Arabian Persian Gulf Research Articles

Two new records of marine bivalves Sheldonella lateralis (Reeve, 1844) and Periglypta crispata (Deshayes, 1854) from the Iraqi coast, Persian-Arabian Gulf

The goal of this research is to acquire new information on the distribution of bivalves along the Iraqi coastline. Between 2020 and 2021, new records of marine bivalves, Sheldonella lateralis (Reeve, 1844) and Periglypta crispata (Deshayes, 1854) were discovered near the Iraqi coast in the northwestern Persian-Arabian Gulf.

New record of amphipod Elasmopus alkhiranensis (Myers and Momtazi, 2015) from the breakwaters at Faw city, Iraq

One male specimen of the new record amphipod Elasmopus alkhiranensis (Myers and Momtazi, 2015) previously recorded from Iraq was discovered. The specimen was collected alive from the intertidal zone at the breakwaters of Faw city on the Iraqi coast. Although this species is widespread in the Persian-Arabian Gulf, our study is the first to report it along the Iraqi coast.

An annotated checklist of the Amphipoda (Crustacea) of the Iraqi coast, north-western Persian- Arabian Gulf

Amphipods are one of the most diverse groups of peracarid crustaceans, living in both marine and fresh waters, including underground and semi-terrestrial settings. Data about amphipods from the Iraqi coast are spread throughout valid published and confused published references. So, a checklist of the amphipods of the Iraq coast is presented listing 8species belonging to six families, using published records and field observations. The present paper shows that the list of amphipoda from the Iraqi coast is very limited compared with lists of other adjacent countries on the Persian-Arabian Gulf close to Iraq.

First record of Dosinia prostrata (Linnaeus, 1758) (Bivalvia: Veneridae) from the Iraqi coast

The objective of this study is to collect novel data on the distribution of bivalves along the Iraqi coastline. Between 2020 and 2021, a new record of the bivalve Dosinia prostrata (Linnaeus, 1758) was discovered along the Iraqi coast in the northwestern Persian-Arabian Gulf.

Rapid diversification of grey mangroves (Avicennia marina) driven by geographic isolation and extreme environmental conditions in the Arabian Peninsula.

Biological systems occurring in ecologically heterogeneous and spatially discontinuous habitats provide an ideal opportunity to investigate the relative roles of neutral and selective factors in driving lineage diversification. The grey mangroves (Avicennia marina) of Arabia occur at the northern edge of the species' range and are subject to variable, often extreme, environmental conditions, as well as historic large fluctuations in habitat availability and connectivity resulting from Quaternary glacial cycles. Here, we analyse fully sequenced genomes sampled from 19 locations across the Red Sea, the Arabian Sea and the Persian/Arabian Gulf (PAG) to reconstruct the evolutionary history of the species in the region and to identify adaptive mechanisms of lineage diversification. Population structure and phylogenetic analyses revealed marked genetic structure correlating with geographic distance and highly supported clades among and within the seas surrounding the Arabian Peninsula. Demographic modelling showed times of divergence consistent with recent periods of geographic isolation and low marine connectivity during glaciations, suggesting the presence of (cryptic) glacial refugia in the Red Sea and the PAG. Significant migration was detected within the Red Sea and the PAG, and across the Strait of Hormuz to the Arabian Sea, suggesting gene flow upon secondary contact among populations. Genetic-environment association analyses revealed high levels of adaptive divergence and detected signs of multi-loci local adaptation driven by temperature extremes and hypersalinity. These results support a process of rapid diversification resulting from the combined effects of historical factors and ecological selection and reveal mangrove peripheral environments as relevant drivers of lineage diversity.

