The invention concerns modular construction of a retainer system which simultaneously can serve both for retaining and temporary storage. The design calls for a few basic elements which can be attached like "lego" and are always based on the same connecting elements (23). However, the design includes both lengthways and crossways coupling. This enables linear, star-shaped and web-shaped retainers to be constructed. The basic element consists of light-weight tubular canisters which serve as containers (13) for the dual sealed tubes folded into themselves. The length of the dual sealed tubes can be adapted to the particular situation and ranges, for example, from 5-100 meters. In the case of large-scale accidents, the new system can be combined with the heavy state-of-the-art retainers. However, it is particularly suited for smaller and medium oil spills, in the course of which the collection and skimming of oil can be particularly well optimized.