|Scientific Name:||Jasus edwardsii|
|Species Authority:||(Hutton, 1875)|
Jasus novaehollandiae Holthuis, 1963
Palinurus edwardsii Hutton, 1875
|Taxonomic Notes:||The Australian stock was previously known as Jasus novaehollandiae.
|Red List Category & Criteria:||Least Concern ver 3.1|
|Assessor/s:||MacDiarmid, A., Butler, M., Cockcroft, A. & Wahle, R.|
|Reviewer/s:||Collen, B., Livingstone, S. & Richman, N.|
|Contributor/s:||Batchelor, A., De Silva, R., Dyer, E., Kasthala, G., Lutz, M.L., McGuinness, S., Milligan, H.T., Soulsby, A.-M. & Whitton, F.|
Jasus edwardsii has been assessed as Least Concern. Although there have been declines that meet the criteria for Endangered under A1 in the past, the population has been stable over the last 40 years. It is predicted that, due to good continuing fisheries management, the stable population will continue into the future. Using criterion A4 looking two generations into the past (40 years) and one into the future (20 years), with no declines, this species is Least Concern.
|Range Description:||This species is known from Australia (Geraldton in western Australia, south and around Tasmania, up to Coffs Harbour on east coast Australia), New Zealand (ranging from Three Kings Islands to Auckland Islands including Chatham Islands), and areas of the Tasman Sea (seamounts and rises) (Phillips et al. 2000, Booth 2000, Booth 2006).|
Native:Australia (New South Wales, South Australia, Tasmania, Victoria, Western Australia); New Zealand (Chatham Is., North Is., South Is.)
|FAO Marine Fishing Areas:||
Indian Ocean – eastern; Pacific – southwest
|Range Map:||Click here to open the map viewer and explore range.|
This species is of huge commercial importance within Australia, New Zealand, and Tasmania. This species is harvested as a human food source; most commonly using baited traps. The majority of the global catch is taken in the South Australia fishery with an annual average landing of 2,500 tonnes (Phillips et al. 2000). Tasmania has an average annual landing of 1,500 tonnes, while Victoria has an annual landing of 400 - 500 tonnes. The Western Australia fishery has the smallest annual landings of less than 100 tonnes.
Commercial catch in 2007/2008 was 1513.435 tonnes which is 99.37% of the TACC set at 1523 tonnes.
Fishing effort and harvest rates vary significantly across the Tasmanian fishery. Effort peaked in 1992/1993 when 2.07 million pots were in use. Today, there are approximately 1.29 million pots in use. In 1998/1999 a quota management system was initiated at which point 1.59 million pots were in use though there has been a slight increase in effort in the last two years. The Tasmanian Southern Rock Lobster fishery is divided into 8 fishery areas. In recent years fishing effort is reported to have declined in areas 1, 2, 4 and 5. Comparatively, there have been slight increases in Areas 3 and 6, and larger increases still in Areas 7 and 8. Record high catches are being seen in Area 1 and 8, with high catches also seen in Area 7. Areas 3, 4 and 5 are showing record low catches despite the reduced effort in 4 and 5. On the whole catch rate has increased by 41% when compared to the reference year (year between 1993 and 1995 with the lowest catch per unit effort (CPUE) but declined by 2.5% compared to the previous fishing season 2006/2007. Over the last 18 years statewide CPUE (defined as total catch divided by total pot lifts) has risen from a low if 0.818 in 1994/1995 to a high of 1.204 in 2005/2006 with a subsequent slight decline to 1.163 in 2007/2008. The Total Allowable Commercial Catch (TACC) is still being attained largely due to the increased effort that has been seen in the southern areas: 1, and 8. It is unlikely that these high catches shall be maintained. When effort and catch are combined, catch rates are as follows: rising or stable in Areas 3, 5, 7 and 8; declining in Areas 1, 2 and 6.
