Unit for Basic and Applied Microbiology, School of Natural Sciences, Autonomous University of Querétaro, Santiago de Querétaro, Mexico.
Adv Exp Med Biol. 2019;1200:163-186. doi: 10.1007/978-3-030-23633-5_6.
There is growing evidence of the adverse effects of global environmental change on marine mammals, particularly in terms of changes in abundance, distribution, habitat use, migratory phenology, feeding habits, risk of infectious diseases, bioaccumulation of contaminants, declines in reproductive success, and reductions in genetic diversity. These anthropogenic stressors have led to an evident conservation crisis: a quarter of the extant marine mammal species that have been assessed and now considered at risk of extinction. However, we still know very little about the subtle, subclinical effects of environmental stressors on various aspects of physiology that could impacts their survival and long-term fertility, or that could impact the performance of future generations. This chapter argues for the need of considering physiological thresholds when examining how drivers of global environmental change can impact marine mammal populations. It also poses questions regarding our understanding of individual phenotypic plasticity and resilience of species in the face of environmental stressors, particularly under abrupt and unpredictable environmental changes. Specifically, I present evidence of how drivers of environmental change can exert effects at different levels of biological organization to influence the viability of individuals and populations, and discuss which aspects of environmental change could be the most likely to shift the physiological thresholds of different marine mammal species. Finally, the chapter identifies areas of further research in marine mammal conservation physiology in the current context of global environmental change.
越来越多的证据表明，全球环境变化对海洋哺乳动物产生了不利影响，特别是在数量、分布、栖息地利用、迁徙物候、觅食习惯、传染病风险、污染物的生物积累、繁殖成功率下降以及遗传多样性减少等方面。这些人为压力因素导致了明显的保护危机：在已评估的现存海洋哺乳动物物种中，有四分之一现在被认为有灭绝的风险。然而，我们仍然对环境压力对生理各个方面的微妙、亚临床影响知之甚少，这些影响可能会影响它们的生存和长期繁殖能力，或者影响后代的表现。本章认为，在研究全球环境变化的驱动因素如何影响海洋哺乳动物种群时，需要考虑生理阈值。它还提出了一些问题，涉及我们对物种在面对环境压力时的个体表型可塑性和弹性的理解，特别是在突然和不可预测的环境变化下。具体来说，我提出了证据，证明环境变化的驱动因素如何在不同的生物学组织水平上发挥作用，从而影响个体和种群的生存能力，并讨论了哪些方面的环境变化最有可能改变不同海洋哺乳动物物种的生理阈值。最后，该章确定了在当前全球环境变化背景下，海洋哺乳动物保护生理学中需要进一步研究的领域。
