Tracking steelhead migration from the Columbia River through the Pacific Ocean: a proposal Michelle Rub and Laurie Weitkamp NOAA 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 ( ) 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 size, (n = 679) Mean size mm FL (range )

Acoustic Transmitters 69 kHz nominal pri interval = 180 sec (range = sec) 21mm V9V7 VEMCO model power output in dB re lifediameterweight in air minimum fish weight to maintain 2% maximum tag: body V7/2L136230d7mm1.6g80g V7/4L136337d7mm1.8g90g V9/6L142275d9mm2.9g145g 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 ( Detection range: V9 tags ~ m V7 tags ~ m

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 modelrecords tag lifedimensions weight in air minimum fish weight Wee Tag Slim temperature and depth18x12x6.75 mm1.7g85g Wee Tag Lighttemperature ~11mm dameter, 6.25mm height1.1g55g

Advantages of archival tags long-lived tag smaller than AT tag less expensive (~$ 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, (n = 679) Archival tags: 80% >189 mm V7-2L tags: 50% >214 mmV7-3L: 40% >222 mmV9: 7% >259 mm Minimum steelhead size by tag Mean size mm FL (range )

Cost Acoustic Tags ~$275 each x 100 = $27,500 Archival Tags ~$90 each x 150 = $13,500 Misc. ~$3,500  Total = $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