Data availability, and unreported and unregulated fishing are significant obstacles to evaluating stock status, especially in tropical areas. Limitations in data quantity and quality can lead to model misspecification and erroneous data treatments, potentially causing important changes in model outputs and subsequent management implications. Red snapper Lutjanus purpureus (Poey) in French Guiana provides an example of a stock with a long-time series of fishery-dependent data subject to large uncertainty. A flexible catch-at-age model (Stock Synthesis) was applied to the available data and compared to an historically applied assessment approach. Inter-model variability based on different model specifications and data treatments were compared to identify better the status of the resource. Results showed that a major source of uncertainty in the model was the inclusion of a catch-per-unit-effort abundance index with questionable ability to track abundance. The Stock Synthesis model provided a more flexible and viable method than the virtual population analysis approach. Despite large uncertainty, models depicted a similar trend with a notable stock depletion in the late 1990s but with two distinct biomass trends in more recent years depending on the treatment. To reduce uncertainty and preserve this important economic resource, new data collection programmes and management policies are needed.

中文翻译：

---

渔业相关数据的种群评估：数据质量和参数化对红鲷鱼渔业的影响

数据可用性以及未报告和无管制的捕捞是评估种群状况的重大障碍，尤其是在热带地区。数据数量和质量的限制可能导致模型错误指定和错误的数据处理，可能导致模型输出和后续管理影响的重要变化。红鲷鱼Lutjanus purpureus(Poey) 在法属圭亚那提供了一个种群的例子，该种群具有大量不确定性的长期渔业相关数据。一个灵活的捕捞年龄模型（股票综合）被应用于可用数据，并与历史应用的评估方法进行比较。比较基于不同模型规范和数据处理的模型间可变性，以更好地识别资源状态。结果表明，模型中不确定性的一个主要来源是包含一个单位努力捕捞量丰度指数，其追踪丰度的能力有问题。股票综合模型提供了比虚拟人口分析方法更灵活和可行的方法。尽管存在很大的不确定性，模型描绘了类似的趋势，在 1990 年代后期存量显着枯竭，但最近几年根据处理方式有两种不同的生物量趋势。为了减少不确定性并保护这一重要的经济资源，需要新的数据收集计划和管理政策。