Inferring marine distribution of Canadian and Irish Atlantic salmon (Salmo salar L.) in the North Atlantic from tissue concentrations of bio-accumulated Caesium 137

This is a pre-copy-editing, author-produced PDF of an article accepted for publication in ICES Journal of Marine Science following peer review. The definitive publisher-authenticated version “Spares A.D., Reader J.M., Stokesbury M.J.W., McDermott T., Zikovsky L., Avery T.S., Dadswell M.J. Inferring marine distribution of Canadian and Irish Atlantic salmon (Salmo salar L.) in the North Atlantic from tissue concentrations of bio-accumulated caesium 137. (2007) ICES Journal of Marine Science, 64 (2), pp. 394–404” is available online at: http://icesjms.oxfordjournals.org/content/64/2/394peer-reviewedAtlantic salmon returning from marine migrations to eastern Canada and western Ireland during 2002 and 2003 were analysed for tissue concentrations of bio-accumulated caesium 137 (137Cs). Salmon from Canadian and Irish waters demonstrated concentrations (0.20 ± 0.14 Bq kg-1 and 0.19 ± 0.09 Bq kg-1, mean ± s.d., respectively) suggesting similar oceanic feeding distributions during migration. Canadian aquaculture escapees had a similar mean tissue concentration (0.28 ± 0.22 Bq kg-1), suggesting migration with wild salmon. However, significantly higher concentrations in 1-sea-winter (1SW) escapees (0.43 ± 0.25 Bq kg-1) may alternatively suggest feeding within local estuaries. High concentrations in some Canadian 1SW salmon indicated trans-Atlantic migration. Low concentrations of Canadian multi-sea-winter (MSW) salmon suggested a feeding distribution in the Labrador and Irminger Seas before homeward migration, because those regions have the lowest surface water 137Cs levels. Estimates of wild Canadian and Irish salmon feeding east of the Faroes (~8oW) were 14.2% and 10.0% (1SW, 24.7% and 11.5%; MSW, 2.9% and 0.0%), respectively. We propose that most anadromous North Atlantic salmon utilize the North Atlantic Gyre for marine migration and should be classified as a single trans-Atlantic straddling stock

Trace analysis with protons [i.e. proton] and heavy ion activation

Vita.The capabilities of 12 MeV proton activation were compared with those of reactor neutron and 35 MeV photon activation. A series of biological specimens (plant and animal tissues) were chosen for this study limited to nondestructive assays. Based on y-ray spectrometry, As, Ca, Cu, Fe, Mo, Pt, Sr, Ti, Zn and Zr at levels ranging from 2 to 20,900 ppm were detected following proton activation of 1 hour. Al, Br, Ca, Cl, Cu. Mg, Mn, Rb and V. ranging from 0.4 to 20,900 ppm, were measured by neutron activation (1 min. irradiation). As, Ba, Br, Cr, Co, Fe, Hg, La, Na, Rb, Sb and Zn, .ranging from 0.2 to 2400 ppm, were determined following a 14 hour neutron irradiation. Photon activation data was obtained by computer simulation of y-ray spectra, based on published radioisotope production yields. Assuming a 4 hour irradiation, As, Ba, Br, Ca, Cl, Fe, I, Mg, Mn, Na, Pb, Rb, Sb, Sr could be detected at concentration levels ranging from 3 to 20,900 ppm. Although covering different elements, the three techniques are comparable in their scope, i.e. detection limits that can be achieved and number of elements that can be detected simultaneously. In terms of determining known essential elements, detection limits below the average concentrations of such elements in the human body were obtained for Co, Fe, Zn with neutron activation, for Cu, Fe, Zn with proton activation and for Fe, I, Zn with photon activation.