On the power to detect changes using the standard methods for monitoring parameters of predatory species
The CCAMLR guidelines (CCAMLR, 1989) for analyzing the statistical power to detect changes are applied using variance estimates from studies at the South Shetland Islands of lengths of first incubation shifts by penguins(Standard Method A2.1), duration of penguin foraging trips (A5.1), penguin breeding success (A6.1), penguin chick diet (A8.1), and fur seal foraging trip duration (C2.0). The other Standard Methods are not evaluated because the power analysis in the CCAMLR guidelines is inappropriate (fur seal pup growth rate C1.0), and/or because data from the studies considered here are insufficient for conducting power analyses (penguin arrival weight A1.1, trend in penguin population size A3.1, penguin demography A4.1, penguin fledging weight A7.1). Alternative forms for analyses of the power of Standard Methods A3.1, A5.1, C1.0, and C2.0 are proposed.