Torres Strait Tropical Rock Lobster Fishery
Chapter 17: Torres Strait Tropical Rock Lobster Fishery
R Noriega, T Emery and AH Steven
|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||Closure of the fishery in 2018 restricted fishing mortality levels to FTARG. Spawning stock biomass in 2018 was above the limit reference point but below the target reference point. Spawning stock biomass is expected to increase in 2019 and fluctuate widely around the target.|
|Economic status||Net economic returns in the fishery are uncertain, although positive economic improvements may have occurred in the 2017–18 fishing season as a result of gross value of production increasing faster than effort.|
Note: FTARG Target reference point for fishing mortality rate.
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 predominantly work from 6-metre vessels (one diver per vessel). 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), or operate fishing vessels individually. The TVH Sector predominantly uses hookah gear and operates 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 long) and undertake trips of one or two days, with divers working from smaller boats that depart from their local island communities. The TIB Sector has significantly increased its supply to market of live lobsters as opposed to tailed lobster over the past five to six years. This has been facilitated by changes in fishing behaviour and improved logistics chains rather than a change in the types of boats used in operations.
During the 2017–18 season, the TSTRLF was managed primarily through effort restrictions (input controls). Since 2006, and in preparation for the Tropical Rock Lobster Fishery Management Plan, a recommended biological catch (RBC) was advised for each fishing season and apportioned between Australia and PNG. Because of a low RBC and the likelihood that catches would exceed the Australian catch share of the RBC in the 2017–18 season, the Torres Strait Fisheries (Tropical Rock Lobster) Management Instrument 2018 was made on 19 July 2018, providing for a binding total allowable catch (TAC) for the TSTRLF. The Australian TAC is Australia’s catch share of the final TAC, as agreed with PNG.
On 26 November 2018, the Torres Strait Fisheries (Quotas for Tropical Rock Lobster (Kaiar)) Management Plan 2018 was determined to coincide with the commencement of the Torres Strait Fisheries Amendment (Tropical Rock Lobster) Management Instrument 2018. This legislation came into force for the start of the 2018–19 season on 1 December 2018. The management plan provides for the introduction and establishment of a fishing quota system for the TSTRLF, following resolution of a formal quota allocation process as prescribed by the management plan. As the TSTRLF transitions to a fully operational management plan, separate interim TAC shares have been implemented for the TIB and TVH sectors through the management instrument. In May 2019, the Australian Fisheries Management Authority and the PNG National Fisheries Authority reached final agreement, as required under the Torres Strait Treaty, on catch-sharing arrangements for the 2018–19 season, resulting in a final TAC of 494.85 t for the TSTRLF.
While the management plan is being implemented, a range of input controls are in place, including 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 specified new and full moon periods; and gear restrictions that limit the collection of lobsters to hand collection, or collection by handheld implements such as snares, scoop nets or spears. In addition to the 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.
A revised harvest strategy for the TSTRLF is being developed, with defined fishery-specific target and limit reference points, which is expected to be introduced from December 2019 (DEE 2018). The revised harvest strategy uses a limit reference point for biomass (32% of spawning biomass in 1973 [SB1973]—0.32SB1973), a target reference point for biomass (0.65SB1973) and a target reference point for fishing mortality rate (FTARG = 0.15). It has decision rules designed to maintain the stock at (or return the stock to) the target biomass reference point (BTARG), maintain the stock above a limit biomass reference point (BLIM) and implement rebuilding strategies if the stock falls below the BLIM in two successive years. An interim harvest strategy is currently used to determine a binding TAC and to control harvest levels.
