SANBI

Rationale

Global

Rhabdosargus sarba is widely distributed throughout the western Indo-Pacific and is relatively common in shallow marine and estuarine environments throughout its distribution. There are undoubtedly areas of localized depletion through habitat destruction and/or overfishing but overall this species cannot be considered as being under threat. However, there is evidence to suggest that the species R. sarba may consist of a number of genetically distinct populations, such as the form found off eastern Australia and that found off southern Africa. Further taxonomic work is currently underway in this regard. This species is listed as Least Concern.

Persian Gulf

Rhabdosargus sarba is overexploited in the Persian Gulf. Landings in the region have decreased and fluctuated significantly within the past decade. With these trends likely to continue, this species is conservation dependent. It is therefore listed as Near Threatened in the region.

Distribution

Rhabdosargus sarba is widely distributed in the Indo-West Pacific and is known from the Red Sea and the Persian Gulf to Eastern Cape, South Africa, eastwards to the South China Sea and Japan, and southwards to Australia (Heemstra and Heemstra 2004), though it is absent from the southern coastline of Australia (D. Pollard pers. comm. 2009). This species is not found on the eastern side of Taiwan (K. Shao pers. comm. 2009). This species occurs to 50 m depth (van der Elst 1993).

Habitat View more ecological information

Population trend

Trend

There is a high degree of fragmentation within the Rhabdosargus sarba complex with limited information on population or stock status throughout its distribution. In South Africa, Rhabdosargus sarba was assessed in KwaZulu-Natal and it was found that the adult stock was not overexploited (SB/R = 63%, F=0) before 2002; however, data from a per-recruit analysis conducted for the KwaZulu-Natal coast indicate that the stock is overexploited and has been reduced to 25–40% of its spawning biomass per recruit while the juvenile stock in estuaries is experiencing high fishing mortality (SB/R = 34%, F=0) (James et al. 2004). More recent research has shown a decline in the CPUE of the adult population with the closure of the St Lucia estuarine system due to prevailing drought conditions (Mann and Pradervand 2007), which forms an important nursery area for this species (Wallace 1975a). No major changes in CPUE of the adult population have been observed between 2004 and 2012 (Mann 2012). An increase in mean size was recorded in St Lucia MPA between 2001 and 2005 and is attributed to a lack of recruitment into the adult population because of the closure of the St. Lucia mouth (Mann and Pradervand 2007, Mann 2012). There was a substantial decline in percentage composition of shore anglers catches along the KwaZulu-Natal coast between 1994–1996 (2.28%) and 2009–2010 (0.24%) (Mann et al. 1997, Dunlop 2011). Decline recorded in the St Lucia MPA between 2001–2005, attributed to closure of St Lucia mouth (Mann 2012).

Persian Gulf

Grandcourt et al. (2011) compiled size frequency data for Rhabdosargus sarba in the southern Persian Gulf from commercial catches made off the coast of the Emirate of Abu Dhabi in the United Arab Emirates between September 2008 and August 2009. Biological data were collected from individuals purchased from commercial catches during the same time period. The mean age and size at sexual maturity for male Rhabdosargus sarba was 2.0 years and 23.5 cm L_m and 2.1 years and 23.7 cm L_mfor females. The ratio of males to females in the southern Persian Gulf was estimated as 1:1.4 (M:F), though Grandcourt et al. (2011) noted the samples were significantly female biased. Grandcourt et al. (2011) estimated the natural, fishing and total mortality for Rhabdosargus sarba to be 0.27 year^-1, 0.77 year^-1, and 1.04 year^-1, respectively. The mean age and size at first capture was 0.59 years and 14.0 cm L_c50. Juvenile retention for Rhabdosargus sarba was 74.0%. Grandcourt et al. (2011) concluded that Rhabdosargus sarba is overexploited in the Persian Gulf due to its estimated fishing mortality (0.77 year^-1), which was considerably greater than F_0.1(0.39). The fishing mortality was also greater than both biological reference points, target (F_SB40 = 0.22) and limit (F_SB30 = 0.30). Relative spawner biomass per recruit was estimated to be 6.4% of the theoretical unexploited level at the fishing mortality rate 0.77 year^-1, indicating both growth and recruitment overfishing were occurring.