The legal-sized biomass of the fishery is declining in Areas 1 and 6, and increasing in Areas 3 and 7. There has also been an observed rise in biomass in Area 5 though is likely due to a reduction in catch as opposed to increased recruitment. Area 7 is currently undergoing high levels of recruitment into legal size. On the whole the biomass levels are significantly higher than the reference year of 1993/1994 when legal-sized biomass was estimated at 2,872 tonnes. The 2006 legal-sized biomass estimate was 5,181 tonnes while the 2007 estimate was 4,982 tonnes which is a 3.8% decrease. Mature biomass is also showing a downward trend since 2004 from a high of ~6,800 tonnes to ~6,250 tonnes in 2006/2007. Mean weight however has been slowly increasing over time.
Statewide egg production is at 47.4% of the virgin population levels, however areas 3,4,5 and 6 are below the recommended 25% threshold. These are the northern areas of the fishery which are currently exhibiting declines in catch.
Recruitment in Areas 3,4 and 5 has been below average for the last few years, but above average in Areas 1,7 and 8 although the source of recruitment for areas 1 and 8 is now in decline (Haddon and Gardner 2009).
The number of licenses within the recreational fishery has increased dramatically from 8,500 in 1995 to 20,008 in 2006/2007.
Despite the record high catches across the state when compared to 1994/1995 levels, the process of stock rebuilding appears to have stalled. Area 5 is the only area in which stock abundance is exhibiting a positive trend which is due to a prolonged period of lower harvest.
Projections looking at the chance of biomass increasing by 2012/2013 (assuming a TACC of 1523 tonnes; recreational catch staying the same; recruitment reverts back to typical levels) indicate that Areas 2,3,4,5,6 have a good chance of biomass increasing while Area 1, 7 and 8 are very likely to decrease further.
Northern Zone Rock Lobster Fishery
This zone incorporates all the South Australian waters between the mouth of the Murray River and the Western Australia border and covers 42 marine fishing areas.
Landings of this species have remained stable throughout the 1970s and early 1980s at around 600 - 700 tonnes. In 1985 the catch rose from 657 tonnes to 1,221 tonnes, and subsequently declined to around 900 tonnes in the mid 1990s. They then rose again over 1,000 tonnes in 1998 and 1999. In 2004 the catches were at a record low of 446 tonnes. Although it is important to note that the decline in catch in 2000 may be partly attributed to an increase in the minimum legal size limit. The decline in 2001 and 2002 may also be a reflection of a lowering of fishing effort.
There was a slight increase in catch to around 491 tonnes in 2006, but in 2007 this fell again to 459 tonnes which is 88% of the TACC (520 tonnes). Fishing quotas were introduced in 2002.
Historically, fishing effort was at its highest in 1991 at 805,139 potlifts when the record landings were made, however it has gradually declined and is now at about 615,732 which is still higher than 1970/1980 levels when landings were higher. Catch per unit effort (CPUE) was at its highest in the late 1980s at ~1.50 kg/potlift but has subsequently declined to around 0.76 kg/potlift in 2007.
The mean weight of lobsters reached its lowest point in 1988 and 1989, with 2001 showing the highest mean weight on record (1.21 kg). However in 2002, 2003, and 2004 mean weight decreased again to 1.08 kg but then increased to 1.13 kg in 2007. Length frequency data suggests that there has been no significant change in the mean length of males and females between 1995 and 2000. Numbers of spawning adults has decreased significantly between 1997 and 2007 by about 77% from around 0.09 spawners/potlift to 0.02 spawners/potlift in 2007. Biomass estimates for the fishery indicate a 70% decline since 1980 when it was estimated at 5,311 tonnes compared to the estimate of 1,581 tonnes in 2007. This fishery is currently considered to be in an overfished state (Linnane, McGarvey and Feenstra 2009).
Southern Zone Rock Lobster Fishery
This zone incorporates all South Australia waters from the mouth of the Murray River to the border of Victoria and is divided in 7 marine fishing areas.
Catches between 1970 and 1983 were variable and there is some sceptisism over the reported catches during this period. From 1984 to 1990 catches were around 1,500 tonnes but then increased in 1991 to 1,940 tonnes but subsequently declined to 1,670 tonnes in 1993. In 1993 a TACC of 1,720 was implemented of which only 1,668 tonnes was harvested. Since 1996 there has been a gradual increase in landings to around 1,900 tonnes but then declined slightly to 1,849 tonnes in 2007. Since the peak in landings in 1991, fishing effort has been reduced dramatically from its peak in 1991 at 2 million potlifts to a low of 854,000 potlifts in 2002. It has since increased again to 1,661,428 potlifts in 2007. Catch per unit effort rose from 0.93 kg/potlift in 1996 to 2.1 kg/potlift in 2002, but then fell again to around 1.1 kg/potlift in 2007.
