HR: 0830h
AN: H51E-03    [Abstracts]
TI: Differential Incorporation of stable carbon and nitrogen isotopes into Liver, Muscle, and Scales of California Sardine (Sardinops sagax) Fed Different Diets
AU: * Field, D
EM: David.Field@noaa.gov
AF: Southwest Fisheries Science Center, 8604 La Jolla Shore Dr., La Jolla, CA 92038-0271
AU: Vetter, R
EM: Russ.Vetter@noaa.gov
AF: Southwest Fisheries Science Center, 8604 La Jolla Shore Dr., La Jolla, CA 92038-0271
AU: Robertson, L
EM: Larry.Robertson@noaa.gov
AF: Southwest Fisheries Science Center, 8604 La Jolla Shore Dr., La Jolla, CA 92038-0271
AB: Stable isotopes offer a unique approach to examine trophic structure of many organisms. Here we quantify the isotopic response of liver, red and white muscle tissue, and scales of the California Sardine, Sardinops sagax caerulea, raised on three different food types. The ŸO13C and ŸO15N of tissues were examined at approximately one month intervals to examine the turnover response time in each tissue type. The growth rates of fish fed squid, copepods, and pellets differed. Nonetheless, isotopic signatures tended towards the composition of their food but with differential rates for each tissue type. The isotopic composition of liver varies most rapidly while that of scales is the least variant. The varying turnover times in different tissues offers the opportunity to determine feeding histories integrated over varying timescales.
DE: 1040 Isotopic composition/chemistry
DE: 4817 Food chains
DE: 4870 Stable isotopes
SC: Hydrology [H]
MN: 2005 Joint Assembly