Doctoral Dissertation Research: The role of early life-stage bottlenecks in Arctic benthic fjord communities

由于北极大部分地区地处偏远，该地区许多地方的基本生态系统功能仍然鲜为人知。例如，我们对海底无脊椎动物的早期生命阶段知之甚少——胚胎、幼虫和幼体——它们对海洋生态系统的健康至关重要，但特别容易受到环境压力的影响。本论文的研究重点是记录海底无脊椎动物的生命周期，以了解海底群落如何受到气候变暖的影响。虽然目前的研究表明，北极冰川峡湾的海底群落随着空间和深度的变化而变化，但目前尚不清楚这些动物在生命早期阶段的扩散和死亡如何塑造这些梯度。这项研究将确定年轻生物何时何地定居海底，并确定整个冰川峡湾的死亡率。这项研究将展示环境压力因素，如变暖的温度或入侵物种的引入，如何影响动物的生命周期，并推动其群落的梯度。本研究将解决斯瓦尔巴群岛Kongsfjorden的三个关键问题：(1)底栖无脊椎动物幼虫在时空尺度上的分布如何变化？(2)在冰川主导的峡湾中，定居（例如，速率和物种组成）是如何变化的？(3)北极硬底系统定居后的死亡模式是什么？一种新发明的摄像系统将首次部署在Kongsfjorden，以连续自主地观察底栖无脊椎动物定居和定居后的死亡率。将使用浮游生物网收集幼虫样本，并使用综合形态学和分子分类学进行鉴定，以了解当地物种和从低纬度向北移动的物种的扩散模式。此外，综合分类将产生成对的照片和遗传数据集，以帮助幼虫的形态鉴定，这将提供给其他研究人员。这些创新的方法将允许对受冰川影响的极地峡湾的气候影响进行精确的预测。该项目还将通过制作供广泛的K-12教育工作者和学生使用的交互式数据和材料来促进北极教育。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Given the remoteness of much of the Arctic, fundamental ecosystem functions are still little understood in many parts of the region. For example, we know little about the early life stages of seafloor invertebrates - embryos, larvae, and juveniles – which are vital for the health of marine ecosystems but are especially vulnerable to environmental stressors. This dissertation research will focus on documenting the life cycles of seafloor invertebrate animals to understand how seafloor communities are impacted by a warming climate. While current research has shown that seafloor community changes over space and depth in Arctic glacial fjords, it is currently unknown how dispersal and mortality in the early life stages of these animals shape these gradients. This research will identify when and where young organisms settle to the seafloor and characterize mortality rates throughout a glacial fjord. The research will demonstrate how environmental stressors, such as warming temperatures or the introduction of invasive species, can impact animals’ life cycles and drive the gradients in their communities. This study will address three critical questions in Kongsfjorden, Svalbard: (1) How do the distributions of benthic invertebrate larvae vary across temporal and spatial scales? (2) How does settlement (e.g., rate and species composition) vary across a glacially dominated fjord? (3) What are the patterns of post-settlement mortality in an Arctic hard bottom system? A newly-invented camera system will be deployed in Kongsfjorden to continuously and autonomously observe settlement and post-settlement mortality in benthic invertebrates for the first time. Larval samples will be collected using plankton nets and identified using integrative morphological and molecular taxonomy to understand dispersal patterns for both local species and those moving north from lower latitudes. Additionally, the integrative taxonomy will yield a paired photographic and genetic dataset to aid in morphological identification of larvae that will be made available to other researchers. These innovative approaches will allow for refined predictions of climate impacts in glacially influenced polar fjords. This project will also promote Arctic education by producing interactive data and materials for use by a wide range of K-12 educators and students.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.