Critical thresholds in sea lice epidemics: evidence, sensitivity and subcritical estimation
Critical thresholds in sea lice epidemics: evidence, sensitivity and subcritical estimation
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DOI：
10.1098/rspb.2011.2210
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发表时间：
2012-05-22
影响因子：
4.7
通讯作者：
Krkosek, Martin
中科院分区：
文献类型：
--
作者：
Frazer, L. Neil;Morton, Alexandra;Krkosek, Martin
宿主密度阈值是病原体种群动态的基本组成部分，但缺乏经验证据和估计。我们研究了主机密度阈值的动态外寄生海虱（Lepeophtheirus鲑鱼）鲑鱼养殖场。经验性的例子包括1994年在加拿大大西洋地区的一次流行病和2001年在加拿大太平洋地区的一次流行病。一个数学模型表明，虱子的动态是由一个稳定的地方病平衡，直到临界主机密度阈值下降，由于环境变化，或超过放养，造成流行病，需要快速收获或治疗。敏感性分析的临界阈值表明依赖于生物参数和温度和盐度的高敏感性的变化。我们提供了一种方法来估计临界阈值寄生虫丰度在亚临界主机密度和估计的临界阈值和传输系数为两种流行病。宿主密度阈值可能是发生鲑鱼养殖的沿海海域疾病动态的基本组成部分。
Host density thresholds are a fundamental component of the population dynamics of pathogens, but empirical evidence and estimates are lacking. We studied host density thresholds in the dynamics of ecto-parasitic sea lice (Lepeophtheirus salmonis) on salmon farms. Empirical examples include a 1994 epidemic in Atlantic Canada and a 2001 epidemic in Pacific Canada. A mathematical model suggests dynamics of lice are governed by a stable endemic equilibrium until the critical host density threshold drops owing to environmental change, or is exceeded by stocking, causing epidemics that require rapid harvest or treatment. Sensitivity analysis of the critical threshold suggests variation in dependence on biotic parameters and high sensitivity to temperature and salinity. We provide a method for estimating the critical threshold from parasite abundances at subcritical host densities and estimate the critical threshold and transmission coefficient for the two epidemics. Host density thresholds may be a fundamental component of disease dynamics in coastal seas where salmon farming occurs.