A total of 40 different fish species were documented in Berlin’s water bodies during the analysis period from 2014 to 2022. The present map description focuses on this time span. The brochure ‘Fische in Berlin’ (Fish in Berlin) encompasses all data, including that collected before this period.
Fourteen of the fish species recorded prior to the end of 2022 were non-native, known as neozoa. Among them, for the first time this year, is the gibel carp, which was previously listed as native. Recent studies revealed, however, that every single historical record and specimen of the gibel carp, including those in the Berliner Naturkundemuseum (museum for natural history), turned out to be or depict crucian carps. It appears the gibel carp was likely introduced to Germany only after 1945, leading to its reclassification as a non-native species (Freyhof et al. 2023). Since the last edition was published in 2013, several new species have been documented. These comprise the Siberian sturgeon, a single specimen found in the Obersee lake in 2017; the round goby, which has been established in major flowing waters since 2015; and the marbled goby, first recorded in the Großer Müggelsee in 2022. On the other hand, the brook trout and the golden orfe have not been documented since 2013. In 2003, it was still believed that both species of bullhead were present in Berlin’s water bodies, given the brown bullhead’s presence in the Lusatia region and the catchment area of the Schwarze Elster river. This was not confirmed by the current survey, however, which only found black bullheads (Ameiurus melas). New sightings of other non-native fish species generally involved only a few specimens or a single individual, except in the case of the round goby. Nonetheless, non-native fish populations continue to decline, except for gobies, the gibel carp, and the pumpkinseed.
Apart from the gibel carp, non-native fish species are generally quite rare in Berlin. The gibel carp is the most common non-native species, recorded in 26.8 % of all surveyed water bodies between 2014 and 2022. Following the gibel carp is the goldfish, the most prevalent among the rare neozoa, appearing in 13.1 % of Berlin’s water bodies. Next is the rapidly spreading round goby, which was spotted in 11.8 % of the surveyed areas. Three non-native species, the Siberian sturgeon, the marbled goby, and the brook trout, were each found in only one water body. Overall, non-native species are less common in Berlin’s compared to native fish, with a few exceptions. Among the native species with only a few recorded sightings or occurrences are the stone loach, the vimba bream, the nase, and the sea trout.
Overall, the roach stands out as the most prevalent fish species in Berlin, recorded in 66 % of water bodies surveyed between 2014 and 2022. Trailing closely are the perch, found in 57.5 % of the water bodies, followed by the rudd (52.9 %), the pike (49 %), and the tench (40.5 %). Pike are notably abundant in smaller water bodies, where individual specimens are found in almost all of them. The eel’s frequent presence is due to extensive stocking efforts and does not reflect water quality. Conversely, the widespread occurrence of the roach, the perch, the ruffe, the bream, the rudd, the white bream, and the bleak in flowing waters and fluvial lakes highlights their remarkable adaptability to Berlin’s aquatic environments. With the exception of the rudd, these species are eurytopic and classified as adaptable, with no specific habitat requirements. Their prevalence also underscores the extent to which Berlin’s main flowing waters have changed: once characterised by the barbel, they are now dominated by the bream (Bleiregion).
When interpreting the results in Table 1, it is essential to recognise that the water bodies examined varied between investigation periods. Therefore, the table offers no insight into fish stocks or shifts in occurrences within individual water bodies.
