Risk assessment of heavy metals and total petroleum hydrocarbons (TPHs) in coastal sediments of commercial and industrial areas of Hormozgan province, Iran.

The significant increase in the pollution of heavy metals and organic pollutants, their stable nature, and their high toxicity are gradually becoming a global crisis. In a recent study, a comprehensive assessment of the spatial distribution of heavy metals and total petroleum hydrocarbons (TPHs), as well as an assessment of their ecological risks in the sediments of 32 stations located in commercial and industrial areas (Mainly focusing on petrochemical and power industries, desalination plants and transit Ports) of Hormozgan province (East and West of Jask, Bandar Abbas, Qeshm, and Bandar Lengeh) was performed during 2021-2022. The sediment samples were digested with HNO3, HCl and HF solvents. The concentration of heavy metals was determined with furnace and flame systems of atomic absorption spectrometer. The concentration of heavy metals showed significant spatial changes between stations. The ecological assessment indices between the regions indicated that the stations located in Shahid Bahonar Port, Suru Beach, and Khor gorsouzuan had a higher intensity of pollution than other places and significant risks of pollution, especially in terms of Cr and Ni. The average contamination degree (CD) (14.89), modified contamination degree (MCD) (2.48), pollution load index (PLI) (2.32), and potential ecological risk index (PERI) (100.30) showed the sediments in the area of Shahid Bahonar Port, Suru beach and Khor gorsouzuan, experience significant to high levels of pollution, especially Cr and Ni. Using contamination factor (CF) and Geoaccumulation index (Igeo), Cr was considered the most dangerous metal in the studied areas. Based on the global classification of marine sediment quality for the concentrations of TPHs, the sediments of the studied stations were classified as non-polluted to low pollution. In all regions, indices of the PELq (General toxicity) and CF (Contamination factor) were much lower than 0.1 and 1 respectively, showing the absence of adverse biological effects caused by TPHs in sediments. It is necessary to consider comprehensive and impressive strategies to control and reduce pollution of heavy metals, especially in the areas of Shahid Bahonar Port, Suru Beach, and Khor gorsouzuan, so that the sources of this pollution are required to be identified and managed.

Projected habitat preferences of commercial fish under different scenarios of climate change.

The challenges of commercial species with the threats of climate change make it necessary to predict the changes in the distributional shifts and habitat preferences of the species under possible future scenarios. We aim to demonstrate how future climatic changes will affect the habitat suitability of three species of commercial fish using the predictive technique MaxEnt. The dataset used to extract geographical records included OBIS (54%), GBIF (1%), and literature (45%). The output of the model indicated accurate projections of MaxEnt (AUC above 0.9). Temperature was the main descriptor responsible for the main effects on the distribution of commercial fish. With increasing RCP from 2.5 to 8.5, the species would prefer saltier, higher temperatures and deeper waters in the future. We observed different percentages of suitable habitats between species during RCPs showing distinct sensitivity of each fish in facing climate changes. Negative effects from climate change on the distribution patterns of commercial fish were predicted to lead to varying degrees of reduction and changes of suitable habitats and movement of species towards higher latitudes. The finding emphasizes to implement adaptive management measures to preserve the stocks of these commercial fish considering that the intensification of the effects of climate change on subtropical areas and overexploited species is predicted.

Introducing bio-indicator fish of the Persian Gulf based on health risk assessment of 27 commercial species.