Increasing knowledge to restore oyster beds and related services in the Arabian-Persian Gulf

The historical collapse of the pearl oyster ecosystem in the Arabian-Persian Gulf contributed to the long-term loss of biological and economic functionality within key shallow-water marine environments. This study introduces important aspects for supporting the restoration of this iconic ecosystem. For instance, resident standing stocks in the southwestern ecoregion would be ideal for an aquaculture initiative; juveniles might be collected after the summer; lower regional salinity (42ppt) might increase the animal sizes in an aquaculture basis; shallow areas near seagrasses might be ideal coastal areas for reintroduction; vertical hard substrates (e.g. artificial reefs) might be used for juvenile’s reintroduction. The results suggest that Pinctada radiata is and was the dominant habitat enhancer within the historical and present ecosystem complexes of the studied Gulf and should be considered a priority species for restoration due to its habitat remediation service. Restoring the filtration functionality of these oyster seascapes and the associated recovery of the trophic chain could also support the rejuvenation of accompanying seascapes within the studied Gulf, such as coral reefs, seagrasses, and the associated fish stock. Illustrating how the southwestern Arabian-Persian Gulf coast presents a unique opportunity to restore and manage an iconic habitat and historical natural asset.

The mid-Holocene sea-level change in the Arabian Gulf

The mid-Holocene sea-level highstand is a well-known phenomenon in sea-level science, yet the knowledge on the highstand’s spatial and temporal distribution remains incomplete. Here we study the southwest coast of the Arabian-Persian Gulf where a mid-Holocene sea-level highstand and subsequent sea-level fall may have occurred due to the Earth crustal response to meltwater load. Sea-level indicators were established using standard facies analysis and error calculations, then constrained through glacio-isostatic adjustment (GIA) modelling and though procedures based on Gaussian Process and exponential decay analysis. This work allowed to identify the highstand at 1.6 ± 0.4 m occurring 6.7–6.0 ka, in excellent agreement with GIA model results. The subsequent shoreline migration followed the geophysical constraint by prograding in line with the sea-level fall until around 3 ka. Then, the strength of the external control weakened and internal processes, in particular sediment binding through microbial activity, started controlling the geometry of the accommodation space.

The Voice of an Asian Expat in a Qatari Short Story by Nurah Al-Saad: The Newspaper Seller

Qatari literature is still budding, as its diffusion can be credited to the birth of the press in the 1960s, and it is yet to have garnered the attention of Western scholars, especially if compared to the literature from Arabian Persian Gulf countries, such as Kuwait, Oman and Saudi Arabia. This study aims at contributing to enrich the discourse on Qatari literature, by analysing the structure and contents of the short story The Newspaper Seller, published in 1989 by Nurah al-Saad (Nūrah ˀāl Saˁad). This piece offers the reader a precious insight about the reality of expats’ lives in the 1980s. The story depicts the harsh daily routine of an Asian immigrant, who attempts to survive by selling newspapers under the scorching sun in the streets of Doha. The main character, named Malik (Mālik), has just moved away from his family and is now dreaming of a better future, while finding himself in an entirely different reality: he is forced to work two jobs, in order to be able to live with some dignity and to help his family of origin. This short story was highly acclaimed by literary critics. Due to its original topic and narrative techniques, through the use of interior monologue, associations, stream of consciousness and symbols, it is considered a pioneering work for that time.

Additional records of marine bivalves from Iraq, with a provisional checklist for the marine bivalves of Iraq

Specimens of four species of Bivalvia not previously recorded from Iraq were discovered. These are Didimacar tenebrica, Aspidopholas obtecta, Neotrapezium sublaevigatum, and Barbatia trapezina which belong to the Noetiidae, Pholadidae, Trapezidae and Arcidae families, respectively. All specimens were collected alive from the intertidal zone of the northwest Persian-Arabian Gulf, Iraq, in the Fao region. Although these species are widespread in the Persian-Arabian Gulf, our study is the first to report them along the Iraqi coast. A provisional checklist of marine bivalves of Iraq is presented listing 32 species of which 21 have been verified from specimens or photographs. This list is compared with data from adjacent coasts of Kuwait and Iran.

