Bomb-Dated Growth Dynamics of Arctic Fishes

这项研究试图独立地验证北极鱼类的年龄测定。据信，北极海鱼可能比耳石(耳骨)上的年生长轮指定的日期更老。如果在种群模型中低估了鱼龄，模型将高估区域渔业从现有或计划的渔获量限制中恢复的能力。这可能是与过度捕捞有关的其他渔业的人口急剧下降的原因之一。为了评估基于耳石环计数的年龄评估的准确性，将对来自各种北极鱼类的耳石进行耳石年龄测试，并测量耳石环的碳-14(C14)含量。由于耳石中C-14的含量与地表水中的C14含量非常接近，而且由于炸弹试验导致C14的地表水含量在过去50年中发生了巨大变化，该方法为传统方法的准确性提供了一种独特且相对简单的测试方法。将尝试一种基于测量耳石中残留的锶-90(Sr90)含量的新方法。此外，还将利用这些方法对鱼鳞的年代进行调查。

ABSTRACTOPP-9985884JonesThis research seeks to independently validate age determinations of Arctic fish. It is believed that Arctic marine fish may be older than the dates typically assigned from annual growth rings in their otoliths (ear-bones). If fish ages are underestimated in population models, the models will overestimate the ability for the regional fisheries to recover from existing or planned catch limits. This may be one reason for drastic population declines in other fisheries which were associated with over-fishing. To evaluate the accuracy of age assessments based on otolith ring counts, otoliths from a variety of Arctic fish species will be tested for otolith age and measuring the carbon-14 (C14) content of the otolith rings. Because otolith C-14 content closely matches the C14content in surface waters, and because the surface water content of C14 has changed dramatically throughout the last 50 years due to bomb testing, this approach provides a unique and relatively simple test of the accuracy of the traditional method. A new approach based on measuring the fall-out derived strontium-90 (Sr90) content of otoliths will be attempted. In addition, dating of fish scales will be investigated by these methods.