BACKGROUND: The increasing consumption of seafood may bring health risks. It will be especially important for the people living along the coasts who are highly dependent on seafood for food and income. METHODS: In this research, a comprehensive health risk assessment was performed on 27 species of high-consumption commercial fish sampled from stations located in Hormozgan province within the Northeast Persian Gulf. Concentrations of trace metals and their health risk were investigated. RESULTS: Spatial distribution of trace metals in commercial fish showed central stations including Kong and Greater Tonb have higher concentrations of all trace metals except Pb. Some metals showed a significant correlation between concentrations. Our finding indicated the average concentration of all trace metals except Ni in all species was below the concentrations proposed by WHO/FAO/USEPA. EDI for all metals in all species in both adult and child age groups was lower than its RfD (oral reference dose of trace metal) showing the daily consumption of these fish does not pose any health risk and implicates seafood consumption guidelines or policies. Values of THQ for each metal and HI for all metals were lower than 1 in all commercial fish indicating the lack of non-cancerous health risk through the long-term consumption of these fish. The research found potential health risks associated with the consumption of these fish, specifically related to the metals Cr, Ni, and Cd. CONCLUSION: In total, health risk indices proposed eight fish as bio-indicator species of the Persian Gulf. The findings emphasize the risk management of commercial fish consumption, especially bio-indicator species, in Hormozgan province, the Northeast Persian Gulf.

Predicting present spatial distribution and habitat preferences of commercial fishes using a maximum entropy approach.

The knowledge of the geographical distribution and habitat preferences of marine species is the key to protecting marine ecosystems. Modeling the distribution of marine species through environmental variables is an essential step to understanding and reducing climate change effects on marine biodiversity and related human populations. In this study, the present distributions of commercial fishes including Acanthopagrus latus, Planiliza klunzingeri, and Pomadasys kaakan were modeled using the maximum entropy (MaxEnt) modeling technique and a set of 22 environmental variables. In total, 1531 geographical records belonging to three species were extracted from online databases Ocean Biodiversity Information System (OBIS, 829 records, 54%), Global Biodiversity Information Facility (GBIF, 17 records, 1%), and literature (685 records, 45%) during September to December 2022. The findings showed the values of area under the receiver operating characteristic (ROC) curve (AUC) above 0.99 for all species indicating the high performance of this technique to reflect the actual distribution of species. Environmental factors such as depth (19.68%), sea surface temperature (SST) (19.40%), and wave height (20.71%) were the strongest environmental predictors determining the present distribution and habitat preferences of the three commercial fish species. The Persian Gulf, Iranian coasts of the Sea of Oman, North Arabian Sea, North-East areas of the Indian Ocean, and North coasts of Australia are among the areas with ideal environmental conditions for the species. For all species, the percentage of habitats with high suitability (13.35%) was higher compared to habitats with low suitability (6.56%). However, a high percentage of species occurrence habitats had unsuitable conditions (68.58%) showing the vulnerability of these commercial fishes. Significant management strategies are needed to protect preferred habitats to minimize the effect of fishery and climate change on the population stocks of these commercial fishes.

The effect of petroleum levels on some soil biological properties under phytoremediation and bioaugmentation.

With the development of industries and excessive use of petroleum compounds, petroleum pollution has become a serious threat to the environment. The aim of this study was to the effect of petroleum levels on the biological activities of soil affected by phytoremediation and bioaugmentation. A surface soil sample was collected from the polluted areas around Bandar Abbas Oil Refinery Company, and the petroleum-degrading bacteria were isolated. M. yunnanensis (native) was selected among the isolated colonies for further experiment. The used soil in this study was a surface soil collected from Baghu region of Bandar Abbas, Sothern Iran, and treatments were added to soil samples. To evaluate removal of petroleum levels (0, 4, and 8%) from the soil by phytoremediation (control, sorghum, barley, and bermudagrass) and bioaugmentation (control, A. brasilense (non-native) and M. yunnanensis) and bioaugmented phytoremediation, a factorial pot experiment with completely randomized design and three replications was performed. The results demonstrated that sorghum and bermudagrass were more resistant than barley to the toxic effects of petroleum. Positive effect of bacteria on dry weight in polluted soil was greater than in the non-polluted soil. The degradation of petroleum reaches 77% in sorghum + M. yunanesis + 4% petroleum. Plants had stronger ability to degrade total petroleum hydrocarbon (TPH), while bacteria could better degrade polyaromatic hydrocarbons (PAHs). Application of bacteria and plants stimulated soil biological characteristics (dehydrogenase, arylsulfatase, lipase, bacterial population, and respiration) in polluted soil. Among measured enzymes, dehydrogenase exhibited a stronger response to petroleum levels. Four-percent level had greater irritating effect on soil biological properties. Plants and bacteria rely on differences in biological properties to attain synergy in petroleum degradation. Results indicated that M. yunnanensis has a high ability to remove petroleum from soil, and plants enhance the efficiency of this bacterium.

