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

Taxa
Acropora arabensis | Hodgson & Carpenter, 1995
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
Invertebrates
Taxonomic Group Level 2
Corals
Assessed taxon level
Species
Taxon distribution as listed in assessment
This species found throughout the entire Gulf (Riegl et al. 2012). In UAE waters, it is known from both coasts (Grandcourt 2007, Riegl et al. 2012); however, acroporids have been largely extirpated from the UAE (Grizzle et al. 2016, Burt et al. 2019). Overall, only about 132 km<sup>2</sup> of coral reef habitat remains in UAE waters (Grizzle et al. 2016), though another estimate suggests coral habitat may be higher, up to 310 km<sup>2</sup> in Abu Dhabi alone (AED 2016); however, the cover of Acropora throughout much of the UAE is negligible. Elsewhere, this species has been reported from disjunct localities including the Red Sea, the Gulf of Aden, and northwestern Madagascar. However, it was originally described from Kuwait and there remains some question about the validity of the records outside of the Gulf.
Habitats and Ecology
Ecological system type
Terrestrial system
No
Freshwater system
No
Marine system
Yes
Habitat
Habitat details as listed in assessment
This species occurs on shallow reefs. It is found on the upper reef slopes and lagoons. This species is found from 0.5-12 m depth.The age of first maturity of most reef building corals is typically three to eight years (Wallace 1999) and therefore we assume that average age of mature individuals is greater than eight years. Total longevity is not known, but likely to be more than ten years. Furthermore, based on average sizes and growth rates, we assume that average generation length is 10 years, unless otherwise stated. Therefore any population decline rates for the Red List assessment are measured over at least 30 years.
Is there a map available in assessment?
Yes
Assessed status
Asessment status in full
Critically Endangered
Assessment status abreviation
CR
Assessment status criteria
A2bc
Assessment rationale/justification
This acroporid coral is common but infrequent along both coasts of the UAE. Acroporids were dominant coral species historically, but have largely been extirpated from reefs within UAE waters since the 1970s. The most important known threat for this species is extensive reduction of coral reef habitat due to a combination of threats. Species-specific population decline data are not available and therefore are inferred based on accelerating decline in coverage of Acropora from about 70% of coral cover in the 1970s to 1.4% in the 2010s. As a result, it is inferred that the population of this species has declined by at least 90% over the past three generations (30 years). Therefore, this species is listed as Critically Endangered A2bc. No regional adjustment is made to the Critically Endangered listing.
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
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
In the Gulf, the major threats to corals include extreme and increasing temperature variability due to climate change, as well as direct destruction and increased turbidity caused by coastal construction (Riegl et al. 2012). Although bleaching thresholds in the Gulf are the highest recorded in the world (Riegl et al. 2012), bleaching events in the UAE have resulted in significant mortality (such as in 1996-1998, 2002, 2010 and 2017) and slow recovery (Burt et al. 2008) as well as shifts in community structure (e.g,. Bento et al. 2016, Grizzle et al. 2016, Burt et al. 2019 ). In Abu Dhabi, the most recent coral bleaching event resulted in nearly 95% of corals bleaching, and by April 2018, mortality reached 73% (Burt et al. 2019). This event resulted in mass mortality of even the more stress-tolerant corals such as poritids and merulinids (Burt et al. 2019). Coastal development, particularly large-scale offshore real estate developments and sedimentation associated with reclamation, has directly buried coral reefs in the Gulf (Burt et al. 2008, 2013; Burt 2014; Burt and Bartholomew 2019). In the Sea of Oman, UAE reefs have experienced major hurricanes and harmful algal blooms that caused high coral mortality and shifted community structure (Bauman et al. 2010, Foster et al. 2011).Globally, the major threat to corals is global climate change, in particular, temperature extremes leading to bleaching and increased susceptibility to disease, increased severity of ENSO events and storms, and ocean acidification. Other threats include the crown-of-thorns starfish (Acanthaster planci), which has been observed preferentially preying upon corals of the genus Acropora (Colgan 1987). These voracious predators of reef-building corals are found throughout the Pacific and Indian Oceans, and the Red Sea. Populations of the crown-of-thorns starfish have greatly increased since the 1970s and have been known to wipe out large areas of coral reef habitat. Increased breakouts have become a major threat to some species, and have contributed to the overall decline and reef destruction in the Indo-Pacific region. The effects of such an outbreak include the reduction of abundance and surface cover of living coral, reduction of species diversity and composition, and overall reduction in habitat area. Coral disease has emerged as a serious threat to coral reefs worldwide and a major cause of reef deterioration (Weil 2006). The numbers of diseases and coral species affected, as well as the distribution of diseases have all increased dramatically within since the 1990s (Green and Bruckner 2000, Porter et al. 2001, Sutherland et al. 2004, Weil 2004). Coral disease epizootics have resulted in significant losses of coral cover and were implicated in the dramatic decline of acroporids in the Florida Keys (Aronson and Precht 2001b, Porter et al. 2001, Patterson et al. 2002). In the Indo-Pacific, disease is also on the rise with disease outbreaks recently reported from the Great Barrier Reef (Willis et al. 2004), Marshall Islands (Jacobson 2006) and the northwestern Hawaiian Islands (Aeby et al. 2006). Increased coral disease levels on the Great Barrier Reef were correlated with increased ocean temperatures (Willis et al. 2004), supporting the prediction that disease levels will be increasing with higher sea surface temperatures. Escalating anthropogenic stressors combined with the threats associated with global climate change of increases in coral disease, frequency and duration of coral bleaching and ocean acidification place coral reefs in the Indo-Pacific at high risk of collapse.Localized threats to corals include fisheries, human development (industry, settlement, tourism, and transportation), changes in native species dynamics (competitors, predators, pathogens and parasites), invasive species (competitors, predators, pathogens and parasites), dynamite fishing, chemical fishing, pollution from agriculture and industry, domestic pollution, sedimentation, and human recreation and tourism activities.
Conservation Measures

Conservation measures:
Conservation measures notes:
Required conservation measures:

Scientific Name Kingdom Phylum Class Order Family Genus
Acropora arabensis Animalia Cnidaria Anthozoa Scleractinia Acroporidae Acropora