Mass mortality events are ubiquitous in nature and can be caused by, for example, diseases, extreme weather and human perturbations such as contamination. Despite being prevalent and rising globally, how mass mortality in early life causes population-level effects such as reduced total population biomass, is not fully explored. In particular for fish, mass mortality affecting early life may be dampened by compensatory density-dependent processes. However, due to large variations in year-class strength, potentially caused by density-independent variability in survival, the impact at the population level may be high in certain years. We quantify population-level impacts at two levels of mass mortality (50% and 99% additional mortality) during early life across 40 fish species using age-structured population dynamics models. The findings from these species-specific models are further supported by an analysis of detailed stock-specific models for three of the species. We find that population impacts are highly variable between years and species. Short-lived species that exhibit a low degree of compensatory density dependence and high interannual variation in survival experience the strongest impacts at the population level. These quantitative and general relationships allow predicting the range of potential impacts of mass mortality events on species based on their life history. This is critical considering that the frequency and severity of mass mortality events are increasing worldwide.

中文翻译：

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早期生命大规模死亡事件对鱼类种群的影响

大规模死亡事件在自然界中无处不在，可能由疾病、极端天气和人为干扰（如污染）引起。尽管在全球范围内普遍存在并且还在上升，但生命早期的大量死亡率如何导致人口水平的影响，例如总人口生物量减少，尚未得到充分探索。特别是对于鱼类，影响早期生命的大规模死亡率可能会受到补偿性密度依赖过程的抑制。然而，由于年级强度的巨大变化，可能是由密度独立的生存变异引起的，在某些年份，人口水平的影响可能很大。我们使用年龄结构的种群动态模型量化了 40 种鱼类早期生命中两种大规模死亡率（50% 和 99% 的额外死亡率）对种群水平的影响。对其中三个物种的详细种群特定模型的分析进一步支持了这些特定物种模型的发现。我们发现人口影响在年份和物种之间变化很大。表现出低程度补偿密度依赖性和高年际生存变化的短命物种在种群水平上受到最强烈的影响。这些定量和一般关系允许根据物种的生活史预测大规模死亡事件对物种的潜在影响范围。考虑到全球范围内大规模死亡事件的频率和严重性正在增加，这一点至关重要。我们发现人口影响在年份和物种之间变化很大。表现出低程度补偿密度依赖性和高年际生存变化的短命物种在种群水平上受到最强烈的影响。这些定量和一般关系允许根据物种的生活史预测大规模死亡事件对物种的潜在影响范围。考虑到全球范围内大规模死亡事件的频率和严重性正在增加，这一点至关重要。我们发现人口影响在年份和物种之间变化很大。表现出低程度补偿密度依赖性和高年际生存变化的短命物种在种群水平上受到最强烈的影响。这些定量和一般关系允许根据物种的生活史预测大规模死亡事件对物种的潜在影响范围。考虑到全球范围内大规模死亡事件的频率和严重性正在增加，这一点至关重要。这些定量和一般关系允许根据物种的生活史预测大规模死亡事件对物种的潜在影响范围。考虑到全球范围内大规模死亡事件的频率和严重性正在增加，这一点至关重要。这些定量和一般关系允许根据物种的生活史预测大规模死亡事件对物种的潜在影响范围。考虑到全球范围内大规模死亡事件的频率和严重性正在增加，这一点至关重要。