CASPIAN JOURNAL OF ENVIRONMENTAL SCIENCES (CJES)
Year:2019 | Volume:17 | Issue:2 |Papers Count:8

The freshwater shrimp, Macrobrachium nipponense is an invasive species which has recently been reported in Anzali Wetland, Iran. It exhibited good tolerance and adaption in this wetland ecosystem. This study examined certain aspects of feeding of M. nipponense in three habitats of this wetland. Shrimps were randomly sampled from April 2016 to March 2017. The stomach contents were obtained from 367 specimens ranging in length from 4. 2 cm to 6. 9 cm. The empty stomach index (VI) showed that this shrimp was a voracious (0 ≤ VI < 20) species in all seasons expect winter, when 99% of the specimens had empty stomachs. Fourteen dietary items were categorized in the three habitats of the wetland, with phytoplankton, mollusks and detritus forms being the dominant food items in the western, central and eastern habitats respectively. The feeding precedence index (FP) revealed that the most abundant portion of food was subsidiary one (50 ≥ FP ≥ 10) and the highest proportions of subsidiary food were phytoplankton (24. 5%), gastropods (34%) and detritus (29. 11%) in the western, central and eastern habitats, respectively. Omnivorous feeding is one of the reasons for the success, high tolerance and adaptation of M. nipponense in the Anzali Wetland ecosystem.

Study of skeletal ontogeny during early development is crucial in a successful larviculture. In this study, ontogeny of the caudal complex skeleton in Caspian kutum, Rutilus kutum, was studied from hatching up to 50-day post hatching (dph). A total of 520 larvae and fry were randomly sampled, cleared and stained for osteological examinations. The results showed that development of caudal skeleton is started with appearing hypurals 1 and 2 on 4 dph and inflexion occurred on 7 dph with formation of eight cartilaginous plates, including two haemal spines, parhypural and five hypurals, below the notochord. The results also revealed that during post flexion from 13 to 50 dph other structures e. g. rudimentary neural arch, second ural and anterior half of the neural arch of PU3 were appeared. The inflexion point of tail growth pattern in R. kutum is in accordance with inflexion caudal complex, showing ontogeny of the caudal complex skeleton in agreements with its function demands during early development.

Landscape diversity is considered as the variety of land cover classes in a landscape and it is usually calculated on land cover maps of entire landscape. However, in this study it is aimed to present a new procedure, that is, the use of field-based national forest inventories (NFIs) to estimate two diversity indices: Shannon’ s diversity and inverse Simpson. Specifically, it is also intended to investigate how well a combination estimator can improve the precision of the estimates. The permanent square cluster plots produced more precise (smaller variance) estimate of the indices than temporary ones. In addition, estimated variance of the indices using combination estimator was smaller than both permanent and temporary square cluster plots. The applied procedure in this study is very simple where classes of land cover are usually determined and recorded by field surveyor. The main advantages of using field-based inventories are that there is no need for land cover/ use maps or images of the landscape. In addition, quality of the landscape diversity assessment through remotely-sensed data is still highly dependent on the availability and quality of field data. As long as historical datasets from forest inventories is available in many countries it is thus possible to do trend analysis in landscape diversity over time.

The freshwater shrimp, Macrobrachium nipponense is an invasive species which has recently been reported in Anzali Wetland, Iran. It exhibited good tolerance and adaption in this wetland ecosystem. This study examined certain aspects of feeding of M. nipponense in three habitats of this wetland. Shrimps were randomly sampled from April 2016 to March 2017. The stomach contents were obtained from 367 specimens ranging in length from 4. 2 cm to 6. 9 cm. The empty stomach index (VI) showed that this shrimp was a voracious (0 ≤ VI < 20) species in all seasons expect winter, when 99% of the specimens had empty stomachs. Fourteen dietary items were categorized in the three habitats of the wetland, with phytoplankton, mollusks and detritus forms being the dominant food items in the western, central and eastern habitats respectively. The feeding precedence index (FP) revealed that the most abundant portion of food was subsidiary one (50 ≥ FP ≥ 10) and the highest proportions of subsidiary food were phytoplankton (24. 5%), gastropods (34%) and detritus (29. 11%) in the western, central and eastern habitats, respectively. Omnivorous feeding is one of the reasons for the success, high tolerance and adaptation of M. nipponense in the Anzali Wetland ecosystem.

