Aquatic Ecology
Year:2020 | Volume:10 | Issue:1|Papers Count:10

In control of lands, the assemblage and determination of effective factors on survival are necessary. The management of habitat is based on speculation and becomes a failure without the information. This study was done to survey the habitat suitability index of the Kura goby (Ponticola cyrius) in the Tajan River. For this purpose, samples were taken during a month from December to January 2014, at 15 stations in Tajan River from the highest point accessible to Crossroads Takam, and then triggering samples were counted. The environmental factors such as temperature, dissolved oxygen, electrical conductivity, pH, width, depth, altitude, slope, diagonal of substrate stones, water velocity, type of cover, and the measure of shadow were recorded in each station. Specimens of fish were caught by electrofishing at each station and were counted. Habitat suitability index was calculated for each. The results showed that the second station (upstream part) is the most favorable habitat for Kura goby, and some parameters such as dissolved oxygen, total dissolved solids, and depth of the river have the key role in the high habitat suitability index of the second station. Also, vegetation cover of bushes and shrubs, 40 to 71 percent of shadow, and the cobblestone bed were observed in habitat selection of Kura goby. According to the results of this study and due to the lack of mobility and the presence of ventral fin, the desirable habitat for this species is rubble beds (diameter 15 cm) and the flow rate of water is less than 0. 5 m/s.

This study was designed to determine the effects of different levels of black cumin seed on pacific white shrimp, Penaeus vannamei plasma cholesterol, and triglyceride concentration. Five levels of black cumin seed including 0, 0. 5, 1. 5, 3, and 5 percent were used and each group was divided into three replicates and 40 shrimp (7. 5± 0. 2 gr) were stocked. After 12 weeks of the feeding trial, plasma cholesterol and triglyceride concentration were significantly lower in shrimp-fed diets containing black cumin seed compared to control (P<0. 05). In conclusion, this study indicated that dietary contained black cumin seed can help to produce safer shrimp with lower plasma cholesterol and triglyceride concentration.

Inland waters, such as wetlands, are considered to be sensitive ecosystems, and sustainable productivity can only be achieved by adopting an appropriate environmental approach. Estimating water quality parameters using models will reduce costs and provide faster access to water resources management. In this study, a 32-year support vector machine (SVM) model was used from 1985 to 2017 to simulate the chlorophyll a and water clarity (Secchi-disk depth) in Choghakhor international wetland. 70% of the data was used to train and the rest of the data was used for testing of the model. The determination coefficient (R2) and root mean square error (RMSE) in the SVM model were 0. 93, 0. 91, and 0. 097 mg / m3, 0. 049 m respectively for the optimal composition of chlorophyll a and Secchi-disk depth. Also, SVM model with the lowest input power also had the power to predict. The results of this study showed that the support vector machine has a high potential for predicting chlorophyll a and water clarity, and it can be used to determine the appropriate strategies for the management of the Choghakhor wetland.

This study was conducted to determine the priority of socio-cultural aspect on illegal fishing occurrence in Hormozgan province using analytic hierarchy process (AHP) in 2020. First, the hierarchy of performance indicators of illegal fishing occurrence was extracted from previous literature. Hereafter, a hybrid approach, which consisted of two sections namely expert-based (15 experts of the Iranian Fisheries Organization) and fisher-based (15 key informant fishermen who had at least 15 years of work experience), were used to gather the paired comparison data. Samples were selected through snow-ball sampling technique. Data analyses were done by SuperDecision software. According to the experts’ viewpoint, the priorities criteria on illegal fishing occurrence includes economic status (with 48% weight percentage), Area features of Hormozgan province (15. 33%), management issues (12. 91%), culture (12. 28%), and personal skills (11. 48%), respectively. Whereas, unemployment (12. 73%) and nonchalant perspective to life (2. 9%) had the maximum and minimum importance among the sub-criteria. Against, fishermen believed that nearly 60% of illegal fishing is occurred because of two criteria namely area features (29. 25%) and management issues (27. 88%), while the cultural aspect (with 10. 92%) has the lowest priority. The results of the present study would be helpful to the executive managers of fisheries in Hormozgan province (or even others) to decision-making and implementing the operational measures to mitigate illegal fishing.

The recent increase in nanomaterials usage has led to rising concerns about the health risks of organisms and their environmental impacts. Thus, there is much attention to investigating environmental parameters which change the nutrition quality of algae. In this study, growth inhabitation was evaluated during 2 steps and chlorophyll-a content of microalgae Chaetoceros muelleri which was exposed to bulk Ti and nano-TiO2 in 3rd, 6th, and 9th days. The results showed algal growth inhabitation up to 70 and 50% in concentration 50 ppm for nano-TiO2 and bulk Ti, respectively. Moreover, we found a reduction of chlorophyll content in comparison with control groups, also observations were illustrated that trend of chlorophyll content reduction on the 9th day was higher than the 6th day and in 6th day was more than 3rd day (9th day> 6th day>3rd day). In addition, findings demonstrated, nano-TiO2 toxicity was higher than bulk Ti. We aimed to investigate the toxic effects of bulk Ti and nano-TiO2 on food chain organisms and transportation of these materials along with the food chain and finally, how to influence the health of humans and the environment.

