Communique 22-23 May 2018

The spanner crab fishery workshop was held in Mooloolaba on 22-23 May 2018. The purpose of the workshop was to review the decision rules, associated data and input controls in the fishery to inform the development of a harvest strategy. The workshop was independently facilitated by Dr Cathy Dichmont.

Fisheries Queensland provided an update on the Sustainable Fisheries Strategy and Harvest Strategy Policy in Queensland. The workshop noted that the total allowable catch (TAC) for the 2018/19 year has been set and it will not be reviewed at this workshop.

Working group members noted a presentation on the status of the spanner crab fishery, which included an overview of the factors that may influence spanner crab recruitment, catchability and stock abundance. Along the East Australian coastline spanner crabs comprise a single genetic stock (including New South Wales). Despite being a single stock, the workshop noted that localised depletion may be an issue for some regions of the fishery such as Bundaberg which was one of the primary producing areas, but no longer sustains significant catches. The workshop also discussed known and unknown biological characteristics for spanner crabs (spawning periods, planktonic phase, sizes at maturity and age structure). While it is very difficult to define growth rates or age spanner crabs, the workshop agreed that spanner crabs are considered to be longer lived and slower growing than other crab species. The complex biology of spanner crabs is a significant consideration for developing appropriate management responses and improving stock resilience.

The workshop discussed several environmental variables that may influence spanner crab catchability and abundance including: salinity, currents, rainfall, flood events/siltation and sea temperature. The need to better understand how the environment (i.e. currents and eddies) effects spanner crabs movement among regions was noted as important for identifying possible source or sink populations.

The workshop spent considerable time reviewing the two fishery indicators/indices; catch per unit effort (CPUE) (kg/boat-day) and the fishery independent survey (FIS) (numbers of crab/ground line). The two indices have been showing diverging trends since 2010 and the workshop debated whether they continue to reflect spanner crab abundance. The workshop felt the FIS was important monitoring tool and should be undertaken annually as an indicator of spanner stock health, noting it reflects a narrow window of the fishery (less than 1% of annual pot lifts) and its confidence to reflect abundance was uncertain. The workshop agreed that the harvest strategy should continue to use both indices with improved rules to inform management action when they are in conflict. Industry members advised that they would be happy to explore options for additional surveys to improve certainty of the FIS.

Draft fisheries objectives were developed by the workshop incorporating a triple bottom line approach (ecological, social and economic) based on vision statements provided by industry ahead of the workshop.

The workshop considered the maximum number of dillies (currently 120 through General Fisheries Permits GFPs) used in the fishery. The workshop did not reach consensus, with the majority view at 75 dillies with alternative views of 90 or 45 dillies. Issues discussed included the following:

  • That the fishery has changed, with larger operators now relying on a higher numbers of dillies to remain economically viable. Some fishers advised that a max of 75 dillies would be unviable and felt the difference between 75 and 90 dillies would not have a significant impact on the fishery;
  • Whether the extra dillies have contributed to the current low stock status, noting that there is uncertainty in this assumption because the effect of additional dillies on crab stocks have not been assessed and that the quota had not acted to constrain the catch previously;
  • There is range of operators using different dilly / crew number combinations and that this needs to be standardised across the fishery. Additional crew members are required to operate more than 45 dillies to minimise handling impacts (e.g. discard mortality) and soak times (e.g. predation); and
  • Some participants of the workshop felt that information to independently validate the ability of operators to handle 90 dillies appropriately would be useful;

The feedback will be considered by Fisheries Queensland to develop a policy position to inform upcoming decisions on GFP applications for the period 1 July 2018 to 31 December 2019. Formal arrangements will provide consistency in the longer-term, as part of the legislative work scheduled for 2019.

The workshop recommended that the spawning closure be revised to the period of 1 November – 15 December. This recommendation would provide the spawning stock in the northern part of the fishery an additional 15 days of protection during the peak spawning period and allow operators better access to the important Christmas market. No change to mesh size and dilly dimension limits were recommended, but there was a view that the size of boats could be increased to 25 metres consistent with other quota managed fisheries to allow innovation with live tanks and marketing opportunities into the future. The workshop noted the history of the management areas and recommended no change.

The workshop reviewed the decision rules and agreed that in principle the current structure was sound, however, a number of shortcomings need addressing, including;

  • To ensure that a review of the decision rules is undertaken or a third indicator be developed (e.g. number of undersize crabs) to inform quota decisions when the primary indicators diverge.
  • Update the current FIS and CPUE indices to improve consistency.
  • Maintain the TAC setting every two years with a review of fishery performance annually and the option to make a decision to change to the TAC if necessary.

The workshop agreed that there is currently not enough certainty in adopting a model based approach to inform routine decision making, but that a stock model may be able to inform sustainable upper and lower limits for the fishery. Given this it was recommended that in the medium term the current empirical approach be used and that alternative harvest strategy frameworks be considered during the Management Strategy Evaluation (MSE) of the new decision rules.

The workshop reviewed data and agreed that the FIS and CPUE target reference points were too low, as they reflected low periods of the fishery, and should instead reflect an aspirational level of catch from when the fishery was in a healthy state. The workshop recommended a FIS target reference point between 16-18 (from 14) and a CPUE target reference point between 1.2-1.3 (from 1.034). The workshop recommended a minimum change buffer of 50 tonnes and maximum change of 200 tonnes, along with revising the upper TAC limit so that it maintains catch within sustainable limits, noting the MSE will inform this.

Throughout the workshop monitoring and research needs were identified. Noting resource constraints, the workshop prioritised the short, medium and long-term priorities for the fishery, with a focus on the data review and MSE testing to support harvest strategy development. A further workshop session is planned for November 2018 to review a draft harvest strategy ahead of public consultation during December 2018. The aim is to finalise the harvest strategy ahead of the 2019/20 season.

The Spanner Crab Workshop participants were: Independent Chair- Cathy Dichmont, commercial participants (Mal Starky, Richard Hamilton, Richard Swanson, Shane Underhill, Andrew Mclean, Richard Freeman, Les Apps, Mark Cook, Vanessa Hughes), conservation (Adrian Gutteridge), independent scientists (Rik Buckworth, Ian Brown, Jim Prescott), Animal Science Queensland (Michael O’Neill), QBFP (Russell Overton) and Fisheries Queensland (Mark Doohan, Kimberly Foster, Sian Breen, Sam Williams, Jason McGilvray). Apologies: NSW Fisheries (Dale Gollan), ASQ (Matthew Campbell)