Comanager Workshop on
Age and Size at Maturity of Pacific Salmon and Steelhead

Date: May 17-19, 2011

Workshop Purpose

Session 1. Why are we here? - Comanager Panel Discussion

• Tim Roth (USFWS): Age and size at maturity – Much ado about nothing or does it really matter?
• Becky Johnson (NPT): Hatchery management questions and issues.
• Jay Hesse (NPT): Natural population questions and issues.
• Chris Kern (ODFW): Harvest management questions and issues.
• Don Campton (USFWS): Science questions and issues.

Session 2: Do we have a problem? Is there evidence that the age and/or size at maturity of Chinook salmon (or other species) are changing? - Case Studies and Populations

• Steve Pastor (USFWS) and Doug Olson (USFWS): National Fish Hatchery observations: variation and trends in age composition and length at return for spring Chinook, tule fall Chinook, upriver-bright fall Chinook, coho, and steelhead.
• Marc Johnson (ODFW) and Tom Friesen (ODFW): Declines in age and size of upper Willamette River spring Chinook salmon.
• Andrew Murdoch (WDFW) and Mike Hughes (WDFW): Influence of hatchery origin spawners on size and age of naturally produced spring Chinook salmon in the Wenatchee Basin and summer Chinook salmon in the upper Columbia Basin.
• Curt Knudsen (Oncorh Consulting), Bill Bosch (YN), Steve Schroder (WDFW), Mark Johnston (YN), and Dave Fast (YN): Trends in demographic and phenotypic traits of upper Yakima River hatchery- and natural-origin spring Chinook salmon.
• Paul Hoffarth (WDFW) and Todd Pearsons (Grant County PUD): Comparison of size and age at maturity of hatchery and natural origin upriver-bright fall Chinook to the Hanford Reach.
• Debbie Milks (WDFW), Mark Schuck (WDFW), and Bill Arnsberg (NPT): Snake River fall Chinook - effects of supplementation on population age structure.
• Michael Gallinat (WDFW) and Mark Schuck (WDFW): Tucannon River spring Chinook - age and size at maturity through 25 years of supplementation.
• Debra Eddy (ODFW), Rich Carmichael (ODFW), Tim Hoffnagle (ODFW), and Joseph Feldhaus (ODFW): Patterns and trends in age composition and size-at-maturity for hatchery and natural-origin Imnaha River Chinook salmon.
• Brian Leth (IDFG), and John Cassinelli (IDFG): Age at maturity and length at age for hatchery and natural populations of spring and summer run Chinook salmon in Idaho streams.
• Kathryn Kostow (ODFW) and Kevleen Melcher (ODFW): Historic trends in size and age structure of Chinook salmon captured in Columbia River mainstem fisheries.

Session 3: What are the effects of hatchery practices on age and size at maturity?

Physiolgy and Nutrition

• Penny Swanson (NMFS): Timing of puberty in salmon.
• Brian Beckman (NMFS): Environmental regulation of puberty in salmon.
• Don Larsen (NMFS): Hatchery influences on puberty in male salmon.
• Pat Connolly (U.S. Geological Survey): Residualization and maturation versus smolting factors for O. mykiss parr.
• Guillaume Salze (University of Guelph, Ontario, Canada): Dietary modulation of puberty and the maturation process in fish.
• Ann Gannam (USFWS): Feed changes over time, ingredients and methods of manufacture, are they having an impact on age/size at maturity of hatchery fish?
  

Genetics and Breeding

Session 4: What are the effects of the natural environment, population processes, and anthropogenic factors on age and size at maturity?

Age and size effects on reproductive behavior, breeding success, and fitness.

• Steve Schroder (WDFW) and Curt Knudsen (Oncorh Consulting): Effects of size at maturity on breeding success and lifetime fitness in males and females and implications for the productivity of natural populations.
• Ewann Berntson (NMFS), Rich Carmichael (ODFW), Robin Waples (NMFS), and Paul Moran (NMFS): Reproductive success of jacks in natural streams (Catherine Creek, Wenatchee River).
• Barry Berejikian (NMFS), Steve Schroder (WDFW), and Ewann Berntson (NMFS): Breeding success of alternative male reproductive phenotypes in Pacific salmon and evidence for frequency dependence selection.
• Summary - Breeding Success
  

Effects of anthropogenic and environmental factors on age and size at maturity.

• Greg Ruggerone (NR Corporation): Density-dependent growth, maturation, and survival of Chinook salmon at sea.
• Jeff Hard (NMFS): The demographic and evolutionary implications of harvest for age and size at maturation in Chinook salmon.
• Neala Kendall* (UW), Jeff Hard (NMFS), and Tom Quinn (UW): Changes in age and size at maturity related to fishery selection: lessons learned from Alaskan populations applied to Columbia River Chinook salmon.
• Tom Cooney (NMFS): Differences in Fishery Selectivity on Male and Female Columbia River Fall Chinook.
• Steve Haeseker (USFWS): An evaluation of the effects of outmigration experience on age-at-maturity
• William Connor (USFWS): Variation in age and size at return associated with fall Chinook salmon juvenile life history.
• Robin Waples (NMFS): The shift toward yearling smolts in Snake River fall Chinook salmon: evolution or phenotypic plasticity?
• Kathryn Kostow* (ODFW), Henry Yuen (USFWS), and Chris Kern (ODFW): The quest for environmental and anthropometric variables that explain annual variation in upriver spring Chinook age structure.
• Summary - Effects of anthropogenic and environmental factors.

A cooperative project with the Oregon Chapter of the American Fisheries Society