Search

Based on surface air temperature and precipitation, the current study examines the climate fluctuations over Sistan-and-Baluchestan Province, Iran's second-largest province. This area suffers from insufficient direct observations and a lack of climatic investigation. Three datasets were utilized including in situ data, gridded data (1984-2013), outputs of historical runs (during 1984-2013), and projections under the SSP5-8.5, SSP3-7.0, and SSP1-2.6 scenarios (in 2020-2049) of twenty-six Global Climate Models (GCMs) from the latest Coupled Model Intercomparison Project (CMIP6). The models' performance has been evaluated and ranked using the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) in Multi-Criteria Decision Making (MCDM) technique including eight metrics in both seasonal and annual scales. The surface air temperature showed an increasing trend in seasonal and annual scales during 1984-2013, while the monthly precipitation trend increased for September-October-November and decreased for the other seasons and annual scale during 1984-2013. The top-ranked models for simulating surface air temperature (precipitation) were CESM2 (GFDL-ESM4), IPSL-CM6A-LR (UKESM1-0-LL), ACCESS-CM2 (GFDL-ESM4), and MIROC-ES2L (MPI-ESM1-2-LR) models in DJF, MAM, JJA, and SON seasons, respectively, while ACCESS-CM2 (CNRM-CM6-1-HR) model outperformed others in annual scale. Bias-corrected outputs of the top-ranked CMIP6 GCMs showed an increasing trend for surface air temperature in all seasons (from a 0.7 K increase in December-January-February season under SSP3-7.0 scenario to a 2.5 K increase in June-July-August season under SSP5-8.5 scenario) for period 2020-2049, comparing with that in 1984-2013 period. Bias-corrected monthly precipitation projected by top-ranked CMIP6 GCMs indicated both increasing and decreasing trends depending on selected season and scenario. This varied from a 5 mm/month decrease within December-January-February season under SSP5-8.5 scenario to a 13 mm/month increase during the March-April-May season under SSP1-2.6 scenario in 2020-2050, comparing with that from previous years., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

The concentrations of heavy metals (Cr, Cd, Ni, and Pb) were investigated in sediment and cyprinid fish (Capoeta razii) from Telar River, Iran in spring, summer, and autumn. Mean concentration of metals in fish and sediment over the seasonal sampling was as follows: Cr > Ni > Pb > Cd. Metal deposition in sediment was higher than their bioaccumulation in fish tissue. Unlike sedimentary metals, the tissue-content of Pb and Cr varied seasonally. Enrichment Factor (EF) values of Cr and Ni showed partial enrichment, implicating the role of anthropogenic inputs, while Pb was derived from natural weathering. When considering Pollution Load Index (PLI), an uneven temporal and spatial distribution of contamination was observed in sediment with moderate contamination level in spring and summer and no pollution in autumn. Tissue-contents of Pb, Cr, and Cd were below permissible limits while a higher risk level of Ni was noted for human consumption., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier Ltd.)

Microplastic pollution in the riverine ecosystems has caught many attentions in the scientific literatures. However, little information is available about the abundance and distribution of microplastics of the rivers discharging to the Caspian Sea. The aim of this study was to assess the spatial and seasonal distribution of microplastics in the surface waters of thirteen rivers discharging to the southern Caspian Sea. Microplastics were found in all stations with uneven distributions. The average concentrations of microplastics in the stations during snowmelt and dry seasons were 1.406 ± 0.1380 microplastics/m 3 and 0.4070 ± 0.01500 microplastics/m 3 , respectively. Positive gradients of the rivers microplastics concentration from upstream to downstream were found. White/transparent polyethylene (PE) particles with the shape of fragment/film and the length (L) of ≤ 1 mm were the most common microplastics in the surface waters of the rivers discharging to the southern Caspian Sea. Also, the mean concentration of microplastics in spring snowmelt and runoff period was 3.45 times higher than in dry period. Factors such as sewage and household wastes; landfills; and recreational-tourism, fishing and agricultural activities along the rivers may contribute to microplastic contamination in downstream stations. Our data provide baseline information of microplastics in surface waters of rivers discharging to the southern Caspian Sea., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Pseudaeginella makranensis sp. nov. is described from the Iranian coast of the Oman Sea. This species differs from other Pseudaeginella species by setose antennae, setae arrangement on mandibular palp, basis of male gnathopod 2 larger than pereonite 2, and bearing subrectangular propodus in second male gnathopod. A key to all species of Pseudaeginella Mayer, 1890 is provided.