First record of Octopus vulgaris (Cuvier, 1797) (Octopodidae) in the Iraqi coastal waters, NW Arabian Gulf

The present study identifies one species of the genus Octopus in the order: Octopoda (Cephalopoda: Mollusca), recorded forthe first time in the Iraqi coastal waters and Arabian-Persian Gulf. The study extended from January 2019 to December of thesame year. The Octopus specimens were seasonally obtained from the fishing trawlers operating in the Iraqi coastal waters inthe South of Al- Fao District, Basrah- Iraq, NW Arabian Gulf. The Octopus was identified as O. vulgaris in Iraqi coastal watersdepending on morphological features. The habitats of living specimens are briefly described. Some observations were reported on the occurrence of this species and the measurement of some environmental factors. The species was identified up to spe-cies level using standard literature. This species looks similar morphologically to the species which is already identified from the other areas around the world. The present study records significant expansion in the distribution range of this species.

Burrowing crabs in arid mangrove forests on the southwestern Arabian Gulf: Ecological and biogeographical considerations

Many species of mangrove crabs are essential in the formation of mangrove ecosystems, and the bioturbation resulting from the excavation of their underground chambers is directly correlated with substrate oxygenation and carbon and nitrogen cycling within the ecosystem. This study examines the ecological and biogeographical characteristics of bioengineering crab assemblages that inhabit the environmentally challenging arid mangroves in the southwestern Persian-Arabian Gulf. Results demonstrated that a hyper-arid environment could directly impact crab diversity, reducing it to only one species per niche or coastal zone. A biogeographic comparison revealed an exclusive divergence of species composition in each Gulf region. Variations in seasonal temperatures were found to have a direct influence on the abundance of species and how the zonation is driven by sediment composition and trophic relations. Two crabs – Nasima dotilliformis in the salt march (supratidal zone) and Macrophthalmus (Mareotis) depressus in the intertidal – were considered to be the most influential functional species for this hyper-arid ecosystem due to their abundance, size, bioturbation potential and niche specificity for the intertidal zone. The limited number of species within the arid mangrove system emphasised the biogeographic pressure and inherent importance of the few active bioengineering species present and adapted to the harsh conditions, indicating that the dominant crabs within the biotope are directly related to the successful evolutionary establishment of these hyperarid mangroves. The study highlights important implications for future forest management strategies of the only forest ecosystem that tolerates the extremes of the southwestern Persian-Arabian Gulf area.

A new record of the Indo-Pacific species, Belzebub hanseni (Nobili, 1905) (Crustacea; Decapoda; Luciferidae) from north western Persian-Arabian Gulf

Specimens of Belzebub hanseni (Nobili, 1905) were collected from North Western Persian-Arabian Gulf July 2012. Morphological features of this species are given to confirm the identification.

A new record of Dorippe quadridens (Fabricius, 1793) (Decapoda, Brachyura, Dorippidae) from the north western Persian-Arabian Gulf, Iraq

In the present note the crab Dorippe quadridens is reported for first time from the north western Persian-Arabian Gulf, Iraq. This species is widely distributed in the Persian-Arabian Gulf. Details of the morphological characters of the species are given.

The first record of the Indo-Pacific benthic ctenophore Coeloplana (Benthoplana) meteoris (Ctenophora: Coeloplanidae) in the Arabian-Persian Gulf

This report presents the first occurrence of the Indo-Pacific benthic ctenophore Coeloplana (Benthoplana) meteoris (Thiel, 1968) in the western part of the Arabian-Persian Gulf, extending its range to 2000km, a record that illustrates a cyclic event observed in the Marine Arabic Province. The seasonal biodiversity influx of invertebrates from the Indian Ocean that establish themselves for a short period of time in the west of the Gulf before the extreme high temperatures takes place in the summer.

Drought severity and increased dust storm frequency in the Middle East: a case study from the Tigris–Euphrates alluvial plain, central Iraq

