JOURNAL OF MARINE BIOLOGY
Year:2018 | Volume:10 | Issue:38|Papers Count:8

The present study investigates the correlation between bleaching event and morphological condition and population dynamics of the symbiotic algae (zooxanthellae) residing within the hermatypic coral Acropora downingi Wallace, 1999 in Qeshm Island, Persian Gulf. Fragments of normal and bleached coral colonies were collected by SCUBA diving from southeastern coastal waters of Qeshm Island in the fall of 2015. Healthy, bleached, degraded and dividing zooxanthellae were observed and appraised with a light microscope using a haemocytometer. Spectrophotometric method was used for the measurement of pigment content of zooxanthellae. Comparisons of the mentioned characteristics between normal and bleached coral colonies showed a 50 percent population decline of zooxanthellae in bleached colonies. While density of normal zooxanthellae decreased by 25 percent in bleached colonies, number of bleached (t=7. 03, P=0. 00) and degraded (t=3. 56, p=0. 02) zooxanthellae along with mitotic index (z=-3/06, P=0. 002) had a significant rise in the mentioned colonies. There was no significant difference between chlorophyll-α (t=0. 49, P=0. 63) and chlorophyll-c (t=0. 13, P=0. 89) content of the studied corals. Our results may reveal that corals in Qeshm Island are probably suffering from severe environmental conditions and it is likely that many of the healthy looking colonies are already half way through bleaching. The present study investigates the correlation between bleaching event and morphological condition and population dynamics of the symbiotic algae (zooxanthellae) residing within the hermatypic coral Acropora downingi Wallace, 1999 in Qeshm Island, Persian Gulf. Fragments of normal and bleached coral colonies were collected by SCUBA diving from southeastern coastal waters of Qeshm Island in the fall of 2015. Healthy, bleached, degraded and dividing zooxanthellae were observed and appraised with a light microscope using a haemocytometer. Spectrophotometric method was used for the measurement of pigment content of zooxanthellae. Comparisons of the mentioned characteristics between normal and bleached coral colonies showed a 50 percent population decline of zooxanthellae in bleached colonies. While density of normal zooxanthellae decreased by 25 percent in bleached colonies, number of bleached (t=7. 03, P=0. 00) and degraded (t=3. 56, p=0. 02) zooxanthellae along with mitotic index (z=-3/06, P=0. 002) had a significant rise in the mentioned colonies. There was no significant difference between chlorophyll-α (t=0. 49, P=0. 63) and chlorophyll-c (t=0. 13, P=0. 89) content of the studied corals. Our results may reveal that corals in Qeshm Island are probably suffering from severe environmental conditions and it is likely that many of the healthy looking colonies are already half way through bleaching. The present study investigates the correlation between bleaching event and morphological condition and population dynamics of the symbiotic algae (zooxanthellae) residing within the hermatypic coral Acropora downingi Wallace, 1999 in Qeshm Island, Persian Gulf. Fragments of normal and bleached coral colonies were collected by SCUBA diving from southeastern coastal waters of Qeshm Island in the fall of 2015. Healthy, bleached, degraded and dividing zooxanthellae were observed and appraised with a light microscope using a haemocytometer. Spectrophotometric method was used for the measurement of pigment content of zooxanthellae. Comparisons of the mentioned characteristics between normal and bleached coral colonies showed a 50 percent population decline of zooxanthellae in bleached colonies. While density of normal zooxanthellae decreased by 25 percent in bleached colonies, number of bleached (t=7. 03, P=0. 00) and degraded (t=3. 56, p=0. 02) zooxanthellae along with mitotic index (z=-3/06, P=0. 002) had a significant rise in the mentioned colonies. There was no significant difference between chlorophyll-α (t=0. 49, P=0. 63) and chlorophyll-c (t=0. 13, P=0. 89) content of the studied corals. Our results may reveal that corals in Qeshm Island are probably suffering from severe environmental conditions and it is likely that many of the healthy looking colonies are already half way through bleaching. The present study investigates the correlation between bleaching event and morphological condition and population dynamics of the symbiotic algae (zooxanthellae) residing within the hermatypic coral Acropora downingi Wallace, 1999 in Qeshm Island, Persian Gulf. Fragments of normal and bleached coral colonies were collected by SCUBA diving from southeastern coastal waters of Qeshm Island in the fall of 2015. Healthy, bleached, degraded and dividing zooxanthellae were observed and appraised with a light microscope using a haemocytometer. Spectrophotometric method was used for the measurement of pigment content of zooxanthellae. Comparisons of the mentioned characteristics between normal and bleached coral colonies showed a 50 percent population decline of zooxanthellae in bleached colonies. While density of normal zooxanthellae decreased by 25 percent in bleached colonies, number of bleached (t=7. 03, P=0. 00) and degraded (t=3. 56, p=0. 02) zooxanthellae along with mitotic index (z=-3/06, P=0. 002) had a significant rise in the mentioned colonies. There was no significant difference between chlorophyll-α (t=0. 49, P=0. 63) and chlorophyll-c (t=0. 13, P=0. 89) content of the studied corals. Our results may reveal that corals in Qeshm Island are probably suffering from severe environmental conditions and it is likely that many of the healthy looking colonies are already half way through bleaching.

