Implementation of a Fishery Independent Survey for the Southern and Eastern Scalefish and Shark Fishery

A review of fishery independent survey methods suitable for a multi-species fishery. Development of a model-based fishery survey design and the success of its implementation.

  1. Review the current fishery independent surveys that are operating in the SESSF and determine their efficacy and potential for use in a multi-species survey.  Determine which survey methods are most suitable for the main species in the SESSF.
  2. Design a suite of cost-efficient fishery independent surveys that will meet the needs of the fishery in providing indices of abundance for most major species in the SESSF.  Determine the most practical way of undertaking the surveys and gain broad stakeholder acceptance of the survey design.
  3. Determine the cost structure for the surveys and how funding and research quota will be allocated.
  4. Undertake a full one-year trial of the survey design.  Review the results of the survey with respect to cost-efficiency, practicality and provision of high quality (precise) indices of abundance and modify the design accordingly.
  5. Implement a long-term (5 – 10 year) survey program that can be progressively funded by industry under standard AFMA CRIS (Cost Recovery Impact Statement) Policy.

In line with the objectives of the project, the following outcomes have been achieved:

Objective 1
A review of the main options for a design of the survey was conducted.  The pros and cons of conducting standard randomized stratified surveys were compared with a model-based survey design; with the latter proving more suitable because it is more logistically flexible and gives abundance estimates with low bias and efficient CVs that make full use of the data.

Objective 2
The major outcome of this project has been the design and implementation of a broad, multi-species fishery independent survey that provides relative abundance indices for major quota and major non-quota species in the Southern and Eastern Scalefish and Shark Fishery (SESSF).  Analysis of the 2010 survey results revealed that conducting just a winter survey would provide reasonable (<30%) CVs for 15 species which account for 87% of the catch weight of the GHaT and CTS sectors and 83% of the catch value.

Objective 3
Prior to the 2008 trial survey, considerable work was done to determine the most cost effective survey design that would deliver reasonable CVs for as many major quota and non-quota species as possible.  Following the 2010 survey the issue of survey structure and funding was revisited. The survey definitely requires three industry vessels operating in the main areas of the fishery (NSW, east and west) to complete the survey within a month.   Vessel charter is the main cost of the survey, accounting for about 70% of total project costs.  Fish sales from the survey offset charter costs by 30 – 40 %.  Analysis of CVs indicated that almost the same abundance index outcomes could be achieved by just conducting a winter survey, rather than running both a summer and winter survey. This produces an overall saving of about 44%. 

During 2008 and 2010, the project operated with two methods of allocating research catch allowance (quota assigned to cover the survey catch).  A post-survey allocation which was then subtracted from the subsequent year’s quota allocation was the most practical and easy to manage.  A pre-survey prediction of research catch allowance was easily made, but variations from this figure were extremely difficult to manage: with under-prediction causing quota availability and reconciliation issues; and over-prediction viewed as a waste of industry’s quota allocation.

Objective 4
A successful trial of the survey design was conducted during 2008.  Only minor modifications were required for the 2010 survey. These included addressing: a lack of shallow sites sampled in the western region; clustering of sampling sites in shallow water in the NSW and eastern regions; and the use of a ‘heavier’ net in the western region that may have different selective properties to the other nets.  Otherwise, the cost-effectiveness, practical implementation and provision of CVs were considered acceptable for ongoing surveys.

Objective 5
Importantly, the fishery independent survey has received strong support from industry, scientists and managers.  As evidence of this, the South East Trawl Fishing Industry Association (SETFIA) took over as the project administrators to undertake the 2012 survey with funding directly from the Australian Fisheries Management Authority, largely cost-recovered from industry in line with the CRIS.  During 2012, the SESSF Resource Assessment Group highlighted continuation of the time series of fishery independent surveys as one of the highest research needs for the fishery.  A decision on the frequency and components of subsequent surveys will be made during 2013 dependent on species CV requirements and budget constraints.   Based on three years of independent surveys, data can be used as an independent index of abundance in stock assessments.