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 (1956-2000) “few and far between” Which way do they go? Gritsenko 2002

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 Tagging technology 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 The reason we tow the net is to catch more juvenile salmon. By towing upriver (in the spring) or downriver (in Sep) we can get a lot more salmon, particularly when salmon abundance is low (and we’d be out all week trying to get our 50 individuals of each spp/age class). It’s not quantitative, however (because the area swept is difficult to determine giving variable towing speed distance & between boats), so they’re excluded from abundance estimates.

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

Pulling it on deck Setting the net Fish in the bunt Pursed net

Sorting, counting and measuring fish

Steelhead timing in the Columbia River estuary

Steelhead size, 2007-2009 (n = 679) Mean size 214.9 mm FL (range 132-320)

minimum fish weight to maintain 2% maximum Acoustic Transmitters 69 kHz nominal pri interval = 180 sec (range = 90-270 sec) VEMCO 21mm V7 V9 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 337d 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’

SWFSC towed hydrophone array The POST project acoustic receiver arrays 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

SWFSC towed hydrophone acoustic surveys from 2008 Red =Aug & Sept Green = Oct & Nov

Detection range: V9 tags ~400-500m V7 tags ~ 200-300m Positions of VEMCO VR2 and VR3 acoustic receiver lines maintained by the Pacific Ocean Shelf Tracking Project (http://www.postcoml.org/)

Photo courtesy of Sean Hayes SWFSC 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.

Elephant Seal Acoustic Array Image from TOPP- Simmons & Costa

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

Archival tags: 80% >189 mm Steelhead size, 2007-2009 (n = 679) Minimum steelhead size by tag Archival tags: 80% >189 mm V7-2L tags: 50% >214 mm V7-3L: 40% >222 mm V9: 7% >259 mm 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. ~$3,500 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