Do sawfish Pristis spp. represent South Africa's first local extirpation of marine elasmobranchs in the modern era?§

@article{Everett2015DoSP,
  title={Do sawfish Pristis spp. represent South Africa's first local extirpation of marine elasmobranchs in the modern era?§},
  author={B. I. Everett and Geremy Cliff and S. F. J. Dudley and S P Wintner and RP van der Elst},
  journal={African Journal of Marine Science},
  year={2015},
  volume={37},
  pages={275 - 284}
}
Largetooth sawfish Pristis pristis and green sawfish P. zijsron were not uncommon in catches made in KwaZulu‑ Natal (KZN) on the east coast of South Africa in the mid part of the last century but apparently have disappeared from this area. This paper traces the decline in sawfish catches from 1951 and assesses the current population status and local extinction risk, based on historical and current records up to 2012. Records were collected from research surveys, literature, media and museum… 
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References

SHOWING 1-10 OF 97 REFERENCES
Cultural importance and decline of sawfish (Pristidae) populations in West Africa
TLDR
The strong contraction of the distribution range of sawfishes in West Africa is confirmed: they are mainly limited to the Bissagos Archipelago (Guinea Bissau), where cultural practices related to sawfish symbolism are still in use.
Distribution of sawfishes (Pristidae) in the Queensland Gulf of Carpentaria, Australia, with notes on sawfish ecology
  • S. Peverell
  • Environmental Science
    Environmental Biology of Fishes
  • 2005
TLDR
Observations on reproductive staging and the capture of neonate specimens suggest that in all four pristids, pupping occurred through the wet season until the beginning of the dry season in May, and a seasonal set net closure for the barramundi, Lates calcarifer and shark fisheries, therefore offers a measure of protection to breeding female sawfish and their offspring.
Status and the potential for extinction of the largetooth sawfish Pristis pristis in the Atlantic Ocean
Sawfishes currently are among the most threatened elasmobranchs in the world. Only two species inhabit Atlantic waters: the largetooth sawfish (Pristis pristis) and the smalltooth sawfish (Pristis
Sawfish (Pristidae) of the Gulf of Carpentaria, Queensland, Australia
TLDR
The findings from the LAICPMS analysis support the hyppothesis that P. microdon utilise freshwater, estuarine Sawfish (Pristidae) of the Gulf of Carpentaria, Queensalnd Australia vii and marine habitats during different stages of their life history.
Freshwater Sawfish Pristis microdon Latham, 1794 (Chondrichthyes : Pristidae) in the Kimberley region of Western Australia
TLDR
Observations of sexual maturity, annuli present on vertebrae, recaptures of tagged individuals and length-frequency data suggested that the freshwaters of the Fitzroy River are a nursery for this species where immature individuals remain for a maximum of four or five years.
Species delineation and global population structure of Critically Endangered sawfishes (Pristidae)
TLDR
It is shown that populations of sawfish exhibit significant geographic structuring across their respective ranges, meaning that regional-level conservation will be required, and the NADH-2 gene may serve as a marker for the identification of rostra and fins involved in illegal trade.
Population status of 14 shark species caught in the protective gillnets off KwaZulu-Natal beaches, South Africa, 1978-2003
TLDR
The potential effect of the shark nets was assessed to be high for two species (Carcharhinus obscurus and Carcharias taurus, neither of which showed declines in catch rate or length), because of very low intrinsic rates of population increase.
Ghosts of the coast: global extinction risk and conservation of sawfishes
TLDR
Sawfish are among the world's largest marine fishes, and they are caught by a wide range of fishing gears owing to their tooth-studded rostra being easily entangled, and their rostra have long been traded as curios.
Ontogenetic depth partitioning by juvenile freshwater sawfish (Pristis microdon: Pristidae) in a riverine environment
TLDR
The utility of acoustic telemetry in monitoring P. microdon in a riverine environment is demonstrated and the need to consider the habitat requirements of different P.microdon cohorts in the strategic planning of natural resources will aid the development of management strategies for this species.
Lake St Lucia, Africa's largest estuarine lake in crisis: Combined effects of mouth closure, low levels and hypersalinity
The Lake St Lucia estuarine system is the most important nursery ground for juvenile marine fish and prawns along the KwaZulu-Natal coast. The estuary mouth closed in June 2002 because of drought and
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