In this study, effects of a commercial dietary probiotic mixture containg Bacillus subtilis and B. licheniformis was assessed on some growth, hematology, and immunology indices of common carp in Agricultural and Cultural Complex of Martyr Mehranzadeh, Khuzestan Province for 60 days. There was three treatments including 0. 5 (T1), 0. 7 (T2), and 0. 9 (T3) g of the probiotic mixture per kg of feed and also a control group (without any probiotic supplementation) were designed. Each treatment with three replicates and each replicate had 35 fry fish (100± 10 g initial weight) with 10. 5 kg/m3 density. Results showed that the highest growth performances including final weight, specific growth rate, practical protein ratio and practical feed ratio were observed in T3 (p<0. 05). The lowest FCR (1. 74) was calculated in T3 (p<0. 05). Hemoglobin concentration, hematocrit, RBC and WBC and lysozyme (129. 33 μ g/L) levels were more in T3 compared to the other treatments (p<0. 05). In conclusion, application of the probiotic mixture at 0. 9 g/kg feed can improve growth performances and immunity system of fish and it is recommended to be added to the diet of common carp.

The concentration of chlorophyll-a (Chl-a) is the major water quality parameters that can be retrieved using remotely sensed data. In this study, using satellite images Landsat 8 and field, Chl-a concentration in November 2016 in Deilam coasts of water covered. We have tried to determine the chlorophyll algorithm consists of several experimental algorithms simple and examine the applicability of using Landsat 8 imagery to estimate and map chlorophyll-a concentration in the coasts of Deilam. The statistical parameters used to evaluate the performance of different algorithms, including root mean square error (RMSE) and coefficient of determination (R2) is. The relationship between the reflectance value of an individual OLI band and in situ chlorophyll-a concentration was examined to identify bands sensitive to chlorophyll-a. We also investigated the performance of ratio-based spectral indices to retrieve chlorophyll-a concentrations in coast of Deilam. POLDER algorithm with the largest amount of R2 (0. 52) and the lowest RMSE (0. 85) was selected as the most appropriate algorithm in the area. The spectral ratio index b5/b1 and b5/b2 have the highest correlation with in situ chlorophyll-a. To estimate chlorophyll-a concentration, various regression models were tested with different band ratio. Among the regression models, we choose the best model (R2=0. 43). Spatial distribution of chlorophyll-a concentration in the Deilam was successfully mapped using Landsat 8 imagery for November in 2016. Despite the limitation of this work, our findings suggest that Landsat 8 imagery can be used to estimate chlorophyll-a concentration in coastal.

In this study, the effects of chronic use of linear alkylbenzene sulfonate (LAS) on the amount of chlorophyll and carotenoids in Nannochloropsis oculata microalgae were investigated. The results of the measurement of chlorophyll content in N. oculata microalgae showed that there were no significant differences among treatment groups in the three periods at the beginning, middle or end of the test (p>0. 05). However, comparing the treatments with the control treatment in the early, middle and end periods showed a decrease in chlorophyll content. The results of carotenoid assay showed that there were no significant differences between the levels of carotenoids in the first and second treatments in the initial, middle and end periods (p>0/05). Surfactants interfere with the formation of chlorophyll in algae through disturbances in protein synthesis and also disrupt photosynthesis. The cause of the non-significant decrease in carotenoids can possibly be attributed to the low concentration of LAS and the antioxidant properties of N. oculata microalgae carotenoids. Microalgae are sensitive to environmental changes, such as increasing the concentration of surfactants, and these changes can cause disturbances in chlorophyll and carotenoids and many of the cellular metabolites. Therefore, the necessity of using surfactants with higher degradability and shorter shelf-life in nature seems to be significant.

