Lethrinus nebulosus | UAE National Red List of Marine Species: Reef-building corals, cartilaginous fishes and select bony fishes

Taxa
Lethrinus nebulosus | (Forsskål, 1775)
Location
Countries in Assessment
United Arab Emirates
Country ISO code(s)
ARE
Does the assessment cover a marine EEZ area(s)?
Off
Scope (Assessment)
National
Taxon
Taxonomic Group
Vertebrates
Taxonomic Group Level 2
Fishes
Assessed taxon level
Species
Taxonomic Notes
Lethrinus nebulosus may represent a complex of species, and further taxonomic work is required (K. Carpenter pers. comm. 2015). A cryptic species under L. nebulosus was detected in a study off southeastern Africa, but further study is required to resolve the taxonomy and distribution (Healey et al. 2018).
Taxon distribution as listed in assessment
This species occurs throughout UAE waters. As is currently understood on the global-level, it is widespread in the Indo-West Pacific (Carpenter and Allen 1989). Its depth range is 0 to 90 m (R. Myers pers. comm. 2015).
Habitats and Ecology
Ecological system type
Terrestrial system
No
Freshwater system
No
Marine system
Yes
Habitat
Habitat details as listed in assessment
This species inhabits nearshore and offshore coral reefs, coralline lagoons, seagrass beds, mangrove swamps, coastal sand and rock areas to depths of 75 m (Carpenter and Allen 1989). It is occasionally observed in small aggregations (Randall 1995), but adults typically occur singly. It primarily consumes molluscs, crustaceans, echinoderms and less often polychaetes and fishes (Carpenter and Allen 1989). The maximum total length is 87 cm (Assadi and Dehghani 1997). This species undergoes a protogynous sex change that occurs over a wide range of year groups starting with age 1, well before maturity (McPherson et al. 1985). Longevity is estimated to be 14-26 years (Mathews and Samuel 1991, Edwards and Shaher 1991, Dalzell et al. 1996, Grandcourt 2006, Ebisawa and Ozawa 2009). Off the Ryukyu Islands of Japan, the age of 50% ovarian maturity was 4 years (Ebisawa and Ozawa 2009). This species forms spawning aggregations (Salem 1999). In the southern Arabian Gulf, spawning occurs between April to May, the mean size and age at first sexual maturity for males and females to be 19.4 cm and 0.5 years for males and 28.9 cm and 2.7 years for females, and maximum age was 11 years (Grandcourt et al. 2006 and 2010). When applying an age at first reproduction of 3 years and longevity of 11 years, its estimated generation length is 7 years based on the following equation recommended by the IUCN Red List methods: Age at first reproduction + (Age at last reproduction -“ age at first reproduction)/2.
Is there a map available in assessment?
Yes
Assessed status
Asessment status in full
Endangered
Assessment status abreviation
EN
Assessment status criteria
A2bcd+4bcd
Assessment rationale/justification
This inshore, reef-associated species occurs throughout UAE waters. It is heavily exploited in the UAE, and stock assessments conducted for Abu Dhabi in 2006, 2010 and 2018 reported it as overfished. Based on catch data and stock assessments, this species has undergone an inferred declined of at least 52-78% over the past two generation lengths, or 14 years. With recent fisheries management measures implemented in Abu Dhabi, it is difficult to say whether fishing effort will continue to increase or decrease within the near future. Considering that other Emirates and surrounding countries that likely share this stock do not have management measures in place to reduce effort in the gargoor fishery, population declines are expected to continue. In addition, degradation of coastal habitats in the UAE and Arabian Gulf region, especially for coral reefs, is expected to continue. The population in UAE is inferred to have some level of connectivity with those in surrounding countries, and declines have been reported from Saudi Arabia, Qatar and Kuwait. It is listed as Endangered A2bcd+A4bcd. In addition to improvements needed in fisheries management, taxonomic research is also recommended.
About the assessment
Assessment year
2019
Assessors/contributors/reviewers listed
UAE National Red List Workshop
Affliation of assessor(s)/contributors/reviewers listed on assessment
Government
IGO
Assessor affiliation specific
Government|IGO
Criteria system
Criteria system specifics
IUCN v3.1 + Regional Guidelines v4.0
Criteria system used
IUCN
Criteria Citation
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.
Endemism
Endemic to region
Not_assigned
Endemism Notes
Is an endemic?: Not_assigned
Conservation
Threats listed in assessment
Overfishing is a major threat to this species in the Arabian Gulf. Corals in the UAE and Arabian Gulf have severely declined due to the increasing frequency of mass bleaching events caused by rising water temperatures, which is a consequence of climate change, as well as pervasive coastal development (Riegl et al. 2018, Burt et al. 2019).
Conservation Measures

Conservation measures:
Conservation measures notes:
Required conservation measures:

Scientific Name Kingdom Phylum Class Order Family Genus
Lethrinus nebulosus Animalia Chordata Actinopterygii Perciformes Lethrinidae Lethrinus