Laser Ablation – Inductively Coupled Plasma – Mass Spectrometer (LA-ICP-MS) An Alternative To The Electron Microscope Introduction • Strontium otolith marking: a successful mass marking technique. • Benefit have been a hatchery component that is 100% marked. • Drawbacks, – – – – Expensive. Labor intensive. Extensive prep work. Not capable of distinct mark for each of the three lakes. Electron Microscope The Strontium Marked Otoliths ICP-MS methods • • • • • • Analyses metals GAS, Liquid, Solids Laser is sample introduction 5u to 200u line sizes 45 element at 1 – 5 ppt mdl 1 minute per sample analyses LA-ICP-MS Strontium Concentrations in Marked and Unmarked Otoliths 0.06 0.030 Sr/Ca concentration in a non spiked otolith 0.05 0.025 0.04 0.020 0.03 0.015 Sr/Ca Sr/Ca Sr/Ca concentration in a spiked otolith 0.02 0.010 0.01 0.005 0.00 0.000 0 2 4 6 8 10 12 14 16 18 20 Distance across the otolith 22 24 26 28 30 0 2 4 6 8 10 12 14 16 18 Distance across the otolith 20 22 24 26 28 0.007 Sr/Ca concentration across the otolith 0.006 0.005 0.004 Sr/Ca 0.003 0.002 0.001 0.000 0 1 2 3 4 5 6 Date 7 8 9 10 11 12 Methods • Fry will be marked with strontium, barium and manganous chlorides. • Using varied solution strengths and time duration. • Chemical analyses will be done at the UAF Probe and EM Lab. • Elemental ratio we are concerned with are Sr/Ca Ba/Ca, and Mg/Ca. Importance • Otolith chemistry techniques is being applied to anadromous fish for the purpose of fisheries management Gulkana Hatchery. Overall Conclusion • Through the application of otolith chemistry it will be possible to develop management strategies that target stocks and the conservation of their source habitat. Acknowledgements • • • • • • • • • Ken Severin Nate Bickford Ken Roberson Denny Patnode Luke Catledge Mike Dansby Douglas Dawson Jane Flygstad The students at UAF
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