Comparative feeding ecology of Pacific herring (Clupea pallasii), surf smelt (Hypomesus pretiosus), and northern anchovy (Engraulis mordax) in the Strait of Georgia, British Columbia, in fall 2014
Presentation Abstract
The feeding ecology of herring, surf smelt, and northern anchovy in the Strait of Georgia were investigated to determine dietary overlap and potential competition for food resources. Samples were collected using a small midwater trawl during September 2014, near and south of the Fraser River Mouth onboard the CCGS Neocaligus. The stomach contents of a total of 113 fish were identified and enumerated, including 57 Pacific herring (standard length (SL): 105-168 mm), 36 surf smelt (SL: 119-166 mm), and 20 northern anchovy (SL: 53-74 mm), and quantitatively analyzed to determine within and between species diet similarities. All fish were actively feeding. Hierarchical cluster analysis of the diets revealed distinct feeding niches for each of these three zooplankton consumers. Herring had the most diverse diet, consisting mainly (93% of the prey mass) of copepods (Calanus pacificus, Epilabidocera amphitrites and C. marshallae), hyperiids (Themisto and Hyperoche) and decapods (brachiurian and caridean zoaea). Anchovies preyed on a mix of gelatinous plankton, euphausiids (Thysanoessa), amphipods, small copepods (Corycaeus, Tigropus, Oncaea, Acartia), as well as barnacle and gastropod larvae. Smelts appeared to be specialist jellyfish consumers (~90% by mass) with occasional ingestion of amphipods, small copepods and fish larvae. The forage fish analyzed here were sampled at the same location, yet showed little overlap in trophic niche. Prey similarity indices were < 25% between herring, smelts and anchovies and only reached ~40% between smelts and anchovies. Our preliminary data show a clear prey resource partitioning between sympatric forage fish suggesting potentially strong competition.
Session Title
Ecological and cultural context of Pacific herring in the Salish Sea
Conference Track
Species and Food Webs
Conference Name
Salish Sea Ecosystem Conference (2016 : Vancouver, B.C.)
Document Type
Event
Start Date
2016 12:00 AM
End Date
2016 12:00 AM
Location
2016SSEC
Type of Presentation
Poster
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)
Pacific herring--Food--Georgia, Strait of (B.C. and Wash.); Smelts--Food--Georgia, Strait of (B.C. and Wash.); Anchovies--Food--Georgia, Strait of (B.C. and Wash.)
Geographic Coverage
Salish Sea (B.C. and Wash.); Georgia, Strait of (B.C. and 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
Comparative feeding ecology of Pacific herring (Clupea pallasii), surf smelt (Hypomesus pretiosus), and northern anchovy (Engraulis mordax) in the Strait of Georgia, British Columbia, in fall 2014
2016SSEC
The feeding ecology of herring, surf smelt, and northern anchovy in the Strait of Georgia were investigated to determine dietary overlap and potential competition for food resources. Samples were collected using a small midwater trawl during September 2014, near and south of the Fraser River Mouth onboard the CCGS Neocaligus. The stomach contents of a total of 113 fish were identified and enumerated, including 57 Pacific herring (standard length (SL): 105-168 mm), 36 surf smelt (SL: 119-166 mm), and 20 northern anchovy (SL: 53-74 mm), and quantitatively analyzed to determine within and between species diet similarities. All fish were actively feeding. Hierarchical cluster analysis of the diets revealed distinct feeding niches for each of these three zooplankton consumers. Herring had the most diverse diet, consisting mainly (93% of the prey mass) of copepods (Calanus pacificus, Epilabidocera amphitrites and C. marshallae), hyperiids (Themisto and Hyperoche) and decapods (brachiurian and caridean zoaea). Anchovies preyed on a mix of gelatinous plankton, euphausiids (Thysanoessa), amphipods, small copepods (Corycaeus, Tigropus, Oncaea, Acartia), as well as barnacle and gastropod larvae. Smelts appeared to be specialist jellyfish consumers (~90% by mass) with occasional ingestion of amphipods, small copepods and fish larvae. The forage fish analyzed here were sampled at the same location, yet showed little overlap in trophic niche. Prey similarity indices were < 25% between herring, smelts and anchovies and only reached ~40% between smelts and anchovies. Our preliminary data show a clear prey resource partitioning between sympatric forage fish suggesting potentially strong competition.
