Effect of ground-baiting on anglers’catches and nutrient budget of water bodies as exemplified by Polish lakes

Abstract

Advantage was taken of 490 questionnaires completed by anglers to study the effectiveness of ground-baiting and its effect on nutrient (phosphorus and nitrogen) budgets in 37 water bodies. There was a strict relationship between daily amounts of baits used and daily catch of sixcyprinid species. However, fish catch increased only to a bait rate of about 2 kg/day. Higher amounts resulted in lower catches. Calculations were also made of daily loads of phosphorus and nitrogen introduced by the‘average’angler into a water body, as well as of the amount of nutrients removed by this angler from the aquatic environment with the fish catch. It was shown that although ground-baiting represented an important source of nutrient input into the environment, using this method anglers removed 22 times more phosphorus and 17 times more nitrogen from the environment (with their catch) than they introduced into it. Turawa Reservoir was used as an example, showing that in Polish conditions, angling may have a beneficial effect on nutrient budgets of such water bodies.