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) for the TVH Sector reached a peak of 5,200 tender-days 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 1,506 in 2017–18 (Table 17.2). Fishing effort in the TIB Sector has been more difficult to estimate because the docket book system used to collect catch-and-effort data up until 2017 has been voluntary. Mandatory catch reporting, known as the Fish Receiver System, became mandatory for all Torres Strait fisheries, except the Torres Strait Prawn Fishery, on 1 December 2017. This system requires all catch from the TSTRLF to be landed to a licensed fish receiver and recorded. Analyses of the TIB effort data (available since 2004) that adjust for under-reporting and remove duplicate records under the docket book system (Campbell 2017) indicate that effort has decreased from more than 9,000 tender-days in 2004–05 to the lowest level of 2,619 in 2012–13. Since then, effort increased to 5,852 tender-days in 2014–15 before declining to 4,874 in 2017–18. 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.
|Fishery statistics a||2016–17 fishing season||2017–18 fishing season|
Stock ||TAC (t)||Catch (t)||Real value (2016–17)||TAC (t)||Catch (t) b||Real value (2017–18)|
|Australia (TVH, TIB)||334||267||$12.9 million||254.15||261||$15.0 million|
|Effort d||TVH: 2,352 tender-days, 942 operation-days|
TIB: 3,842 tender-days
PNG: 0 tender-days (in Australian waters)
|TVH: 1,506 tender-days, 558 operation-days|
TIB: 4,874 tender-days
PNG: 0 tender-days (in Australian waters)
|Fishing permits||TVH: 12 licences, 34 tenders|
PNG: 0 PNG cross-endorsed; hundreds of PNG dinghies and canoes fish from coastal villages in PNG waters
|TVH: 12 licences, 34 tenders|
TIB: 398 e
PNG: 0 PNG cross-endorsed; hundreds of PNG dinghies and canoes fish from coastal villages in PNG waters
|Active vessels||TVH: 10|
PNG: 0 (cross-endorsed)
PNG: 0 (cross-endorsed)
|Fishing methods||Hand collection using 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 closures, vessel length restriction|
Output controls: TAC, 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 recreational fishing
|Primary markets||Domestic: live lobsters and frozen tails|
International: Hong Kong/China (live lobsters); United States (frozen tails)
|Management plan||Torres Strait Fisheries (Quotas for Tropical Rock Lobster (Kaiar)) Management Plan 2018 (came into effect on 1 December 2018)|
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.
Notes: 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 Protected Zone Joint Authority), 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. 2018). 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 352 t for the Australian sectors and 187 t for PNG.
The statistical catch-at-age model developed by Plagányi et al. (2009) was used for the 2018 assessment (Plagányi et al. 2019). The assessment used a time series of catch data from 1973 to 2017, and incorporates annual fishery-independent preseason (2005–2008 and 2014–2018) and mid-season (1989–2014) survey data, and catch-per-unit-effort data from the TVH (1994–2018) and TIB (2004–2018) sectors (Plagányi et al. 2019).
The stock assessment for the 2018–19 season estimated the 2018 spawning biomass to be 1,969 t (90% confidence interval 1,260–2,678 t), or 46% of the estimated unfished (1973) level (0.46SB1973) (Plagányi et al. 2019). 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 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 the 2017–18 season, the Tropical Rock Lobster Resource Assessment Group recommended a TAC of 299 t, but 346 t was caught (Table 17.2). The Australian portion of this TAC was 254.15 t, with 261 t caught, so the fishery was closed early from 31 July 2018 (PZJA 2018b). The RBC for the 2018–19 season was 641 t, based on the outputs from the reference case assessment model (Plagányi et al. 2019). This is higher than 2017–18 due to the higher densities of lobsters observed in the 2018 preseason survey (Plagányi et al. 2019); however, the spawning biomass remains lower than average, estimated to be at 46% of unfished levels (0.46SB1973). Nevertheless, the spawning biomass is expected to fluctuate widely around the average target spawning biomass level and to increase in 2019 (Plagányi et al. 2019).
Stock status determination
The model-estimated biomass in 2018 (0.46SB1973) was below the interim target reference point (0.65SB1973) but above the interim limit reference point (0.40SB1973). In 2018, the TAC of 299 t (based on a target fishing mortality rate of 0.15 [FTARG]) was exceeded, resulting in a management decision to close the fishery early to ensure that there was enough spawning stock for subsequent fishing seasons. Spawning stock biomass is expected to increase in 2019 and fluctuate widely around the target (Plagányi et al. 2019). As a result, this stock is classified as not overfished.The total catch of 346 t in 2018 was above the TAC of 299 t, which was assessed to have been at the target fishing mortality of 0.15 (Plagányi et al. 2019). However, the recommended TAC of 641 t in 2019, based on a target fishing mortality rate of 0.15, is much higher than the catch in 2018, indicating that the catch in 2018 is unlikely to drive the stock below the limit reference point. 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.
