Presentation Abstract
There is growing recognition that maintaining diversity in life history traits contributes to the sustainable management of wild populations. One important life history characteristic is reproductive phenology, and it has been shown that differences in the timing of reproduction can act as a barrier to gene flow between populations. If the difference in reproductive timing determines the level of connectivity, one would expect that genetic differentiation between populations would increase as a function of difference in reproductive date. This pattern, known as “isolation by time” (IBT), has been observed in wild populations of salmonids containing early and late runs. Pacific herring in the Salish Sea also exhibit a wide diversity of spawn times; some populations start reproducing as early as January and reproductive activity in the region continues through May. Here, we test whether these temporal differences in reproduction influence the genetic population structure of herring. We collected adult herring from seven different locations in the Salish Sea during active spawning events (N = 48 per site). Samples were sequenced using a restriction site-associated (RAD) approach and approximately 3,000 polymorphic loci were genotyped in each sample. We found a positive correlation between genetic differentiation and difference in spawn date, with evidence of migration between populations with similar spawn timing. Several loci exhibited exceptionally steep gradients in allele frequencies, including one locus linked to the photoperiodic regulation of reproduction. Our discovery of IBT in Pacific herring support the adaptive significance of spawn timing and underscore the importance of conserving spawning time diversity in Puget Sound herring.
Session Title
Advances in the Understanding of Drivers of Change and Potential Conservation Actions for Pacific Herring in the Salish Sea
Keywords
Genetics, Pacific herring, Dispersal
Conference Track
SSE11: Species and Food Webs
Conference Name
Salish Sea Ecosystem Conference (2018 : Seattle, Wash.)
Document Type
Event
SSEC Identifier
SSE11-253
Start Date
6-4-2018 2:30 PM
End Date
6-4-2018 2:45 PM
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)
Pacific herring populations--Washington (State)--Puget Sound; Pacific herring--Spawning--Washington (State)--Puget Sound; Gene flow--Washington (State)--Puget Sound
Geographic Coverage
Washington (State)--Puget Sound
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
The role of reproductive timing as a driver of genetic differentiation in populations of Pacific herring
There is growing recognition that maintaining diversity in life history traits contributes to the sustainable management of wild populations. One important life history characteristic is reproductive phenology, and it has been shown that differences in the timing of reproduction can act as a barrier to gene flow between populations. If the difference in reproductive timing determines the level of connectivity, one would expect that genetic differentiation between populations would increase as a function of difference in reproductive date. This pattern, known as “isolation by time” (IBT), has been observed in wild populations of salmonids containing early and late runs. Pacific herring in the Salish Sea also exhibit a wide diversity of spawn times; some populations start reproducing as early as January and reproductive activity in the region continues through May. Here, we test whether these temporal differences in reproduction influence the genetic population structure of herring. We collected adult herring from seven different locations in the Salish Sea during active spawning events (N = 48 per site). Samples were sequenced using a restriction site-associated (RAD) approach and approximately 3,000 polymorphic loci were genotyped in each sample. We found a positive correlation between genetic differentiation and difference in spawn date, with evidence of migration between populations with similar spawn timing. Several loci exhibited exceptionally steep gradients in allele frequencies, including one locus linked to the photoperiodic regulation of reproduction. Our discovery of IBT in Pacific herring support the adaptive significance of spawn timing and underscore the importance of conserving spawning time diversity in Puget Sound herring.
