Does maternal life history strategy influence optimal management regimes for wild salmon?

即使在一个种群中，许多生物体在事件发生的时间上也表现出明显的个体差异，例如它们变质、达到性成熟和/或第一次繁殖的年龄。这种变异可能与个体之间的遗传差异有关，也可能是早期环境条件差异的结果，这些环境条件决定了青少年的生长和发育速度。虽然不同的少年发展速度可能会导致成年人出现，至少在表面上，形态上无法区分，但他们达到特定发育阶段的年龄的相关变化可能会影响他们产生的后代的数量和形式。因此，幼年发育相对较快的个体可能会产生与发育较慢的个体不同的后代。父母的发育速度和他们产生的后代类型之间的这种联系可能是适应性的，也可能不是。它们可以使父母调整或“编程”他们的后代，以适应后代在成长过程中最有可能遇到的条件，正如父母自己的早期生活经验所告知的那样。或者，生长和发育缓慢的父母（因为他们要么处于低质量的环境中，要么不适应环境）可能是低质量的成年人，然后产生低质量的后代。然而，到目前为止，几乎没有严格的调查如何产生的后代父母与不同的早期生活轨迹实际上表现在不同的环境条件。特定父母的后代是否“适合”特定的环境条件，除了对进化生物学家非常感兴趣之外，在应用背景下也相当重要。负责动物再引入和补充计划的管理人员需要知道特定种类的父母的后代是否在某些环境中比在其他环境中表现得更好。例如，在野生鱼类管理方案中，目前在决定在何处投放鱼卵或鱼苗时，并不考虑亲鱼亲鱼以往生活史的变化。该项目是NERC知识转移伙伴关系计划下的一个应用程序，涉及鱼类生物学家和管理人员之间的合作，以解决这一问题。这将是第一个在自然环境中进行实验测试的项目之一，在不同的环境条件下，鲑鱼的亲本发育速度是否会影响其后代的生存能力，重要的是，考虑到这一点是否可以直接提高重新放养计划的成功率。通过使用一系列实验，其中来自不同种类的雌性的卵的命运在自然河流中进行评估，它将测试雌性鲑鱼是否需要更长的时间才能达到它们迁移到海洋的阶段，从而产生最适合河流流域生产力较低的地区的后代，例如营养供应较低或海拔较高的地区。然后，它将测试使用这些信息是否可以改善渔业管理人员通过储备鲑鱼卵来补充鲑鱼种群的方法。

Even within a single population, many organisms show marked variation between individuals in the timing of events such as the ages at which they metamorphose, reach sexual maturity and/or first reproduce. This variation can be linked to genetic differences among individuals and/or can be a consequence of differences in early environmental conditions that shape the rate of juvenile growth and development. While different rates of juvenile development can give rise to adults that appear, superficially at least, morphologically indistinguishable, the associated variation in the age at which they reach particular developmental stages can influence both the number and form of offspring they produce. Thus individuals with a relatively fast juvenile development may produce a different kind of offspring from those that developed more slowly. Such links between parental developmental rate and type of offspring they produce may or may not be adaptive. They could enable parents to adjust or 'program' their offspring to suit the conditions that the offspring are most likely to encounter during growth, as informed by the parents' own early life experience. Alternatively, parents that grew and developed slowly (because they were either in a low quality environment or poorly adapted to it) may be low quality adults, that then produce low quality offspring. However, as yet there has been little rigorous investigation of how offspring produced by parents with different early life trajectories actually perform in different environmental circumstances. Whether or not the offspring of particular parents are 'tailored' to particular environmental conditions is, in addition to being of great interest to evolutionary biologists, also of considerable importance in an applied context. Managers responsible for animal reintroduction and supplementation programmes need to know whether offspring from particular kinds of parents would perform better in some environments than in others. In wild fish management programmes, for example, variation in the previous life history of the parental broodstock is not currently taken into account when deciding where to release eggs or fry. This project, which is an application under NERC's Knowledge Transfer Partnership Scheme, involves a collaboration between fish biologists and managers to address this issue. It will be one of the first to test experimentally in the natural environment whether parental development rate in salmon influences the viability of their offspring under different environmental conditions - and, importantly, whether taking this into account can directly improve the success of re-stocking programmes. By using a series of experiments in which the fate of eggs from different kinds of female are evaluated in natural rivers, it will test whether female salmon that took longer when juveniles to reach the stage when they migrate to sea produce offspring that are best suited to less productive parts of a river catchment, such as areas of lower nutrient supply or higher altitude. It will then test whether use of this information can improve the methods that fishery managers use to supplement salmon populations by stocking out of eggs.