Ibrahim Al-Maslamani

Benthic surveys of the historic pearl oyster beds of Qatar reveal a dramatic ecological change

The study aimed to confirm the presence of historic oyster banks of Qatar and code the biotopes present. The research also collated historical records and scientific publications to create a timeline of fishery activity. The oyster banks where once an extremely productive economic resource however, intense overfishing, extreme environmental conditions and anthropogenic impacts caused a fishery collapse. The timeline highlighted the vulnerability of ecosystem engineering bivalves if overexploited. The current status of the oyster banks meant only one site could be described as oyster dominant. This was unexpected as the sites were located in areas which once supported a highly productive oyster fishery. The research revealed the devastating effect that anthropogenic impacts can have on a relatively robust marine habitat like an oyster bed and it is hoped these findings will act as a driver to investigate and map other vulnerable habitats within the region before they too become compromised.

Macrobenthos in the central Arabian Gulf: a reflection of climate extremes and variability

AbstractThe arid subtropical ecosystem of the central Arabian Gulf was used to explore the combined effects of low primary productivity, high salinities, and variable temperatures on the composition and structure of benthic macrofauna at 13 sites encircling the Qatar Peninsula in winter and summer (or late spring) of 2010 and 2011. The low abundance, biomass, and remarkably high species turnover may be a reflection of the oligotrophic, thermally variable, hypersaline coastal environment. The number of species and within-habitat diversity was lowest in the highest salinities but increased with finer-grained sediments and lower salinity. A remarkable temporal variation in species composition observed may reflect insufficient primary production to sustain new populations recruited from the seasonal exchange of water from the adjacent Sea of Oman. Low abundances accompanied by continued replacement of species may be a “new model” for extremely arid conditions associated with global warming.

Nesting ecology of hawksbill turtles, Eretmochelys imbricata, in an extreme environmental setting

Relatively few details of hawksbill turtle (Eretmochelys imbricata) nesting ecology exist within the Arabian Gulf. Moreover, little is known about how their nesting dynamics compare to nesting populations throughout the rest of the world. Due to the extreme environmental setting, nesting ecology of hawksbills in the Arabian Gulf is of significant interest to researchers and conservationists. The current research reports on a long-term tagging and monitoring program undertaken at Fuwairit beach, Qatar. To investigate nesting behavior, site surveys and tagging were employed from 2010 to 2016. Presence of nests and clutch sizes were confirmed by excavation. Over the entire study period, nesting hawksbills had a mean curved carapace length of 70.8 cm (SD±2.8). A total 187 nests were confirmed, which contained a mean 78.9 eggs per clutch (SD±17.1), over an annual nesting season that lasted an average of 52.2 days (SD±6.3) from the start of April to the start of June. Meta-analysis with other global regions showed these characteristics to be significantly reduced when compared to nesting hawksbills from other populations. Meteorological data analysis showed air temperatures in the Arabian Gulf to increase on average 13.2°C (SD±0.26) from start to the end of nesting annually, which is significantly greater than other global nesting regions. Their smaller body size and reduced fecundity coupled with the extreme change in ambient air temperatures support the hypothesis that hawksbills in the region are more at risk than the already critically endangered hawksbill populations elsewhere in the world.

A new species of leucosiid crab (Decapoda: Brachyura: Leucosiidae) from the Arabian Gulf

The Indo-West Pacific genus Coleusia Galil 2006, was recently described and now comprises seven species. We describe a new species from the western Arabian Gulf, Coleusia janani n. sp. The new species is closely related to the congener C. biannulata (Tyndale-Biscoe & George, 1962), and can be distinguished from other species at these genus congeners mainly by the straight upward apical shape of the male first pleopod (G1). An updated identification key to the species of Coleusia, as well as an overview of the geographical distribution of the species included in the genus are also presented.

Mercury accumulation in Lethrinus nebulosus from the marine waters of the Qatar EEZ

Total mercury (THg) and methylmercury (MeHg) were recorded in the commercial demersal fish Lethrinus nebulosus, caught from six locations in Qatar EEZ (Exclusive Economic Zone). Concentrations of THg decreased in the order: liver˃muscle˃gonad. THg concentrations in fish tissue ranged from 0.016ppm in gonad to 0.855ppm (mgkg-1w/w) in liver tissues, while concentrations in muscle tissue ranged from 0.24 to 0.49ppm (mgkg-1w/w) among sampling sites. MeHg concentrations were used to validate food web transfer rate calculations. Intake rates were calculated to assess the potential health impact of the fish consumption. There is no major threat to human health from the presence of Hg in L. nebulosus, based upon reasonable consumption patterns, limited to no more than three meals of L. nebulosus per week.