Estimated Catch: 7810 tonnes

Stock status of target species

Source: Patterson, H, Williams, A, Woodhams, J and Curtotti, R 2019, Fishery status reports 2019, Australian Bureau of Agricultural and Resource Economics and Sciences, Canberra. CC BY 4.0.

MANAGEMENT PLANS/ARRANGEMENTS

The principal legal framework for the management of the fishery is specified in the Northern Prawn Fishery Management Plan 1995 (the Plan). The Northern Prawn Fishery is a multi-species fishery managed through input controls including limited entry, season length and individual transferable effort units – based on fishing gear size. The fishery relies on: a size and sex-based stock assessment model for brown and grooved tiger prawns; a biomass dynamic assessment model for blue endeavour prawns; and a quarterly age based biological stock assessment model for redleg banana prawns. There is currently no formal stock assessment for the white banana prawn fishery as the species is short lived and its abundance is driven by environmental factors, principally rainfall. The operational objective of the white banana prawn Harvest Strategy is to allow sufficient escapement to ensure an adequate spawning biomass of banana prawns (based on historical data), and to achieve the maximum economic yield from the fishery.

The Plan was reviewed during the period and will be subject to some changes durinc 2019-20, primarily to reflect the revised Commonwealth Harvest Strategy Policy and Bycatch Policy. Overall the Plan remains effective for the management of the fishery.

ANALYSIS OF PERFORMANCE

Performance – status of fish stocks

Tropical prawn species are very short-lived animals and their stock size is prone to wide inter-annual fluctuation with strong dependence on prevailing environmental conditions. For this reason, the assessment of prawn stock health is based on a five-year moving average of spawning stock abundance relative to a spawning stock abundance that produces maximum sustainable yield, which should not fall below the limit reference point of 50 per cent.

The last stock assessment for brown and grooved tiger prawns was completed in 2018 and determined that the stocks are not overfished and overfishing is not occurring. The assessment indicated that the five-year year moving average of spawning stocks was at 131 per cent and 135 per cent of the maximum sustainable yield respectively, meaning that neither stock is overfished.

The management objective of maximising economic yield is also assessed against an annual target reference point, which is a spawning stock size equal to that which is estimated to produce maximum economic yield. Both brown and grooved tiger prawn spawning stocks were assessed as being below target in the 2018 assessment at 75 per cent and 63 per cent, respectively.

An additional in-season catch-rate trigger for pursuing maximum economic yield is also used in the fishery. The catch rate was below the trigger during the reporting period and the tiger prawn season closed early on 20 November.

All 52 boat statutory fishing rights were utilised during the 2018 tiger prawn season.

As with the tiger prawn fishery, all 52 boat statutory fishing rights were utilised during the 2019 banana prawn season (1 April to 15 June 2019). Total catch in the 2019 banana prawn fishery was higher than in 2018, increasing from 4400 tonnes to 5450 tonnes. This level of catch is above average and the season started with some of the highest catch rates on record. Changes in environmental conditions, such as rainfall, normally cause fluctuations in year-to-year stock size (and therefore catch) in this short-lived, tropical prawn species.

During 2018, fishing catch and effort in the redleg banana prawn fishery was lower than in 2017 but much higher than the relatively low effort of 79 and 76 boat days for 2015 and 2016 respectively. The total catch in 2018 was 248 tonnes across 213 boat days compared to 365 tonnes across 548 boat days in 2017. The latest catch per unit effort data suggests a reversal of the declining trend in spawning biomass that was predicted for the period 2012 to 2016. The 2018 stock size is estimated to be well above the limit reference point and slightly below the target level, although there is uncertainty with this prediction. The harvest strategy is being reviewed to explore options that allow catch and effort levels to be progressively adjusted to levels that achieve maximum economic yield.

Performance – status of bycatch

There has been great progress under the Northern Prawn Fishery Bycatch Strategy 2015-18 with trials achieving up to 40 per cent reduction in bycatch compared to the standard device (the square mesh panel) previously used in the fishery. The newest device known as ‘Tom's Fisheye' creates an area of low pressure in the trawl net as it is pulled through the water, increasing access to a gap in the net for fish to escape. There will be a choice for Northern Prawn Fishery trawl boat operators to use one of four more effective devices from 2020, following further commercial testing in the fishery during this year's tiger prawn season. The Northern Prawn Fishery fishers, led by the Northern Prawn Fishery Industry Pty Ltd, continue to demonstrate commitment to reducing bycatch through design and trial of new equipment and technology. It is important that fishers can use an effective device that will suit different operating conditions.