Health risk assessment of commercial fish and shrimp from the North Persian Gulf.

BACKGROUND: Bioaccumulation of trace metals in the food web demands continuous monitoring of seafood safety. Here, the food safety of commercial fish bluespot mullet Crenimugil seheli, deep flounder Pseudorhombus elevates, and Jinga shrimp Metapenaeus affinis was assessed from commercial and industrial region of the West Bandar Abbas, the North Persian Gulf, for the first time. METHODS: For this purpose, concentrations of trace metals Ni, Zn, Cu, Cr, Cd, and Pb, and their health risks were investigated. RESULTS: Results showed the average concentration of all trace metals in all species was below concentrations proposed by WHO/FAO/USEPA. The finding on risk assessment of three species indicated three species are safe for daily consumption. Long-term consumption of three species would not pose potential non-carcinogenic health risk. However, it would result in carcinogenic effects from the ingestion of trace metals Ni, Cr, and Cd. CONCLUSIONS: The data emphasizes the need for the continuous monitoring in this industrial region in the future to manage and control pollutant sources and to ensure the quality of seafood.

Algal blooms historical outbreaks in the northern coastal waters of the Persian Gulf and Oman Sea (1980-2015).

Harmful algal blooms (HABs) have been serious environmental problems in the Persian Gulf and Oman Sea in recent years. There has been an increase in occurrence of HABs in coastal waters of Hormuzgan Province (to the north of the Persian Gulf and Oman Sea) in recent decade, due to eutrophication as a result of human activities. In this review, HAB phenomena in coastal waters of Hormuzgan Province are summarized, including, causative species, timing and the location of blooms during a 35-year time span from 1980 to 2015. This review illustrates that 436 algal blooms have been recorded in the north of the Persian Gulf, formed by 17 species of phytoplankton; 270 of harmful dinoflagellate (Margalefidinium polykrikoides) blooms have led to huge catastrophic impacts on the economy, environment, and society. In addition, most algal blooms (49%) have occurred in the coasts of Bandar Abbas. The data in this review suggest supporting the establishment of an algal bloom monitoring and control program in the coastal waters of the northern part of the Persian Gulf and Oman Sea (Hormuzgan Province).

Bentonite addition to a PCB-contaminated sandy soil improved the growth and phytoremediation efficiency of Zea mays L. and Alternanthera sessilis L.

In this study, the removal of 17 selected PCBi congeners was assessed in a transformer oil-contaminated soil amended with bentonite clay powder applied at the three levels of 0, 2, and 4% and cultivated by Zea mays L. or Alternanthera sessilis L. in a pot experiment. Results showed that Z. mays and A. sessilis were able to reduce the residual concentrations of the PCBi congeners in the contaminated soil significantly (p < 0.05). The average reductions in the Æ©PCBi due to Z. mays or A. sessilis cultivations were 34.3 and 21.4%, respectively, depending on initial soil Æ©PCBi loading and plant growth period. Moreover, addition of bentonite led to significant (p < 0.05) enhancements in plant growth and dissipation of residual soil PCBi congeners under Z. mays and A. sessilis cultivations. Addition of 4% bentonite to the soil was found to have the greatest positive impact on PCBi removal so that average PCBi dissipations in the soil were 56.1 and 51.8% after growing Z. mays and A. sessilis, respectively. It might be concluded that the combined phytoremediation and bentonite addition is an effective technique for removing PCBi and remediating transformer oil-contaminated coarse-textured soils.

