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

Woods Hole Oceanographic Institution, Woods Hole MA

Investigators

Abstract

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.