The 27th Chatham Rise trawl survey on the RV Tangaroa (TAN2201) was successfully completed for Fisheries New Zealand in January 2022.
The RV Tangaroa had a couple of extra passengers on board for the biennial Chatham Rise fish survey. Georgia Third studies snapper at the University of Auckland and Tim Currie is at the University of Otago studying sand flounder. On the Tangaroa Georgia and Tim followed the NIWA scientists’ lead and worked through the fish catches to provide information for the survey.
Fisheries scientist and voyage leader Darren Stevens explains: “The main aim of the survey was to provide abundance estimates for adult and juvenile hoki but it also provided abundance estimates for a variety of other important commercial and non-commercial species. With a current annual catch limit of 110 000 t, hoki is New Zealand’s largest finfish fishery.”
The trawl survey was being carried out under contract to Fisheries New Zealand and results are an important input into the stock assessment process used to set commercial catch quotas. During the survey fish were caught and analysed from depths of 200 to 1300 m. The catch from each trawl was sorted into species and weighed. A random sample of each species was also measured and sexed. Georgia and Tim were immersed in the measuring and counting. They are both passionate about the marine environment, adjusted well to being on the Tangaroa and enjoyed life onboard.
A total of 135 trawls were completed, including 6 “phase 2” trawls – a process where extra effort is put into some areas where catches are more variable than expected.
“We also looked into the diet of hoki, hake and ling. Ling eat a wide variety of fish and invertebrates including plenty of squat lobsters (Munida gracilis) but it seems they also have quite expensive tastes with one individual eating several scampi”, says Darren.
The voyage in numbers:
- 27th survey of fish abundance on the Chatham Rise from RV Tangaroa
- 15 scientists
- 20 vessel crew
- 30 days at sea
- 135 trawls completed
- Trawls in depths of 200-1300m
- Only 3 hours lost to bad weather
- 350 different species caught, including a giant squid and a baby ghost shark!
- 79,000 fish and invertebrates measured
The voyage in the media
Listen to the interview Blake Ambassador Georgia Third did on NewstalkZB.
Map
Below is a map showing the course of RV Tangaroa taken during the TAN2201 voyage 4-23 Jan 2022.
Select anywhere on the red track to see position details and time as well as other vessel information. N.B. Dates and times are in UTC. New Zealand Standard Time (NZST) is 12 hours ahead of Coordinated Universal Time (UTC). Click on the ship icons for points of interest during the voyage.
This survey is carried out every two years for Fisheries New Zealand and provides abundance estimates and biological information for a variety of important commercial and non-commercial species, in particular hoki. Results from the survey are an important input into the stock assessment process used to set commercial catch quotas.
