On inconsistencies amongst the rationales offered by Sherley et al., Weller et al. and Pichegru et al. regarding the impact of fishing restrictions around islands on penguins

Inconsistencies in the arguments offered in the papers referenced are pointed out. They arise, in particular, from the flawed assumption in the first two papers that catch provides a reliable index of the abundance of a pelagic fish species. The analyses by Pichegru and colleagues are defensible in so far as they attempt to adjust for the confounding effects of catch and abundance indices on penguin breeding success; the other two papers fail to do this, rendering their conclusions flawed.