Tracking steelhead migration from the Columbia River through

the Pacific Ocean: a proposal

Michelle Rub and Laurie WeitkampNOAA Fisheries

Northwest Fisheries Science Center

The salmon life cycle

Major questions Where do they go

(migratory route)? What habitats do they

use (temp, depth, prey)?

Are there survival bottlenecks?

Ocean distribution of North American steelhead (1956-2000)

Gritsenko 2002

Which way do they go?

“few and far between”

Why we need to know more about Columbia steelhead ocean residence

• Better understand how if or how ocean conditions influence growth and survival– Where and when does it happen?

• Determine what “good” ocean conditions are for steelhead

• Predict how they might fare with climate change– Changing productivity of California current– Explosion of Humboldt squid

Study Objectives• Determine feasibility of tagging Columbia

River steelhead in estuary• Test three acoustic ‘detection systems’ in

the North Pacific• Supplement ‘sporadic’ but precise

information on geo-position with continuous information on temperature and depth

►Increase our understanding of ocean residence period for Columbia steelhead

Talk outline• Collecting Columbia steelhead

– Existing sampling in Columbia estuary• Tagging technology

– Acoustic, archival• Listening arrays

– Coastal, oceanic, living• Expected results

Collecting juvenile Columbia River steelhead• Existing NWFSC sampling for out-migrating yearling smolts• Sampling at edges of deep channels• Every other week, mid April to late June • 2007-present: caught over 200 steelhead/yr• CWT & PIT tags = fish from throughout basin

Sampling equipment: purse seine

• Minimizes injury and descaling to fish

• Post-release survival expected to be high

• Allows sampling in deep water (far from beach)

• Net dimensions: 500 x 35 ft

Setting the net

Pursed net

Pulling it on deck

Fish in the bunt

Sorting, counting and measuring fish

Steelhead timing in the Columbia River estuary

Steelhead

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Apr

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Date

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2007

2008

2009

Steelhead size, 2007-2009 (n = 679)

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12013

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Fork length (mm)

Freq

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Mean size 214.9 mm FL (range 132-320)

Acoustic Transmitters• 69 kHz• nominal pri interval = 180 sec(range = 90-270 sec)

21mm

V9V7

VEMCO

model

power output in

dB re 1µPa @1m tag life diameter weight in air

minimum fish weight to

maintain 2% maximum tag: body

V7/2L 136 230d 7mm 1.6g 80g

V7/4L 136 337d 7mm 1.8g 90g

V9/6L 142 275d 9mm 2.9g 145g

Goal is to maximize tag life and power output while keeping the weight of the tag to a minimum.

Advantages of acoustic transmitters for this study• can be used to collect precise geo-positional information

• information transferred to receiver for collection

Disadvantages of acoustic transmitters• long-lived tags are large/heavy• expensive (~$275 each)• must be ‘heard’

In 2010, there will be three different types of ‘receivers’ operating in the Northern Pacific Ocean with the capability of hearing or detecting VEMCO acoustic tags. • SWFSC towed hydrophone array• The POST project acoustic receiver arrays

• SWFSC elephant seal array *Extensive collection of acoustic receivers in the lower Columbia River and estuary

Red =Aug & Sept

Green = Oct & Nov

SWFSC towed hydrophone acoustic surveys from 2008

Positions of VEMCO VR2 and VR3 acoustic receiver lines maintained by the Pacific Ocean Shelf Tracking Project (http://www.postcoml.org/)

Detection range:V9 tags ~400-500mV7 tags ~ 200-300m

Juvenile elephant seal with a BCT, and an archival tag attached to the animal’s back, and a satellite tag attached to the animal’s head.

Photo courtesy of Sean Hayes SWFSC

Elephant Seal Acoustic Array

Image from TOPP- Simmons & Costa

Archival Tags• record temperature and depth• pre-programmed sampling interval from 1/10 sec to 32hrs• Capacity = 32,000 records

model recordstag life dimensions

weight in air

minimum fish weight

Wee Tag Slim

temperature and depth 18x12x6.75 mm 1.7g 85g

Wee Tag Light temperature

~11mm dameter, 6.25mm height 1.1g 55g

Advantages of archival tags• long-lived tag smaller than AT tag• less expensive (~$90-125 each)• large storage capacity• collects a continuous record of

temperature and or pressure

Disadvantages of archival tags• no precise information on geo-position• must be physically retrieved

Retrieving Archival Tags• stocks originating above Bonneville Dam can potentially

be collected in the separation-by-code system • lower river stocks could be collected upon return to the

hatchery of origin, from a trap or concrete collection facility

SARs range from ~1-3% for SR steelhead depending on the migration year and origin

Steelhead size, 2007-2009 (n = 679)

0

20

40

60

80

100

12013

0

150

170

190

210

230

250

270

290

310

Fork length (mm)

Freq

uenc

y

Archival tags: 80% >189 mm

V7-2L tags: 50% >214 mm

V7-3L: 40% >222 mm

V9: 7% >259 mm

Minimum steelhead size by tag

Mean size 214.9 mm FL (range 132-320)

Cost• Acoustic Tags ~$275 each x 100 =

$27,500• Archival Tags ~$90 each x 150 = $13,500• Misc. ~$3,500Total = $44,500

Expected results• Determine feasibility of tagging Columbia

River steelhead in estuary• Acoustically-tagged steelhead will be

“heard” somewhere in the North Pacific• Archival-tagged steelhead will return with

temperature record of ocean migration►Increase our understanding of ocean

residence/migration patterns for Columbia steelhead