Chapter 17: Torres Strait Tropical Rock Lobster Fishery
A Williams, T Emery and K Mazur
TABLE 17.1 Status of the Torres Strait Tropical Rock Lobster Fishery
| Biological status || Fishing mortality|| Biomass||Fishing mortality||Biomass|| |
|Tropical rock lobster (Panulirus ornatus)||Not subject to overfishing||Not overfished||Not subject to overfishing||Not overfished||Current catches equate to fishing mortality rates below the target and limit|
reference points. Spawning stock biomass is above the target level.
Economic status||NER movement in 2016–17 remain uncertain. A decrease in effort in the fishery in 2016–17 suggests a reduction in fishing costs, but this occurred with a fall in gross value of production.|
NER Net economic returns.
17.1 Description of the fishery
The Torres Strait Tropical Rock Lobster Fishery (TSTRLF) is commercially fished in the Torres Strait Protected Zone (TSPZ) by Australian and Papua New Guinean nationals. Australians hold Transferable Vessel Holder (TVH) licences or Traditional Inhabitant Boat (TIB) licences (see Chapter 15).
The TSTRLF extends from Cape York to the northern border of the TSPZ (Figure 17.1). Most catch comes from the western and south-eastern parts of the fishery, where the densities of tropical rock lobster are highest (AFMA 2013). Access to this fishery is shared by Australia and Papua New Guinea (PNG) under formal arrangements in the Torres Strait Treaty (see Chapter 15).
Fishing methods and key species
The TSTRLF is based on a single species: tropical rock lobster (Panulirus ornatus). It is predominantly a dive-based, hand-collection fishery. Divers use surface-supplied air (hookah) or free-dive, and work from 4–6 metre tenders (one diver per tender). Some lobsters are also collected at night on shallow reef flats by fishers using a light and handheld spear or scoop net.
Operators can use motherships (primary vessels; large catch-storage vessels) in conjunction with smaller fishing vessels (tenders). The TVH vessels predominately use hookah gear and operate using primary vessels with tenders. This allows these vessels to travel to more distant fishing grounds and fish for a few days to several weeks. In contrast, TIB Sector operators predominantly work from small dinghies (<6 metres) and undertake trips of one or two days, with divers working from smaller boats that depart from their local island communities. In recent years, however, an increasing number of TIB Sector operators have used motherships in conjunction with fishing tenders and hookah equipment. This has allowed TIB Sector operators to retain a greater number of live rock lobster, which attracts a higher and more consistent market price than frozen rock lobster tails.
The TSTRLF is currently managed primarily through effort restrictions (input controls). In 2016, the Protected Zone Joint Authority (PZJA) released a draft management plan, the Torres Strait Fishery (Quotas for Tropical Rock Lobster [Kaiar]) Management Plan 2016, for public comment. The draft plan proposes the introduction of a quota-based allocation system (output controls). Under the proposed output controls, allocation of rock lobster quota to the TVH Sector is based on catch history between 1997 and 2001, with provisions for leasing quota. The draft plan is not in force. A process for managing and allocating rock lobster quota within the TIB Sector is still to be determined.
As part of the transition planning, the Tropical Rock Lobster Resource Assessment Group (TRLRAG) is developing a harvest strategy for the TSTRLF, and fishery-specific target and limit reference points are being defined. The interim harvest strategy uses a limit reference point for biomass (32 per cent of spawning biomass in 1973 [SB1973]—0.32SB1973), a trigger reference point for biomass (0.48SB1973), a target reference point for biomass (0.65SB1973) and a target reference point for fishing mortality rate (FTARG = 0.15). The proposed harvest control rule uses a constant exploitation rate (FTARG = 0.15 per year), while the stock size is at or above the trigger reference point for biomass. The exploitation rate then decreases linearly to zero as the spawning biomass decreases from the trigger to the limit reference point. The interim harvest strategy is used to determine a notional (non-binding) total allowable catch (TAC). However, since the TAC is currently non-binding, it is not used to control harvest.
Allocations for the Australian and PNG sectors have been based on agreed shares of the non-binding TAC recommended to the TSPZ by the TRLRAG each year. For the 2016–17 fishing season, shares for the two commercial fishing sectors were approximately 67 per cent for the Australian share and 33 per cent for PNG.
The input controls that currently apply to the TSTRLF include a limited commercial fishing season (from 1 December to 30 September); a ban on the use of hookah gear between 1 October and 31 January, and around most new and full moon periods; and gear restrictions that limit the collection of lobsters only by hand or by handheld implements such as snares, nets or spears. In addition to the non-binding TAC, other output controls include minimum size limits for commercially caught lobsters of 90 mm carapace length or 115 mm tail length; and a prohibition on the possession of tropical rock lobster meat that has been removed from any part of a tropical rock lobster, on any boat, unless that lobster was taken in the course of traditional fishing.