A new species of eucalliacid ghost shrimp is described from the Gulf of Oman, Iran. Andamancalliax poorei sp. nov. is the first species of the genus described from Iranian subtidal waters and the third species worldwide. Andamancalliax poorei sp. nov. most resembles A. arafura Poore, 2021 from the Arafura Sea but can be differentiated by characters of the minor cheliped, maxilliped 3 and uropodal endopod.

Chabahar Bay will undergo industrial and coastal pressures according to the government plan to develop the Makran coasts. Therefore, knowing its biological community as well as their possible interactions with environmental variables, before and after coastal development, is important. The amphipod community structure and their response to the structural and contaminant parameters of the sediment include: granulometry, total organic matter (TOM) overloading, heavy metal contamination based on the Pollution Load Index (PLI) and polycyclic aromatic hydrocarbons (PAHs) during post monsoon season of 2017 were investigated from 19 stations. Traditional diversity and taxonomic distinctness indices were calculated. Multivariate analysis revealed the main role of sediment grain size and depth in shaping amphipod community structure. Consequently, two specific ecological niches were determined: species that prefer non-muddy substrates; and those dwelling in muddy or muddy sandy biotopes. No correlation was found between the Shannon diversity (H'), the average taxonomic distinctness indices (Δ+) together and both with contamination parameters. The Δ+ funnel plot well separated under-stressed stations from the healthy ones. The presence of only Ampelisca congeners in under-stressed stations revealed the tolerant nature as well as species-specific response of the genus to anthropogenic impacts. Considerable tolerant response (P > 0.05, r 2  = 0.4) of A. zamboangae to PAHs; A. persicus to TOM were observed. High concentration of nickel (Ni) in the studied area already stated due to erosion of ophiolite units from Makran Mountains. The significant correlation of the recently described Iranian species A. lowryi with Ni assumes that it is a native species that is well adapted to the geological conditions of the seabed. Instead Urothoe platydactyla can be considered as early warning signal for PAHs, TOM, Ni and cadmium (Cd) contamination particularly for non-muddy substrates. Our findings help to localize common biotic indices (e.g. AMBI, BENTIX, and BOPA) for studied area through correctly assignment of amphipods to the sensitive/tolerant ecological groups. Finally, we state that in the current situation of Chabahar Bay, in which no special industrial complexes have been established, any sediment-disrupting activity (i.e. sedimentation, dredging, trawling) affects its amphipod communities more than chemical pollutants., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

In this study, heavy metal levels in sediments, human hair, and fish muscle tissue as well as organic matter (OM%) content in surface sediments of Chabahar Bay were determined to assess their ecological risks and sources. Totally, 96 samples were collected from 16 stations (Tiss, Konarak, desalination plant, entrance of Chabahar Bay, Posm, Ramin, and reference stations) and were analyzed using inductively coupled plasma mass spectrometry (ICP-MS). Abundances of elements were of the following order: Ca>Al>Fe>Mg>Na>K>S>P>Ti>Mn>Sr>Ba>Cr>Ni>V>Li>Zn>Cu>Co>Pb>As>Cd>Ag>Se>Sb>Be>Mo>Bi. Element levels in sediments were within the range of low pollution areas, except for Cr, As, Ni, and Cd. Dominant sources of elements were natural, except for Cd, which was anthropogenic. All geo-accumulation index (I geo ) values were less than zero, except for Ag, Cd, and Sr from heavily to moderately contaminated areas. E r values indicated low ecological risk, except for Cd which showed a high ecological risk. The As levels limit the consumption of fish meal per month.i values indicated low ecological risk, except for Cd which showed a high ecological risk. The As levels limit the consumption of fish meal per month., (Copyright © 2021. Published by Elsevier Ltd.)

