I recently came across a 2017 study by Buckley et al. evaluating the future sustainability and current population figures of threatened captive sharks and rays in Australian aquariums and zoos. The researchers defined a sustainable population as either self-maintaining or to possess the ability to harvest animals from a source population that wouldn’t lower the overall population to unsustainable numbers. Out of the threatened species mentioned, the study concluded that two species were found to have unsustainable captive populations in Australian public facilities – the Grey Nurse Shark, Carcharias taurus, and the Largetooth Sawfish, Pristis pristis.
The researchers collected data on the threatened species from the ZAA Census discussing that at the time of writing there were 739 individuals across 46 elasmobranch species in Australian facilities. 58.7% of these species in Australia have either exhibited breeding behaviour or have bred in captivity exceeding the global average of 47.7%. In 2015, Australian facilities displayed 16 species that were threatened or DD [Data Deficient]. I should note this is not a full nor current summary especially considering Cairns Aquarium wasn’t even open yet during the data collection.
Study: https://www.researchgate.net/public...th_a_case_study_of_Australian_sharks_and_rays
*Nervous Shark, Carcharhinus cautus – one individual in captivity.
*Dusky Whaler, Carcharhinus obscurus – 11 individuals in captivity.
*Sandbar Whaler, Carcharhinus plumbeus – six individuals in captivity.
*Speartooth Shark, Glyphis glyphis – three individuals in captivity [Sea Life Melbourne] that were collected from the wild to commence a planned breeding programme. No breeding activity had been reported and there were no plans to collect further stock.
*Sharptooth Lemon Shark, Negaprion acutidens – six individuals in captivity.
*Estuary Stingray, Hemitrygon fluviorum – 113 individuals in captivity with one facility housing 111 individual stingrays being a robust breeding group. In 2015, one aquarium planned to acquired 10 females to join their lone male but the source of this acquisition was not specified.
*Leopard Whipray, Himantura leoparda – five individuals in captivity.
*Blotched Fantail Whipray, Taeniurops meyeni – 33 individuals in captivity.
*Mangrove Whipray, Urogymnus granulatus – five individuals in captivity.
*Tawny Nurse Shark, Nebrius ferrugineus – 14 individuals in captivity.
*Giant Shovelnose Ray, Glaucostegus typus – 24 individuals in captivity.
*Grey Nurse Shark, Carcharias taurus – 15 individuals in captivity with planned wild harvests to support the breeding programme. Eight sharks had been born since 1995 but only two have survived with the majority being stillborn. Since 2002 there has been a moratorium on public harvests as supplying these sharks to public aquaria has been identified as a secondary threat. It is predicted that without population supplementation, Grey Nurse Sharks will disappear from Australian public aquaria in the next 30 years.
*Largetooth Sawfish, Pristis pristis – 11 individuals with no plans for breeding and future wild harvests are proposed as they are allowed in Queensland and the Northern Territory for display and education purposes. The majority of sawfish are rereleased when they reach a size the facility cannot accommodate.
*Bowmouth Guitarfish, Rhina ancylostoma – one individual in captivity.
*White-spotted Guitarfish, Rhynchobatus australiae – three individuals in captivity.
*Leopard [Zebra] Shark, Stegostoma fasciatum – 14 individuals in captivity.
The researchers collected data on the threatened species from the ZAA Census discussing that at the time of writing there were 739 individuals across 46 elasmobranch species in Australian facilities. 58.7% of these species in Australia have either exhibited breeding behaviour or have bred in captivity exceeding the global average of 47.7%. In 2015, Australian facilities displayed 16 species that were threatened or DD [Data Deficient]. I should note this is not a full nor current summary especially considering Cairns Aquarium wasn’t even open yet during the data collection.
Study: https://www.researchgate.net/public...th_a_case_study_of_Australian_sharks_and_rays
*Nervous Shark, Carcharhinus cautus – one individual in captivity.
*Dusky Whaler, Carcharhinus obscurus – 11 individuals in captivity.
*Sandbar Whaler, Carcharhinus plumbeus – six individuals in captivity.
*Speartooth Shark, Glyphis glyphis – three individuals in captivity [Sea Life Melbourne] that were collected from the wild to commence a planned breeding programme. No breeding activity had been reported and there were no plans to collect further stock.
*Sharptooth Lemon Shark, Negaprion acutidens – six individuals in captivity.
*Estuary Stingray, Hemitrygon fluviorum – 113 individuals in captivity with one facility housing 111 individual stingrays being a robust breeding group. In 2015, one aquarium planned to acquired 10 females to join their lone male but the source of this acquisition was not specified.
*Leopard Whipray, Himantura leoparda – five individuals in captivity.
*Blotched Fantail Whipray, Taeniurops meyeni – 33 individuals in captivity.
*Mangrove Whipray, Urogymnus granulatus – five individuals in captivity.
*Tawny Nurse Shark, Nebrius ferrugineus – 14 individuals in captivity.
*Giant Shovelnose Ray, Glaucostegus typus – 24 individuals in captivity.
*Grey Nurse Shark, Carcharias taurus – 15 individuals in captivity with planned wild harvests to support the breeding programme. Eight sharks had been born since 1995 but only two have survived with the majority being stillborn. Since 2002 there has been a moratorium on public harvests as supplying these sharks to public aquaria has been identified as a secondary threat. It is predicted that without population supplementation, Grey Nurse Sharks will disappear from Australian public aquaria in the next 30 years.
*Largetooth Sawfish, Pristis pristis – 11 individuals with no plans for breeding and future wild harvests are proposed as they are allowed in Queensland and the Northern Territory for display and education purposes. The majority of sawfish are rereleased when they reach a size the facility cannot accommodate.
*Bowmouth Guitarfish, Rhina ancylostoma – one individual in captivity.
*White-spotted Guitarfish, Rhynchobatus australiae – three individuals in captivity.
*Leopard [Zebra] Shark, Stegostoma fasciatum – 14 individuals in captivity.