Fishing effort in the TSTRLF is reported as tender-days, which is the common unit of effort across all sectors. Reported fishing effort (available since 1994), in tender-days, for the TVH Sector reached a peak of 5,200 in 2003–04 before decreasing to approximately 1,200 in 2008–09. Effort then increased to 3,008 tender-days in 2012–13 before decreasing to 2,491 in 2016–17 (Table 17.2). Fishing effort in the TIB Sector has been more difficult to estimate because of under-reporting and duplication in the docket book system used to collect catch-and-effort data. Analyses of the TIB effort data (available since 2004) that adjust for under-reporting and remove duplicate records (Campbell 2017) indicate that effort, in tender-days, has decreased from more than 9,000 in 2004–05 to the lowest level of 2,619 in 2012–13. Since then, effort in tender-days has increased to 9,009 in 2015–16 and declined to 3,585 in 2016–17. Fishing effort for the PNG sector in Australian waters has decreased from a peak of more than 2,200 tender-days in 2009–10, and has been zero since 2013–14.
TABLE 17.2 Main features and statistics for the TSTRLF
2015–16 fishing season||
2016–17 fishing season|
Real value (2015–16)||
Catch (t) b||
Real value (2016–17)|
|Australia (TVH, TIB)||537||510||$14.5 million||334||255||$12.9 million|
c||TVH: 2,654 tender-days, 1,187 operation-days
TIB: 9,009 tender-days
PNG: 0 tender-days (in Australian waters)
|TVH: 2,491 tender-days, 986 operation-days
TIB: 3,585 tender-days
PNG: 0 tender-days (in Australian waters)
|Fishing permits||TVH: 12 licences, 31 tenders
PNG: 0 PNG cross-endorsed; hundreds of PNG dinghies and canoes fish from coastal villages in PNG waters
|TVH: 12 licences, 34 tenders
PNG: 0 PNG cross-endorsed; hundreds of PNG dinghies and canoes fish from coastal villages in PNG waters
|Active vessels||TVH: 11
PNG: 0 (cross-endorsed)
PNG: 0 (cross-endorsed)
|Fishing methods||Handheld implements (snare, net or spear) on shallow reef flats at night; free-diving or use of hookah gear during the day|
|Primary landing ports||Cairns, Thursday Island (Queensland); Daru (PNG)|
|Management methods||Input controls: gear controls, seasonal and lunar closures
Output controls: minimum size limit (>115 mm tail length or >90 mm carapace length), bag limit of 3 lobsters per person (or 6 lobsters per dinghy if more than one person aboard the boat) for traditional and recreational fishing
|Primary markets||Domestic: live lobsters and frozen tails
International: Hong Kong/China (live lobsters), United States (frozen tails)
a Fishery statistics are provided by fishing season, unless otherwise indicated. Fishing season is 1 December – 30 September. Real-value statistics are by financial year.
b Estimate at time of publishing; this figure is preliminary and likely to be updated in future editions of this publication.
c Tender-day is a day of fishing effort using a fishing tender or dory.
na Not available. PNG Papua New Guinea.
TAC Total allowable catch.
TIB Traditional Inhabitant Boat.
TVH Transferable Vessel Holder.
17.2 Biological status
Tropical rock lobster (Panulirus ornatus)
Line drawing: Karina Hansen
Although postlarval-stage lobsters are locally resident, tropical rock lobster populations in Torres Strait (managed under the PZJA), the Coral Sea (managed by the Commonwealth) and Queensland (managed by Queensland) are considered to comprise a single biological stock as a result of the mixing of larvae in the Coral Sea (Pitcher et al. 2005; Plagányi et al. 2018a). Assessments presented here relate specifically to the stock resident in Torres Strait.
Total catch of tropical rock lobster since 1978 has fluctuated between 122 and 932 t per year for the Australian sectors (TVH and TIB) and 70 and 225 t for PNG (Figure 17.2). Average catches over the past five years were 420 t for the Australian sectors and 193 t for PNG.
The statistical catch-at-age model developed by Plagányi et al. (2009) was used for the 2018 assessment (Plagányi et al. 2018b). The assessment used a time series of catch data from 1973 to 2017, and incorporates annual fishery-independent pre-season (2005–2008 and 2014–2017) and mid-season (1989–2014) survey data, and catch-per-unit-effort data from the TVH (1994–2017) and TIB (2004–2017) sectors (Plagányi et al. 2018b).
