Catchability of trawl surveys
Project: Catchability of trawl surveys
Project Code: SAM2004/03
Start Date: 1 October 2004
Completion Date: 30 September 2005
Overall Objectives:
-
To develop techniques to improve stock assessments of harvested fish stocks.
Specific Objectives:
-
To review experimental methods for determining the catchability and selectivity of trawl surveys.
Rationale:
General
Random stratified trawl surveys are a standard technique for determining relative abundance indices for many inshore and middle depth fish species in New Zealand. Time series of abundance indices have been derived for hoki and associated middle depth species on the Chatham Rise and Sub-Antarctic, However, the catchability and selectivity of the trawl gear for each species are unknown. They are currently estimated within stock assessment models, but are poorly determined; better a priori knowledge of catchability and selectivity would improve the accuracy of stock assessments. The objective of this project is to review the relevant research conducted around the world in order to evaluate the cost effectiveness and likely accuracy of further experimental work in New Zealand
Strategic Relevance
All the objectives in this project are consistent with the Fisheries Resources goal in the Ministry of Fisheries Strategic Research Directions document.
Cost Recovery Information:
The percentage allocation for this project will be attributed to the following Fishstocks according to rule 9.2 of the Fisheries (Cost Recovery) Rules 2001:
-
All these deepwater stocks: CDL, OEO, ORH, RIB
-
All these middle depth stocks: BAR, FRO, GSH, GSP, HAK, HOK, LIN, SBW, SKI, SWA, WAR, WWA
-
All these inshore stocks: BCO, BNS, BUT, BYX, ELE, FLA, GAR, GMU, GUR, HPB, JDO, MOK, RBY, RCO, SCH, SKA, SPD, SPE, SPO, SPR, STA, TAR, TRU, YEM
The project is estimated to cost between $0 – $50,000.