Assessing the environmental and ecological drives of interannual variability in the life histories and population dynamics of icefishes (Family Channi

评估冰鱼生命史和种群动态的年际变化的环境和生态驱动力（Family Channi

• 批准号: 2879084
• 金额: --
• 依托单位: Newcastle University
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2879084
• 关键词: Assessing; environmental; ecological; drives; interannual

The sub-Antarctic island of South Georgia is a hotspot of regional marine biodiversity in the Southern Ocean and supports high levels of endemic and range-edge fauna. It is also one of the fastest warming areas in the Southern Ocean. This means that many species may find toleration and adaptation to higher temperatures difficult. In addition, it is an important fishing region in the Southern Ocean. The management of the fisheries is conducted by the Government of South Georgia and the South Sandwich Islands (GSGSSI) under the auspices of CCAMLR. This means GSGSSI are managing fisheries whilst mitigating against longer-term changes in climate. A key component of the fish fauna around South Georgia are the family Channichthyidae, also known as icefishes. Icefish are unique amongst vertebrates, in lacking the blood pigment haemoglobin, an adaption that may make them particularly susceptible to future warming. Icefish also exhibit unusual reproductive behaviours with some species known to show nesting behaviours. There are three species of closely related icefish Champsocephalus gunnari (mackeral icefish), Chaenocephalus aceratus and Pseudochaenichthys georgianus, which make up a substantial proportion of the fish biomass on the continental shelves of South Georgia and Shag Rocks and have undergone niche differentiation for successful coexistence. Champsocephalus gunnari is a commercial fisheries target while management measures are in place for the other two species. However, there are still important gaps in our knowledge of key life history processes, especially related to reproductive cycles and behaviour, and ecological and environmental drives of spatio-temporal variability in biomass and life history stages within these species.The main objectives of this project are to quantify key life history processes, demographic properties and resource partitioning in the icefishes C. gunnari, C. aceratus and P. georgianus on the South Georgia and Shag Rocks continental shelves. Given the differences in ecological niches for these species, it is expected that they will respond differently to fluctuating environmental conditions. At present, there are management measures in place which limit the total biomass caught as target or by-catch in the commercial fisheries, but further information is required at the regional scale to help inform the spatial management and maintain viable populations to help mitigate against future warming. Key questions which need to be addressed include:1) identify potential spawning locations, timings and nursery grounds and assess whether these are linked to environmental or bathymetric features;2) assess the environmental drivers of interannual variability in recruitment, hatching times and growth rates of larvae;3) assess the distribution of life history stages around the island and how they vary between and within years;4) quantify resource partitioning among life history stages of the different species.

南格鲁吉亚亚南极岛屿是南大洋区域海洋生物多样性的热点，有大量的地方性动物和分布区边缘动物。它也是南大洋变暖最快的地区之一。这意味着许多物种可能难以耐受和适应更高的温度。此外，它还是南大洋的一个重要捕鱼区。渔业管理由南格鲁吉亚和南桑威奇群岛政府在南极海生委主持下进行。这意味着GSGSSI正在管理渔业，同时减轻气候的长期变化。南格鲁吉亚周围鱼类区系的一个关键组成部分是冰鱼科，也被称为冰鱼。在脊椎动物中，冰鱼是独一无二的，因为它缺乏血红蛋白，这种适应性可能使它们特别容易受到未来变暖的影响。冰鱼也表现出不寻常的生殖行为，一些物种已知会表现出筑巢行为。有三个物种的密切相关的冰鱼Champsocephalus gunnari（mackeral冰鱼），Chaenocephalus aceratus和Pseudochaenichthys georgianus，这构成了相当大的比例的鱼类生物量的大陆架上的南格鲁吉亚和沙格岩，并经历了生态位分化的成功共存。Champsocephalus gunnari是一个商业渔业目标，而其他两个物种的管理措施已经到位。然而，我们在关键的生活史过程，特别是与生殖周期和行为，以及生态和环境驱动的时空变化的生物量和生活史阶段在这些物种的知识仍然存在重大差距。gunnari，C. aceratus和P. georgianus分布于南格鲁吉亚和沙格岩大陆架。鉴于这些物种的生态位不同，预计它们对波动的环境条件的反应也不同。目前，已采取管理措施，限制商业渔业中作为目标或副渔获物捕获的总生物量，但需要区域一级的进一步信息，以帮助为空间管理提供信息，并维持可生存的种群，以帮助减缓未来的变暖。需要解决的关键问题包括：（1）确定潜在的产卵地点、时间和育苗场，并评估这些是否与环境或水深特征有关;（2）评估幼虫补充、孵化时间和生长率年际变化的环境驱动因素;（3）评估生命史阶段在岛屿周围的分布情况，以及它们在不同年份之间和年份之内的变化情况;（4）不同物种生活史阶段间资源分配的量化。