## 1 Introduction  
The process of eutrophication is one of the most severe anthropogenic disturbances to the functioning of aquatic ecosystems. The most common causes of eutrophication are: Flow of mineral fertilizers from fields, sewage of agricultural origin (animal production), and sewage inflows from cities. Many methods for preventing eutrophication of (mainly standing) waters are used. Littoral zone plants capture excessive amounts of biogenic elements (mainly N and P) and thus can play an important role as a protective barrier to the water. However, excessive plant development and death at the margins of reservoirs can lead to deterioration of oxygen conditions in water which may negatively restrict biodiversity [1; 2; 3; 4; 5].  
Uncontrolled proliferation of littoral plants leads to successive shallowing and gradual overgrowth of waters. These phenomena diminish their use (drawing potable water) and recreational value (fishing, sailing, and other water sports).  
Littoral plants are being used more often for cleaning surface waters with increased concentration of heavy metals [6; 7; 8; 9]. Although macrophytes can filter toxic metals from the surface waters and immobilize them in their biomass and in sediments, in the long term these plants return these metals into circulation [10]. This group of plants is resistant to high levels of biogenic elements, is characterized by rapid growth and large biomass and can accumulate high concentrations of metals in their tissues [11; 12]. What is more, numerous studies have shown that the intake, accumulation and translocation of heavy metals may differ significantly between littoral plant species [13; 14; 15].  
Expansive species that rapidly contribute to overgrowing of small, silty and at the same time often naturally valuable water reservoirs include, among others broadleaf cattail (_Typha latifolia_ L.) [16], yellow flag iris (_Iris pseudacorus_ L.) [17], and hornwort (_Ceratophyllum demersum_ L.) [18].  
Mechanical removal is most often used to eliminate excessive littoral plants. In such situations, proper management of these, often large, amounts of plant biomass becomes problematic. It has been established that the use of earthworms in utilization of organic matter considerably accelerates the above-mentioned process and leads to the production of manure with better quality, compared to the traditional methods of composting [19].  
As littoral plants are able to accumulate e.g., heavy metals that are present in water, it is possible that the vermicompost obtained will contain the harmful pollutants as well. Taking the aspect of biomagnification in the food chain into consideration, this may pose a serious threat for the environment and human health [20; 21; 22].  
The major aim of this work was to discover if specified littoral plants, periodically removed from around reservoirs, could be processed to produce a usable end product. Specific objectives were: To test the suitability of _E. fetida_ earthworms as agents of vermicomposting of littoral plants; to record physico-chemical changes brought about through such a process on specified littoral species; to record the changes in selected characteristics of the earthworm populations with each littoral species used