The assessment estimated the 2017 spawning biomass to be 2,421 t (90 per cent confidence interval 1,541–3,301 t), or 76 per cent of the estimated unfished (1973) level (0.76SB1973) (Plagányi et al. 2018b). Estimates of parameters related to maximum sustainable yield (MSY) are considered to be uncertain because of highly variable annual recruitment and a limited number of age classes in the fishery. For such recruitment-driven fisheries, annual yields can be expected to fluctuate widely about deterministic quantities such as MSY. The (non-binding) TAC is calculated each year based on the target fishing mortality rate of 0.15 (FTARG), which is estimated to keep the biomass at a recent average level agreed by stakeholders. For 2017, the TRLRAG recommended a non-binding TAC of 495 t, of which 368 t (74 per cent) was caught (Table 17.2). The recommended non-binding TAC for 2018 is 299 t, based on the outputs from the reference case assessment model (Plagányi et al. 2018b). The recommended 2018 TAC is lower than for previous years because of low densities of recruits observed in 2017 and subsequent model predictions that the spawning biomass in 2018 will drop to 59 per cent of unfished levels (0.59SB1973).
Stock status determination
The model-estimated biomass in 2017 (0.76SB1973) was above the target (0.65SB1973) and limit (0.32SB1973) reference points. As a result, this stock is classified as not overfished.The total catch of 368 t in 2017 was lower than the non-binding TAC of 495 t, and equated to a fishing mortality of 0.14, which is lower than the target reference point of 0.15. Therefore, the stock is classified as not subject to overfishing.
17.3 Economic status
Key economic trends
Catch in the fishery is landed as either whole lobster or lobster tails, with whole lobsters generally being landed live. All catch and value figures discussed here have been converted to whole weight to allow comparisons of catch composition.
Landed catch in the fishery decreased by 25 per cent in the 2016–17 financial year, from 376 t in 2015–16 to 283 t in 2016–17 (Figure 17.3).1 The quantity of whole lobster decreased from 293 t (whole-weight equivalent) in 2015–16 to 236 t (whole-weight equivalent) in 2016–17. The quantity of tails landed in 2016–17 decreased by 43 per cent (to 47 t [whole-weight equivalent]) compared with the previous year. Effort in the TIB Sector of the fishery declined by 60 per cent between the 2015–16 fishing season (9,009 tender-days) and the 2016–17 fishing season (3,585 tender-days). The commercial fishing season runs from 1 December to 30 September and so spans financial years (Table 17.2).
The gross value of production (GVP) of the Australian fishery (not including PNG) decreased by 11 per cent, from $14.5 million in 2015–16 to $12.2 million in 2016–17 (Figure 17.4). Because fewer tails were landed, the value of rock lobster tails decreased by 35 per cent, from $1.2 million in 2015–16 to $0.8 million in 2016–17. The value of whole lobster also decreased during this period, by 9 per cent, from $13.4 million in 2015–16 to $12.2 million in 2016–17. The decline in effort over the same period suggests a reduction in fishing costs and, when combined with the fall in GVP, indicates that the movement in net economic returns to the fishery is uncertain.
The fishery is currently managed under input controls, including seasonal closures, temporal restrictions on the use of hookah equipment and minimum size limits (Table 17.2; AFMA, 2013, pers. comm.; PZJA 2015). A voluntary buyout of fishing licences for non–Traditional Inhabitants commenced in 2011, aimed at increasing the ownership and participation of Traditional Inhabitants in the fishery (PZJA 2013). The buyback, through an open tender process, resulted in a 2 per cent increase in the Traditional Inhabitants’ share of fishery catch, to 56.2 per cent of the Australian share (PZJA 2013). The buyback was completed in 2012, with the PZJA committed to developing a management plan for the fishery that ensures the sustainability of the resource. Since then, the Torres Strait Regional Authority has independently purchased a further three TVH licence packages that were operating in the TSTRLF.
The management strategy evaluation results of the three potential management options predicted that an individual transferable quota (ITQ) system is unlikely to achieve the aim of increasing the TIB share of total Australian catch in the fishery to 70 per cent (Pascoe et al. 2012). Monitoring in the TIB Sector is difficult because of its small scale, and an ITQ system requires a substantial investment in science and accurate reporting of catches (van Putten et al. 2013). Pascoe et al. (2012) noted that a competitive quota arrangement for the TIB fleet might limit the benefits of quota management if there is a race to fish, although effort in the TIB Sector remains well below the sector’s nominal allocation. They discussed a community-based arrangement as a potential option. However, van Putten et al. (2013) noted that this type of arrangement is associated with several challenges, including concerns about potentially undermining the supply chain that all fishers rely on, and concerns about maintaining the principles of equity and continued community access to the resource.