The aim of this study is to use an edible chitosan coating containing Mentha piperita L. essential oil in order to increase the shelf life of rainbow trout fillet at refrigerator temperature (4± 1° C). Trout fillets were set in 5 orders including control treatment, treatment with chitosan coating without essential oil, treatment with chitosan coating containing 0/5, 1, and 2% essential oil, then stored at refrigerator temperature for 20 days. All treatments were analyzed, every 5 days of storage time periodically to determine microbiological total viable count (TVC) and psychrotrophic count (PTC) and chemical characteristics contain pH, (TBA), (TVB-N), (PV), and (FFA) content. The Statistical results indicated that the use of this Chitosan coating with Mentha piperita L. essential oil also led to a reduction of all values during storage (P<0/05). The minimum level of all values was observed in the treatment with chitosan coating containing 2% essential oil and the maximum level of all values in the control treatment at the end of the storage time. On the basis of the results, The level of TVC, PTC, pH, PV, TBA, TVB-N, and FFA values were in the fillets coated with Chitosan and 2% essential oil 6/55± 0/14 (log10 cfu/g), 6/90± 0/18 (log10 cfu/g), 6/7± 0/02, 2/80± 0/05 (meq o2/kg lipid), 0/12± 0/02 (mg MDA/kg), 24/88± 0/46 (mg N/100 g) and 1/52± 0/08 (% oleic acid). The results indicate that the chitosan coating enriched with Mentha piperita L. essential oil has the potential to reduce bacterial growth and oxidation in rainbow trout fillets during refrigerated storage (4± 1° C).

Metal pollution has always been a major cause of contamination of the environment and is considered a major concern for food health. In this study, the human health risk due to the consumption of muscle of Rastrelliger kanagurta was evaluated by measuring the concentrations of copper and zinc in caviar and muscle samples. After preparation operation, biometry, and digestion of muscle parts, measurement of heavy metal concentrations were done using atomic absorption spectrophotometer (AAS). Mean concentrations of copper and zinc were lower than the international standard limits. In addition, the calculations indicated that daily and weekly copper and zinc uptake for the Iranian consumers, according to Statistical Yearbook of Iran Fisheries organization (the amount consumed per capita), is lower than the guideline values (PTWI and PTDI) provided by WHO, USEPA. In general, the THQ and total THQ measured in this study were <1. In conclusion, metals concentration in this species is acceptable for human consumption from a toxicity point of view. The consumption of the R. Kanagurta is not to cause any adverse health effects to consumers.

The present study was carried out to provide basic information on the physiological damages (biochemical indicators of serum) of Round Goby under laboratory and environmental conditions of lead pollution and finally the design of Biochemical biomarkers of lead pollution in the Gulf of Gorgan in the summer of 2018. In both conditions, the effect of lead contamination on biochemical indicators of serum of Round Goby was investigated. In addition to biochemical indicators of serum, lead levels in the liver, water, and sediments were also measured. According to the results, glucose, cortisol, and ALT parameters showed a positive and significant correlation with lead contamination of Round Goby liver, and total protein and immunoglobin M parameters showed a negative and significant correlation with lead contamination of Round Goby liver under laboratory conditions (P< 0. 05), and under environmental conditions, ALT enzyme showed a positive and significant correlation with lead contamination of Round Goby liver, while serum total protein and glucose values showed a negative and significant correlation with lead contamination of Round Goby liver (P< 0. 05). Finally, the protein levels due to a significant negative correlation and ALT due to a significant positive correlation with the liver lead levels in both environmental and laboratory conditions can be considered as the most effective and efficient biochemical biomarkers of lead in Round Goby.

The population parameters of G. suppositus were studied for a period of 18 months from November 2016 to April 2018 in the coastal waters of the Persian Gulf (Hormozgan province). A total of 635 fish were selected as bycatch from shrimp bottom trawler and measured biometric data. The correlation between total length and weight for males and females showed high values (R2 were estimated at 0. 83 and 0. 86 for males and females, respectively. The b-value for the length-weight relationship was 3. 35 and 3. 21 for males and females, respectively, indicating positive allometric growth patterns in this species (P <0. 05). The TL∞ was estimated at 35 cm for males and 40 cm for females as well as the growth coefficient (K) for males and females was estimated at 0. 74 and 0. 65 Y-1, respectively. Also, t0 for males and females were estimated at-0. 20 and-0. 22 Y-1, respectively. The recorded results of this study showed that the natural mortality rate (M) in males was 1. 38 Y-1and for females were 1. 22 Y-1and the fishing mortality rate (F) was 2. 95 in males and 3. 05 Y-1 in females, respectively. The total mortality (Z) for males and females was estimated at 4. 33 and 4. 27 Y-1, respectively. Also, the exploitation coefficient (E) for this species was 0. 68 and 0. 71 in males and females, respectively.

This research was conducted to investigate the lethality concentration of Cadmium and Lead in species Artemia Franciscana in laboratory conditions. Artemia was fed individually from the micro Algae Isochrysis galbana and Nannochloropsis oculata for seven days. Among the heavy metals, Cadmium and Lead, are oil pollution indicators and industrial activities in the marine ecosystem, Therefore, the type of response of these organisms to contaminants such as Lead and Cadmium, due to its increasing contamination, is very important. In this study, Artemia was exposed to 10 concentrations of (120 to 230 mg / L and one control group), Cadmium, and Lead. LC5024h for Artemia fed with micro Algae Isochrysisis galbana and Nannochloropsis oculata in the vicinity of Cadmium was 170 mg / L and 189 mg / L, respectively, and for the Lead metal in Artemia fed with both types of microalgae Equal to 180 mg/liter was obtained. The results of this study showed that Cadmium toxicity in Artemia fed with microalgae I. galbana was higher than that of Lead, but the Lead toxicity of N. oculata. fed with Artemia was higher than that of Cadmium.