Elemental composition and microbial decomposition of different angling baits

Recreational fishing, through groundbaiting, provides a potentially important trophic subsidy to freshwater ecosystems that could promote eutrophication. To date, our understanding of the role of bait properties on their fate when they are not consumed remains limited. The present study aimed to determine if the C:N:P composition of some of the most commonly used angling baits modulated microbial decomposition. The C:N:P composition of 28 models of four commercially available angling baits was assessed and a microcosm experiment was used to quantify microbial decomposition. Elemental composition strongly varied among angling baits, with N content varying by a factor of three and P content varying by a factor of five. Microbial decomposition of angling baits was highly variable and faster for more industrialised baits. Microbial decomposition was five times faster for angling baits rather than natural subsidies (leaves) and was not significantly correlated with high N or P content. Compared to natural subsidies, angling baits were a favourable substrate for bacterial growth. Angling baits represent a source of highly available nutrients and the most-enriched angling baits might affect ecological processes and water quality in ecosystems with high angling pressure, especially when their use is not regulated.

Automated summary

Recreational fishing provides a potential nutrition supplement to freshwater ecosystems through groundbaiting. The C:N:P composition of angling baits affects microbial decomposition, with faster decomposition for more industrialised baits. Compared to natural subsidies, angling baits are more conducive to bacterial growth.