An increase in dust and sand storms has been experienced in Iraq over recent times and seems likely to increase further under future climate change. Iraq is now known as a highly active source region of dust. The impact of dust storms affects most of Iraq and extends to include large parts of Iran, Kuwait, Saudi Arabia, and the Arabian-Persian Gulf. Dust storms are a regional strategic problem for arid and semi-arid regions that have an impact on many different aspects of human life. The problem has been exacerbated by high temperatures and changing precipitation distribution patterns and has resulted in many direct environmental impacts. These include agriculture, food security, rural-urban migration, changes in the pattern of land use, effects on biodiversity and negative health effects of air pollution. It is therefore important to describe dust storm frequency and determine which climatic factors are most significant in driving dust storm fluctuations in order to take the necessary measures to avoid or reduce these negative environmental effects. This paper explores the relationship between drought, wind speed and dust storms in Iraq, including their emergence, frequency and extent. Drought was determined using the Standardized Precipitation Index (SPI) applied to 36-year–long datasets (1977 to 2012) from four locations (Baghdad, Hai in Wasit, Diwaniyah, Nasiriyah in Thi Qar, all in central Iraq). Drought intensities have increased significantly from 2008-2012 in all weather stations, coincident with high dust frequencies. Comparison of monthly wind speed and dust variables for the four weather stations all showed statistically significant relationships, indicating that wind speed is associated with dust storms of all kinds in arid and semi-arid regions such as Central Iraq.

A new record of Eurycarcinus orientalis A. Milne-Edwards, 1867 (Decapoda, Brachyura, Pilumnidae) from the north western part of the Persian-Arabian Gulf

The present note lists the first record of the pilumnid crab Eurycarcinus orientalis from the north western part of the Persian-Arabian Gulf, Iraq, in the muddy area of Fao region. Morphological features and distribution information are given.

Fine-Scale Biogeographical Boundary Delineation and Sub-population Resolution in the Symbiodinium thermophilum Coral Symbiont Group From the Persian/Arabian Gulf and Gulf of Oman

The adaptation of tropical coral communities to the world’s hottest sea, the Persian / Arabian Gulf (PAG), has recently been associated with ecological selection acting on a group of coral-associated algal symbionts, the Symbiodinium thermophilum group. Previous studies have shown that considerable genetic diversity exists within the group and that group members found within the PAG are significantly differentiated from those found externally, in the Gulf of Oman and wider waters. However, little is known about this genetic diversity. As an initial step towards understanding whether this diversity could represent niche adapted, selectable populations within the S. thermophilum group that may act as natural sources of stress tolerant associations to Indo-Pacific reefs, we investigate whether the diversity is structured between populations and where the location of the internal-external genetic partition lies. We use regions of the nuclear ribosomal DNA (ITS1-5.8S-ITS2) and chloroplastic psbA gene (non-coding region) from > 100 S. thermophilum group-harbouring Porites spp. (P. lobata, P. lutea and P. harrisoni) sampled across steep temperature and salinity gradients to conduct analyses of variance and create maximum parsimony networks to assess genetic structure and (dis)similarity within and between populations of S. thermophilum found within the PAG and externally in the Gulf of Oman. Our analyses resolve a sharp genetic boundary between Symbiodinium populations in the western Strait of Hormuz and identify significant genetic structure between populations with as little as 20km between them demonstrating that differentiation between populations is likely due to factors other than limited connectivity. Further, we hypothesize that genotypes identified outside of the PAG in the Gulf of Oman existing in near-oceanic salinities, yet thermally challenging waters, putatively represent candidates for stress-tolerant symbionts that could act as natural seed populations of stress tolerant genotypes to the wider indo-Pacific.

Demographic Mechanisms of Reef Coral Species Winnowing from Communities under Increased Environmental Stress

