Estimation of peacock bass (Cichla spp.) mortality rate during catch-release fishing employing different post-capture procedures

Abstract The effect of catch-and-release fishing on the survival of peacock bass (Cichla spp.) was evaluated by comparing two types of artificial bait (jig and shallow-diver plugs) and two types of post-catch confinement. Two experiments were conducted during the periods January-February and October-November 2012 in the Unini River, a right-bank tributary of the Negro River. In total, 191 peacock bass were captured. Both groups of fish were subjected to experimental confinement (collective and individual) for three days. Additionally, 11 fish were tagged with radio transmitters for telemetry monitoring. Mortality rate was estimated as the percentage of dead individuals for each type of bait and confinement. For peacock bass caught with jig baits, mortality was zero. The corresponding figure for shallow-diver bait was 1.66% for fish in collective containment, 18.18% for fish monitored by telemetry and 0% for individuals confined individually. Our results show low post-release mortality rates for peacock bass. Furthermore, neither the type of confinement nor the type of bait had a statistically significant influence on mortality rates. While future studies could include other factors in the analysis, our results show that catch-and-release fishing results in low mortality rates.

摘要 本研究旨在评估钓获放流对孔雀鲈（Cichla spp.）存活率的影响，通过对比两种人工饵料（铅头钩拟饵jig与浅潜型硬饵shallow-diver plugs）及两种钓获后暂养方式开展实验。实验于2012年1—2月及10—11月期间，在内格罗河右岸支流乌尼尼河（Unini River）进行。本研究共捕获191尾孔雀鲈。所有受试鱼均接受为期3天的实验暂养，分为集体暂养与单独暂养两类。另有11尾鱼被植入无线电发射器以开展遥测监测。死亡率以各饵料类型与暂养方式组的死亡个体占比进行估算。结果显示，使用铅头钩拟饵（jig）捕获的孔雀鲈死亡率为0；使用浅潜型硬饵（shallow-diver plugs）捕获的个体中，集体暂养组死亡率为1.66%，遥测监测组为18.18%，单独暂养组为0%。本研究结果表明，孔雀鲈的放流后死亡率整体较低。此外，暂养方式与饵料类型均未对死亡率产生统计学显著影响。尽管未来研究可纳入更多分析变量，但本研究结果证实，钓获放流活动可导致较低的孔雀鲈死亡率。