Marine Vertebrate Ecology Research Group, School of Biological Sciences, The University of Queensland, St Lucia, QLD, Australia.
Anderson Cabot Center for Ocean Life, New England Aquarium, Boston, MA, USA.
Adv Exp Med Biol. 2019;1200:363-411. doi: 10.1007/978-3-030-23633-5_13.
Determining reproductive rates of marine mammal populations can give insight into their persistence and resilience in changing environments. As our marine environments continue to degrade along developed coastal fringes and as mankind's influences extend across even our widest oceans, there is a concern that the reproductive functioning of marine mammals may be affected adversely. Since many marine mammal species and populations are still in the recovery phase post-commercial harvest, and yet others are endangered or threatened by ongoing pressures, further environmental changes may represent direct or indirect threats to their reproductive potential. In this chapter, we review the current methods employed to investigate various aspects of reproductive science in fully-marine mammals, including direct observation of reproductive behavior and output, endocrinology to determine reproductive state, and assisted reproductive technologies to enhance reproductive outcomes. In particular, we focus on the most recent developments and innovations to reproductively sample marine mammals. Two case studies are presented to illustrate the challenges thrown up to researchers studying free-ranging marine mammals, and to highlight diversity in research approach. The North Atlantic right whale is on the brink of extinction through historic overharvest and present-day entanglement and ship strike. Environmental disruption to their migration routes and declining population health has resulted in reduced reproductive rates. In contrast, the main current threats to the reproductive success and survival of the vulnerable dugong are extreme weather events that affect availability of its seagrass diet. Climate disruption with increasingly severe coastal storms and flooding threaten the health of coastal seagrass beds, and consequently reproductive success and survival of this species. It is anticipated that climate change may have diverse and often serious effects on marine mammal reproduction in populations around the globe.
确定海洋哺乳动物种群的繁殖率可以深入了解它们在不断变化的环境中的持久性和适应能力。随着我们的海洋环境在沿海发达地区继续恶化，以及人类的影响延伸到我们最广阔的海洋，人们担心海洋哺乳动物的繁殖功能可能会受到不利影响。由于许多海洋哺乳动物物种和种群在商业捕捞后仍处于恢复阶段，而其他物种则因持续的压力而濒危或受到威胁，因此进一步的环境变化可能对它们的繁殖潜力构成直接或间接的威胁。在本章中，我们回顾了目前用于研究海洋哺乳动物各个生殖科学方面的方法，包括对生殖行为和生殖输出的直接观察、内分泌学确定生殖状态，以及辅助生殖技术以提高生殖结果。特别是，我们专注于研究海洋哺乳动物的最新发展和创新，以进行生殖采样。提出了两个案例研究，以说明对研究自由生活海洋哺乳动物的研究人员提出的挑战，并突出研究方法的多样性。北大西洋露脊鲸由于历史上过度捕捞以及目前的纠缠和船只撞击而濒临灭绝。它们的迁徙路线和种群健康的环境破坏导致繁殖率下降。相比之下，脆弱的儒艮的主要当前威胁是影响其海草饮食供应的极端天气事件，这对其繁殖成功率和生存构成威胁。预计气候变化可能对全球各地的海洋哺乳动物繁殖产生多样化且通常严重的影响。
