Visbestandopnames in het Lippenbroek, een gecontroleerd overstromingsgebied met gereduceerd getij in het Zeeschelde-estuarium: viscampagnes 2006-2012
Breine, J.; Van Thuyne, G. (2012). Visbestandopnames in het Lippenbroek, een gecontroleerd overstromingsgebied met gereduceerd getij in het Zeeschelde-estuarium: viscampagnes 2006-2012. Rapport van het Instituut voor Natuur- en Bosonderzoek, INBO.R.2012.67. Instituut voor Natuur- en Bosonderzoek (INBO): Brussel. 66 pp.
Part of: Rapporten van het Instituut voor Natuur- en Bosonderzoek. Instituut voor Natuur- en Bosonderzoek: Brussel. ISSN 1782-9054, more
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Document type: Scientific report
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| Abstract |
Between 2006 and 2012 researchers of the Research Institute for Nature and Forest (INBO) performed several fish surveys in the Lippenbroek. This is a reduced flood controlled tidal area along the River Zeeschelde nearby Hamme. The ten acre area has been active since March 2006 with water entering and leaving the area daily. The reduction of the tide allowed the development of different habitat types and the creation of mud flats and marshes. We selected three types of habitats: the reservoir situated at the sluices an adjacent creek and a permanently flooded pool. Fish techniques used were electric fishing and fyke netting.In total 20 fish species were caught. With fykes we captured 16 species in the creek and 17 in the reservoir. With electric fishing 8 species were caught in the creek, 11 in the reservoir and 17 in the pool.Over the years smelt, common goby, flounder and roach dominated in numbers the fyke net catches in the creek. In the reservoir roach, Prussian carp and stone moroko were dominant. With electric fishing the most abundant species were stone moroko and flounder in the creek while in the other habitats threespined stickleback and stone moroko were the most abundant species.Statistical analysis with fyke net data showed that the species composition changed over the years in both the creek and reservoir. However, there was no indication of different fish composition in the two habitats. In addition, no seasonal patterns could be found.The statistical analysis with fish data from the pool revealed again a change in fish composition over the years. Although flounder and common goby disappeared from this habitat, an increase in species and individuals caught was apparent. No seasonal pattern could be seen.The length frequency distribution indicated that Prussian carp, stone moroko and roach spawn in theLippenbroek. Prussian carp larvae occur mainly in the pool while the other larvae are found especially in the creek and reservoir. These species also use the Lippenbroek as a nursery. Perch uses the creek and reservoir as a nursery while larger species are captured in the pool.Diadromous species as flounder and smelt use the area as a nursery. Juvenile smelt occurs especially in the creek. Flounder migrated from the pool to the creek and reservoir.The common goby, a typical estuarine species, also disappeared from the pool and uses now mainly the creek as a nursery and permanent residence.Seabass is a marine species using the Lippenbroek as a nursery ground. The smallest individuals are found in the creek. The larger specimens occur in the reservoir. In the pool we also caught some seabass.Pikeperch is foraging in the reservoir; the smaller individuals are growing up in the creek. This species is not captured in the pool.The habitat diversity influences the fish diversity. E.g. less frequently caught species such as white bream and carp were captured mainly in the creek. Pumpkinseed and rudd were caught especially in the pool.Bream and eel occur mainly in the reservoir while bitterling has no apparent habitat preference as it was captured regularly in all habitat types. |
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