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Coordination of Tag and Mark Recovery Programs Dan Rawding WDFW
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Mark & Tag Recovery Coordination Except for recent advances in PIT tag infrastructure at mainstem dam and tributary or instream array, the CWT recovery platform has been used to collect data for genetic marker and PIT tag programs CWT recovery platform has two distinct parts: 1) Fisheries Sampling, and 2) Spawning Ground Recoveries at hatcheries & for hatchery fish that spawning naturally (in the river).
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CWT Coordination Management Implementation of Recovery Data Sharing (RMIS) Pros and Cons Thoughts on tag and mark technologies
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CWT Management Coordination Pacific Salmon Treaty & US vs. Oregon Allocation ESA incidental harvest rates –NOAA developed recovery exploitation rates (RERs) that are consistent with salmon recovery Run-reconstruction/Pre-season &Post-season review –Forecasts developed by Co-managers –North of Falcon Process for coastwide annual coordinated salmon management (conservation & fishing opportunity) –Compare pre-season forecast & allocation with actual In-season management –Columbia R fishery CWT sampling and dam & trap counts (conservation & fishing opportunity) PIT tags are now part of forecast & Inseason management because time series is long enough and tag groups are large enough
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CWT Recovery CWT recovery is most commonly based on dead fish including harvested fish, fish taken for broodstock, and carcasses from fish that have spawned in the river. However, tag recovery in some cases is based on sampling of live fish scanned for CWT presence (Cowlitz @ Barrier Dam). Tagging recovery goals are to sample ~20% of the population
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Harvest Implementation Coordination Tributary fishery sampling is done by co-managers for their individual fisheries (Kalama-WDFW, Clackamas- ODFW, Klickitat Dip Net -YN). Some difference in tributary fishery sampling depending on funding levels Columbia River (mouth to MCN) CWT sampling is coordinated between entities (States & Tribes) to provide spatial and temporal coverage, cost-effective (no overlap or duplicative effort), etc. Similar coordination on other multi-state rivers such as the Snake and Grande Ronde Col. R. Fishery sampling (often referred to as the CWT sampling program) is responsible for collecting all tag and genetic marker data. Regardless of what tag or marker types are recommended by the tagging forum a mainstem Columbia River sampling crew is needed to meeting fishery sampling needs PST, US vs. Oregon, BiOP RPA, etc.
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CWT Spawning Implementation Coordination Hatchery Sampling –Goal is to sample all fish returning to hatcheries for CWT; therefore hatchery are often sampled near 100% –Management Agency operating hatchery responsible for adult CWT recovery Natural Spawn (River Sampling) –Not all hatchery fish return to a hatchery or are captured by a hatchery weir. In some cases significant spawning of hatchery fish occurs in rivers and CWT recovery is needed on spawning grounds –Generally similar approaches of CWT recovery & bio-sampling on spawning ground surveys, although different methods may be used to estimate escapement (redds, peak count, mark- recapture, etc.). CWT & abundance collected concurrently. Since spawning fish often expel PIT tags, PIT tag recoveries are based on in-stream detectors not carcasses
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CWT Completeness If fisheries and spawning grounds are not sampled, then some CWT are unaccounted for. –If fisheries are not sampled harvest & hatchery survival estimates are biased low. –If major spawning areas (hatchery or rivers) are not sampled harvest & survival estimates are biased high If representative populations are not CWT tagged fish from those populations are not directly accounted for in fisheries. Lack of sampling and tagging leads to policy implications for conservation, recovery, harvest sharing, and hatchery evaluation
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Coded-Wire-Tags Pros –Coordinated coastwide monitoring program with database (RMIS). Proven technology and accepted by fishery managers in all harvest forums –Low cost of tags (10 cents) and tagging effort & only current coordinated source of annual ocean harvest & distribution –Tag very small fish (40mm) & minimal tag effects –Recovery from dead fish (fishery, spawning areas – carcasses) & integrated into VSP or escapement monitoring –Infrastructure are tagging and sampling crews –Inseason updates by week –Provide known ages and origins for reference to age and genetic analysis Pros –Current Col R. CWT fishery program is used for PIT tag and marker sampling –Tool for hatchery salmon evaluation (survival -SAR, straying) Cons –Batch mark so can not track individuals (PBT or PIT) –Tags are recovered from snouts of dead fish prevents non-lethal sampling (genetic or PIT) –Coarse spatial scale of information in Col R compared to PIT tags. Does not take advantage of Columbia River adult & juvenile PIT tag infrastructure –CWT hatchery fish are used as surrogates for wild fish harvest (DIT groups)
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CWT Summary CWT is currently the only tagging or marking technology with ongoing coastwide application to salmon fisheries For species with significant ocean fisheries such as fall Chinook, coho, & some spring Chinook populations, it is difficult to provide an immediate replacement for CWT For other salmon populations, with negligible ocean harvest (steelhead, chum, some Chinook populations), it is possible to use other tag and marker technologies to estimate harvest & hatchery management needs in the Columbia River
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CWT Summary (Continued) Other technologies are possible but coastwide & international agreements would be need in the next PST Since many troll and some sport fish are cleaned before being sampled at a port, PIT tags are lost prior to sampling. In these cases, it is a challenge to estimate harvest based on PIT tags. Currently, there is not the infrastructure for genetic markers for fine population scale monitoring of ocean harvest and this would require a substantial investment in infrastructure (coastwide genetic baseline & database) and analysis of genetic markers is more costly than CWT
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CWT Management Questions Harvest - ocean, estuary, freshwater Hatchery evaluation especially for salmon because of carcass recoveries on spawning grounds Ocean distribution & survival It will be difficult to answer Ocean management questions with PIT tags
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Mark & Tag Programs Mark and tag programs are complimentary. If tag/mark recovery designs use the same population units, maximum likelihood theory or other statistical techniques can be used to combine all information (CWT, PIT, genetic markers) into a single estimate. There may be different tag/mark strategies by species or different geographic area depending on management questions, cost- effectiveness, and infrastructure. There is little PIT tag infrastructure below BON but there are recent efforts on the Willamette. PIT tag cost-effectiveness benefits from infrastructure, while CWT programs are very cost- effective with little infrastructure except tagging trailers & CWT labs. Regardless of what tag or marker types are recommended by the tagging forum a mainstem Columbia River sampling crew is needed to meet fishery sampling needs. Spawning ground crews, with a primary purpose to recovery CWT and estimate abundance are often used to collect genetic baselines.
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CWT Recovery Estimates Estimate of the population –# of fish returning to a hatchery –# of spawners in a river –# of fish caught in a fishery Fraction sampled from a representative sample –# of fish sampled / population estimate # of CWT in population –# of fish detected with CWT / fraction sampled
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