An overview of management and monitoring of harmful algal blooms in the northern part of the Persian Gulf and Oman Sea (Hormuzgan Province).

Algal bloom as a common phenomenon in the Persian Gulf and the Sea of Oman had catastrophic effects on environmental, social, economic, and human health aspects from 2008 to 2009. Since 2008, the Persian Gulf and the Sea of Oman Ecological Research Institute (PGSOERI) has monitored and managed algal blooms in the Hormuzgan coast along the northern Persian Gulf and the Sea of Oman. Management strategies have included regular monitoring of chlorophyll, water quality, and remote sensing. In this regard, relevant departments and the Regional Organization for Protection of Marine Environment (ROPME) collaborated with each other to prevent and forecast algal blooms. We reviewed historical and current monitoring, mitigation, and management systems of algal blooms in the Hormuzgan coast. In addition, complications and challenges of algal bloom monitoring and management were also discussed. Documenting algal bloom monitoring and research, improving forecasting and modeling of blooms, educating the public and fishermen, developing a cooperative monitoring framework, and controlling pollution input entering the ROPME region are the main challenges of algal bloom management in the Hormuzgan coast.

An "olivomycin A" derivative from a sponge-associated Streptomyces sp. strain SP 85.

We isolated an actinobacterium, Streptomyces sp. strain SP 85 from the marine sponge Dysidea avara. Polyphasic identification of the microorganism showed that the strain SP 85 had high 16S rRNA gene similarity (99%) with Streptomyces olivaceus strain NBRC 12805, while some physiological and biochemical differences were observed. A cytotoxic compound, SP 85 was isolated from the active culture extract of the strain SP 85 by bioassay-guided purification over silica gel column chromatography, preparative TLC, and HPLC. The structure elucidation based on the spectroscopic analysis, including UV, ESI-MS, and 13C NMR data revealed that SP 85 compound is an analog of anti-tumor drug, "olivomycin A". The SP 85 compound showed high cytotoxic activity against three human cancer cell lines, including SW480, HepG2, and MCF7 with IC50 values of 16, 93, and 78 nM, respectively. SP 85 exhibited significantly (2-10 times) higher cytotoxicity against the tumor cell lines in comparison with HUVECs as the normal cell line, which also induced apoptosis in the tested cancerous cell line. This is the first report on the production of an "olivomycin A" derivative by a sponge-associated Streptomyces, showing the great potential of sponge-associated actinobacteria in producing cytotoxic natural products.

Effects of refrigerated storage on the microstructure and quality of Grouper (Epinephelus coioides) fillets.

Refrigerated storage is the simplest method of preserving for short time handling and storage of fish. The objective of this study was to investigate the effects of refrigerated storage on the microstructure, physicochemical (proximate composition, pH, TVB-N, LHC), microbial (total mesophilic count, TMC and total psychrotrophic count, TPC) and sensory changes of grouper (Epinephelus coioides) fillets during a 14-day period at +4 °C. The estimated TVB-N value was significantly different in all days of storage. TPC value reached to a limiting level for human consumption (10(7) micro-organism/g) after the 10th day of storage while TMC remained under the limited acceptability until 14 days. Cellular tissue damage was observed after 7 days of storage. The shelf life of grouper was approximately ~8-9 days according to the results of sensory, chemical and microbial analysis.

Metal concentrations in two commercial fish from Persian Gulf, in relation to body length and sex.

The relationship between sex, size (length and weight) and metal concentrations in the tissues of two commercially valuable fish species (silver pomfret, Pampus argenteus and tiger tooth croaker, Otolithes ruber) from Persian Gulf were evaluated. Concentrations of the metals in fish species ranged as follows: Mn 0.743-11.279; Cd 0.175-2.375; Pb 2.406-11.297; Zn 10.837-80.389; Fe 2.263-86.110; Cu 1.503-6.333 µg/g dry weight, respectively. Metal content in both fish varied with type of metals, organ, and sex. Results showed that, except in a few cases, significant relationships between metal concentrations and fish size were negative.