Monitoring Results

Blue Cod Research

Introduction

In 2005, as part of the Guardians of Fiordland Strategy for the Fiordland Marine Area, Milford and Doubtful Sounds were closed to blue cod fishing. This closure is primarily to allow the blue cod stocks in these two sounds to recover but also to assess the impact of recreational fishing on blue cod abundance.

The closure is temporary and was in place for two years initially. In 2007, the closure was extended for a further two year period, to 29 June 2009. The effects of the closure on the blue cod stocks will continue to be assessed and if necessary the closure may be extended for a further period.

Overview of Research:

To assess the effects of the closure on blue cod stocks, a three year research project has been commissioned to monitor the relative abundance in the two sounds. Research has been completed for years one and two of the closure (summer 2005-06 and summer 2006-07). Surveys will also be conducted in 2007/08.

• To record blue cod catch and fishing effort during the closure period.
• To tag blue cod caught to study movement both into and within the fiords.

Blue cod stocks, size, and numbers are monitored within the marine reserves to assess the effect that a marine reserve closure has on the abundance of the blue cod stocks.

• 2-3 experimental fishing trips per season.
• One fishing vessel with 3 fishers using the same gear and bait, and each fisher fishing for the same length of time.
• 15-20 sample sites will be fished in each sound during each fishing trip. An additional 10 -15 sites will be fished within the longstanding marine reserve in Milford Sound from 2006/07.
• All blue cod that are caught are measured and tagged before release.
• To minimise stress and the risk of injury to the fish the blue cod are not weighed.
• The lengths and numbers of all other fish caught during the survey are recorded.

Results from the survey trips

If you would like to read the full research report on the two research trips made during summer 2005-06 please click here. (39k)

The 2006/07 stage of the research project has been completed and the latest results will be available shortly.

Remember:

• If you accidentally catch a blue cod in Milford and Doubtful Sounds please carefully return the cod to the water.
• If you catch a tagged blue cod outside Milford and Doubtful Sounds please return the tag to NIWA at the address listed on the tag, detailing where the fish was caught and its length.

Come back and check the website from time-to-time to see how this research is going.

Photograph courtesy of Steve Wing, University of Otago.