捕获和释放垂钓使鱼类面临可能导致亚致命影响或死亡的挑战。由于基于大小的收获规定或自愿的垂钓者行为,鳟鱼湖(Salvelinusnamaycush)的释放率很高。这里,我们研究了夏季(n=74)和秋季产卵期(n=33)对鳟鱼的短期损害,以告知垂钓的最佳实践。捕获后或捕获后0.5小时,鱼接受了反射和气压伤评估,并收集了少量血样。鱼还配备了一个外部安装的生物制品,温度和三轴加速度传感器,将其拴在一起,以便在14分钟后检索记录器。在夏天,反射障碍和气压伤在0和0.5h显著相关。取向丧失和腹胀是观察到的最多的指标。较大的鱼和在增加的深度捕获的鱼的气压伤得分更高,而无论采样时间如何,延长的战斗时间都会降低气压伤评分。血浆皮质醇,乳酸和葡萄糖在捕获后0.5小时增加,细胞外和细胞内的pH值下降,所有的迹象表明垂钓正在诱导代谢反应。然而,没有发现血液指数和死亡率之间的关系(18.9%)。对于暴露于空气中的鱼类,释放后达到最大深度所需的时间更长,而对于战斗时间更长的鱼类则更短。在秋天,鱼没有表现出死亡或反射障碍。肛门脱垂是最明显的气压伤指标,但仅在女性中观察到。捕获后0.5小时血液指标变化最大,雌性鱼的皮质醇值增加,特别大或在更深的深度捕获。男性的运动活动最高,随深度增加而增加。一起,我们的研究结果表明,捕捞和释放垂钓的影响可能取决于几个因素,包括性,季节和垂钓深度。
Catch-and-release angling exposes fish to challenges that may result in sub-lethal effects or mortality. Lake trout (Salvelinus namaycush) undergo high rates of release because of size-based harvest regulations or voluntary angler behaviour. Here, we examine short-term impairment in lake trout angled during the summer (n = 74) and fall spawning period (n = 33) to inform best practices for angling. Immediately following capture or 0.5 h post-capture, fish underwent reflex and
barotrauma assessments, and a small blood sample was collected. Fish were also fitted with an externally mounted biologger equipped with depth, temperature and tri-axial acceleration sensors, that was tethered to allow retrieval of the logger after 14 min. In the summer, reflex impairment and
barotrauma at 0 and 0.5 h were significantly correlated. Loss of orientation and bloating were the most observed indicators. Larger fish and those captured at increased depth had higher
barotrauma scores, while prolonged fight times decreased the
barotrauma score regardless of sampling time. Plasma cortisol, lactate and glucose increased 0.5 h after capture, and extracellular and intracellular pH decreased, all signs that angling was inducing a metabolic response. However, no relationships were found between blood indices and mortality (18.9%). The time required to reach maximum depth after release was longer for fish with increased air exposure but shorter for those with longer fight times. During the fall, fish displayed no mortality or reflex impairment. Anal prolapse was the most observed indicator of
barotrauma but only observed in females. Blood indices were most altered 0.5 h after capture, with increased cortisol values for fish that were female, particularly large or captured at deeper depth. Locomotor activity was highest for males and increased with depth. Together, our findings suggest that the effects of catch-and-release angling may be dependent on several factors, including sex, season and angling depth.