In this article dissolved oxygen results of research cruises through the Persian Gulf during 2018-2019 are discussed. The results showed that summer to autumn hypoxia occurred mainly at depths ≥ 50 m to the bottom. This seasonal hypoxia started in late summer reaching its greatest severity in mid-autumn with an area of 50,000 km 2 in the Persian Gulf. The minimum oxygen measured at the near-bottom layer of the western basin in autumn (25.8 μmol/kg) was lower than any previous measurement in the open waters of the Persian Gulf. In the Strait of Hormuz, the seasonal hypoxia appeared in summer in the near bottom of the most eastern part at the Iranian side. pH T values recorded in hypoxic waters were as low as what is predicted for surface ocean under ocean acidification in 2100. Considering the results, we suggest evaluating the effects of hypoxia and acidification on the Persian Gulf ecosystems., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

In this study, selected PCB congeners (IUPAC numbers 28, 52, 101, 138, 153, and 180) were quantified in 34 stations of Chabahr bay and around it in the Makran region of Iran. The sum of total PCB concentrations varied from below the detection limit to 485 ng kg -1 dry weight of sediment. Based on the Canadian Sediment Quality Guidelines, the effect of detected PCBs was negligible for aquatic organisms. According to the dominance of PCB 28 and 52 with average range of 62 to 100% of total PCBs, maritime transportation and atmospheric deposition appear to be the important source of PCBs in this region. Further, the presence of components of commercial products such as ClophenA50 appears to be one of the probable sources., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

The Caspian Sea hosts areas of high ecological value as well as industrial, leisure, and agricultural activities that dump into the water body different kinds of pollutants. In this complex context, a proper description of the origin and potential sources of pollution is necessary to address management and mitigation actions aimed at preserving the quality of the water resource and the integrity of the ecosystems. Here, we aimed at detecting sources of both nitrogen inputs, by N stable isotope analysis of macroalgae, and metals in macroalgae and sediments in two highly anthropized coastal stretches at the Iranian side of the Caspian Sea. Sampling was done near the mouth of rivers and canals draining agricultural and urbanized areas. In the westernmost waters, facing a port city, low macroalgal δ 15 N signatures indicated industrial fertilizers as the principal source of pollution. By contrast, in the central coastal waters, facing touristic areas, the high macroalgal δ 15 N indicated N inputs from wastewaters. Here the lowest dissolved oxygen concentrations in waters were associated with excess dissolved inorganic nitrogen. Metal concentrations varied largely in the study areas and were lower in macroalgae than in sediments. Localized peaks of Pb and Zn in sediments were observed in the central coastal sites as probable byproducts of mining activity transported downstream. By contrast, Cr and Ni concentrations were high in all sampling sites, thus potentially representing hazardous elements for marine biota. Overall, macroalgal δ 15 N coupled with metal analysis in macroalgae and sediments was useful for identifying the main sources of pollution in these highly anthropized coastal areas. This double approach in comprehensive monitoring programs could thus effectively inform stakeholders on major environmental threats, allowing targeted management measures.

Caprella moradi sp. nov. is described from intertidal zone of the Gulf of Oman, Iran. This species is differentiated from the most similar species Caprella danilevskii (Czerniavski, 1868), by four rows of fine setae on the body surface and bears a curved anterior surface of propodus in the second male gnathopod.

A third species of Michaelcallianassa Sakai, 2002 is described based on two specimens from subtidal waters of the Persian Gulf. Michaelcallianassa persica sp. nov. resembles M. indica Sakai, 2002 from the Andaman Sea, but can be differentiated by possession of six spines on the cutting edge of the large cheliped, a telson with two pairs of lateral movable spines as well as two spines dorsally in the center of the telson and an exopod with a row of spines on the postero-distal margin. The new species compares favorably with congeners M. indica Sakai, 2002 and M. sinica Liu Liu, 2009 in many diagnostic aspects, including body shape, the relative size and shape of pereopods 2-4, maxilliped 3, and the rostrum. Some limited comparison is made to the related genus Balsscallianassa Sakai, 2011.

