Changes in population parameters and behaviour of blue cod (Parapercis colias; Pinguipedidae) in Long Island—Kokomohua Marine Reserve, Marlborough Sounds, New Zealand

Published source details Davidson R.J. (2001) Changes in population parameters and behaviour of blue cod (Parapercis colias; Pinguipedidae) in Long Island—Kokomohua Marine Reserve, Marlborough Sounds, New Zealand. Aquatic Living Resources, 11, 417-435.
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This study is summarised as evidence for the following.

	Action	Category
	Cease or prohibit all types of fishing in a marine protected area Action Link

Cease or prohibit all types of fishing in a marine protected area

A before-and-after, site comparison study in 1992–2001 of an area of shallow rocky reef in the Tasman Sea, New Zealand (Davidson 2001) found that the average density, size and catch abundance of blue cod Parapercis colias increased inside a marine reserve in the eight years after all fishing was prohibited, compared to before and recreationally fished areas outside. Cod density was higher inside the unfished reserve than outside from two years after closure (1995) compared to before (1995, inside: 3.2, outside: 1.9 fish/60 m²; 2001, inside: 6.5, outside: 2.9 fish/60 m²). Across all years following closure (1993–2000), average length of blue cod was higher in the unfished reserve than fished areas (data reported as statistical model results), and increased over time inside the reserve (2000: 265 mm, 1993: 228 mm) while outside lengths decreased (2000: 71 mm, 1993: 154 mm). Over the same period, experimental catch rates were higher and increased over time inside the reserve compared to outside (data reported as statistical model results). Long Island-Kokomohua Marine Reserve (619 ha) in the Cook Strait was designated as no-take (no-fishing) in April 1993. Blue cod numbers were surveyed annually from March 1992 to April 2001 by underwater visual transects (2 × 2 × 30 m), inside (four/five sites) and outside (four sites) the reserve. Size and catch rates were monitored from September 1993 to April 2000 at three sites inside and six outside the reserve using experimental baited hook and line fishing.

(Summarised by: Leo Clarke)