Presentation Abstract

Pacific herring, Clupea pallasi, undertake annual migrations between feeding and spawning grounds that link life stages, habitats, populations, communities, and ecosystems. However, movement patterns of these highly mobile fish are poorly understood. Declines in Pacific herring abundance and slow population recoveries in the absence of fishing pressure have elevated concerns over the status of this ecologically, economically, and culturally important species. Pacific herring spawn on substrate in nearshore habitats where eggs and larvae develop for approximately two weeks before hatching. Early development within discrete spawning grounds could facilitate the incorporation of distinctive chemical signatures within otoliths that could be used as intrinsic markers to trace movements and mixing among groups or regions. Identifying the direction and strength of connectivity among groups can reveal source populations and promote the development of population- and ecosystem-based management strategies that reflect ecologically relevant spatial scales. We applied otolith microchemistry data to: 1) test the utility of elemental signatures to distinguish the natal origins of larval herring; 2) evaluate inter-annual variation in natal signatures within spawning sites; and 3) assess the similarity of edge and natal signatures of adult herring within and among spawning sites. In 2015 and 2016, we sampled actively spawning adult herring and their offspring in the northern Salish Sea and across British Columbia, Canada. Otoliths were extracted, aged, and their elemental composition analyzed using laser ablation inductively coupled plasma mass spectrometry. Cohort-specific analyses were applied to assess consistency among elemental signatures and broader, age-specific movement patterns. Our analyses show that otolith elemental signatures of Pacific herring can provide insight into complex population structure at scales of 10s – 1000 kms to inform and enhance spatially-explicit approaches to conservation and management.

Session Title

Advances in the Understanding of Drivers of Change and Potential Conservation Actions for Pacific Herring in the Salish Sea

Keywords

Herring, Connectivity, Otolith, Population structure

Conference Track

SSE11: Species and Food Webs

Conference Name

Salish Sea Ecosystem Conference (Seattle, WA : 2018)

Document Type

Event

SSEC Identifier

SSE11-194

Start Date

6-4-2018 2:45 PM

End Date

6-4-2018 3:00 PM

Type of Presentation

Oral

Contributing Repository

Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.

Geographic Coverage

Salish Sea (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

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Apr 6th, 2:45 PM Apr 6th, 3:00 PM

Discerning population connectivity and natal origins of Pacific herring (Clupea pallasi): inferences on population structure from otolith chemistry

Pacific herring, Clupea pallasi, undertake annual migrations between feeding and spawning grounds that link life stages, habitats, populations, communities, and ecosystems. However, movement patterns of these highly mobile fish are poorly understood. Declines in Pacific herring abundance and slow population recoveries in the absence of fishing pressure have elevated concerns over the status of this ecologically, economically, and culturally important species. Pacific herring spawn on substrate in nearshore habitats where eggs and larvae develop for approximately two weeks before hatching. Early development within discrete spawning grounds could facilitate the incorporation of distinctive chemical signatures within otoliths that could be used as intrinsic markers to trace movements and mixing among groups or regions. Identifying the direction and strength of connectivity among groups can reveal source populations and promote the development of population- and ecosystem-based management strategies that reflect ecologically relevant spatial scales. We applied otolith microchemistry data to: 1) test the utility of elemental signatures to distinguish the natal origins of larval herring; 2) evaluate inter-annual variation in natal signatures within spawning sites; and 3) assess the similarity of edge and natal signatures of adult herring within and among spawning sites. In 2015 and 2016, we sampled actively spawning adult herring and their offspring in the northern Salish Sea and across British Columbia, Canada. Otoliths were extracted, aged, and their elemental composition analyzed using laser ablation inductively coupled plasma mass spectrometry. Cohort-specific analyses were applied to assess consistency among elemental signatures and broader, age-specific movement patterns. Our analyses show that otolith elemental signatures of Pacific herring can provide insight into complex population structure at scales of 10s – 1000 kms to inform and enhance spatially-explicit approaches to conservation and management.