Microplastic (MPs) pollution in the aquatic and terrestrial environments has caught many attentions in the scientific literatures. Currently, no information is available about MPs pollution in Caspian Sea, the largest lake in the world. This study indicates the first report on the MPs pollution in the sediments of the southern Caspian coastal zones, northern Iran. Density separation method was conducted on 17 surficial sediments. The combination of observation techniques including SEM-EDS analysis, polarized light microscopy and Raman micro-spectroscopy were used to identify MPs. The abundance and size of microplastics in the samples ranged between 25 and 330 items/kg and 250-500 μm, respectively. Fibers constituted the most common MPs shape and polystyrene (PS) and polyethylene (PE) were major polymer types in the samples. The distribution of MPs in the study area reflected a patchy and irregular spatial pattern implying that the higher MPs concentration are near mouth of permanent rivers and in the regions with higher level of the fishing and tourism activities. The results showed the wide occurrence of MPs in the sediments of the world's largest lake which extend the knowledge on MPs pollution in the marine system. We also recommend further research on microplastics in different compartments of Caspian Sea to inform policy discussions and the development of appropriate management responses., Competing Interests: Declaration of competing interest The authors have no conflict of interest., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Current study aimed to evaluate the microplastics abundance in the surface waters of Chabahar Bay for the first time. 21 neuston net water samples were collected from 7 stations. Microplastics were visually counted by stereomicroscope, sorted into 4 size categories, 4 shape categories, and identified by ATR-FTIR spectroscopy. Density of microplastics varied from 0.07 ± 0.03 to 1.14 ± 0.27 with an average density of 0.49 ± 0.43 particle·m -3 . Microplastics were mostly found in the shape of fibers. 69% of analyzed particles were polyethylene and polypropylene. Main colors of the collected microplastics were white, blue and red. The results showed that the largest number of microplastics was found at station near populated area. Therefore, it can be concluded that, there is a pressing-need to investigate the distribution of microplastics in sediments and biota of this Bay as well as their effects on marine life and human health., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Surface sediments, sampled from Iranian coast of the Persian Gulf (n = 134), were analyzed in order to track spatial distribution of PAHs and their related eco-hazards. The levels of PAHs were in the range of 1.98-814 ng g -1 dw and the region was lowly to moderately polluted. The profile of PAHs was mainly composed of 2,3-ring chemicals and suggested a local source of PAHs and relatively fresh inputs. Statistical analysis and molecular fingerprints proposed that the basin receives PAHs from multiple origins including petrogenic and pyrogenic (traffic and auto emission) ones. Spatial distribution of organic matter and fine fraction of the sediments had a horizontally increasing trend in the studied basin. ∑ 16 PAHs showed significant positive correlation with TOC and fine fraction (p < 0.05) and the spatial deposition of ∑ 16 PAHs followed the spatial trends of TOC and fine fraction. Spatial mapping techniques confirmed that Pars Special Economic Energy Zone (PSEEZ) is the hot zone of PAH pollution. A combination of source availability, finer sediments, and great organic matter levels were the main effective factors that highlighted the deposition of PAHs in the PSEEZ. The Nayband Bay, as the Iran's first national marine Park, possibly received PAHs from its adjacent zone, the PSEEZ. On the other hand, low organic matter and sandy nature of the Nayband Bay was not suitable for effective sequestration of PAHs. Thus, the biota of Nayband Park was encountering with relatively severe multiple eco-hazards due to both ecological and economic factors., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Surface sediments (n = 35) and a core sample around Pars Special Economic Energy Zone were analyzed to address spatiotemporal variations of heavy metals. Enrichment factors classified the elements as: (1) poorly enriched, geogenic elements (Co, Cr, Fe, Li, Mn, Mo, Ni, Ti, and V), (2) minimal enriched elements (Zn and Mg), (3) moderately enriched elements (Ag, Cd, Pb, Se, and Sr), and (4) significantly enriched element (As and Hg). The core profile showed that As, Hg, Ag, and Cd had considerable anthropogenic inventories. Arsenic levels were continuously increasing toward the top of the core and sedimentary cycling was not an effective factor on its enrichment. Pollution load index classified the area as a severely affected region and Risk Index values suggested that 57% of the sediments had a moderate potential risks. The mapping techniques proposed a polluted and hazardous patch at the entrance and center part of the Nayband Bay., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Two species of the callianassid ghost shrimp genus Neocallichirus Sakai, 1988 are newly recorded from Iran. Neocallichirus darvishi n. sp. appears close to N. jousseaumei (Nobili, 1904), but combined morphological and genetic analyses provide evidence for recognition of the new taxon. Neocallichirus manningi Kazmi Kazmi, 1992, originally described from Pakistan, is reported for the first time since its original description. A supplemental description and figures are given for N. manningi.

