Abstract Abobi SM, Mildenberger TK, Kolding J, Wolff M. 2019. Assessing the exploitation status of main fisheries resources in Ghana’s reservoirs based on reconstructed catches and a length-based bootstrapping stock assessment method. Lake Reserv Manage. 35:415–434. The cichlid species Oreochromis niloticus, Sarotherondon galilaeus, and Coptodon zillii, which are among the most exploited resources in the small-scale fisheries of the Tono, Bontanga, and Golinga reservoirs in northern Ghana, were assessed based on length frequency samples. Growth, mortality, exploitation status, stock size, and relative yield per recruit reference points were determined using bootstrapping fish stock assessment (BFSA), a novel framework that allows for the estimation of uncertainties around the life-history parameters and reference levels (e.g., L∞, K, and F0.1). The results suggest that the 3 species studied are heavily exploited in all 3 reservoirs, but with no alarming signs of overexploitation. The fishing effort at Golinga is comparatively low as a result of insignificant fishing during the agriculture season, which relates to low exploitation rates. Sarotherondon galilaeus and C. zillii have the highest and lowest biomass (t/km2) respectively in all the 3 reservoirs. The small shallow reservoir (Golinga) has the highest biomass of the target resources per unit area. According to a second assessment approach, based on length-based indicators, all species at Bontanga and O. niloticus and S. galilaeus populations at Golinga have spawning stock biomasses below 40% of the unfished biomass. This points to a situation of a possible ongoing recruitment overfishing of those species in the 2 reservoirs and suggests that a further increase in fishing effort should be prevented. Further monitoring of these fisheries will be needed for the improvement of assessments and thus management advice.

中文翻译：

---

基于重建渔获量和基于长度的自举种群评估方法评估加纳水库主要渔业资源的开发状况

摘要 Abobi SM, Mildenberger TK, Kolding J, Wolff M. 2019. 基于重建渔获量和基于长度的自举种群评估方法评估加纳水库主要渔业资源的开发状况。湖泊保护区管理。35:415–434。丽鱼科鱼类 Oreochromis niloticus、Sarotherondon galilaeus 和 Coptodon zillii 是加纳北部 Tono、Bontanga 和 Golinga 水库小规模渔业中开发最多的资源，根据长度频率样本进行了评估。使用引导鱼类种群评估 (BFSA) 确定每个招募参考点的生长、死亡率、开发状态、种群大小和相对产量，BFSA 是一种新颖的框架，可以估计围绕生活史参数和参考水平的不确定性（例如， L∞、K 和 F0.1)。结果表明，研究的 3 个物种在所有 3 个水库中都得到了大量开发，但没有过度开发的惊人迹象。Golinga 的捕捞努力量相对较低，这是由于农业季节捕捞量很少，这与低开发率有关。Sarotherondon galilaeus 和 C. zillii 在所有 3 个水库中分别具有最高和最低的生物量 (t/km2)。小型浅水库 (Golinga) 的单位面积目标资源生物量最高。根据第二种评估方法，基于基于长度的指标，Bontanga 和 O. niloticus 以及 Golinga 的 S. galilaeus 种群的所有物种的产卵种群生物量低于未捕捞生物量的 40%。这表明 2 个水库中这些物种可能持续过度捕捞，并表明应防止进一步增加捕捞努力量。需要对这些渔业进行进一步监测，以改进评估和管理建议。