Stock-specific use of tidal freshwater wetlands Northwest Fisheries Science Center Fish Ecology Division Pt. Adams and Newport Research Stations Regan A. McNatt, Susan A. Hinton, and Daniel L. Bottom May 25, 2016
Historic Modern Wetlands wetlands Washington Oregon 68% to 70% of tidal wetlands (mouth to Bonneville) lost since 1871 (Marcoe and Pilson, LCEP) Image by: J. Burke, UW; Historical data from Thomas (1983)
Restoration efforts in the estuary are underway but which stocks benefit?
Estuary Habitat Study 2002-2008 A 0.00 0.20 0.40 0.60 0.80 B 0.00 0.03 0.06 0.09 0.12 0.15 Chinook Salmon 2002-2008 Emergent Russian Rul Russian 120 Sl Seal Seal N 100 80 60 40 Forest / Scrub- Shrub Mixed Karlson F K l - F Karlson Sh Kl Sh Wel Welch Wallace UC Wal Lord Lord UC Karlson F Karlson Sh Welch Wallace UC Lord UC 20 0 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120 125 130 135 140 Snake Fall Upper Columbia Summer / Fall Willamette Spring West Cascade Spring Fork Length (mm) Deschutes Fall West Cascade Fall Spring Creek Group Fall Data from Bottom et al. 2011
Estuary-wide genetics survey Table 4. Sample sizes, percentages marked, and estimated percentage composition of the 11 genetic stocks observed in samples of juvenile Chinook salmon collected at main-stem and back-channel sites in the Columbia River estuary, 2010-2012. Data are shown for all surveys and for each reach. Confidence intervals for each estimate are shown in Appendix Table 1. Percentage stock composition of Chinook salmon West Cascade Mid and Spring Upper Upper Willamette Creek Deschutes Columbia Columbia Snake River Estuary Reach N Percent marked fall spring River spring group fall River fall River spring summer/ fall fall spring Rogue River Coast All Reaches 2,644 28 43 6 8 18 2 0 20 2 0 1 0 A 264 53 39 4 2 39 0 0 7 0 0 7 2 C 423 32 73 11 6 7 0 0 2 1 0 0 1 D 546 23 73 9 6 10 0 0 2 0 0 0 0 E 417 30 30 3 17 23 2 0 24 2 0 0 0 F 368 41 30 3 13 26 2 1 23 2 0 0 0 G 324 19 21 4 13 17 5 1 35 4 0 0 0 H 302 35 3 1 0 20 6 0 62 7 1 0 0 Teel et al. 2014
Estuary wetland PIT array locations 2008-2014 Washington Russian Island, rkm 36 2008-2014 Woody Island, rkm 47 2011-2013 Astoria Wallace Island, rkm 80 2012-2013 Sauvie Island, rkm 139 2012-2013 Portland Oregon Bonneville Dam
Tagging study metrics Wetland residence time Secondary channel residence time Timing of channel entry/exit Tide Diel Growth McNatt, R. A., D. L. Bottom, and S. A. Hinton. Residency and movement of juvenile Chinook Salmon at multiple spatial scales in a tidal marsh of the Columbia River estuary. Transactions of the American Fisheries Society. In press.
Estuary wetland PIT array locations 2008-2014 Washington Russian Island, rkm 36 2008-2014 Woody Island, rkm 47 2011-2013 Astoria Wallace Island, rkm 80 2012-2013 Sauvie Island, rkm 139 2012-2013 Portland Oregon Bonneville Dam
Sources of fish detected in estuary wetlands 264 fish > 50 release sites, 11-1400 km Lower Columbia Not Listed Unknown Upper Willamette Listed Interior 10% Listed Interior Stocks
ESA-listed interior stocks detected Up Columbia Spr-chin Site N Russian = 14 Woody = 7 Wallace = 2 Sauvie = 4 Total = 27 Snake -Spr/Sum-chin Snake-Fall-chin Up Columbia-sthd Snake-sthd Mid Columbia-sthd Juveniles = 25 Adult steelhead = 2
km/d km/d Median travel rate 2008-2014 90 80 70 60 50 40 30 20 10 0 Solid = run-of-river Patterned= barged 90 N=32 80 N=28594 70 60 50 40 30 20 10 0 Outmigrating juveniles detected in wetland channels Outmigrating juveniles detected in main stem estuary PIT-trawl rkm 75
h:mm:ss h:mm:ss Median channel residence time, 2008-2014 0:43:12 0:36:00 0:28:48 0:21:36 0:14:24 0:07:12 0:00:00 Solid = run-of-river juveniles Checkered = adults 3:50:24 3:21:36 2:52:48 2:24:00 1:55:12 1:26:24 0:57:36 0:28:48 0:00:00 Striped = barged juveniles
Channel entry/exit timing 3.0 Channel Entry 3.0 Channel Exit 2.5 2.0 1.5 1.0 0.5 UCR-Spr-Chin SR-Spr/Sum-Chin SR-Fall-Chin UCR-sthd SRB-sthd MCR-sthd Average Depth 2.5 2.0 1.5 1.0 0.5 0.0 0.0 Low High Low Low High Low
Depth (m) Depth (m) Stock-specific timing of channel use Lower river Chinook 2008 Interior stocks 2008-2014 3.0 3.0 2.5 2.5 UCR-Spr-Chin 2.0 1.5 2.0 1.5 SR-Spr/Sum-Chin SR-Fall-Chin UCR-sthd 1.0 1.0 SRB-sthd 0.5 0.5 MCR-sthd Average Depth 0.0-1 -0.5 0 0.5 1 Low High Low 0.0 Low High Low Water depth? Fish size?
Implications of stock-specific channel use and future study Excluded interior stocks from previous surveys? Underestimate presence of interior stocks in tidal wetlands? Further study to determine the mechanism of varying wetland use by multiple stocks Fish size Water depth/high tide Size of channel Distance to marsh edge
Conclusions Recorded Chinook and steelhead stocks from all reaches of the Columbia River Basin in estuary wetlands Fish with faster travel rates, especially barged migrants, may have greater reliance on estuary wetlands for rearing prior to ocean entry Interior stocks use small wetland channels during the latter part of tide cycle Sampling bias may have led to an underestimate of interior stock abundance in tidal wetlands Further study to identify mechanism of stock-specific use of tidal wetlands Feed into restoration design Through the lens of climate change Population resiliency through life history diversity Estuaries may become increasingly more important for interior stocks
Acknowledgements George T. McCabe, Jr. Pt. Adams Fabrication Shop Dennis Umphfries Tom Campbell Joel Holcomb FED Electronics Shop Bruce Jonasson Gabriel Brooks Matt Morris Ben Sandford Staff at Pt. Adams Research Station