We investigated the bioavailability, mobility, and origin of heavy metals present in sediments from the Anzali Wetland. Chemical speciation of the metals was performed according to the Tessier method. Results indicated that Cd and As showed the highest level of bioavailability, whereas Cr showed the lowest level. Cr, Co, and V were shown to have a terrestrial origin. The metal As was mostly found in the reducible fraction (F3), whereas other metals were highest in the residual phase. The levels of Co present in the oxidizable fraction (F4); Pb and Cd present in the carbonate fraction (F2); and the other metals present in the exchangeable fraction (F1) were found to be the lowest. On the basis of the Risk Assessment Code of metals, Cd at most stations, As and Ni at some stations, and Zn at one station revealed to have a moderate risk. Co and Pb were found to have a low risk at all stations. Considering Pollution Load Index, stations 2 and 3 were classified as moderately polluted and the remaining stations were unpolluted. As suggested by enrichment factor analysis, As was moderately enriched and other metals had a deficiency to minimal enrichment at all the stations., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

The first member of Cephaloecetes in the north-western part of the Indian Ocean, Cephaloecetes ungulatus sp. nov., is described from Chabahar Bay, the Gulf of Oman and Qeshm Island in the western Hormuz Strait, Iran. The new species is characterized from the other two species of genus Cephaloecetes by a unique claw-shaped ventral plate on antenna 2 article 2.

A new species of callianassid ghost shrimp is described from the Persian Gulf, Iran. Cheramus iranicus sp. nov. is the first member of Cheramus described from Iranian subtidal waters and can be differentiated by a large cheliped with a ventroproximal spine on the merus and 7 spines on the ventral margin of the ischium, the endopod of the uropod has 4 movable spines on the distal margin and the posterior margin of the telson is strongly bilobed with a prominent medial tooth and two pairs of lateral movable spines. It is compared to other described Cheramus-like species showing a high degree of morphological similarity.

The objectives of this study were to determine the reproductive cycle of largescale tonguesole Cynoglossus arel, a commercially valuable flatfish species, in coastal waters of Bandar Abbas, along the south coast of Iran in the Persian Gulf. From October 2009 to September 2010, 905 fish were collected in monthly samples, and their length, weight, sex, gonad weight, and maturity status recorded. These data revealed that ovary weight in females is low from July to September, then increases to a peak in February followed by a decrease, indicating that the peak spawning season is from February to March with some spawning lasting until June. Males showed a corresponding seasonal pattern in testis weight, although with much less pronounced seasonal differences than gonad weight in females. Five maturity classes were described based on ovarian and testicular histology, corresponding with macroscopic analysis of gonads. The spawning season in C. arel is prolonged, similar to several other tropical flatfish species, and larger adult females tended to have an even more prolonged spawning period than smaller, presumably younger adult females. Combined, our results indicated that C. arel is a winter-to-spring batch spawner with an asynchronous type of ovarian development., (Copyright © 2014 Elsevier B.V. All rights reserved.)

New record and new species of the families Melitidae Bousfield, 1973 and Maeridae Krapp-Schickel, 2008 are described from the Iranian shorelines of the Persian Gulf. Melita persia sp. nov. is differentiated from other members of M. zeylanica Stebbing, 1904 group by: the presence of two setae on inner ramus of third uropod, the setal arrangement on the telson, and a recurved proximal lobe of sixth coxa in females. Also, Elasmopus menurte Barnard, 1974 previously described from Western Australia and Mauritius is recorded, for the first time, from Persian Gulf in the north-western Indian Ocean.

