A. Gimpel et al. 
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Science of the Total Environment 878 (2023) 162902 
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Fig. 2. Length frequencies of cod individuals sampled inside the Offshore Wind Farm during summer (OWF summer, yellow) (A); inside the Offshore Wind Farm during 
winter (OWF winter, blue) (B); at stations outside the OWF in the German Bight during summer (GB summer, red) (C); at stations outside the OWF in the German Bight 
during winter (GB winter, grey) (D). Further given are the lengths at age of cod individuals sampled inside the Offshore Wind Farm during summer (yellow), during 
winter (blue) and at stations outside the OWF in the German Bight during summer (red) and winter (grey) (E). Moreover, the relative proportion of individuals from 
different Surveys per age group is shown (OWF summer = yellow; OWF winter = blue; GB summer = red and GB winter = grey). Please note: On-site samples 
collected by angling were combined with data from outside the OWF collected with bottom trawls. (For interpretation of the references to color in this figure legend, the 
reader is referred to the web version of this article.) 
ındividuals in the OWF in summer. Nevertheless, the majority of individ- 
Jals +3 years were caught in the German Bight (Fig. 2E-F). 
We observed spatial differences in stomach contents, with cod caught in 
+ he OWF having a more diverse prey composition compared to samples from 
he GB (Fig. 3). A CCA was used to investigate the relationship between body 
length, study area and diet composition (Fig. 4). Both predictors and their in- 
:eraction were highly significant (Table 2), indicating that diet composition 
changes ontogenetically and differs between study areas. Moreover, the im- 
pact of the study area on diet varies with size class, as indicated by the signif- 
icant interactive term (Fig. 3). The diet of cod caught in the GB consisted of 
flatfish and brown shrimp (Crangon sp.), which are typically associated to 
sandy bottoms (Fig. 4, Appendix A, Table A.1). In contrast, cod in the 
JWF fed mainly on species associated to hard substrates, such as porcelain 
crab or butterfish (Fig. 4). Fish above 45 cm were associated with a diet 
zonsisting of flatfish and swimming crabs, while the diet of smaller fish 
was associated with consumption of shrimps, for instance (Fig. 4). 
individuals selected for stable isotope analyses confirmed the observed 
variation of stomach contents between the OWF and the GB samples. The 
1igh 8*°N results in the OWF in summer suggest that cod fed higher in 
:he food web than either in GB summer or in OWF winter (Fig. 5, 
Table 1). Mean 8'°N differed significantly between cod from stations sam- 
led in the GB with 15.37 %o (+ 1.49) and cod sampled in the OWF during