Technisches Monitoring mit einem Infrarot-Fischzähler am Lachsbach, Sachsen

Monitoring of Fish Migration in Fishways and Rivers—The Infrared Fish Counter “Riverwatcher” as a Suitable Tool for Long-Term Monitoring

“…Sequential triggering of these light barriers determines the direction, and a silhouette of the passing specimen is generated (Figure 1). Based on the silhouette, an estimate of the fish length can be automatically calculated using speciesor population-specific relationships between body depth and fish length [4,11,12]. In locations where only one or a few easily distinguishable (i.e., with charismatic silhouettes) species occur, the silhouette is sufficient to determine species-specific passage counts.…”

“…Herein, we describe the function of the device and present examples of specific applications and experiences from central Europe and North America (Table 1). The manufacturer states that more than 500 rivers are monitored with the Riverwatcher globally [9], i.e., rivers in Australia (e.g., [18][19][20]), Austria (e.g., [5,21]), Canada (e.g., [22]), the Czech Republic (e.g., [23]), Finland (e.g., [24]), France (e.g., [25]), Germany (e.g., [5,23]), Iceland (e.g., [26]), Ireland (e.g., [27]), Norway (e.g., [28,29]), Portugal (e.g., [13]), Poland (e.g., [30]), Spain (e.g., [31]), Switzerland (e.g., [32]), Sweden (e.g., [33,34]), the UK (e.g., [35][36][37]), and the USA (e.g., [38,39]). As shown in Table 1, some installations have been selected to show the long-term performance of the hardware.…”