Table 4.

Exponential decay equations and half-lives representing stable isotope turnover in epidermis sampled from rehabilitated Florida manatees

R2 range
Carbon turnoverAnimal IDEquationR2Half-life (days)δ13C at day 0 (‰)Min.Max.
Coastal manatees0301y=–24.4+14.2e–0.01094x1.0063–10.21.001.00
0318y=–24.8+15.1e–0.01158x0.9760–9.70.960.97
0322y=–24.5+14.3e–0.01550x0.8345–10.20.790.84
0431y=–24.1+11.6e–0.01657x 0.97 42– 12.50.970.97
Mean53–10.7
Riverine manatees0334y=–24.6+8.2e–0.00963x0.9572–16.40.900.96
0340y=–24.7+0.9e–0.01787x0.3639–23.80.050.51
0341y=–23.8+1.9e–20920x0.50n.d.–21.90.430.51
0501y=–24.5+6.2e–0.01028x 0.70 67– 18.30.590.75
Mean59–20.1
R2 range
Nitrogen turnoverAnimal IDEquation R 2 Half-life (days)δ15N at day 0 (‰)Min.Max.
Coastal manatees0301y=2.3+3.4e–0.01918x0.96365.70.831.00
0318y=2.4+2.4e–0.02125x0.57334.80.460.62
0322y=2.3+3.6e–0.04898x0.56145.90.290.68
0431y=2.5+4.7e–0.03038x 0.97 23 7.20.910.97
Mean275.9
Riverine manatees0334y=2.6+4.9e–0.00601x1.001157.50.981.00
0340y=2.7+6.4e–0.02055x0.92349.10.900.92
0341y=2.3+5.9e–0.01125x0.85628.20.800.87
0501y=2.0+9.4e–0.03273x 0.95 21 11.40.920.97
Mean589.1
  • n.d., not determined (see text)