Annual Fisheries Statistics Report for Abu Dhabi Emirate (2005-2012)
Abu Dhabi Emirate fisheries collected, on average, 52.89 tonnes of Rhabdosargus sarba between 2005–2012. A peak of 127.5 tonnes were collected in 2007, followed by a decline to 17.7 tonnes in 2011. There was a slight increase to 24.7 tonnes in 2012.

Catches from Bahrain decreased overall from 2009–243.2 tonnes , 2010–171.9 tonnes, to 119.3 tonnes in 2011. This species is not reported from Kuwait (Bishop pers comm. 2013), or Qatar.

FAO production statistics from Taiwan mostly come from mariculture. Rhabdosargus sarba is rarely caught in the wild (W. Liao pers. comm. 2009). FAO production figures in 2007 were: Australia (Eastern Indian Ocean) - 2,563 tonnes, (Southwest Pacific) - 215 tonnes, (Western Central Pacific) - 521 tonnes, Japan - 15,600 tonnes, Republic of Korea - 686 tonnes, Taiwan - 1,648 tonnes and New Zealand (Southwest Pacific) 5,919 tonnes. In New South Wales, Australia, between 1995–1996 and 2005–2006, landings averaged ~53 tonnes per year worth an estimated AU$240,000 a year (NSW DPI Catch Statistics).

Threats

The main threats to populations of Rhabdosargus sarba include habitat destruction (especially of the estuarine habitat), pollution of shallow coastal waters and overfishing (James et al. 2004).

Uses and trade

Rhabdosargus sarba is utilized in both commercial (El-Agamy 1989) and recreational fisheries (James et al. 2001, Mann et al. 2002), throughout its distribution. In southern Mozambique and northern KwaZulu-Natal R. sarba is harvested in artisanal gill net and trap fisheries (Mann 1995, Kyle 1999). In Western Australia, R. sarba is commonly caught as bycatch by boat and shore-based linefishers in coastal and estuarine systems within the West Coast and South Coast bioregions (Malseed and Sumner 2001, Cusack and Roennfeldt 2002). This species is occasionally targeted by recreational fisheries in some locations including the lower Swan Estuary and in the Cockburn Sound (Hesp 2003). Rhabdosargus sarba is of minor commercial importance in the South Coast bioregion in nearshore estuarine gill net and haul net finfish fisheries (Smith et al. 2012).

Conservation

In South Africa, R. sarba has been decommercialized to prohibit sale (James et al. 2004) as well as having a bag limit of five fish per person per day and a minimum landing size of 25 cm TL for recreational and subsistence fishers (Department of Agriculture, Forestry and Fisheries 2012). This species is protected in several marine and estuarine no-take MPAs such as iSimangaliso Wetland Park in KwaZulu-Natal, South Africa, and this has also undoubtedly benefited populations of this species. In New South Wales, the minimum landing size if 20 cm (TL) but it is recommended that the minimum landings size be raised to 22 or 24 cm TL in order to allow 50% or 100% of R. sarba individuals to reproduce at least once, respectively (Hughes et al. 2008).

Rhabdosargus sarba also occurs in marine protected areas in other parts of its range including the Shark Bay World Heritage Site in Western Australia (Department of Parks and Wildlife Portal, accessed March 2014, World Database of Protected Areas, accessed March 2014). In Taiwan, a reseeding program has been implemented by the government. The source of stock is unknown (Liao pers. comm. 2009).

There is evidence to suggest that the species, R. sarba, may consist of a number of genetically distinct populations, such as the form found off eastern Australia and that found off southern Africa (T. Trnski pers. comm.). Further taxonomic work is currently underway in this regard (Y. Iwatsuki pers. comm.).

