Dohan, Kathleen: Earth and Space Research (Project Lead)
Project Funding:
2017 - 2020
NRA: 2016 NASA: Interdisciplinary Research in Earth Science
Funded by NASA, Other US Funding: NASA
Abstract:
This project is an investigation of the moveable nature of marine eco-regions (dynamic biogeography) at an unprecedented spatial scale in the North Pacific using unique biological datasets in conjunction with NASA-based satellite observations of oceanographic characteristics (currents, eddies, SSTs).
Large Marine Ecosystems (LME) are large (often > 200,000 km2) regions of the ocean structured by similar atmospheric and oceanographic conditions, containing similar biotic communities. They are assumed to be stationary and mostly reflect coastal/continental shelf regions. There is mounting evidence that LME classifications may be inappropriate for interpretations of low-frequency change, such as ocean warming associated with anthropogenic climate change. Furthermore, LME often lack key information on mesoscale variability in oceanographic processes that drive productivity across trophic levels. A new approach is desired.Meso-Marine Ecosystems (MME) have been introduced for sub-regions of the subarctic North Pacific, defined by multivariate analyses of phytoplankton and zooplankton community composition. MME are tied to some static boundaries (shelf areas), but also to oceanographic features such as eddy formations, so they may move with variable ocean conditions. The North Pacific Continuous Plankton Recorder (CPR) program has been collecting lower trophic level samples along a 6,500 km route from British Columbia to Japan, as well as transects running south to north in the Northeast Pacific from 2000 to present. From 2002 - 2007, coincident observations of marine birds and mammals were also collected. These data have typically been processed with a resolution of 74 km. During this project additional samples will be processed at 18.5 km resolution, creating a database of small-scale plankton observations across the Pacific basin, covering over 15 years, specifically chosen to capture potential hotspots of abundance or diversity that may be associated with moveable oceanic eddies and other current-based features.
We propose to explore the persistence of MME community structure and delineations across seasons, years, and stanzas (multi-annual periods) using this unique macro-scale biological database, as it relates to variations in the North Pacific Current (NPC), associated eddies, and thermal environment, through 3 main hypotheses.
1) We will test the hypothesis that MME community structure is persistent between seasons and years, but influenced by variability in NPC flow rates, streamlines, and bifurcation points. To test this hypothesis, we will couple biological observations with satellite-based currents (OSCAR), and SST to model MME structuring.
2) We will test the hypothesis that eddies play a crucial role in the MME structuring. Using the additional CPR processing, we will examine the connection between community structuring and the characteristics of eddies such as SST fronts, age, rotation direction, and generation location.
3) We will test the hypothesis that as we experience changing climate, and more extreme marine heat waves (e.g. the Blob), the MMEs will respond. A key question is: can we predict the effects those changes will have on the ecosystems to better inform the management of those biological resources?
This project is timely. We now have the CPR data from 2000 onwards, continuous, and spanning the North Pacific. There have been major shifts in the Pacific Ocean environment during this period (Pacific Decadal Oscillation, ENSO, and the Blob). This project will facilitate understanding of the distribution and abundance of key marine life (plankton and predators) in understudied regions of the North Pacific (open ocean and southern Bering Sea) that will have application to ecological forecasting of fish and wildlife and will contribute significantly to understanding how recent climate variability and low-frequency change has impacted North Pacific marine ecosystems.
Publications:
Sydeman, W. J., Thompson, S. A., Garcia-Reyes, M., Kroeger, C., Hoover, B., Batten, S. D., Rojek, N. A. 2023. Effects of currents and temperature on ecosystem productivity in Unimak Pass, Alaska, a premier seabird and biodiversity hotspot. Progress in Oceanography. 216, 103082. DOI: 10.1016/j.pocean.2023.103082
More details may be found in the following project profile(s):
