By Carl Stiefel Idaho Department of Fish and Game

Strategies to Maximize the Efficiency of Using Parentage-based Tagging as a Tool to Meet Management and Research Objectives By Carl Stiefel Idaho Department of Fish and Game

Idaho’s Hatchery Steelhead Programs • 5 Hatcheries • Annually Release • 7.6 m hatchery smolts • Of which, 1.9 m (25%) are coded-wired tagged (CWT) Clearwater River Snake River Salmon River

Parentage-based tagging (PBT) • Anderson and Garza (2005) • Annual sampling and genotyping of broodstock • Parental genotype database • Assign the progeny to parents • Essentially all fish are genetically tagged • Pilot Study (Steele et al. IDFG Report 11-111) • 100 % assignment accuracy • 97.3% assignment rate or

Why use PBT? • Advantages of PBT • Noninvasive tag • No tag loss • No tag induced effects • Near complete representation of production • Nonlethal sampling • Extremely high resolution, identify parents!!! • Brood Year • Hatchery • Rearing information

Can PBT be applied at a mass production scale and still meet management and research needs? Depends on • Ability to track family units through culture phase of life cycle. • Level of interest. • Large scale • To brood year, hatchery, and stock. • Adult accounting • Moderate scale • To release group. • Fishery management • Straying • Fine scale • To experimental group. • Heritability of Age at Maturity • Manipulative Rearing Experiments

Facility/program characteristics that facilitate tracking of family units to release group • Every hatchery will require a unique PBT Plan/Model. • Lumping family units is good. • Splitting family units may cause complications if not managed. • Release goals set in intervals of the largest group of intact family units.

Best case scenariolumping to the release Raceway-A Release Group A Vat-A Raceway-A Release Group B Vat-B

Best case scenariolumping to the release Largest group of intact family units Raceway-A Release Group A Vat-A Raceway-A Release Group B Vat-B

Worst case scenariolumping and splitting Raceway-A Release Group A Vat-A Raceway-B Raceway-C Release Group B Raceway-D Vat-B Egg Trays Raceway-E Raceway-F Release Group C Raceway-G Vat-C Raceway-H Release Group D Raceway-I

Maximized PBT Scenario • Release group size are in intervals of your largest group of intact family units. Raceway-A Vat-A Release Group A Raceway-B Raceway-C Raceway-D Vat-B Release Group B Egg Trays Raceway-E Raceway-F Raceway-G Vat-C Release Group C Raceway-H Raceway-I

Alternative scenario lumping and managed splitting M&E activities do not have to dictate release goals!!!! Raceway-A Vat-A Raceway-B Release Group A Raceway-C Raceway-D Raceway-G Vat-B Egg Trays Raceway-E Raceway-H Raceway-F Raceway-I Release Group B Vat-C

Alternative scenario lumping and managed splitting M&E activities do not have to dictate release goals!!!! Raceway-A Vat-A Raceway-B Release Group A Raceway-C X Raceway-D Raceway-G Vat-B Egg Trays Raceway-E Raceway-H Raceway-F Raceway-I Release Group B Vat-C

Alternative scenario lumping and managed splitting M&E activities do not have to dictate release goals!!!! 75% PBT Tagging Rate Raceway-A Vat-A Raceway-B Release Group A Raceway-C X Raceway-D Raceway-G Vat-B Egg Trays Raceway-E Raceway-H Raceway-F Raceway-I Release Group B Vat-C 60% PBT Tagging Rate

Approaches to tracking family units to release group • Set release group size in intervals of the largest group of intact family units. • When not possible due to logistics or management needs. • Limit the number of split family units. • Apply a “PBT tagging rate”. • Pool multiple release groups into a single release group.

Considerations for hatcheries regarding PBT • More detail oriented than “standard production” • Minimize or eliminate “topping off” to meet production goals • Develop egg request for each release group • Maintaining intact family units during • Egg enumeration • Marking • Catastrophic events may impact ability to track family units • This has happened and has been managed effectively • Coordination of information essential • Tracking family groups • Relating release information to recovered samples

Sounds like a logistic nightmare? • Not really • Initial PBT plan development • Requires a lot of work and coordination • Unique for each facility • Subsequent PBT plan refinement/modification • Is much easier

Proposed PBT Tagging Rate Brood Year 2012 • Of the 7.6 m steelhead to be released. • Approximately 6.8 m (90%) will be PBT tagged to release group. • The remaining 10% will be PBT tagged to hatchery. • 24 out of 28 release groups have a PBT tagging rate of at least 80%.

By tracking family units to release group you can… • Assess contribution to run. • Evaluate contribution to fisheries. • Evaluate hatchery straying into natural production areas. • Conduct other research • Manipulative Rearing Experiments

Conclusions • M&E and hatchery staff need to work closely together to develop a PBT plan for each facility. • Facility/program characteristics that facilitate tracking family units to release group. • Lumping production to release. • Large release group sizes. • Release group size in intervals of your largest group of intact family units. • Even with less than ideal circumstances a large proportion of family units can be tracked to release group resulting in a high “PBT tagging rate”. • These same strategies could be employed at a finer scale, such as experimental unit, as well. • Get creative, you would be surprised at what can be accomplished in maximizing the opportunities to utilize PBT.

Acknowledgments • IDFG Genetics Lab • Matt Campbell • Craig Steele • Hatchery Staff • Clearwater, Dworshak National, Hagerman National, Magic Valley, Niagara Springs fish hatcheries. • PSMFC Marking Crew • Stuart Rosenberger –IPC • Brian Leth

Questions?

By Carl Stiefel Idaho Department of Fish and Game