15 research outputs found
LC50 and bioaccumulation of Cd in different life stages of Artemia urmiana
This study was conducted in vitro to assess lethality, LC50 and the possibility of bioaccumulation of cadmium in various life stages of Artemia urmiana. Artemia is highly used in aquaculture; hence the response of the organisms to pollutants, such as cadmium regarding the increase in environmental pollution is of high importance. This experiment was performed in Faculty of Marine science and Technology, Islamic Azad University and Atomic Energy Organization of Iran in 2009. In the first stage, smaller than 1day naupliis were exposed to 10 different concentrations from 0 to 250mg/l Cd. LC50 of Cd in 24h of A. urmiana exposure was 189.33mg/L. Next, the accumulations of Cd in 5, 10, 15 and 20mg/l Cd were examined in 1, 5, 11 and 17 days of Artemia urmiana life. The results showed that Artemia urmiana has the ability of accumulation of cadmium and the accumulation level depends upon the concentration of the cadmium in the environment as well as different living periods of Artemia. We found that increasing the concentration of cadmium in the environment increases its accumulation in Artemia. There was a significant difference in accumulation of Cd between 5mg/l Cd (0.267ppm) and 20mg/l Cd (0.364ppm) in the first day of A. urmiana life (P<0.05). In all treatments of the 11 day Artemia, bioaccumulations of Cd increased with increasing of cadmium concentration. Maximum accumulation of Cd was in 20mg/l Cd in the 11 day Artemia. Results showed that although A.urmiana is resistant to Cd, however in 250mg/l, cadmium has significant toxic effects on Artemia survival (3.33%)
Evaluating the bioaccumulation of nickel and vanadium and their effects on the growth of Artemia urmiana and A. franciscana
Although there is growing evidence that metals can be toxic to various aquatic species, there is still insufficient knowledge to integrate this information in environmental risk assessment procedures. In this study, we have investigated bioaccumulation and effects of nickel and vanadium on mortality and growth of Artemia urmiana and Artemia franciscana. The in 24 h of A. urmiana and A. franciscana exposed to nickel and vanadium were 0.0072, 0.0114 mg/l and 0.0107 and 0.011 mg/l respectively. In growth experiments, the length of animals was considered as growth index. Results indicates that the mean length of animals in (0.001, 0.002 and 0.003 mg/l) Ni and V on first, 5th, 7th and 11th days of life significantly decreases in comparison with control groups (p<0.05).Bioaccumulation of Ni and V in the same concentration, after 24 h in nauplius and also in adults of A. urmiana and A. fransicana were statistically significantly higher than of the control groups (P < 0.05). Both species accumulate nickel and vanadium in their bodies. However A. urmiana is more resistant to the heavy metals. Results show, nickel is less toxic than vanadium on Artemia
Effects of toxins induced by phytoplankton bloom on physiological function of indicator animals in Anzali Lagoon
The present overview summarizes data from one year's study during the period of 1379 to 1380 in the regions by "Anzali" lagoon called "Abkenar" and "Hendkhale". Specimens from this lagoon obtained weekly during mordad and shahrivar mounths (July 21 to september 21). The study included 67 types of 5 phytoplanktonal phylum. In "Abkenar" region Cyanobacters with maximum of 97% and minimum of 64.5% of total combination of phytoplanktones made the dominating combination during the period of study , while in "hendkhale" chyrsophyta with maximum of 89% and minimum of 38.7% of total phytoplanktonal was the dominating figure at the same period of time.
