Post on 30-Nov-2014
description
The Influence of Estuarine Habitats on Expression of Life History Characteristics of Smolting Coho Salmon
Research Project ReviewFor
KBRR NERRS Community CouncilMay 26, 2010
Presented by
Tammy Hoem, GRF, University of Alaska Fairbanks
AcknowledgementsUniversity of Alaska FairbanksKachemak Bay Research Reserve, NOAA, NERRSAlaska Department of Fish and Game, Sport FishGraduate Committee:
Amanda RosenbergerChristian ZimmermanMegan McPheeFranz Mueter
Cooperators and full-time staff:Coowe Walker (and the Walker family)Steve BairdMichelle GutschJason Neher
And the amazing army of staff and volunteers who have helped out for the past two years!!
Summary
• Background and purpose• Objectives • 2009 project review• 2010-2011 sampling plan• Questions and discussion
OverviewVariability in life history strategies is a solution to ecological
problemsWhat is the problem for salmon? Our changing climate.
Variability (of conditions)
Resilienceto environmental change
Variability(of fish traits)
Coho Salmon in Estuaries
Coho (Silver) salmon• Northern CA to West Coast AK• Wide range of life histories• Estuary use is short but important
Estuary use in Pacific Salmon• Very dynamic areas, not well understood• Potential area of hard selection pressure• Important for smolting
The Question:Do estuary habitats select for salmon smolt traits?Two-part Investigation1. Smolts in an estuary• Traits: size, condition, age class • Environmental conditions: salinity, temperature
2. Adults returning to two different estuarine systems• Traits: size, movement patterns, genetic diversity and
structure• Environmental conditions: tidal inundation, stream flow
events, size
Study Area
~1.0 km2
~12 km2
PredictionsSmolt traits within a single type of estuarine habitat
• Greater range of environmental conditions results in fish with greater range of traits
• More developed smolt will be associated with increasing salinity and temperature
PredictionsSalmon traits compared between estuaries
The larger, more complex estuary(Fox)will have fish with:1. A wider range in time using the estuary and patterns of
movement between fresh and salt water.2. Wider ranges in the age and length at ocean entry3. Weaker genetic structure but greater genetic diversity
2009 Pilot Study GoalsThree Objectives
1. Determine sampling methods2. Determine sites3. Develop baseline data set
2009 Pilot Study Results• Sampled ten sites, four channel types in the Fox,
six sites, three channel types within the Anchor• Captured >4k fish, 13 species in the Fox and >1k
fish, 8 species within the Anchor• Determined best sampling method and selected
sites for focused sampling• Developed baseline species composition, size, and
distribution data
2010 Study ObjectivesCompare traits of smolts using the estuary• Salinity, temperature• Size, condition, age
Compare salmon traits between two different estuary systems• Stream discharge, size, watershed type• Size at marine entry, time of estuary occupancy,
movement patterns, genetic structure, diversity
Methods: Smolt Traits Compared Within a Single Estuary
Measure environmental conditions• Temperature (continuous logging)• Salinity (point measurements)
Capture salmon smolt, measure traits• Size measured in field and in photos• Condition and age determined from
scale and specimens
Test predictions regarding conditions and smolt traits
Methods: Salmon Traits Compared Between Estuaries
Collect environmental data• Stream flow (gauges, depth loggers)• Tidal inundation (depth loggers)• Size (existing maps)
Collect samples from adult returns• Standard length and photos from angled fish • Otoliths, fin clips from angled fish
Complete analysis of adult otoliths• Microstructure for age and size• Microchemistry for behavior and movement
Complete analysis of genetic samples• Examine diversity and structure of markers
Test predictions regarding estuaries and fish traits
The End…for now!