Description Usage Arguments Details Value Author(s) References Examples

Estimates of population abundance from Schnabel (1938) and Schumacher and Eschmeyer (1943) are calculated from repeated mark-recapture experiments following Krebs (1989).

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`catch` |
A vector containing the number of animal caught in each mark-recapture experiment. |

`recaps` |
A vector containing the number of animal recaptured in each mark-recapture experiment. |

`newmarks` |
A vector containing the newly marked animals in each mark-recapture experiment. |

`alpha` |
the alpha level for confidence intervals. Default = 0.05 |

All computations follow Krebs (1989: p. 30-34). For the Schnabel method, the poisson distribution is used to set confidence intervals if the sum of all recaptures is <50,and the t distribution is used if the sum of all recaptures is >=50. For the Schumacher-Eschmeyer method, the t distribution is used to set confidence intervals.

Dataframe containing the population estimates for the Schnabel and Schumacher & Eschmeyer methods (N), the inverse standard errors (invSE), lower (LCI) and upper (UCI) confidence intervals, and the type of distribution used to set confidence intervals (CI Distribution).

Gary A. Nelson, Massachusetts Division of Marine Fisheries [email protected]

Krebs, C. J. 1989. *Ecological Methodologies*. Harper and Row, New York, NY. 654 p.

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```
Loading required package: MASS
Loading required package: boot
Loading required package: bootstrap
Loading required package: lme4
Loading required package: Matrix
Loading required package: numDeriv
N invSE LCI UCI CI_Distribution
Schnabel 447.5000 0.0004561433 335.6250 671.2500 Poisson
Schumacher-Eschmeyer 422.9712 0.0004465280 316.4489 637.5983 t
```

fishmethods documentation built on Nov. 21, 2018, 1:04 a.m.

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