At basin level, the River Nete basin scored best, 23% of the water bodies were in ‘good condition’ followed by the River Maas basin, where 12.5% of the sampled water bodies were in the ‘good condition’ status.

For EQR results of channels we have data from 31 sites located in 19 different water bodies; 17 Flemish water bodies and two local water bodies. The major part of the water bodies was in the category ‘poor quality’ (58%) while 10% achieved a ’good ecological potential’.

From 118 water bodies type "river" and 17 water bodies type "artificial river" (channels) we have EQR values for both cycles 2010-2012 and 2013-2015. 47% of the water bodies remain in the same class, for24% of the water bodies the quality class increased by 1 and for 5% of the water bodies the EQR class increased by two or three classes. 21% of water bodies decreased by one class, 2% decreased by two or three classes.