Winnowing of poorly-adapted species from local communities causes shifts/declines in species richness, making ecosystems increasingly ecologically depauperate. Low diversity can be associated with marginality of environments, which is increasing as climate change impacts ecosystems globally. This paper demonstrates the demographic mechanisms (size-specific mortality, growth, fertility; and metapopulation connectivity) associated with population-level changes due to thermal stress extremes for five zooxanthellate reef-coral species. Effects vary among species, leading to predictable changes in population size and, consequently, community structure. The Persian/Arabian Gulf (PAG) is an ecologically marginal reef environment with a subset of Indo-Pacific species, plus endemics. Local heating correlates with changes in coral population dynamics and community structure. Recent population dynamics of PAG corals were quantified in two phases (medium disturbed MD 1998-2010 and 2013-17, severely disturbed SD 1996/8, 2010/11/12) with two stable states of declining coral frequency and cover. The strongest changes in life-dynamics, as expressed by transition matrices solved for MD and SD periods were in Acropora downingi and Porites harrisoni, which showed significant partial and whole-colony mortality (termed “shrinkers”). But in Dipsastrea pallida, Platygyra daedalea, Cyphastraea microphthalma the changes to life dynamics were more subtle, with only partial tissue mortality (termed “persisters”). Metapopulation models suggested recovery predominantly in species experiencing partial rather than whole-colony mortality. Increased frequency of disturbance caused progressive reduction in coral size, cover, and population fecundity. Also, the greater the frequency of disturbance, the more larval connectivity is required to maintain the metapopulation. An oceanographic model revealed important local larval retention and connectivity primarily between adjacent populations, suggesting that correlated disturbances across populations will lead to winnowing of species due to colony, tissue, and fertility losses, with resultant insufficient dispersal potential to make up for losses – especially if disturbances increase under climate change. Variable extinction thresholds exists based on the susceptibility of species to disturbance (“shrinkers” versus “persisters”), determining which species will be winnowed from the community. Besides projected changes in coral community and population structure, no species are projected to increase in cover. Increased marginality due to climate change will lead to a net loss of coral cover and novel communities in PAG.

Stable mucus-associated bacterial communities in bleached and healthy corals of Porites lobata from the Arabian Seas

Coral reefs are subject to coral bleaching manifested by the loss of endosymbiotic algae from coral host tissue. Besides algae, corals associate with bacteria. In particular, bacteria residing in the surface mucus layer are thought to mediate coral health, but their role in coral bleaching is unknown. We collected mucus from bleached and healthy Porites lobata colonies in the Persian/Arabian Gulf (PAG) and the Red Sea (RS) to investigate bacterial microbiome composition using 16S rRNA gene amplicon sequencing. We found that bacterial community structure was notably similar in bleached and healthy corals, and the most abundant bacterial taxa were identical. However, fine-scale differences in bacterial community composition between the PAG and RS were present and aligned with predicted differences in sulfur- and nitrogen-cycling processes. Based on our data, we argue that bleached corals benefit from the stable composition of mucus bacteria that resemble their healthy coral counterparts and presumably provide a conserved suite of protective functions, but monitoring of post-bleaching survival is needed to further confirm this assumption. Conversely, fine-scale site-specific differences highlight flexibility of the bacterial microbiome that may underlie adjustment to local environmental conditions and contribute to the widespread success of Porites lobata.

Biogeography and molecular diversity of coral symbionts in the genus Symbiodinium around the Arabian Peninsula

AimCoral reefs rely on the symbiosis between scleractinian corals and intracellular, photosynthetic dinoflagellates of the genus Symbiodinium making the assessment of symbiont diversity critical to our understanding of ecological resilience of these ecosystems. This study characterizes Symbiodinium diversity around the Arabian Peninsula, which contains some of the most thermally diverse and understudied reefs on Earth.LocationShallow water coral reefs throughout the Red Sea (RS), Sea of Oman (SO), and Persian/Arabian Gulf (PAG).MethodsNext‐generation sequencing of the ITS2 marker gene was used to assess Symbiodinium community composition and diversity comprising 892 samples from 46 hard and soft coral genera.ResultsCorals were associated with a large diversity of Symbiodinium, which usually consisted of one or two prevalent symbiont types and many types at low abundance. Symbiodinium communities were strongly structured according to geographical region and to a lesser extent by coral host identity. Overall symbiont communities were composed primarily of species from clade A and C in the RS, clade A, C, and D in the SO, and clade C and D in the PAG, representing a gradual shift from C‐ to D‐dominated coral hosts. The analysis of symbiont diversity in an Operational Taxonomic Unit (OTU)‐based framework allowed the identification of differences in symbiont taxon richness over geographical regions and host genera.Main conclusionsOur study represents a comprehensive overview over biogeography and molecular diversity of Symbiodinium in the Arabian Seas, where coral reefs thrive in one of the most extreme environmental settings on the planet. As such our data will serve as a baseline for further exploration into the effects of environmental change on host–symbiont pairings and the identification and ecological significance of Symbiodinium types from regions already experiencing ‘Future Ocean’ conditions.