Taxon name
Eusphyra blochii
(Cuvier, 1816)
Uploaded by
National Red List Database
Taxonomic information
Scientific name
Eusphyra blochii
(Cuvier, 1816)
Assessed taxon level
Species
Higher level taxonomic groupings
Vertebrates
Fishes
Species authority
(Cuvier, 1816)
Location and scope
Specific locality or subnational name or regional name
United Arab Emirates (the)
Scope (of the Assessment)
National
Countries included within the scope of the assessment
United Arab Emirates (the)
Does the assessment cover a marine EEZ area(s)?
Not_assigned
Conservation Status
Assessed as
Critically Endangered
Qualifying criteria (if given)
A2d
Criteria system used
IUCN
(see Assessment details)
Assessment rationale/justification
In UAE waters, the Winghead Shark has only been confirmed from coastal waters on the Sea of Oman coast. No information on catch in the UAE is available, but it is taken in gill net, longline and bottom trawl fisheries in the Arabian Seas region. Anecdotal evidence from India and Pakistan suggests this species has drastically declined over the past 30-40 years. Furthermore, significant declines in landings of commercial shark species have been documented in the Arabian Sea region with other more abundant hammerhead species suspected to have declined by at least 50-80% over the past three generations. Although there are limited data on its status, other shark species in the Arabian Gulf have undergone significant declines due to exploitation. It is apparently highly migratory, and has slow life history characteristics including low fecundity and a low annual rate of population increase. Considering this, the species has a low capacity to recover from even moderate levels of exploitation. It is especially susceptible to exploitation (target and bycatch) in many largely unregulated gill net, longline and trawl fisheries that operate within its range outside and surrounding UAE waters. Some management measures are now in place in the Arabian Sea region, although domestic fisheries are likely to continue. Though data specifically from the UAE are not available, individuals in the UAE are a component of a larger, interconnected and migratory population that occurs broadly in the north-western Indian Ocean. It is inferred that declines reported in the Arabian Sea region are representative of its status in the UAE. Based on recorded levels of exploitation, it is suspected to have declined by at least 80% over the past three generation lengths, or about 42 years. It is listed as Critically Endangered A2d.
Assessment details
Assessors/contributors/reviewers listed
UAE National Red List Workshop
Criteria system used
IUCN
Reference for methods given
IUCN. 2012. IUCN Red List Categories and Criteria: Version 3.1, Second edition. IUCN, Gland, Switzerland and Cambridge, UK. iv + 32pp pp. And IUCN. 2012. Guidelines for Application of IUCN Red List Criteria at Regional and National Levels: Version 4.0. Gland, Switzerland and Cambridge, UK: IUCN. iii + 41pp.
Further information
Endemism (according to assessment)
Endemic to region
Not assigned
Taxon distribution as listed in assessment
The Winghead Shark occurs in UAE waters on the Sea of Oman coast (Randall 1986, Randall 1995, Environment Agency Abu Dhabi unpublished data). Records from the Arabian Gulf require verification (Ali et al. 2018). Carpenter (1997) also notes that the species' range includes the Arabian Gulf. Globally, it is widespread in the Indo-West Pacific (Last and Stevens 2009).
Is there a map available in assessment?
Yes
Habitat and systems
Ecological system type
Habitat
Habitat details as listed in assessment
The Winghead Shark occurs on continental shelves and is mainly found in coastal nearshore waters, including muddy river deltas and estuaries (Ebert et al. 2013). It attains a maximum size of 186 cm total length (TL) with males maturing at around 108 cm TL and females at 120 cm TL (Stevens and Lyle 1989). Females produce litters of 6-“25 (mean = 11) every year after a gestation period of 8 to 11 months with size at birth at approximately 32-47 cm TL (Compagno 1984, Stevens and Lyle 1989). This is a slow growing species that reaches maturity at 7.2 years for females and 5.5 years for males. The oldest documented maximum age is 21 years according to vertebral analysis (Stevens and Lyle 1989, Smart et al. 2013). Age at maturity was calculated from Last and Stevens (2009) female size at maturity data and Smart et al. (2013) von Bertalanffy growth estimates. Based on these data, generation length is estimated to be 14 years.
Threats and conservation measures listed
Threats listed in assessment
Information pertaining to threats specific to the UAE are unavailable. This species is impacted by target and bycatch fisheries that are active elsewhere in its range.
Publication
Ralph, G.M., Stump, E., Linardich, C., Bullock, R.W., Carpenter, K.E., Allen D.J., Hilton-Taylor, C., Al Mheiri, R., and Alshamsi, O. 2021. UAE National Red List of Marine Species: Reef-building corals, cartilaginous fishes and select bony fishes. 2021. Ministry of Climate Change and Environment, Dubai, United Arab Emirates.