Exploration of DIDSION Technology; Spawning Site, Confirmation/Characterization and Spawner Behaviour Observation May 26 – 29, 2009 Pilot Explorations on the Nechako River Pilot Explorations on the Nechako River

Purpose(s) Interested in spawning site selection (confirming) Interested in spawning site selection (confirming) –Information habitat restoration planning re –Depth, velocity, substrate Spawning behaviour – poorly documented Spawning behaviour – poorly documented –General interest Deep water with poor visibility – possible utility in DIDSON technology? Deep water with poor visibility – possible utility in DIDSON technology?

What’s a DIDSON? Relatively new technology – –Dual-Frequency Identification Sonar DIDSON operates at 2 frequencies, 1.8 MHz or 1.0 MHz, - forms 96 beams spaced 0.3° apart, or 48 beams spaced 0.6° apart Images out to 12 m at 1.8 MHz and 40 m at 1.0 MHz. Update rate between 5-27 frames/s. Sufficiently high resolution and rapid refresh rate that it can substitute for optical systems in turbid or deep water

Commonly Utilized in Salmon Spawner Enumeration Programs - Stationary Consumes 30 Watts – need a generator DIDSON Video 12 o horizontal DIDSON sonar has large angle beam and bottom subtraction

Data Monitoring and Interpretation Not typically utilized as a mobile device

Imaging Examples qQ qQ served/aquatic-life/fish-surveys

First Challenge – Not typically utilized in mobile deployment Compare with echogram Compare with echogram Much more intuitive Much more intuitive Video Clip

Imaging Captured

Learning and Recommendations A larger and more stable boat should be employed in future work. The instability of the boat affected the ability to insonify a moving target consistently. The boat-mount system should be adjustable to port or starboard An improved anchor system – dual point

Learning and Recommendations During daylight hours, need a mechanism to shade PC screen Future work should be conducted throughout the day and night for a longer overall time period (recommend at least 10 days to allow for maximum opportunity to locate potential spawning sites and spawners – in coordination with telemetry).

Existing Management Process Hydroacoustics In-season Test fishing In-season Stock-specific abundance estimates In-season Stock-specific escapement estimates Preseason Modeled Estimates Exploit Terminal Stock-specific abundance estimates Probe Gone BAD!

Daily Sampling Effort (after the 1998 optimization): 15 hours of mobile + 6 hours of stationary samplings. PSC’s Mission Echo-Sounding Vessel: Rita

MobileSampling (from N =>S) StationarySampling off the south bank

Acoustically Sampled Fish by 15 Hours of Mobile Sounding. Estimated Statistic: Fish Density

Acoustically Sampled Fish by 9 sets of Stationary Sounding. Estimated Statistic: Duration-in-beam (Fish Speed) S CN

Problem: All of US catch allocation occurs outside Fraser river (most 2-4 days seaward of Mission All of US catch allocation occurs outside Fraser river (most 2-4 days seaward of Mission 80% of Canadian catch allocation occurs 5-8 days seaward of Mission 80% of Canadian catch allocation occurs 5-8 days seaward of Mission The design of run size assessment programs is ultimately defined by the tradeoffs between desired certainty, acceptable risks, and costs. The design of run size assessment programs is ultimately defined by the tradeoffs between desired certainty, acceptable risks, and costs. Run-size Certainty- Catch Allocation Mismatch

The Mission Split-Beam Sampling System(under development) Total Upstream FishFlux = SouthBank Flux + Mobile Flux Upstream Fish-Flux by Mobile System Upstream Fish-Flux by SouthBank System 100m300m

Weaver freshwater growth zone In a Chilko fish, this zone would be smaller

Racial analysis: the why and how (so far) 1. Our rationale 2. How scales are used 3. Other methods (incl. DNA)

Racial analysis: the why and how (so far) 1. Our rationale 2. How scales are used 3. Other methods (incl. DNA)