The presence of PAHs compounds in the marine ecosystem is of a great importance case study due to the effects of carcinogenesis and genetic mutations and fatal in organisms. Therefore, the accumulation of various polycyclic aromatic hydrocarbon compounds in the Clibanarius Signatus hepatopancreas tissue was studied at 10 stations in 2017 along the northern coast of Makoran Sea. Determination of the PAHs was performed by using HPLC. The concentration of total polycyclic aromatic hydrocarbon compounds in hepatopancreatic tissue was between 19. 11-62. 22 ng g-1dw. The highest amount of contamination was observed in Chabahar Bay station and the lowest was in Pasabandar station. One-way analysis of variance showed a significant difference between stations (p<0. 05). The results of this study indicated that the measured values of PAHs are lower than the international standard for NOAA for marine organisms. The presence of compounds with low number of rings indicates the presence of pollutants of petrogeneic origin. This study shows and confirms the use of C. signatus as a bioindicator of coastal pollution, especially polycyclic aromatic hydrocarbon compounds.

Persian Gulf is one of the most diverse ecosystems in the word and because of its strategic location constantly exposed to oil pollution. As a result, development of efficient techniques for treating contaminants is required. The aims of the present study were to determine biosurfactant production by TA1 (Alcanivorax dieselolei), to study the ability of TA1 to utilize different fractions of oil and crude oil biodegradation kinetic was studied. TA1 ability to produce biosurfactant in mineral salt medium containing different carbon sources was measured. The ability of TA1 to degrade different fractions of crude oil was studied using gravimetrically. Biodegradation kinetics of crude oil was performed in the mediums containing different concentrations of crude oil. Various substrate inhibition models were compared by fitting them to the experimental data using software. The results showed TA1 only in a medium containing crude oil was able to produce biosurfactant. Respectively, 95. 46 percent, 89. 52 percent, 29. 95 percent and 27. 20 percent of aliphatic, aromatic, resin and asphaltenes in crude oil were consumed by TA1. TA1 grew on culture medium containing different concentrations of crude oil and with increasing concentrations lag phase be longer and growth rate and biodegradation reduced. Experimentally it was observed that the kinetic biodegradation of crude oil was best described by Aiba model. According to the biosurfactant production, the ability of this strain to degrade different fractions of oil and the ability of TA1 in the consumption of hydrocarbon compounds in high concentrations, this strain can be efficiently used for bioremediation of petroleum-contaminated areas.

Essential elements such as iron, zinc and copper in the body of the fish have a biological role. Increased concentrations of these elements in the organs of fish are due to toxicity. This present study was carried out to investigate and comparison the concentration of heavy metals such as, Fe, Zn and Cu in muscle, liver and caviar of farmed Acipenser baerii from Khuozestan Province, 2014. 30 samples of Acipenser baerii were prepared from five ponds of Hantoshzadeh sturgeon breeding complex. Heavy metal levels in fish samples were analyzed by Perkin Elmer 4100 zl atomic absorption. Data analysis was performed with the software SPSS17 and comparison of the mean to T-test. The highest concentration of Fe, Zn and Cu were 7. 42± 0. 68, 42. 22± 3. 48 and 3. 72± 0. 32 mg/Kg in liver of Acipenser baerii, respectively. The lowest concentrations of these elements were obtained 2. 22± 0. 16, 10. 62± 0. 76 and 0. 51± 0. 02 mg/Kg in muscle of this species, respectively. Concentrations of heavy elements in liver of Acipenser baerii from all samples were higher than muscle and caviar. The concentrations of iron, zinc and copper content of caviar in Acipenser baerii was 4. 74± 0. 35, 34. 29± 2. 27 and 1. 66± 0. 02 mg / kg, respectively. In this study concentration of Fe, Zn and Cu in muscle and caviar of Acipenser baerii were lower than comparison of WHO, FDA, MAFF and NHMRC standards.

Sparidae family has an important economic value in southern waters of Iran. This research was carried out to assess the amount of the biomass and Catch per Unit of Area (CPUA) and also to determine the distribution pattern of Sparidae family in the north of the Oman Sea (Sistan and Baluchistan Waters) based on trawl survey results in 2012 by R/V Ferdows-1. Samples were collected at a total 75 trawl stations selected a stratified random procedure. The area divided to four deep layers of 10-20 meters, 20-30 meters, 30-50 meters and 50-100 meters were determined. The biomass of Sparidae was estimated to be 477. 3 tons. The highest biomass was recorded approximately 163. 9 tons for depth layer of 50-100 m in Biahi, Meidani, Rabech and Galak area. The catch rates of CPUA were estimated to be approximately 205. 0 kg/nm2. The highest value of CPUA was recorded Biahi, Meidani, Rabech and Galak area, approximately 706. 6 kg/nm2, and for depth layer of 30-50 m with value of 304. 9 kg/nm2. The distribution map was drawn with Arc-GIS software.