This study was conducted in the Sylt-Rømø bight (SRB) (54°52' N - 55°10' N, 8°20' E - 8°40' E), which is situated between the islands of Sylt (Germany) and Rømø (Denmark). Fish, meio- and macrofauna were sampled employing block nets and tube cores in a S. muticum forest in 2010. Additionally the meio- and macrofauna attached on thalli of Sargassum muticum were collected. Sampling data including Biomass, length weight relationships, and gut content analyses, together with literature data were used to calculate necessary parameters (Biomass, Respiration, Consumption, Production, Egestion) for each component of the food web. Carbon was used as currency to measure the flow of energy between the single components of the food web. To calculate the flows of energy, ash free dry weight (AFDW) to carbon (C) ratios were employed. Flows of energy inside the food web were calculated employing the routines of the program Netwrk 4.2 (Ulanowicz and Kay, 1991; Ulanowicz et al., 2005).