In order to clarify stock status and biological characteristics of Dissostichus spp. in Division 58.4.4 a & b, a total of 124 research hauls are allocated on 10-minute latitude x 20-minute longitude grid points (spaced approximately 10 nautical miles apart). Almost all of the research hauls are distributed between 500 and 2,000 m sea depths over each SSRU, except only 2 hauls which are distributed at shallow points of < 500 m in SSRU A in order to avoid catching small fishes. A Trot line system will be employed for 93 research hauls (three quarters of the total) in order to make an evaluation of the stock status and biological characteristics of Dissostichus spp. with the information collected by the Trot line system in the same Division in 2007/08. The applied methodology is also considered to maintain the consistency of the data from the two serial survey seasons, 2008/09 and 2009/10, and lead the efficient utilities of the data and reducing uncertainties. In 31 hauls (a quarter of total sets), the experimental gear, which consists of three segments of Trotline system and Spanish line system respectively within one fishing line, will be used in order to standardize the CPUE of Trot line more accurately in this Division. The proposed sample size is 140,000 kg for Dissostichus spp. It is calculated taking into account the need for completion of the proposed survey (124 research hauls) and impacts on the stock. Concentrated tagging, 3 fish/ton, will be made to apply the mark-and-recapture studies.
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