A new species of acotylean polyclad, Imogine qeshmensis sp. nov. is described from Qeshm Island, Persian Gulf, Iran. I. qeshmensis is characterized by the number and arrangement of the tentacular, cerebral and frontal eyes, a body margin with opaque white bands and eyespots and a male genital complex with an highly muscular seminal vesicle equal in size to the prostatic vesicle.

In this study, the levels of natural and anthropogenic metal contamination (aluminum (Al), iron (Fe), manganese (Mn), arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn)) in surface sediments of three harbors along the Iranian coast of Gulf of Oman were examined and reported for the first time. Effect of grain size, mineralogy, normalization technique using Fe concentrations, and different sediment quality guidelines were discussed. Data from the harbors were compared with other harbors worldwide. Sediments inside the harbors are characterized by moderate and high levels of pollution by trace metals Cu (12-287 μg/g), Pb (11-1,780 μg/g), Zn (38-547 μg/g), Cr (70-2,370 μg/g), and Ni (31-116 μg/g). However, As and Cd did not show considerable pollution inside and outside the harbors. Considering that there is no industrial activity around the study harbors, the major sources of contamination in the harbors are repairing, fueling, greasing, and painting of fishing ships and boats. Mineralogy of sediments in the study area as well as trace metal concentration in reference samples taken from onshore geological units confirmed that natural inputs of Cd, Cu, Pb, and Zn in the harbors are very low while most of Ni and Cr contamination in the study area comes from erosion of ophiolitic mélange units at the North of Makran mountains.

We investigated heavy metal concentrations of zinc (Zn), copper (Cu), chromium (Cr), and lead (Pb), their spatial distribution and enrichment factor index in surface sediments of the Gorgan Bay. Sediment Quality Guidelines were also applied to assess adverse biological effects of these metals. Heavy metals were determined by inductively coupled plasma-mass spectroscopy (ICP-MS). The results indicated mean concentrations (ppm) of heavy metals were (mean±S.D.) Pb: 11.5±4.88, Cu: 18±8.83, Zn: 42±22.15 and Cr: 32±15.19. Based on Enrichment index, the Gorgan Bay is a low-enriched to non-enriched bay. Heavy metal contents were lower than the standard limits of PEL, ERL, and ERM that reveal no threatening influence of the metals in the Bay., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Heavy metal pollution caused by traffic activities is increasingly becoming a great threat to urban environmental quality and human health. In this paper, soils of Kerman urban and suburban areas were collected to assess the potential effects of traffic and other vehicle-related pollution by heavy metal accumulation in soils. Eighty-six samples were collected along streets and from residential and rural sectors, as well as vehicle-related workshops from depth of 0-5 and 15-20 cm and analyzed by flame atomic absorption spectrometry (FAAS) for heavy metals (Cd, Cr, Cu, Pb, Sn and Zn), as well as major elements (Al, Ca, Fe and Mn). Several hot-spot areas were identified in the composite geochemical maps produced based on Geographical Information System (GIS) technology. The majority of the hot-spot areas were identified to be vehicle-related workshops, fuel stations and road junctions. The most polluted hot-spot in the study area was located in soils close to a car battery processing workshop in the southwestern part of Kerman city, with concentrations of Cd (0.32 mg/kg), Cr (169 mg/kg), Cu (250 mg/kg), Pb (5,780 mg/kg), Sn (27.2 mg/kg) and Zn (178 mg/kg) of 1, 8.5, 8.3, 230, 13.5 and 3 times more than the relevant mean concentrations in natural soils, respectively. Traffic pollution has resulted in significant accumulation of heavy metals in soils and sediments, and that level of accumulation varied remarkably among elements. Based on X-ray diffraction analysis, most parts of soils and sediments of the Kerman basement consist of calcite and clay minerals. Abundance of clay minerals and medium to alkaline pH causes low mobility of heavy metals in soils of Kerman.