Download presentation
Presentation is loading. Please wait.
Published byHubert Lucas Modified over 9 years ago
1
Combining PIT Tags with Scale Reading to Better Understand the Life History of Snake River Fall Chinook Salmon Douglas Marsh and William Muir - NOAA Fisheries Dr. William Connor - US Fish and Wildlife Service
2
Background – The early years Mid to late 1990’s –USFWS & NOAA
3
Background – The early years Mid to late 1990’s –USFWS & NOAA –Production fish behavior different from natural fish
4
Background – The early years Mid to late 1990’s –USFWS & NOAA –Production fish behavior different from natural fish –Small hatchery fish (~70mm) performed much like natural fish (surrogate-size)
5
Background – The early years Mid to late 1990’s –USFWS & NOAA –Production fish behavior different from natural fish –Small hatchery fish (~70mm) performed much like natural fish (surrogate-size) –1998 – USFWS began collecting adults at LGR for scales
6
Background – The age of expansion Early to Mid-2000’s –2001-2004 NOAA transport studies conducted
7
Background – The age of expansion Early to Mid-2000’s –2001-2004 NOAA transport studies conducted –Attempted to use surrogate-sized hatchery fish
8
Background – The age of expansion Early to Mid-2000’s –2001-2004 NOAA transport studies conducted –Attempted to use surrogate-sized hatchery fish –Tag numbers ranged from 50-100,000 per year
9
Background – The age of expansion Early to Mid-2000’s –2001-2004 NOAA transport studies conducted –Attempted to use surrogate-sized hatchery fish –Tag numbers ranged from 50-100,000 per year –2004 - No hatchery fish available, tagged at LGR
10
Background – The age of expansion Early to Mid-2000’s –2001-2004 NOAA transport studies conducted –Attempted to use surrogate-sized hatchery fish –Tag numbers ranged from 50-100,000 per year –2004 - No hatchery fish available, tagged at LGR –Connor et al. showed a more complicated life history than expected
11
Background – The age of expansion Early to Mid-2000’s –2001-2004 NOAA transport studies conducted –Attempted to use surrogate-sized hatchery fish –Tag numbers ranged from 50-100,000 per year –2004 - No hatchery fish available, tagged at LGR –Connor et al. showed a more complicated life history than expected –2005 - NOAA joined with USFWS in the scale sampling effort and in transport evaluations
14
Number of juvenile tag codes in SbyC database 2005307,663 2006454,972 2007936,854 2008849,337 20091,416,344 20101,942,691 20112,202,585
17
2009 – Targeted 1,416,344 NOAA, USFWS, & NPT
18
Determine age-at-ocean-entry Scales read by Washington Department of Fish and Wildlife S0.1… SRR1.2… RR1.0… Scales #123A 09/25/07 3D9.1BF234E5FA
19
Juvenile detection history Age at ocean entry Life History
20
Age-at-Ocean-Entry by Return Year
21
Age-at-Ocean-Entry by Migration path
22
Age-at-Ocean-Entry by Migration path and River
23
Migration timing vs. Return rate (SAR)
24
Adult age class distribution vs. Age-of-Ocean-Entry
25
Adult length vs. Age-of-Ocean- Entry
26
Snake River Fall Chinook Salmon employ a wide range of juvenile life histories Conclusions
27
Snake River Fall Chinook Salmon employ a wide range of juvenile life histories –Ocean-type salmonids typically enter the ocean as subyearlings; can take a year Conclusions
28
Snake River Fall Chinook Salmon employ a wide range of juvenile life histories –Ocean-type salmonids typically enter the ocean as subyearlings; can take a year –Summer passage - > 90% age-0 ocean entry Conclusions
29
Snake River Fall Chinook Salmon employ a wide range of juvenile life histories –Ocean-type salmonids typically enter the ocean as subyearlings; can take a year –Summer passage - > 90% age-0 ocean entry –Fall passage - >80% age-1 ocean entry Conclusions
30
Snake River Fall Chinook Salmon employ a wide range of juvenile life histories –Ocean-type salmonids typically enter the ocean as subyearlings; can take a year –Summer passage - > 90% age-0 ocean entry –Fall passage - >80% age-1 ocean entry –Passage after October - 100% age-1 ocean entry Conclusions
31
Snake River Fall Chinook Salmon employ a wide range of juvenile life histories –Ocean-type salmonids typically enter the ocean as subyearlings; can take a year –Summer passage - > 90% age-0 ocean entry –Fall passage - >80% age-1 ocean entry –Passage after October - 100% age-1 ocean entry Snake and Clearwater similar except for never detected fish Conclusions
32
The later a fish outmigrates, the higher the SAR Conclusions (cont.)
33
The later a fish outmigrates, the higher the SAR Age-at-ocean entry affects adult characteristics (based on brood year) Conclusions (cont.)
34
The later a fish outmigrates, the higher the SAR Age-at-ocean entry affects adult characteristics (based on brood year) –Adult age class distribution – Age-1 adults tend to be older Conclusions (cont.)
35
The later a fish outmigrates, the higher the SAR Age-at-ocean entry affects adult characteristics (based on brood year) –Adult age class distribution – Age-1 adults tend to be older –Adult size at return – Age-1 adults are smaller Conclusions (cont.)
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.