Lanthanide metals as shark repellants

Transcription

1 Lanthanide metals as shark repellants Stephen M. Kajiura 1 & John W. Mandelman 2 1 Biological Sciences, Florida Atlantic University 2 Edgerton Research Laboratory, New England Aquarium

2 Longline bycatch

3 Electroreceptors

4 Electroreception; preysimulating electric field

5 Electroreception; preysimulating electric field

6 1 H He 3 Li Be 5 B C N O F Ne 11 Na Mg 13 Al 14 Si 15 P S Cl Ar 19 K Ca Sc 22 Ti 23 V Cr Mn 26 Fe 27 Co 28 Ni 29 Cu 30 Zn Ga Ge 33 As Se Br Kr Rb Sr Y 40 Zr Nb Mo 43 Tc 44 Ru 45 Rh 46 Pd 47 Ag 48 Cd In Sn 51 Sb 52 Te I Xe Cs Ba La* 72 Hf 73 Ta 74 W Re 76 Os 77 Ir 78 Pt 79 Au Hg 81 Tl 82 Pb 83 Bi 84 Po At 86 Rn Fr Ra Ac~ 104 Rf 105 Db 106 Sg 107 Bh 108 Hs 109 Mt Lanthanides * 58 Ce 59 Pr 60 Nd 61 Pm 62 Sm 63 Eu 64 Gd 65 Tb 66 Dy 67 Ho 68 Er 69 Tm 70 Yb 71 Lu Actinides ~ 90 Th 91 Pa 92 U Np 94 Pu 95 Am 96 Cm 97 Bk 98 Cf 99 Es 100 Fm 101 Md 102 No 103 Lr Periodic Table

7 1 H He 3 Li Be 5 B C N O F Ne 11 Na Mg 13 Al 14 Si 15 P S Cl Ar 19 K Ca Sc 22 Ti 23 V Cr Mn 26 Fe 27 Co 28 Ni 29 Cu 30 Zn Ga Ge 33 As Se Br Kr Rb Sr Y 40 Zr Nb Mo 43 Tc 44 Ru 45 Rh 46 Pd 47 Ag 48 Cd In Sn 51 Sb 52 Te I Xe Cs Ba La* 72 Hf 73 Ta 74 W Re 76 Os 77 Ir 78 Pt 79 Au Hg 81 Tl 82 Pb 83 Bi 84 Po At 86 Rn Fr Ra Ac~ 104 Rf 105 Db 106 Sg 107 Bh 108 Hs 109 Mt Lanthanides * 58 Ce 59 Pr 60 Nd 61 Pm 62 Sm 63 Eu 64 Gd 65 Tb 66 Dy 67 Ho 68 Er 69 Tm 70 Yb 71 Lu Actinides ~ 90 Th 91 Pa 92 U Np 94 Pu 95 Am 96 Cm 97 Bk 98 Cf 99 Es 100 Fm 101 Md 102 No 103 Lr Periodic Table high low electronegativity

8 Previous studies Study Metal Lab Field Species Stoner & Kaimmer, 2008 CeLa Misch 70% reduction Spiny dogfish Pacific Kaimmer & Stoner, 2008 Tallack & Mandelman, 2008 Brill et al., 2009 CeLa Misch 19% reduction on protected longline hooks CeLa Misch NdPr Metal Alloy Some avoidance, but only for satiated fish Avoid metal when no food present 510% fewer on protected hooks (Not Significant) Significant deterrent for sharks, not rays Spiny dogfish Pacific Spiny dogfish Atlantic Juvenile sandbar sharks

9 Proposed research Treatment metals: Controls: Cerium (Ce) Praseodymium (Pr) Neodymium (Nd) CeLa misch metal PrNd misch metal PrNd metal alloy Lead (Pb) Stainless Steel Acrylic 1 Measure efields of various metals 2 Neurophysiology of various species 3 Behavioral tank trials 4 Scientific fishing field trials 5 Commercial longline trials

10 Measuring electric fields

11 Measure electric field at various distances Output (uv/gram) Nd Pr PrNd Pb Distance (cm)

12 Compare electric output of various metals Output (uv/gram) Ce Nd Pr PrNdM Pb SS

13 Compare electric output at various salinities Nd Pr PrNd Output (uv/gram) Salinity (ppt)

14 50 Measure dissolution rate of various metals 45 Mass (grams) Nd Pr PrNd Pb Time (hours)

15 Determine which metals provide greatest potential Treatment metals: Cerium (Ce) Praseodymium (Pr) Neodymium (Nd) CeLa misch metal PrNd misch metal PrNd metal alloy Consider: Electrical output (volts/gram) Dissolution rate Machinability Price

16 SS Pb Nd 1m 20cm Ac 1m

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18 40 Individuals Preliminary data Percent bites Ac SS Nd Ac SS Nd Pb Mustelus canis Sphyrna tiburo Squalus acanthias and Negaprion brevirostris still pending

19 45 Groups Preliminary data Percent bites Ac SS Nd Ac SS Nd Pb Squalus acanthias Sphyrna tiburo Mustelus canis and Negaprion brevirostris still pending

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21 Pending research Scientific longline fishing n=20 sets completed metal redesigned to minimize interference restart fishing in spring 2011 Commercial longline application awaiting results of scientific longlining Neurophysiology technical hurdles overcome data collection will begin in Nov

22 Acknowledgements Christine Bedore Lindsay Harris Laura Jordan Sara McCutcheon Jack Morris Mark Royer Mote Marine Laboratory Marine Biological Laboratory Gumbo Limbo Environmental Complex National Marine Fisheries Service Bycatch Consortium

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