Presentation Abstract
Hypoxia is a regular, yet increasingly prevalent feature of southern regions of Hood Canal, WA. While occasional fish kill events garner much public attention, these events are rare and may therefore may not be as important as effects from non-lethal levels of dissolved oxygen. Low levels (near 2 mg / l ) are common and species have a range of responses Here I use results from multiple investigations to illustrate the nature and magnitude of effects. On a population level, long lived sessile species like geoduck clams show clear evidence of substantial impacts from hypoxia. In addition, several sessile invertebrate species are locally impacted. In contrast, mobile demersal fish and invertebrates show a behavioral response to periods of low dissolved oxygen but these are temporary. We also find that valuable species such as Dungeness crab shoal in nearshore habitats where they are vulnerable to recreational fishing gear. We find that effects at the food web level are unclear. Specifically, euphausiids play a key role in the food web, yet show little evidence of density or distributional response. However, detailed tracking of planktivorous fish feeding and distribution suggests that low dissolved oxygen might tighten trophic connectivity between these two species. Notably, this occurs despite levels of dissolved oxygen that are physiologically stressful. Future work should focus more on ecological consequences of localized depletion and behavioral responses to low dissolved oxygen
Session Title
Interdisciplinary Approaches to Understanding Eutrophication and Over-enrichment of Nutrients in Puget Sound and Effects on Marine Species
Keywords
Hypoxia, Ecosystem
Conference Track
SSE16: Long-Term Monitoring of Salish Sea Ecosystems
Conference Name
Salish Sea Ecosystem Conference (2018 : Seattle, Wash.)
Document Type
Event
SSEC Identifier
SSE16-160
Start Date
6-4-2018 9:30 AM
End Date
6-4-2018 9:45 AM
Type of Presentation
Oral
Genre/Form
conference proceedings; presentations (communicative events)
Contributing Repository
Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.
Subjects – Topical (LCSH)
Hypoxia (Water)--Washington (State)--Hood Canal; Fish kills--Washington (State)--Hood Canal; Food chains (Ecology)--Washington (State)--Hood Canal
Geographic Coverage
Hood Canal (Wash.)
Rights
This resource is displayed for educational purposes only and may be subject to U.S. and international copyright laws. For more information about rights or obtaining copies of this resource, please contact University Archives, Heritage Resources, Western Libraries, Western Washington University, Bellingham, WA 98225-9103, USA (360-650-7534; heritage.resources@wwu.edu) and refer to the collection name and identifier. Any materials cited must be attributed to the Salish Sea Ecosystem Conference Records, University Archives, Heritage Resources, Western Libraries, Western Washington University.
Type
Text
Language
English
Format
application/pdf
Included in
Fresh Water Studies Commons, Marine Biology Commons, Natural Resources and Conservation Commons, Terrestrial and Aquatic Ecology Commons
Population, community and food web impacts of hypoxia : a synthesis of findings from Hood Canal
Hypoxia is a regular, yet increasingly prevalent feature of southern regions of Hood Canal, WA. While occasional fish kill events garner much public attention, these events are rare and may therefore may not be as important as effects from non-lethal levels of dissolved oxygen. Low levels (near 2 mg / l ) are common and species have a range of responses Here I use results from multiple investigations to illustrate the nature and magnitude of effects. On a population level, long lived sessile species like geoduck clams show clear evidence of substantial impacts from hypoxia. In addition, several sessile invertebrate species are locally impacted. In contrast, mobile demersal fish and invertebrates show a behavioral response to periods of low dissolved oxygen but these are temporary. We also find that valuable species such as Dungeness crab shoal in nearshore habitats where they are vulnerable to recreational fishing gear. We find that effects at the food web level are unclear. Specifically, euphausiids play a key role in the food web, yet show little evidence of density or distributional response. However, detailed tracking of planktivorous fish feeding and distribution suggests that low dissolved oxygen might tighten trophic connectivity between these two species. Notably, this occurs despite levels of dissolved oxygen that are physiologically stressful. Future work should focus more on ecological consequences of localized depletion and behavioral responses to low dissolved oxygen