Quality maintaining, packaging and coating are of particular importance in food industry. Hence, the present study aimed to examine the effects of chitosan and ginger extract on the fillets shelf life. The experiment was conducted on six treatments, including control, coated with chitosan solution, coated with ginger extract, coated with chitosan solution + ginger extract, packaged with chitosan film and packaged with chitosan film + ginger extract. The samples were stored in a refrigerator for 12 days and examined during the storage period for the spoilage factors (PV, TBA, TVN, TVC and PTC). The results indicated that the application of ginger extract alone or in combination with chitosan had a significant effect on increasing the quality of fish fillets (P < 0. 05). In all treatments, the optimal result was related to the treatment packaged with chitosan film + ginger extract, which resulted in maintaining the desired fillet quality for 12 days.

Information about the spatial patterns of soil biodiversity and understanding the effects of biodiversity on ecosystem processes are limited. This study was conducted to determine whether biodiversity of soil macrofauna features demonstrate spatial patterns in the Populus deltoides plantation in north of Iran. 150 soil samples were taken using a grid sample of 40 × 40 m. Soil macrofauna were sampled by digging and hand sorting two 50 × 50 cm areas into a depth of 20 cm in each treatment. Abundance (the number of macrofauna) diversity (Shannon-Weiner index), richness (Menhinick index) and evenness (Smith– Wilson index) were calculated using geostatistics (variogram) in order to describe and quantify the spatial continuity. Some soil chemical and physical properties were determined. The variograms of variable revealed the presence of spatial autocorrelation. The range of influence was 710. 9 m for abundance, 650. 3 m for diversity, 720. 90 m for richness and 410. 9 m for evenness. The kriging maps indicated that the soil macrofauna have spatial variability. Moreover, the spatial pattern of macrofauna biomass is similar to the pattern of clay and pH of soil.

Thirty years activities in Semnan industrial complex (SIC) have arisen concerns on accumulation of heavy metals in surface soil. The objectives of this study were to determine the concentration and spatial distribution of Pb, Zn, Cu, Ni, Cd and Cr in surface soils of SIC and surrounding areas and to identify origin of these heavy metals. Study area was divided into seven geomorphic units according to landforms and parent materials diversity. Ninety-three composite surface (0-10 cm) soil samples were collected in an area of 117 km2. Concentrations of heavy metals were measured in aqua-regia extracts, using atomic absorption spectrometry. Average concentrations of Pb, Zn, Cd, Cu, Ni and Cr were 49. 2, 84. 4, 1. 6, 22, 20. 1 and 9. 7 mg kg-1 with ranges of 11. 6-511. 2, 34. 1-247. 9, 0. 7-2. 8, 16. 9-42. 0, 9. 2-27. 9 and 3. 5-22. 3 mg kg-1, respectively. The maximum concentrations of Pb, Zn, Cd and Cu were found in the SIC. The spatial distribution of these heavy metals indicated gradual increase in concentrations along the prevailing wind direction. Concentrations of Ni and Cr did not show any specific spatial distribution pattern in relation to activities in SIC and other geomorphic units. According to the principal components analysis results, PC1 with the highest loadings for Pb, Zn, Cd and Cu was recognized as anthropogenic components, whereas the PC2 including Ni and Cr was lithogenic components. The cluster analysis also showed similar grouping. The results indicated considerable increasing in the Pb, Zn and Cd concentrations in the soil, during nearly short period of industrialization. It should be consider to make necessary decision to prevent more pollution.

Since global studies on the health risk assessment of heavy metals in foodstuffs, including biscuits, potato chips, chocolates, and traditional pastries are limited, hence, this study was conducted to determine the contents and the human health risk assessment of lead (Pb), cadmium (Cd) and chromium (Cr) via the consumption of different brands of these foodstuffs. In this descriptive study, a total of 84 samples of 28 brands/kinds of food under consideration were collected from a market basket in city of Hamedan, Iran in 2016. After preparation and processing the samples in the laboratory, the metal concentrations were measured using the inductively coupled plasma-optical emission spectrometer (ICP-OES). In addition, all statistical analyses including One-Way ANOVA and one-sample t test were performed using the SPSS statistical package (Version 19). The results showed that the mean concentrations (mg kg-1) of Pb in all the foodstuff samples (2. 25 ± 0. 76 for biscuits, 1. 60 ± 0. 35 for potato chips, 2. 61 ± 0. 68 for chocolates, and 3. 66 ± 0. 64 for traditional pastries) were higher than the Maximum Permissible Limit (MPL). Furthermore, the computed health risk index showed no potential risk for adults and children via consumption of the studied foodstuffs under the current consumption rate. Based on the results, as the mean contents of Pb observed in all the foodstuff samples exceeded the MPL, serious attention toward the discharge of pollutants into the environment and chemical residue monitoring, especially of heavy metals in foodstuffs, is recommended.