References

[@book{12137,
 address = {Cape Town},
 author = {van der Elst, R.},
 publisher = {Struik Publishers},
 title = {A guide to the common sea fishes of Southern Africa (2nd edition)},
 year = {1988}
}
,@techreport{12137,
 author = {Mann, B.Q., Beckley, L.E. and R.P. van der Elst},
 institution = {Oceanographic Research Institute Unpublished Report 134},
 title = {Evaluation of linefishery participation and management along the KwaZulu-Natal coast},
 year = {1997}
}
,@techreport{12137,
 address = {Staatskoerant},
 author = {Department of Agriculture, Forestry and Fisheries},
 title = {Marine Living Resources Act, 1998 (Act No. 18 of 1998) and relevant government gazettes and notices},
 year = {2012}
}
,@book{170160,
 address = {Grahamstown, South Africa},
 author = {Heemstra, P.C. and Heemstra, E.},
 publisher = {South African Institute for Aquatic Biodiversity and National Inquiry Service Centre},
 title = {Coastal Fishes of southern Africa},
 year = {2004}
}
,@book{170169,
 address = {Cape Town, South Africa},
 author = {van der Elst, R},
 publisher = {Struik Publishers},
 title = {A guide to the common sea fishes of southern Africa},
 year = {1993}
}
,@phdthesis{170169,
 author = {Dunlop, M.I.},
 school = {University of KwaZulu- Natal, Durban, South Africa},
 title = {An assessment of the shore-based and offshore boat-based linefisheries of KwaZulu-Natal, South Africa},
 year = {2011}
}
,@phdthesis{170173,
 author = {Garratt, P.A.},
 school = {Rhodes University},
 title = {Comparative aspects of the reproductive biology of seabreams (Pisces: Sparidae), Vol 1},
 year = {1993}
}
,@article{170173,
 author = {James, N.C., Beckley, L.E., Mann, B.Q and Kyle, R.},
 journal = {African Zoology},
 number = {2},
 pages = {217–228},
 title = {The recreational fishery in the Kosi estuarine lake system, South Africa},
 volume = {36},
 year = {2001}
}
,@article{170173,
 author = {Kyle, R.},
 journal = {Biological Conservation},
 pages = {183--192},
 title = {Gill netting in nature reserves: a case study from the Kosi Lakes, South Africa},
 volume = {88},
 year = {1999}
}
,@article{170173,
 author = {Mann, B.Q.},
 journal = {Biological Conservation},
 number = {2},
 pages = {107--113},
 title = {Quantification of illicit fish harvesting in the Lake St Lucia Game Reserve, South Africa},
 volume = {74},
 year = {1995}
}
,@techreport{170173,
 author = {Wallace, J.H.},
 institution = {Oceanographic Research Institute 40},
 title = {The estuarine fishes of the east coast of South Africa: I Species composition and length distribution in the estuarine and marine environments. II Seasonal abundance and migrations},
 year = {1975}
}
,@article{170173,
 author = {Mann, B.Q., James, N.C. and Beckley, L.E.},
 journal = {South African Journal of Marine Science},
 pages = {263--279},
 title = {An assessment of the recreational fishery in the St Lucia estuarine system, KwaZulu-Natal, South Africa},
 volume = {24},
 year = {2002}
}
,@techreport{170173,
 author = {Wallace, J.H.},
 institution = {Oceanographic Research Institute 41},
 title = {The estuarine fishes of the east coast of South Africa: III Reproduction},
 year = {1975}
}
,@article{170198,
 author = {Whitefield, A.K},
 journal = {Ichthyological Monographs of the J.L.B. Smith Institute of Ichthyology},
 pages = {223},
 title = {Biology and ecology of fishes in southern Africa estuaries},
 volume = {2},
 year = {1998}
}
,@article{170198,
 author = {Hesp, S.A. Hall, N.G. and Potter, I.C.},
 journal = {Marine Biology},
 pages = {449--462},
 title = {Size-related movements of <i>Rhabdosargus sarba</i> in three different environments and their influence on estimates of von Bertalanffy growth parameters},
 volume = {144},
 year = {2004}
}
,@phdthesis{170198,
 author = {Hesp, S.A.},
 school = {Murdoch University},
 title = {Biology of two species of sparids on the west coast of Australia},
 year = {2003}
}
,@article{170198,
 author = {Whitley, G.P.},
 journal = {Australian Zoologist},
 number = {4},
 pages = {310--334, 1 fig. plates 25--27},
 title = {New names for Australian fishes},
 volume = {6},
 year = {1931}
}
,@article{170198,
 author = {El-Agamy, A.E.},
 journal = {Journal of the Marine Biological Association of India},
 pages = {129--137},
