Event Title

Trophic position of jellyfish in the pelagic food web of Hood Canal

Presentation Abstract

Jellyfish may play a key role in pelagic food webs. Their interactions with fish are potentially complex, as they may compete with pelagic fish for prey, may be prey for fish and may be a predator on larval fish. To investigate these interactions, we must also understand how the trophic role of jellyfish varies with factors such as size, species, season and environmental conditions. Hypoxia, in particular, is an increasing problem worldwide and is thought to likely affect fish-jellyfish interactions. We estimated the trophic level of jellyfish using stable isotope analysis on multiple large jellyfish species collected in Hood Canal, Washington. A paired-site sampling design was used to compare hypoxic and non-hypoxic regions. Jellyfish and prey samples were collected from June to October during two years at each site and across a size range. After determining the influence of these factors on the trophic role of jellyfish, we will then be able to better investigate diet overlap with zooplanktivorous fish. Preliminary results indicate that size does not affect the trophic level of jellyfish. Jellyfish also appear to have similar isotopic signatures to fish, which allows for the possibility of competition between jellyfish and fish.

Session Title

Session S-02D: Pelagic Ecology in the Salish Sea II

Conference Track

Species and Food Webs

Conference Name

Salish Sea Ecosystem Conference (2014 : Seattle, Wash.)

Document Type

Event

Start Date

30-4-2014 1:30 PM

End Date

30-4-2014 3:00 PM

Location

Room 611-612

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)

Jellyfishes--Washington (State)--Hood Canal; Jellyfishes--Food--Washington (State)--Hood Canal; Hypoxia (Water)--Washington (State)--Hood Canal

Geographic Coverage

Salish Sea (B.C. and Wash.); 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

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COinS
 
Apr 30th, 1:30 PM Apr 30th, 3:00 PM

Trophic position of jellyfish in the pelagic food web of Hood Canal

Room 611-612

Jellyfish may play a key role in pelagic food webs. Their interactions with fish are potentially complex, as they may compete with pelagic fish for prey, may be prey for fish and may be a predator on larval fish. To investigate these interactions, we must also understand how the trophic role of jellyfish varies with factors such as size, species, season and environmental conditions. Hypoxia, in particular, is an increasing problem worldwide and is thought to likely affect fish-jellyfish interactions. We estimated the trophic level of jellyfish using stable isotope analysis on multiple large jellyfish species collected in Hood Canal, Washington. A paired-site sampling design was used to compare hypoxic and non-hypoxic regions. Jellyfish and prey samples were collected from June to October during two years at each site and across a size range. After determining the influence of these factors on the trophic role of jellyfish, we will then be able to better investigate diet overlap with zooplanktivorous fish. Preliminary results indicate that size does not affect the trophic level of jellyfish. Jellyfish also appear to have similar isotopic signatures to fish, which allows for the possibility of competition between jellyfish and fish.