Mean weight of lobsters in 2007 is similar to that seen in the 1970s at around 0.83 kg though it has varied considerably over time between 0.77 and 0.89 kg. Length frequency data suggests that there has been no significant change in the mean length of males and females since 1993 when the quota was introduced. Numbers of spawning individuals has dramatically declined from a high in 2002 of 0.51 spawners/potlift to 0.14 spawners/potlift in 2007. Biomass estimates for this fishery show that it peaked in 2002 at 6,085 tonnes but has since declined to around 4,041 tonnes in 2007. Egg production levels have also shown a similar trend with a high of 684 billion eggs in 2003 and a low of 460 billion eggs in 2007.
Victorian Rock Lobster Fishery
This fishing zone is split into the Western Zone and Eastern Zone.
Landings in the Western Zone have fluctuated considerably since 1978 but recently peaked at ~550 tonnes in 2000 and then declined to ~330 tonnes in 2006 (Department of Primary Industries 2008). CPUE in this zone started at ~0.85kg/potlift in 1978 and declined to ~0.50 kg/potlift in 1990 but then rose again to ~0.71 kg/potlift in 2003 but have since fallen to ~0.49 kg/potlift in 2006(Department of Primary Industries 2008). In the Eastern Zone landings were high in the late 1970s at ~120 tonnes but declined to ~70 tonnes in the late 1980s where they have remained ever since(Department of Primary Industries 2008). CPUE in this region also declined from around 0.70 kg/potlift in the late 1970s to a low of ~0.25 kg/potlift in 1996 but have since increased to ~0.42 kg/potlift in 2006 (Department of Primary Industries 2008).
New Zealand Fishery
This fishery covers the North and South Islands, as well as the Chatham Islands. The fishery is divided into 3 substocks: NSN - northern stocks CRA1 and 2; NSC - central stocks CRA3, 4 and 5; NSS - southern stocks CRA7 and 8.
Since 1991, there has been a decline in the catch of this species from 2,907.4 tonnes, to 2,464.8 tonnes in 2007/2008. However, over this time a TACC limit has been imposed which has also declined from around 3,793 tonnes in 1991 to 2,766.6 tonnes in 2007/2008.Catch per unit effort data for both the North and South Islands indicates some variability since the early 1980s from a high of 1.96 kg/potlift in 1979/1980 to a low of 0.48 kg/potlift in 1992/1993, however it has since increased again to 1.04 kg/potlift in 2007/2008. The Chatham Island stock also declined in CPUE from 2.33 kg/potlift in 1979/1980 to 0.88 kg/potlift in 1996/1997 but then increased again to around 1.53 kg/potlift in 2007/2008.
|Habitat and Ecology:||
This species is most commonly found on rocky reefs; but may also be found on light foul ground, seamounts and rises (Booth 2006). It is typically found from the intertidal zone to a depth of 200 m (Holthuis 1991).
This species feeds on molluscs, other crustacea, echiniods, and algae (Booth 2006). This species can make migrations of 460 km (Street 1971).
The maximum size recorded for a male specimen is 235 mm (CL) and for a female 180 mm (CL) (Holthuis 1991). Female age at maturity is estimated to range from 3 - 7 years (NIWA unpublished data cited in Booth 2006, Annala et al. 1980).
|Major Threat(s):||Overexploitation has been consigned to history as the fisheries are now well managed. This is an attempt to increase the biomass. In some cases there have been increases, and stable fluctuation.|
|Conservation Actions:||There are a number of conservation measures in place for this species including minimum legal size, protection of berried females, restriction on the number of fishing boats, types of gear allowed, number of lobster pots, sanctuaries, closed fishing seasons, total allowable catch (Booth 2006).|
|Citation:||MacDiarmid, A., Butler, M., Cockcroft, A. & Wahle, R. 2011. Jasus edwardsii. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. <www.iucnredlist.org>. Downloaded on 20 May 2013.|
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