Efeitos do pesque e solte sobre o comportamento, estresse e aspectos reprodutivos de um peixe Neotropical

Abstract

Utilization of fishery resources through recreational fishing is growing in numbers of practitioners in developing countries such as Brazil. Thus, the management of this activity deserve attention, because its improper management can lead to negative impacts over the fish populations exploited. An alternative that has been applied in many countries is the use of catch-and-release (CR) as a tool for conservation of game fish stocks. The effectiveness of the CR and its use as a management action is based on the assumption that the released fish will survive, have its welfare guaranteed and contribute reproductively to the exploited populations. In this context, assessments of physiological disturbances, as well as determining the effects of CR on the reproduction, are the most common to examine the welfare and condition of fish. Thus, they were tested experimentally the hypotheses (i) that the continuous CR is not a stressor that affects the welfare and behavior of the exploited populations and (ii) that the CR does not have a negative influence on the reproduction of Neotropical fish. For this purpose, an experiment was carried out with populations groups of Astyanax lacustris isolated in ponds, constituting 4 groups submitted to fishery management of CR and 4 ponds of control (C), without any fishing activity. Were assessed mortality, catch rate, immediate predation response to bait, stress indicators cortisol and glucose, condition factor, gonadosomatic index, gonadal development stages and occurrence of spawning. Except for the catch rate and behavior of immediate predation of baits, which decreased over time, there were no significant differences in the tested variables between the CR and C fish. Despite the observed behavioral changes, the CR did not prove to be a stimulus capable causing stress and negative effects on the reproductive aspects over the A. lacustris population. It is assumed that the fish populations are able to recognize baits as threats and after experiencing CR, they begin to avoid them. This way, we consider that CR can be conducted over Neotropical fish populations without damages related to physiological stress and reproduction. Thus, the CR activity has potential to be applied in management programs which aim the sustainable use of the fishery resources.