KRILLPODYM modelled estimates of Antarctic krill circumpolar distribution

Robust prediction of population responses to changing environments requires the integration of factors controlling population dynamics with processes affecting distribution. This is true everywhere but especially in polar pelagic environments. Biological cycles for many polar species are synchronised to extreme seasonality, while their distributions may be influenced by both the prevailing oceanic circulation and sea-ice distribution. Antarctic krill (krill, Euphausia superba) is one such species exhibiting a complex life history that is finely tuned to the extreme seasonality of the Southern Ocean. Dependencies on the timing of optimal seasonal conditions has led to concerns over the effects of future climate on krill’s population status, particularly given the species’ important role within Southern Ocean ecosystems.Under a changing climate, established correlations between environment and species may breakdown. Developing the capacity for predicting krill responses to climate change therefore requires methods that can explicitly consider the interplay between life history, biological conditions, and transport. The Spatial Ecosystem And Population Dynamics Model (SEAPODYM) is one such framework that integrates population and general circulation modelling to simulate the spatial dynamics of key organisms. Here, we describe a modification to SEAPODYM, creating a novel model – KRILLPODYM – that generates spatially resolved estimates of krill biomass and demographics. This new model consists of three major components: (1) an age-structured population consisting of five key life stages, each with multiple age classes, which undergo age-dependent growth and mortality, (2) six key habitats that mediate the production of larvae and life stage survival, and (3) spatial dynamics driven by both the underlying circulation of ocean currents and advection of sea-ice. Here we present the first results of KRILLPODYM, using published deterministic functions of population processes and habitat suitability rules. Initialising from a non-informative uniform density across the Southern Ocean our model independently develops a circumpolar population distribution of krill that approximates observations. The model framework lends itself to applied experiments aimed at resolving key population parameters, life-stage specific habitat requirements, and dominant transport regimes, ultimately informing sustainable fishery management. ____This dataset represents KRILLPODYM modelled estimates of Antarctic krill circumpolar biomass distribution for the final year of a 12-year spin up. Biomass distributions are given for each of the five key life stages outlined above. The accompanying background, model framework and initialisation description can be found in the following reference paper:Green, D. B., Titaud, O., Bestley, S., Corney, S. P., Hindell, M. A., Trebilco, R., Conchon, A. and Lehodey, P. in review. KRILLPODYM: a mechanistic, spatially resolved model of Antarctic krill distribution and abundance. - Frontiers in Marine Science

要稳健预测种群对环境变化的响应，需将调控种群动态的各类因子与影响物种分布的过程进行整合。这一原则放之四海而皆准，在极地远洋环境中尤为关键。许多极地物种的生物周期与极端季节性节律高度同步，而其分布同时受主流海洋环流与海冰分布的影响。南极磷虾（Antarctic krill，学名*Euphausia superba*，下文简称磷虾）便是这类物种之一，其复杂的生活史与南大洋的极端季节性节律高度适配。由于依赖最优季节条件的出现时间，人们愈发担忧未来气候变化对磷虾种群现状的影响——考虑到该物种在南大洋生态系统中的核心地位，这一担忧更显迫切。
在气候变化背景下，已建立的环境-物种关联可能失效。因此，要构建磷虾对气候变化响应的预测能力，需开发能够明确考量生活史、生物条件与输运过程间相互作用的方法。空间生态系统与种群动态模型（Spatial Ecosystem And Population Dynamics Model，SEAPODYM）便是此类框架之一，它整合了种群模型与环流模型，以模拟关键生物的空间动态。
本研究对SEAPODYM进行改进，构建了全新模型——KRILLPODYM，可生成磷虾生物量与种群结构的空间解析估计结果。该新模型包含三大核心组分：(1) 年龄结构种群：涵盖5个关键生活史阶段，每个阶段包含多个年龄组，种群生长与死亡率均随年龄变化；(2) 6类关键生境：调控幼体产生与各生活史阶段的存活率；(3) 空间动态：由底层海洋环流与海冰平流共同驱动。
本研究基于已发表的种群过程确定性函数与生境适宜性规则，首次展示了KRILLPODYM的运行结果。模型以全南大洋的非信息性均匀密度作为初始条件，独立模拟出了近似观测结果的环极磷虾种群分布。该模型框架可用于开展应用实验，以明确关键种群参数、特定生活史阶段的生境需求与主导输运机制，最终为可持续渔业管理提供科学依据。
本数据集为KRILLPODYM模型的模拟结果，对应12年自旋模拟期末的南极磷虾环极生物量分布。数据集提供了前文所述5个关键生活史阶段各自的生物量分布。相关背景、模型框架与初始化细节可参阅以下已投稿论文：
Green, D. B., Titaud, O., Bestley, S., Corney, S. P., Hindell, M. A., Trebilco, R., Conchon, A. and Lehodey, P. in review. KRILLPODYM: a mechanistic, spatially resolved model of Antarctic krill distribution and abundance. - Frontiers in Marine Science

搜集汇总

背景与挑战

背景概述

该数据集是基于KRILLPODYM模型生成的南极磷虾环南极分布估算数据，涵盖2010年五个关键生命阶段的生物量空间分布。KRILLPODYM是一个整合种群动态、栖息地适宜性和海洋环流的空间解析模型，旨在预测气候变化对南极磷虾种群的影响，为可持续渔业管理提供科学依据。