Synthesis of marine time series to detect, understand, and predict benthic community responses to a rapidly warming Arctic

University Of Maryland Center For Environmental Sciences, Cambridge MD

Investigators

Abstract

1. The Arctic is one of the fastest warming regions of the planet and long-term observations have revealed that natural systems in this region are undergoing substantial changes. Observed changes have been especially pronounced in the Pacific Arctic, where increases in ocean temperature, decreases in sea ice extent, and changes in currents have been observed alongside changes in the composition of ecologically important biological communities that live in sediments on the seafloor. Changes in these communities likely will have cascading impacts on fisheries and seabird and marine mammal populations that rely on food from the seafloor. The goal of this project is to examine coincident changes in seafloor biological communities and physical environments as recorded in samples collected over the last several decades to understand relationships between environmental change and ecological responses in the Pacific Arctic. In particular, this project will test how well observational data collected annually for decades can be used to make forecasts of how marine systems are likely to change in response to environmental change. A secondary goal is to assess how well ongoing sampling efforts may be able to detect biological changes in these systems. Ecological and environmental changes in the Pacific Arctic also will have immediate economic and social implications, especially for Indigenous communities that rely on subsistence harvests of walruses and bearded seals. By helping to improve our ability to detect, explain, and predict changes in these systems, this project will support effective management and sustainable use of marine resources, while mitigating social impacts on local communities. This project also will combine research and education by providing interdisciplinary training in polar biology, modeling, statistics, and data science to students at all levels and from backgrounds that are historically underrepresented in these fields, including interns from rural Appalachia, undergraduates, and an early career scientist. Lastly, we will share research outcomes and acquire shared knowledge from Indigenous communities in the region. 2. Biological communities found in seafloor sediments of the Pacific Arctic are highly productive, influence ecosystem processes, and are critical food resources for marine mammals and birds. These seafloor communities are also sensitive to environmental change, and recent observations indicate shifts in taxonomic composition associated with increases in ocean temperature, decreases in sea ice extent, and changes in currents. Changes in Pacific Arctic seafloor communities are likely to have cascading impacts on seabird and marine mammal populations, ecosystem function, and fisheries. However, improving our ability to explain and predict responses of Arctic marine systems to rapid climate change remains a substantial challenge. In remote, data-limited ecosystems like the Arctic seafloor, where direct observation and experimentation are difficult, correlative models are often used to link biological patterns to environmental gradients and to make forecasts of ecosystem trajectories. However, few studies have performed rigorous tests of the ability of these so-called “space-for-time substitution” approaches to predict changes in community composition, in large part due to a lack of contemporary datasets with sufficient spatial and temporal coverage. At the same time, we lack a basic understanding of the role of thresholds, where incremental changes in the physical environment result in sudden and fundamental changes to community composition and ecosystem function, in driving biological responses to environmental change. To address these hurdles, this project will (1) analyze multi-decadal time series of paired biological and physical observations that have been collected in the northern Bering and Chukchi seas since the 1980s to characterize relationships between the physical environment and responses of ecologically important marine seafloor communities; (2) test the extent to which observational time series can inform forecasts of changes in these systems; and (3) evaluate the efficiency of ongoing sampling efforts to detect biological changes. In doing so, this project will improve our ability to explain, detect, and predict biological responses in changing Arctic environments and address associated knowledge gaps using novel modeling methods. The Arctic is one of the most rapidly warming regions on the planet and associated impacts on high biomass seafloor communities in the northern Bering and Chukchi seas will have immediate economic and social implications for potential northward fisheries expansion as well as co-management of subsistence harvests of walruses and bearded seals by Indigenous communities. Our goal is to improve our ability to detect, explain, and predict changes in these systems, and in doing so we will support effective management and sustainable use of marine resources, while mitigating social impacts on local communities. In addition, we will integrate research and education in multiple ways by: (i) mentoring summer interns from underrepresented groups attending a local college in rural Appalachia; (ii) providing research experiences to undergraduates through an existing Research Experiences for Undergraduates program; and (iii) training of a graduate student in spatial modeling, marine science, and global change ecology. These programs will provide interdisciplinary training that spans polar biology, spatial modeling, statistics, and data science for students from backgrounds that are historically underrepresented in these fields. Lastly, we will share research outcomes and acquire shared knowledge from Indigenous communities in the Bering Strait region. 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.