Performance against economic objective
Like other Torres Strait fisheries, the TSTRLF is managed against objectives that differ from those of solely Australian Government–managed fisheries. The TSTRLF management objectives are relevant to economic performance, but have a broader focus on social and cultural factors. They include the objectives of (PZJA 2015):
- maintaining the fishing mortality at a level below the level that produces MSY (FMSY), accounting for all sources of fishing mortality
- in accordance with the Torres Strait Treaty, protecting the traditional way of life and livelihood of Traditional Inhabitants, particularly in relation to their traditional fishing for tropical rock lobster
- providing for optimal utilisation, cooperative management with Queensland and PNG, and catch sharing with PNG
- monitoring interactions between the prawn and lobster fisheries
- maintaining appropriate controls on fishing gear allowed in the fishery, to minimise impacts on the environment
- promoting economic development in the Torres Strait area, with an emphasis on providing the framework for commercial opportunities for Traditional Inhabitants, and ensuring that the opportunities available to all stakeholders are socially and culturally appropriate for Torres Strait, and the wider Queensland and Australian communities
- optimising the value of the fishery.
17.4 Environmental status
The TSTRLF is included in the List of Exempt Native Specimens under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) and is exempt from export controls until 18 December 2020.
The fishery has little direct impact on the marine environment or other fish species, since hand-collection fishing methods allow careful selection of catch. The level 1 ecological risk assessment did not identify any species at medium or high risk, and found that interactions with protected species were negligible or low because of the nature of the fishery (Furlani et al. 2007). Therefore, no further risk assessments were undertaken (AFMA 2009).
The Australian Fisheries Management Authority publishes quarterly summaries of logbook reports of interactions with protected species on its website. No interactions with species protected under the EPBC Act were reported in the TSTRLF in 2017.
AFMA 2009, Ecological risk management report for the Torres Strait Tropical Rock Lobster Fishery, Australian Fisheries Management Authority, Canberra.
—— 2013, Torres Strait Tropical Rock Lobster Fishery 2013, annual report, AFMA, Canberra.
Campbell, R 2017, Estimation of total annual effort in the Torres Strait Rock Lobster Fishery, CSIRO Oceans and Atmosphere Flagship, Hobart.
Furlani, D, Dennis, D, Dowdney, J, Butler, A & Mason, F 2007, Ecological risk assessment for the effects of fishing: report for the Torres Strait Rock Lobster Fishery, report for AFMA, Canberra.
Pascoe, S, Hutton, T, van Putten, I, Dennis, D, Skewes, T, Plagányi, É & Deng, R 2012, ‘Estimating fleet size changes when modelling the introduction of rights based management: the case of the Torres Strait Rock Lobster Fishery’, in ÉE Plagányi, R Deng, D Dennis, T Hutton, S Pascoe, I van Putten & T Skewes (eds), An integrated management strategy evaluation (MSE) for the Torres Strait Tropical Rock Lobster, Panulirus ornatus Fishery, AFMA & CSIRO draft final project report, AFMA project 2009/839, CSIRO, Cleveland, Queensland.
Pitcher, CR, Turnbull, CT, Atfield, J, Griffin, D, Dennis, D & Skewes, T 2005, Biology, larval transport modelling and commercial logbook data analysis to support management of the NE Queensland rocklobster Panulirus ornatus fishery, Fisheries Research and Development Corporation project 2002/008, CSIRO Marine Research, Brisbane.
Plagányi, ÉE, Dennis, D, Kienzle, M, Ye, Y, Haywood, M, Mcleod, I, Wassenberg, T, Pillans, R, Dell, Q, Coman, G, Tonks, M & Murphy, N 2009, TAC estimation & relative lobster abundance surveys 2008/09, AFMA project 2008/837, CSIRO, Cleveland, Queensland.
——, Haywood, M, Gorton, B & Condie, S 2018a, Environmental drivers of variability and climate projections for Torres Strait tropical lobster Panulirus ornatus, AFMA & CSIRO final project report, AFMA project 2017/0816, CSIRO, Cleveland, Queensland.
——, Campbell, R, Tonks, M, Haywood, M, Deng, R, Murphy, N & Salee, K 2018b, Torres Strait rock lobster (TRL) 2017 fishery surveys, CPUE and stock assessment, AFMA project 2016/0822, CSIRO Oceans and Atmosphere, Brisbane.
PZJA 2013, ‘Tropical rock lobster fishery—voluntary buyback complete’, Protected Zone Joint Authority, Canberra, pzja.gov.au/2013/01/tropical-rock-lobster-fishery-voluntary-buyback-complete, accessed 14 June 2018.
—— 2015, ‘Torres Strait Tropical Rock Lobster Fishery’, PZJA, Canberra, pzja.gov.au/the-fisheries/torres-strait-tropical-rock-lobster-fishery, accessed 14 June 2018.
van Putten, I, Deng, R, Dennis, D, Hutton, T, Pascoe, S, Plagányi, É & Skewes, T 2013, ‘The quandary of quota management in the Torres Strait Rock Lobster Fishery’, Fisheries Management and Ecology, vol. 20, no. 4, pp. 326–37.
1 Catch weights and gross value of production in this section are given by financial year.