1. Greg Albrecht Dr. Sarah M. Hardy Dr. Kris Hundertmark

2. Species information Study area Factors influencing current populations Purpose of study Methods Progress

3. Distribution (Approximated) Koryaks.net

4. Life History Planktonic zoea – (hatch in winter – spring, 2 stages, 3-5 months) Settle as megalopae Molt through 7-9 instars Males: 5-10 years Females: 3-7 years Terminal molt to maturity Up to 7 years post terminal molt Males: 11-17 years Females: 10-13 years uwlax.edu Kruse et al. 2007

5. Shell condition Index (Not full representation) 12 34 Abdominal flap is proportionally larger in mature females

6. Mating Mating in late winter Females can store sperm in spermathaeca for later use Males can fertilize several females Young are brooded 12-15 months then released into water column FemaleMale

7. Larval Dispersal Predominantly northward flow Bering Strait to Pt. Barrow ~6 months Weingartner et al. 2005

8. Bering Sea Local recruitment Eddies Weak currents in central Southward migration? Stabeno 2001 Mean circulation of upper 40 m

9. Migration Adult females move from coastal domain towards outer domain (SW) Male migration not studied as well Koryaks.net Ernst et al. 2005

10. The forces at work Commercial fishing pressure Concentrating on southern extent of population Climate change Temperatures, ice extent, ocean currents, wind & mixing Predator prey Pacific Cod (Gadus macrocephalus) and other bottom fish Resource exploration

11. Commercial Harvest One of the largest crab fisheries in the world 2008~ 90 million dollars 1992~ 192 million Replaced dwindling Tanner (C. bairdi) stocks in 1980s rcrawford79.wordpress.com Kruse et al. 2007

13. Climate change Ice extent determines cold pool (<2  C) Cold pool trapped by stratified warm water Crabs follow cold pool Can crabs re-colonize south after a warm year? Cod predation may be too intense Orensanz et al. 2004

14. Resource Exploration Areas Alaska Annual Studies Plan. U.S. Dept. of Interior 2009

15. Purpose of Study Gain a better understanding of genetic connectivity Identify genetically distinct subpopulations if they exist Gain a better understanding of larval dispersal distances

16. Sampling Sampled Commercial fishing Planned sampling Resource development

17. Methods Based on Puebla et al. 2008 (North Atlantic) Extract DNA samples from tissue in ~ 1000 adult female C. opilio samples collected from throughout their range Amplify DNA using PCR at 8 microsatellite locations Genotype each individual Use statistical programs to analyze results and look for distinct populations Match larval crabs with upstream populations

18. Why Microsatellites? Definition: Molecular markers consisting of repeat nucleotide units at various locations within nuclear DNA Previously established for this species by Puebla et al. 2003 Shown to be informative in this species Highly polymorphic, yet not under selection pressures Deviation from Hardy-Weinberg equilibrium can be used to detect isolation of a group of individuals

19. Statistics A suite of computer programs will be used to identify genetically isolated populations F-statistics Compare pre-established groups in a framework similar to ANOVA Bayesian methods Assemble populations based on similarity of genetic signatures

20. The big picture 8 primers (Identify region for copying) Taq polymerase (Copies DNA) Crab DNA PCR (Copying of target DNA) Electrophoresis Scoring of each individual’s electropherogram Statistical analysis of genetic signatures

21. Microsatellite locations are represented by different colors

23. So how does this work?

24. 100 110 100 110 PCR Allele “A”Allele “B” Heterozygote Primer region Population “A” Population “B” Electropherogram Mating Electrophoresis

25. 100 PCR Allele “A” Homozygote Primer region Population “A” Electropherogram PCR conditions must be optimized for good amplification Mating Electrophoresis

28. Chukchi

29. Beaufort

30. Progress to date Extracted ~150 samples Tested DNA quality and found donated Bering samples to be low Multiplexed all 8 primers Trial and error of PCR conditions (various annealing temperatures and times, Taq polymerases) Initial genotyping of individuals

31. Timeline Winter 2009/10 – begin genotyping (currently underway) May 2010 – have completed genotyping and preliminary statistical analysis for 60 individuals July 2010 – Collect samples from Bering Sea on F&G trawl survey cruise February 2011 – have completed genotyping and analysis for entire sample collection September 2011 – have written and defended thesis

32. Literature Cited Ernst, B., Orensanz J. M. & Armstrong, D. A. 2005. Spatial dynamics of female snow crab (Chionoecetes opilio) in the eastern Bering Sea. Canadian Journal of Fisheries and Aquatic Science 62:250-268. Kruse, G.H., Tyler, A.V, Sainte-Marie, B., Pengilly, D. 2007. A workshop on mechanisms affecting year-class strength formation in snow crabs Chionoecetes opilio in the Eastern Bering Sea Orensanz, J., B. Ernst, D. A. Armstrong, P. Stabeno, and P. Livingston. 2004. Contraction of the geographic range of distribution of snow crab (Chionoecetes opilio) in the Eastern Bering Sea: An environmental ratchet? Pages 65-79, CalCOFI Report. Puebla, O., Parent, E. & Sevigny, J.-M. 2003. New microsatellite markers for the snow crab Chionoecetes opilio (Brachyura: Majidae). Molecular Ecology Notes. 3:644-646. Puebla, O., Sevigny, J.-M., Sainte-Marie, B., Brethes, J.-C., Burmeister, A., Dawe, E. G. and Moriyasu. M. 2008. Population genetic structure of the snow crab (Chionoecetes opilio) at the Northwest Atlantic scale. Canadian Journal of Fisheries and Aquatic Sciences 65:425-436. Stabeno, P.J., Kachel, N.B., Salo, S.A. & Schumacher, J.D. 2001. On the temporal variability of the physical environment over the south-eastern Bering Sea. Fisheries Oceanography 10(1) 81-98. Weingartner, T., Aagaard, K., Woodgate, R., Danielson, S., Yasunori, S. & Cavalieri, D. 2005. Circulation on the north central Chukchi Sea shelf. Deep-Sea Research II 52: 3150-3174.

33. Questions and Comments?