Title: Herring Program - Studies of Reproductive Maturity among Age Cohorts of Pacific Herring in PWS
Project Year and Number: 2017: 17170111-D
Other Fiscal Years and Numbers for this Project: None
Principal Investigator (PI): Kristen Gorman
Assisting Personnel: None
Injured Resources Addressed: Not Specified
Abstract: To address the lack of recovery of Pacific herring (Clupea pallasii) in Prince William Sound (PWS), Alaska, research by the Herring Research and Monitoring (HRM) Program has been focused on improving predictive models of PWS herring stocks through observations and research. To this end, the goal of the project described here is to improve the HRM program’s updated (Bayesian) PWS herring Age-Structured Assessment model’s ability to more accurately predict the total population’s biomass by empirically assessing reproductive maturity among age cohorts. Currently, the age at maturity function in the ASA model is not based on empirical data. An improved understanding of age at maturity will allow for more accurate estimates of the total population biomass, which is central to the management of this fishery. The objectives of the studies proposed here are fourfold: 1) assess the seasonal timing (spring, summer, and fall) that allows for accurate determination of both previously spawned and maturing female herring based on ovary histology to determine maturation states; 2) couple histology results with annual scale growth information at the individual level, within specific age cohorts, to understand if scale growth patterns reflect reproductive investment; 3) assess whether annual scale growth patterns can be used to infer age at maturity at the individual level across age cohorts given results from objectives 1 and 2, and 4) assess inter-annual variability in age at maturity based on coupled histology and scale growth over a five-year period by focused, increased sampling during the optimal seasonal period given results from objectives 1-3. The proposed approach will advance preliminary worked conducted previously by HRM investigators by testing the appropriate sampling time of wild PWS herring for ovary characteristics, as opposed to lab-based studies, and increasing sample sizes for more powerful analyses. Studies proposed here address a key demographic parameter, therefore, this research will not only contribute to the management of PWS herring, but also to a more general understanding of herring demography. As world-wide herring populations encounter more variable environmental conditions in the future, basic knowledge of herring demography and ecology will be invaluable.
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Proposal: View PDF (629 KB)
Funding Recommendations: View
Funding Detail For: 2017
Quarterly Project Tasks For: 2017
Annual Report: 2017: Due 09/01/2017
Final Report: Draft Final Report Due 4/15/18
Publications from this Project: None Available