Are marine reserves and temporary closed areas effective in enhancing blue cod (Parapercis colias) sub-populations?

The primary aim of this study was to determine if blue cod (Parapercis colias) sub-populations demonstrate increases in abundance and size when protected from fishing. (1) Four South Island, New Zealand no-take marine reserves (MR) (Long Island Kokomohua, LIMR; Hikurangi, HMR; Ulva Island, UIMR; and Five Fingers, FFMR), and areas directly outside these MRs were surveyed using potting surveys. Abundance was higher and mean length larger inside than outside the MRs in thirteen and eleven of the fourteen surveys, respectively. Protection from fishing within three of the four MRs (LIMR, HMR, UIMR), appears to have allowed recovery of blue cod to a lesser or greater extent. (2) Three potting surveys spanned the temporary 2.5 year (2008-2011) closure of the inner Queen Charlotte and Pelorus Sounds to blue cod fishing. Blue cod abundance and mean length increased after closure for two years, and then decreased 30 months after opening as did blue cod presence. Growth alone may be sufficient to account for the observed increases in abundance and size during the closure. Protection from fishing during the temporary inner sounds closures, resulted in a dramatic recovery of blue cod followed by a return to towards pre-closure levels after re-opening.