In the 2017–18 fishing season, landed catch across the fishery exceeded the TAC by 47 t; Australia (TVH and TIB) exceeded the TAC by 7 t. Landed catch declined by 9% in the 2017–18 fishing season, from 380 t in 2016–17 to 346 t in 2017–18, with Australia’s share declining by 2% (from 267 t in 2016–17 to 261 t in 2017–18) (Figure 17.3).1 The 2017–18 TAC for the fishery was reduced by 40%; Australia’s share of the TAC declined by 24%.
The catch quantity of whole lobster decreased from 236 t in 2016–17 to 227 t in 2017–18. However, the quantity of tails landed in 2017–18 increased by 10% (to 51 t [whole-weight equivalent]) compared with the previous year (47 t). Effort in the TIB Sector of the fishery increased by 27% in the 2017–18 fishing season compared with the 2016–17 season. The number of fishing permits in 2017–18 increased by 60%, but the number of active vessels decreased by 14%. In comparison, effort in the TVH Sector decreased by 36%, and concurrently the number of active vessels decreased by 10% in the 2017–18 fishing season. Across the two sectors, effort (tender-days) increased by 3%. The Australian 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 increased by 19%, from $12.9 million in 2016–17 to $15 million in 2017–18 (Figure 17.4). The increase in GVP can be attributed to an increase in the landing price of whole lobster and lobster tail. Although net economic returns in the fishery are uncertain, it is likely that the TSTRLF experienced some positive economic improvements in the 2017–18 fishing season, since GVP grew faster than effort.
The fishery was previously managed under input controls that included seasonal closures, temporal restrictions on the use of hookah equipment and minimum size limits (Table 17.2; AFMA, 2013, pers. comm.; PZJA 2015). In previous years, nominal non-binding TACs were also in place.
Under new legislation that came into effect on 1 December 2018, a number of output controls will be established for the fishery, such as a fishing quota system and a binding TAC. The fishing quota system will allocate a quota to the TIB Sector as a whole and separate quotas to individuals in the TVH Sector. Until the quota allocation process is finalised, separate interim TAC shares have been implemented: the TIB Sector will be able to take a 66.17% share of the TAC and the remaining 33.83% of the TAC will be apportioned to individuals in the TVH Sector. The introduction of a binding TAC will help stabilise the fishery’s ecological condition, and individual quotas will potentially reduce competition between sectors for the resource (PZJA 2018a).
A voluntary buyout of TVH Sector fishing licences began 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% increase in the Traditional Inhabitants’ share of fishery catch, to 56.2% of the Australian share (PZJA 2013). The buyback was completed in 2012, with the Protected Zone Joint Authority 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.
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.
In conjunction with increases in landing price and GVP in the 2017–18 fishing season, the number of tender-days and fishing permits increased in the TIB Sector. These indicators suggest that the fishery is playing a role in promoting economic development and commercial opportunities for Traditional Inhabitants in Torres Strait.
17.4 Environmental status
The TSTRLF is included on 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 2018.
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.
DEE 2018, Strategic assessment of the Torres Strait Tropical Rock Lobster Fishery, Department of Environment and Energy, Canberra.
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.
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 2018, 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, Upston, J, Deng, R, Murphy, N, Salee, K & Edgar, S 2019, Torres Strait rock lobster (TRL) 2018 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.
—— 2018a, ‘Explanatory statement’, PZJA, Canberra, pzja.gov.au/sites/default/files/trl_management_plan_explantory_statement.pdf, accessed 30 June 2019.
—— 2018b, ‘Tropical Rock Lobster Fishery to close’, PZJA, Canberra, pzja.gov.au/tropical-rock-lobster-fishery-close, accessed 30 June 2019.
1 Catch weights and gross value of production in this section are given by financial year.