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Phase angle as a new independent condition index for fish?

Phase angle as a new independent condition index for fish?. SSSC. M. Keith Cox Sitka Sound Science Center Ron Heintz Alaska NOAA Fisheries. Outline. Background BIA and phase angle Objective Experiments measuring fish condition with phase angle

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Phase angle as a new independent condition index for fish?

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  1. Phase angle as a new independent condition index for fish? SSSC M. Keith Cox Sitka Sound Science Center Ron Heintz Alaska NOAA Fisheries

  2. Outline • Background BIA and phase angle • Objective • Experiments measuring fish condition with phase angle • Temporal, spatial and proximate composition data • Summary

  3. Bioelectrical impedance analysis = used for 60 years in human health nutrition studies, when applied to fish… Total Body Water Total Body Protein

  4. Small, portable and easy to use

  5. Take two measurements • Resistance (R) • Reactance (Xc)

  6. l R =ρ (L/A) A V What is Resistance (R)? Resistance (R) (ohms) • Definition - dissipation of energy in a conductive medium • Physical property of extracellular material • Sensitive to extra-cellular water (ECW)

  7. What is Reactance (Xc)? Reactance (Xc) (ohms) • Definition - circuit element's opposition to an alternating current • Reflective of cell membrane surface area academic.brooklyn.cuny.edu

  8. What is phase angle? Phase angle – degrees • Definition - time delay between a stimulating current and the voltage generated by an alternating current in a conductive medium. • Reflective of condition • Cell membrane / ECW

  9. What is phase angle? • Lower phase angles appear to be consistent with low reactance and either cell death or a breakdown in the selective permeability of the cell membrane (Schwenk et al., 2000a; Schwenk et al., 2000b). • Higher phase angles are consistent with high reactance and large quantities of intact cell membranes and body cell mass (Abu Khaled et al., 1988; Foster and Lukaski, 1996).

  10. Phase angle in human medicine HIV – (Schwenk et al. 2000b; Paton et al. 1998) • High phase angle better health and prognosis • Low phase angle, decreasing progression and survival Chronic kidney disease (CKD) – (Nagano et al. 2000; Maggiore et al. 1996) • Lower phase angle, lower nutritional status and higher stage CKD Anorexia nervosa – (Mika et al. 2004; Nagano et al. 2000) • Phase angle increased and decreased with the nutritional status of patient • Phase angle did not increase due to edema influenced weight gains Age and sex – (Barbosa-Silva et al. 2005) • Compared healthy persons, phase angles changed with age and sex, global conditional index

  11. Objective: Is phase angle reflective of fish condition? Looked at BIA data we had: • Brook and rainbow trout – starved and fed • Juvenile Chinook salmon – starved and fed • Pacific herring – over wintering Then apply data to… Took NPRB data on forage fish, compared phase angles spatially, temporally and with proximate composition

  12. Fed and starved brook and rainbow trout

  13. Fed and starved brook and rainbow trout

  14. Fed and starved chinook and spring herring in Sitka Sound Time

  15. Fed and starved chinook and spring herring in Sitka Sound Time

  16. Is phase angle reflective of fish condition? Looked at BIA data we had: • Brook and rainbow trout – starved and fed • Juvenile Chinook salmon – starved and fed • Pacific herring – over-wintering Phase angle Better condition

  17. Is phase angle reflective of fish condition? Looked at BIA data we had: • Brook and rainbow trout – starved and fed • Juvenile Chinook salmon – starved and fed • Pacific herring – over-wintering Phase angle Worse condition

  18. Is phase angle reflective of fish condition? Looked at BIA data we had: • Brook and rainbow trout – starved and fed • Juvenile Chinook salmon – starved and fed • Pacific herring – over-wintering Common value of 15 degrees

  19. NPRB Gulf of Alaska forage fish Methods: Forage fish collected (n=481) with a beach seine in bedrock, eelgrass, and kelp habitats in July and September in PWS. Crescent gunnels (Pholis laeta), Saffron cod (Eliginus gracilis), Pacific herring (Clupea pallasii), Walleye pollock (Theragra chalcogramma)

  20. Temporal differences

  21. Pacific herring (n=130) Crescent gunnel (n=112) Saffron cod (n=145) Walleye pollock (n=94)

  22. Pacific herring (n=130) Crescent gunnel (n=112) Saffron cod (n=145) Walleye pollock (n=94)

  23. Spatial Differences

  24. Pacific herring (n=130) Crescent gunnel (n=112) Saffron cod (n=145) Walleye pollock (n=94)

  25. Pacific herring – proximate composition

  26. Walleye Pollock – proximate composition

  27. Summary • Phase angle has been used in human medicine with lower phase angles = decreased condition • Global health index • We found like results with fish in various conditions • Found a 15 degree common value • Were able to use phase angle to both temporally and spatially to see differences in condition • Comparing proximate analysis, encountered the same problem as human medicine in determining what exactly phase angle is measuring other than overall condition increases

  28. Acknowledgements • Rudy Liedtke, RJL Systems • JJ Vollenweider, NOAA Fisheries • Kyle Hartman, WVU • Scott Johnson • Heather Woody, Sitka Tribe of Alaska • Joe Margraf, University of Alaska, Fairbanks • NOAA Fisheries, Auke Bay Lab • North Pacific Research Board • Exxon Valdez Oil Spill Trustee Council

  29. Questions?

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