Search

The ever-increasing anthropogenic activities have adversely impacted coral reef ecosystems and their ecological functions. This calls for an urgent assessment of the health state of these valuable ecosystems to justify the need for mitigation and proper management efforts. In this contribution, we used multiple indicators to assess the impact of intense oil-related activities on coral reefs in two near-by impacted and non-impacted islands in the northwestern Persian Gulf. The efficacy of indices was assessed using estimations of the effect size (omega-squared), precision, and decision trees (Classification and Regression Tree (CART)). The results demonstrated that the combination of bioaccumulation of ƩPAH in coral tissues, the percent of live coral cover, and the Sediment Constituent (SEDCON) Index were the most robust proxies reflecting the influence of human activities on reef's health. Based on sedimentary PAH concentration, the CART classified most of the indicators into two classes consisting of those in impacted and those in non-impacted locations, further supporting the feasibility of the employed indices. The findings of this study provided a warning of degradation in coral reefs of the island subjected to PAH pollution. This encourages decision-makers to execute routine monitoring and mitigation practices to maintain healthy reefs in the study areas. ga1 • Ʃ 15 PAHs were much higher in corals tissue than the ambient sediment and seawater. • Phenanthrene that causes oxidative damage had the highest concentration in corals. • Sedimentary Σ 15 PAH was positively correlated with silt/clay content. • The CART classified most indicators into two classes (impacted vs. non-impacted). • Live coral cover, β-diversity, and SEDCON were reliable oil pollution indicators. [ABSTRACT FROM AUTHOR]

Variations in environmental factors can alter the species distribution pattern in intertidal rocky shores. The Persian Gulf (PG) and the Gulf of Oman (GO) vary substantially with respect to environmental and oceanographic conditions. The abundance and biodiversity of intertidal rocky gastropods in five locations across the northern PG and the GO were compared, and the environmental variables underlying the distribution pattern of these organisms were investigated. A total of 67 gastropod species were identified. The largest average density (294 ind./m2) and diversity (N = 43) for gastropods occurred in the Hotel Lipar station (LIP) located in Chabahar Bay in the GO. Clypeomorus bifasciata (107.43 ind./m2) followed by Cerithium caeruleum (94.67 ind./m2) were the most abundant species. Planaxis sulcatus and Siphonaria spp. occurred in all locations during both sampling occasions. Species richness and abundance of gastropods showed significant differences between LIP and remaining locations. A significant difference was found in assemblage structure across locations. In general, the species richness and density in the locations at GO were significantly larger than those locations in the PG, suggesting that the harsh environmental condition in the PG might be the forcing factor for this diminish. Distinct grouping was observed in both assemblage structure and species composition between locations in the PG and the GO. The spatial and temporal distribution patterns of gastropods assemblages were significantly correlated with variation in salinity and substrate rugosity. [ABSTRACT FROM AUTHOR]

Barbatia decussatais a member of intertidal communities occurring at rocky shores in the northern Persian Gulf. Population dynamic for this clam was explored from August 2011 to September 2012 on rocky intertidal shores in the northern Persian Gulf. The results showed that the Ark clam mostly occurred in the middle followed by lower intertidal zones and its distribution was associated with substrate morphology mostly occurring on shaded sides of boulders and cobbles followed by in crevices. Total shell length (SL) for 7064 individuals of Ark clams ranged from 2.21 to 53.93 mm. The growth parameters for the von Bertalanffy function wereL∞ = 57.75 mm,K = 0.47 year− 1, andt0 = − 0.29 year. The growth performance index (Φ′), longevity, asymptotic weight (W∞), and natural mortality were 3.2, 6.29 years, 40.38 g, and 1.79 year− 1, respectively. The exponent “b” value was 3.181 indicating that this clam bears a positive allometric growth pattern. The recruitment pattern was continuous with two major peaks. The sex ratio did not deviate from 1:1. The SL–total live weight (TLW) relationship, the SL–wet weight (WW) relationship, the SL–dry weight (DW) relationship, and the SL–ash-free dry weight (AFDW) relationship were TLW = 0.0001 × SL3.181, WW = 0.000015SL3.347, DW = 0.000009SL3.047, and AFDW = 0.000009SL3.22, respectively. [ABSTRACT FROM AUTHOR]

Three species of hard corals including Echinopora gemmacea Leptoria irregularis (Faviidae) and Montipora incrassata (Acroporidae) were recorded for the first time from north-east of Larak Island in the Strait of Hurmoz, Persian Gulf in late 2008. The review of previous studies revealed that these species were new reports from Larak Island situated in the northern Persian Gulf. Of these species only Echinopora gemmacea has previously been reported from the Oman Sea. No evidence of Leptoria irregularis and Montipora incrassata has been reported from the southern Persian Gulf and Oman Sea. [ABSTRACT FROM AUTHOR]

While the impact of ocean warming on single species is well described, the impact on marine biofouling communities is not well understood. Effluents of power plants have higher temperatures and can be used as natural large-scale test sites to investigate warming effects on marine ecosystems. In the present study, we evaluated the impact of elevated temperatures in the vicinity of a power plant on macro-biofouling communities in the northern coast of the Persian Gulf. The impact site was on average 2 °C warmer than the control site. Our results demonstrate a significantly different structure and composition of biofouling communities between control and impact sites. Warming led to a 1.5-fold increase in the mean coverage of biofouling communities and slightly decreased functional and species richness. Our results indicated that future warming will likely increase biofouling pressure, while decreasing diversity of communities, particularly in habitats where organisms exist at their upper tolerance limits of temperature. • Structure and composition of biofouling communities were different between control and impact sites. • Warming led to a 1.5-fold increase in the mean coverage of biofouling communities. • Warming slightly decreased functional and species richness of biofouling communities. • Future ocean warming will likely increase biofouling pressure in the northern Persian Gulf. [ABSTRACT FROM AUTHOR]