Characteristics of Macrozoobenthos Lakes of the Barlinek-Gorzów Landscape Park (North-West Poland) on the Basis of the European Union Water Framework Directive

Contamination of lake waters is one of the factors affecting the qualitative and quantitative development of benthic organisms. Aside from contamination, the abundance of macrozoobenthos is determined by other conditions, i.e. predation pressure, phytoplankton biomass, detritus biomass, as well as the accessibility and quality of water reservoir bottom.The Barlinek-Gorzów Landscape Park was established in October 1991. The Barlinek-Gorzów Landscape Park includes more than 55 000 ha of forests, lakes, fields, meadows, and is characterized by a great diversity of habitats and abundant life forms [46].To protect the most valuable plant communities and animal habitats, five nature reserves were created within the boundaries of the Park:“Skalisty Jar Libberta” includes Libbert’s Gorge, and the surrounding moraine hills and glacial erratics. It is the only site featuring lime stones and boulders in Western Pomerania and is surrounded by oak and beech forests [46].“Dębina” forest conservation complex known as the Central European wet-ground forest, featuring stately oaks and beeches with some lime, hornbeam and old pine trees. In its clean environment, as many as 50 species of arboreal lichen have been preserved [46]. “Markowe Błota” – marshland, with its typical vegetation such as the Sphagnopsida, wild rosemary, ordinary cranberry, cottongrass. The site is visited quite often by white-tailed eagles [46].The water reserve of the “River Przyłężek”. It includes a section of the River, the slopes of the riverbank and the surrounding beech stand with some tree specimens that are more than 100 years old. Seen as the watercourse resembles mountain streams, with its pure and cold water, it provides appropriate conditions for Salmonidae to live and spawn [46].The forest reserve “Wilanów” aims to protects the natural mixed forest with vintage beech, oak and pine trees. Thanks to the varied topography, diverse rare types of forests have been preserved here [46].The objective of the research conducted in the course of 2008 – 2012 was to determine the qualitative and quantitative structure of macrozoobenthos in the lakes of the Barlinek-Gorzów Landscape Park in the summer season.The research enabled estimating how far the eutrophication processes have advanced in selected lakes of the Barlinek-Gorzów Landscape Park.Qualitative and quantitative analyses of the macrozoobenthos structure in the lakes Barlinek-Gorzów Landscape Park were conducted in the summer seasons of 2008, 2010 and 2012.By comparing the average density of benthic fauna of the lakes Barlinek-Gorzów Landscape Park with the lakes Western and Northern Polish you can see big changes in the density of taxa studied.In comparison with other lakes Western and Northern Polish in the lakes Barlinek-Gorzów Landscape Park is a large number of taxa, however, as a result of the distribution of non-harmonic doesn't translate to the indicator value of biodiversity index PIE.On the basis of the analysis of research in the Western and Northern Polish Lakes summer macrozoobenthos it can be concluded that in the lakes Barlinek-Gorzów Landscape Park very intensively develop Oligochaeta. While the larvae of Chironomidae subdominants status in the period under review amounting to water, developed in other lakes much more intensely, acting mostly the main ingredient of benthic fauna.