 title = {Biology of Sparus sarba Forskal from the Quatari water, Arabian Gulf},
 volume = {31},
 year = {1989}
}
,@article{170198,
 author = {Hesp, S.A. and Potter, I.C.},
 journal = {Journal of the Marine Biological Association of the UK},
 title = {Reproductive biology of the tarwine <i>Rhabdosargus sarba</i> (Sparidae) in three different environments on the west coast of Australia},
 year = {2003}
}
,@article{170198,
 author = {James, N.C., Mann, B.Q. and Radebe, P.V.},
 journal = {African Journal of Aquatic Science},
 number = {1},
 pages = {67--74},
 title = {Mortality estimates and biological reference points for the Natal stumpnose Rhabdosargus sarba (Pisces: Sparidae) in KwaZulu-Natal, South Africa},
 volume = {29},
 year = {2004}
}
,@article{170198,
 author = {Mann, B.Q. and Pradervand, P.},
 journal = {African Journal of Aquatic Science},
 number = {2},
 pages = {133--138},
 title = {Declining catch per unit effort of an estuarine-dependent fish, Rhabdosargus sarba (Teleostei: Sparidae), in the marine environment following closure of the St Lucia estuarine system, South Africa},
 volume = {32},
 year = {2007}
}
,@article{170198,
 author = {Munro},
 journal = {Memoirs of the Queensland Museum},
 number = {4},
 pages = {182--223},
 title = {Revision of Australian silver breams Mylio and Rhabdosargus},
 volume = {12},
 year = {1949}
}
,@article{170198,
 author = {Radebe, P.V., Mann, B.Q, Beckley, L.E. & Govender, A.},
 journal = {Fisheries Research},
 number = {(2)},
 pages = {193--201},
 title = {Age and growth of Natal stumpnose Rhabdosargus sarba (Pisces: Sparidae), from KwaZulu-Natal, South Africa},
 volume = {58},
 year = {2002}
}
,@article{170198,
 author = {Whitley, G.P.},
 journal = {Proceedings of the Linnaean Society of NSW},
 number = {(1)},
 pages = {11--127},
 title = {A survey of Australian Ichthyology},
 volume = {89},
 year = {1964}
}
,@article{170198,
 author = {Yeung, W.S. and S.T. Chan},
 journal = {Journal of Zoology},
 number = {(3)},
 pages = {521--532},
 title = {The gonadal anatomy and sexual pattern of the protandrous, sex reversing fish, Rhabdosargus sarba (Teleostei: Sparidae)},
 volume = {212},
 year = {1987}
}
,@book{170198,
 address = {Berlin},
 author = {Smith, M.M. and Heemstra, P.C.},
 publisher = {Springer-Verlag},
 title = {Smiths' sea fishes},
 year = {1986}
}
,@article{170198,
 author = {Grandcourt, E., Al Abdessalaam, T.Z., Francis, F. and Al Shamsi, A.},
 journal = {Journal of Applied Ichthyology},
 pages = {1--9},
 title = {Demographic parameters and status assessments of <i>Lutjanus ehrenbergii</i>, <i>Lethrinus lentjan</i>, <i>Plectorhinchus sordidus</i> and <i>Rhabdosargus sarba</i> in the southern Arabian Gulf},
 year = {2011}
}
,@techreport{170198,
 address = {Durban},
 author = {Mann, B.Q.},
 institution = {Oceanographic Research Institute},
 title = {St. Lucia Marine Reserve surf-zone fish monitoring and tagging project: a 10 year analysis},
 year = {2012}
}
,@article{170198,
 author = {Hughes, J.M., Stewart, J., Kendall, B.W. and Gray, C.A.},
 journal = {Marine and Freshwater Research},
 pages = {1111–1123},
 title = {Growth and reproductive biology of tarwhine <i>Rhabdosargus sarba</i> (Sparidae) in eastern Australia},
 volume = {59},
 year = {2008}
}
,@article{170198,
 author = {Potter, I.C. and Hyndes, G.A.},
 journal = {Australian Journal of Ecology},
 pages = {395–421},
 title = {Characteristics of the ichthyofaunas of southwestern Australian estuaries, including comparisions with holarctic estuaries elsewhere in temperate Australia: A review},
 volume = {24},
 year = {1999}
}
,@techreport{170198,
 author = {Malseed, B. E. and Sumner, N. R.},
 institution = {Western Australian Department of Fisheries},
 title = {A 12-month survey of recreational fishing in the Swan-Canning Estuary basin of Western Australia during 1998-99},
 year = {2001}
}
,@inbook{170198,
 address = {Perth},
 author = {},
 booktitle = {South Coast nearshore and estuarine finfish resources status report},
 editor = {Smith, K., Brown, J., Howard, A. and Stadler, M.},
 pages = {266--278},
 title = {Status reports of the fisheries and aquatic resources of Western Australia 2011/2012: The State of the Fisheries.},
 year = {2012}
}
,]

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