Award: OCE-1154648

Award Title: Consequences of hypoxia on food web linkages in a pelagic marine ecosystem
Funding Source: NSF Division of Ocean Sciences (NSF OCE)
Program Manager: David L. Garrison

Outcomes Report

Coastal marine ecosystems are threatened by widespread and frequent periods when oxygen levels are severely reduced. While marine life may suffer direct mortality as result of low dissolved oxygen, species more commonly undergo physiological or behavioral change to minimize their exposure to harmful conditions. This study evaluated the joint effects of these changes on a marine food web, focusing on the key connection between large zooplankton and their primary prey, herring and hake. This food web linkage is critical to provide food for valued species such as sea mammals, seabirds, and large piscivorous fish such as salmon, cod, and sharks. By tracking changes in what fish were eating, how much they were eating, the density of fish and zooplankton, and their spatial overlap, we were able to identify how eroding oxygen conditions in Hood Canal, WA, affected this critical food web link. We find that spatial overlap is largely maintained, despite the fact that fish and zooplankton have different tolerances for reduced oxygen. The maintenance of spatial overlap is likely due the relatively cold water conditions, which reduced species? oxygen requirements. However, we find that the nature of the food web linkage was substantially affected, as individual herring had reduced feeding rates, possible leading to smaller growth and lower energy stores. However, total energy flow from zooplankton to fish was maintained though shifts in local fish abundance. Future predictions of how coastal marine ecosystems will respond to increasing oxygen depletion, coupled with warming temperatures and lowered pH, will benefit from a new approach that considers effects on key ecological processes rather than on species abundance and distribution. Last Modified: 08/07/2017 Submitted by: Timothy E Essington
DatasetLatest Version DateCurrent State
CTD data from multiple R/V Clifford A. Barnes cruises in the Hood Canal, WA from 2012-2013 (Pelagic Hypoxia project)2016-06-14Final with updates expected
Zooplankton densities collected from a seasonally hypoxic fjord on R/V Clifford A Barnes cruises from 2012-2013 (Pelagic Hypoxia project)2017-02-08Final no updates expected
Species list from R/V Centennial trawl surveys in the Hood Canal, WA from 2012-2013 (PelagicHypoxia project)2017-11-02Final no updates expected
Survey locations and times for R/V Centennial trawl surveys in the Hood Canal, WA from 2012-2013 (PelagicHypoxia project)2017-11-02Final no updates expected
Trawl catch composition from R/V Centennial trawl surveys in the Hood Canal, WA from 2012-2013 (PelagicHypoxia project)2017-11-02Final no updates expected
Fish and jellyfish stomach contents from R/V Centennial trawl surveys in the Hood Canal, WA from 2012-2013 (PelagicHypoxia project)2021-06-10Final no updates expected
Fish and jellyfish sample data from R/V Centennial trawl surveys in the Hood Canal, WA from 2012-2013 (PelagicHypoxia project)2017-11-02Final no updates expected
Site information for R/V Centennial trawl surveys in the Hood Canal, WA from 2012-2013 (PelagicHypoxia project)2017-11-02Final no updates expected
Physiological observations of Euphausia pacifica after a ten-day acclimation to dissolved oxygen (DO) and pH conditions in two separate laboratory experiments.2021-02-11Final no updates expected
Physiological observations of Euphausia pacifica sampled in Puget Sound, WA aboard R/V Clifford A. Barnes during cruises CB1073 and CB1078 in 2017.2021-03-22Final no updates expected
Seawater carbonate chemistry and dissolved oxygen of discrete samples taken in Puget Sound, WA during R/V Clifford A. Barnes cruises CB1073 and CB1078 in 2017.2021-03-01Final no updates expected
Depth-stratified krill net samples taken in Puget Sound, WA aboard R/V Clifford A. Barnes during cruises CB1073 and CB1078 in 2017.2021-03-01Final no updates expected
Seawater conditions monitored and recorded during two separate laboratory experiments in 2017 to acclimate krill to dissolved oxygen (DO) or pH conditions.2021-03-02Final no updates expected
CTD profiles acquired in Puget Sound, WA aboard R/V Clifford A. Barnes during cruises CB1073 and CB1078 in 2017.2021-03-02Final no updates expected

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NSF Research Results Report


People

Principal Investigator: Timothy E. Essington (University of Washington)

Co-Principal Investigator: John K Horne

Co-Principal Investigator: Julie E Keister

Co-Principal Investigator: Sandra Parker-Stetter