Using empirical negative cumulative extropy and image quality assessment to determine the accumulation of elements in marine organisms.

In this study, the assessment of metals absorption capacity by macroalgae using image analysis was investigated for the first time and compared with fish bioaccumulatio. Empirical cumulative entropy (ECE), and also empirical negative cumulative extropy (ENCEX) were used as a newly introduced (information-based) indices. The regression equation was obtained between fish tissue-seawater in muscle of Sphyraena putnamiae (ENCEX=0.2001BAF; R2=0.96); In the case of muscle of Liza subviridis, the regression model was as (ENCEX=0.1950BAF; R2=0.93). The regression equation was obtained between algae-sediment (ENCEXH. hamulosa=0.2695BAF; R2=0.97). The studied indices showed a high accumulation of Hypnea hamulosa compared to the other algae (ECE=0.2601; ENCEX=0.3995). IQA method showed the same result exhibiting that the algae can be evaluated as a bio-indicator of element accumulation using image analysis. Image analysis can help us find macro algae with high absorption capacity without laboratory examinations.

Pollution zoning on the southern shores of the Caspian Sea by measuring metals in Rutilus kutum tissue.

The aim of this study was to bio monitor the status of heavy metals on the southern shores of the Caspian Sea by determining the concentration of these metals in the tissue of Rutilus kutum. Sampling of kidney tissue, liver, muscle, skin, and gonad of this fish was performed in 5 sites. Sampling was performed in Anzali, Kiashahr, Astara, Farahabad, and Bandar Torkaman from September 2017 to January 2018. In this study, the concentration of elements in different tissues was determined. Contamination zonation was determined by the concentration of metals in fish tissues. The highest amount of Pb accumulation (0.73 ppb) was determined in Astara and Anzali regions and in liver tissue. The highest amount of Cd (0.23 ppb) was reported in Astara region and in fish liver. Zoning showed that the concentration of most elements in the west of the Caspian Sea is higher than in the east; in other words, the west of the Caspian Sea is more polluted than the east. Existence of polluting sources such as ports, customs, agricultural lands, and tourism industry are important factors of pollution in these areas. Annual biological monitoring along with accurate identification of pollutant sources can help reduce this pollution, especially in the western part of the Caspian Sea. This study showed that the use of zoning technique in environmental studies as an effective management tool can be very useful in providing appropriate ways to identify and control sources and pollutants in the coast.

Predicting the Trace Element Levels in Caspian Kutum (Rutilus kutum) from South of the Caspian Sea Based on Locality, Season and Fish Tissue.

Elements are the shared result of the erosion of rocks in the catchment area and human activities. Nutritional habits, ecological needs, heavy metal concentrations in water and sediment, duration of fishing in the aquatic environment, fishing season, and physicochemical properties of water (salinity, pH, hardness, and temperature) are among the effective factors in the accumulation of heavy metals in various fish organs. In this study, 150 specimens of Rutilus kutum were collected from the southern shores of the Caspian Sea including Astara, Anzali, and Kiashahr in Guilan Province, Farahabad in Mazandaran Province, and Bandar Torkaman in Golestan Province from December 2018 through October 2019. It is possible to predict the metal concentrations using the variables such as fish tissue, sampling region, and season. Akaike information criterion (AIC) was used to select the best regression model. We used fish muscle tissue and Anzali sampling site which were considered reference variables in the regression model. For some elements, a better model is obtained by considering all variables (AIC criterion is its lowest value). The best model obtained for Cu, Mn, and Si was only with region (as a variable). The best model obtained for Sn and Sr only concerns the region and tissue variables. The best model obtained for Sb only related to tissue variable. Using these models, environmental monitoring becomes easier and cheaper. We suggest further studies to be carried out in the shortest possible time along with the least laboratory cost.

Assessing the relationship between the abundance of microplastics in sediments, surface waters, and fish in the Iran southern shores.

The purpose of this study was to investigate the microplastic (MP) pollution in sediments, surface waters, and four fish species in the northern coast of the Persian Gulf. Sampling was conducted in seven important regions during December 2019. The abundance of MPs was respectively 190 ± 35.5 items/kg dry weight for sediments, 9.28 ± 2.1 items/km2 for surface waters, and 0.33 ± 0.05 items/individual for fish. There was no correlation between MP abundance in surface water, sediment, and fish samples. Except for Cynoglossus arel, abundance of isolated MPs did not show significant relationships with body weight, body length, and gastrointestinal tract weight (P > 0.05). MPs were ranged from 0.3 to 5 mm in size and were prevailed by fiber in shape; black, red, and blue in color; and polypropylene and polyethylene in polymer. This study may help in increasing our knowledge regarding MP pollution in marine water systems and biota.

Empirical cumulative entropy as a new trace elements indicator to determine the relationship between algae-sediment pollution in the Persian Gulf, southern Iran.

In this paper, the amount of 19 elements in three species of algae and associated sediment in the northern margin of the Persian Gulf was investigated. A sampling of algae was performed on the coast with a length of 5 km in each station and surface sediment was sampled at the same time in low and middle intertidal zones. The values of elements in the samples were measured by using an inductively coupled plasma mass spectrometry (ICP-MS) device. Then, the amount of bioaccumulation factor in algae tissue relative to sediment (biota-sediment accumulation factor, BSAF) was determined. The value of BSAF was compared with the empirical cumulative entropy (ECE). ECE is based on comparing the element information in algae with those in sediments. The results showed that BSAF was very closely related to the ECE factor so that significant correlations were obtained for algae species of P. gymnospora (ECE = 0.477 BSAF, R2: 0.967), H. hamulosa (ECE = 0.542 BSAF, R2: 0.979), and C. membranacea (ECE = 0.356 BSAF, R2: 0.976). The ECE values > 0.4 were similar to those obtained for BSAF > 1, exhibiting that the element accumulation in algae was higher than in sediments. Based on ECE, to determine the vanadium accumulation in the environment, the C. membranacea algae are more appropriate than H. hamulosa. Overall, the data showed that ECE is a good alternative to BSAF in estimating marine pollution.

Trace and Major Elements Concentration in Fish and Associated Sediment-Seawater, Northern Shores of the Persian Gulf.

The concentration of 19 metal and non-metal elements in two fishes (Liza subviridis and Sphyraena jello) and associated sediment-seawater from the northern part of the Persian Gulf was measured. The samples were gathered from two industrial ports, one commercial port, and one residential port. The metal accumulation in the muscle and liver of fishes was evaluated. Nickel (mean 362.07-712.83 µg/g) and chromium (mean 470.00-691.47 µg/g) in sediment and zinc (mean 9.01-31.15 µg/L) and arsenic (mean 18.22-22.14 µg/L) in seawater had the most abundancy among studied elements. The accumulation of elements in S. jello (a pelagic species) was higher than L. subviridis (a demersal species). For both species, major elements of S and Mg and trace elements of Fe, Al, Si, Zn, and Cu showed highest accumulation. Also, fish samples from Emam Hassan Port were more contaminated than other stations. Ecological indexes values have revealed a low to moderate elemental pollution of sediment and fish samples in the north part of the Persian Gulf.