An updated Bycatch Strategy is under development for the Northern Prawn Fishery and will be published during 2019-20. The new strategy will continue to build on previous achievements with bycatch reduction and respond to updated guidance from the Commonwealth Fisheries Bycatch Policy (2018).

Performance – economic returns

During the most recent financial year (2017-18) the Northern Prawn Fishery gross value of production was $98.15 million and the Northern Prawn Fishery was the highest valued Commonwealth managed fishery.

The fishery is broadly (across the two key species groups – banana and tiger prawns) managed to pursue maximum economic yield. Overall fishing effort limits (fishing gear and season lengths) are set on the result of outputs from the bio-economic model for tiger and endeavour prawns. Additionally, season length is further controlled through catch-rate triggers in the banana and tiger prawn sub-fisheries to account for annual variability in these stocks. Recent assessments of economic performance by the Australian Bureau of Agricultural and Resource Economics and Sciences indicates that the level of fishing effort in the fishery is close to maximum economic yield targets. However, the finding that both tiger prawn species are slightly below the economic target reference points, and the early closure of the 2018 tiger prawn season based on lower catch rates suggest that additional attention is required to ensure that the fishery does continue to meet the economic goals that have been set in conjunction with industry.

Net economic returns are positive reaching a peak of $30.9m in 2015-16. The performance in 2016-17 remained stable at $30.3 million and in 2017-18, lower gross value of production and higher unit fuel prices are expected to have a dampening effect on net economic returns.

INNOVATIONS

The Northern Prawn Fishery industry works closely with us and cooperates through co-management arrangements to assist with a range of key management functions. For example, the industry manages the collection and provision of catch and effort information, the quality control of the information and its dissemination to all users.

As part of these co-management arrangements, the industry undertakes additional crew-based observations of interactions with protected species and provides these records directly to the Commonwealth Scientific and Industrial Research Organisation for analysis as part of a project ‘monitoring interactions with bycatch species using crew-member observer data collected in the Northern Prawn Fishery: 2017-19'. The industry also assists in facilitating the supply of a trawl vessel and crew for Commonwealth Scientific and Industrial Research Organisation scientists to undertake the annual, independent scientific monitoring program. The data collected in this program is an integral part of the Northern Prawn Fishery stock assessment.

These co-management measures add value to the management of the fishery and are cost effective for industry and AFMA. They increase stewardship outcomes in the fishery and provide valuable information which will enhance future management decisions.

In February 2019 the NPF Industry Pty Ltd together with AFMA facilitated a strategic planning workshop to guide the development of a new five year strategic research plan. The workshop had strong participation with numerous skippers, fishing business owners, scientists and fishery managers supporting discussions. Key recommendations included improving understanding of sawfish interactions and population dynamics, maintaining strong economic performance and continuing effective research and data collection to ensure sustainability and address emerging issues.

EXTERNAL REVIEWS

The Northern Prawn Fishery was re-accredited under Part 13 and species included in the Northern Prawn Fishery Management Plan were added to the List of Exempt Native Specimens under Part 13A of the Environment Protection and Biodiversity Conservation Act 1999. The re-approval applies for a further five years from December 2018.

The fishery is also certified as a sustainable fishery by the Marine Stewardship Council, which is an independent global certifier of sustainable fisheries. In January 2018, the fishery was granted recertification after an independent assessment, reaffirming the industry's commitment to the world's best standard on sustainability and management.

EMERGING ISSUES

Throughout 2018-19, heavy new investment into prawn aquaculture, as well as loss of domesticated aquaculture stock through the prawn white spot virus outbreak in Queensland saw increased interest in the Northern Prawn Fishery as a source of black tiger prawn (P. monodon) as aquaculture broodstock. This has been managed in the past through additional permits issued to trawlers to specifically target black tiger prawns outside of the main fishing seasons of the fishery.

The increased demand (and indications of greater needs in the future) present several management challenges for AFMA and the fishery. The minor role that black tiger prawns have played on the fishery in the past has led to a generally poor understanding of the stock status and the key drivers of that status. We have initiated a project to use available information to determine the likely sustainable harvest levels of black tiger prawns.

Detailed stakeholder consultation, innovation and commercial relationships will also be essential in order to find the right balance between the needs of the aquaculture industry and the existing management arrangements and statutory fishing rights in the Northern Prawn Fishery.