Researches on ecological parameteres showed that the avarage dissolved oxygen in -Abkenar" and "hendlchale" regions was 10.7 and 8.0 mg/lit respectivly, also total rate of Phosphat in these regions was 0.085 and 0.15 mg/lit respectivly. This study showed that the rates of Nitrat and Amonium in "Abkenar" region was 0.043 and 0.79 mg / lit while for the same substances in "Ilendkhale" measured 0.08 and 0.7 mg I lit respective. Also the avarage rate of chlorophyll a in these two areas measured 58,38 and 40.45 j.un /ht respectivly. Depending on results of correlation cofficient in "Abkenar" region we had Cyanobacters , water and air temperature , Chlorophyll a and total amount of Phosphat as a poitive correlation with transparency while Amonium and Nitrat showed , a negative correlation , EC and finally dissolved oxygen showed a very low rate of correlation coffiocient. To perform this research 5 genus of Cyanobacteres horn "Anzali" lagoon have been isolated and cultured in a laboratorial conditions Later by using Mouse Bioassay method one of these genus identified as a toxic algae. Levels of LD50 with intra peritoneal injection of toxin on mouse in 24 hours was 660 mg/kg and Levels of LC50 by using Bioassay method on Artemia and Daphnia has been shown 618 and 1000 mg kg respectively. Also the physiological effects of were investigated. algae on two types of Cypronides family called Cyprinus carpi° and Hypophrthabnichthys Resultes of blood analyses of Cypronides who were feeded by toxic algae showed a significant decline (P < 0.05) in white and red blood cells and their hematocrites. Levels of LDH , SGOT and SGPT in their blood serum had a significant increase in porportion to control group (P < 0.05) but there was no evidance a differences in Total Protein levels. Pathological studies show damage and destruction of hepato pancreas and kidney of these fishes. Signs and symptoms of intoxication caused by Cyanobacter called Planktohrix agardlltii in mouse and fish show heptotoxic character. This toxin belongs to cyclicpeptides of microcystines group
Optimal conditions for tissue growth and branch induction of Gracilariopsis persica
The species Gracilariopsis persica was first described by Bellorin et al. (2008). G. persica grows from late September to July and shows high growth rate from January to May in the Persian Gulf. Tissue growth and branch induction of red seaweed, Gracilariopsis persica from the Persian Gulf investigated under various culture levels of temperature, light intensity, photoperiod, salinity, initial length, propagule density and chemical preservatives. Optimal size of propagules used as seed was 2 cm and faster growth of tissue and branch induction obtained at lower density. The apical part of the G. persica showed as the starting point of growth. The G. persica showed optimal growth in PES medium at 24°C, 60μmol m-2 s-1 light intensity, 12L: 12D and salinity of 39‰. But maximum branch production occurred under condition of 24°C, 20 μmol m-2 s-1 light intensity, photoperiod of 16L: 8D and salinity 39‰. Addition of chemical preservatives of p-hydroxybenzoic acid and potassium sorbate in culture medium showed marginal suppression on tissue growth and branch induction, that suitable for preparation of semi-axenic culture condition
The relative contribution of applied inputs of rapeseed (Brassica napus L.) agro-ecosystem on environmental factors
In this study, the environmental impacts of rapeseed production were studied using the SimaPro software. The initial data were collected from 30 farmers in the Alborz Province by face-to-face questionnaire method. The selected functional unit (FU) was one Mton-1 rapeseed production. Five environmental indices were evaluated, including the potential of abiotic depletion, acidification, eutrophication, global warming and ozone layer depletion. To produce each ton of rapeseed, 84 kg of nitrogen, 63 kg of phosphate, 63 kg of potassium, 133.5 l of diesel fuel and 586 kW of electricity were used. Also, the CO2, CO, N2O and NOX (different types of oxides of nitrogen) emissions were about 361, 4.1, 11.5 and 4.8 kg per ton of rapeseed respectively. The results indicate that the global warming potential amounts to 1629.52 kg CO2 eq. Also, the acidification and eutrophication potentials were found to be 8.31 kg SO2 eq. and 2.73 kg PO4 eq. respectively. It was also revealed that the chemical fertilizers had the highest contribution among the evaluated inputs within the rapeseed growing period. Overall, this study showed that reducing the consumption of chemical fertilizers, especially nitrogen-based ones, is important for reducing environmental footprints in rapeseed production
Bloom of phytoplankton in Anzali Lagoon and identification of poisonous algae
During the period of 1979-1980 in Abkenar and Hendkhaleh in Anzali lagoon, 67 I genus of phytoplanktons belong to 5 phylum were identified. The results showed that there is two peaks of phytoplankton blooms during a year (summer and, autumn) in which Cyanobacteria (blue-green algae) were the most abundant groups. 5 species of them were identified in which one species was recognized toxic. This toxicity was confirmed through bioassay studies on mouse. Also, This toxin was hepatotoxin belongs to microcystins. Microcystins are cyclic peptides and contain seven aminoacids
EFFECTS OF ZINC AND COPPER EXPOSURE ON GROWTH AND SURVIVAL OF ARTEMIA URMIANA AND ARTEMIA FRANCISCANA
The effects of exposure to Zinc and Copper in developing from nauplius to adult stages in two species, A. urmiana and A. franciscana were studied. The growth and lifespan of the specimens under treatments also have been investigated.
During the period of the experiments, both species of Artemia were exposed by Zinc-treated groups (23, 68, 114 mg/l) and also copper-treated groups (13, 25, 38 mg/l) and compared with control group without any metal treatment. However, in treatments with Zinc and Copper concentrations, lifespan was reduced in comparison with that of the control treatments.
Results showed that Zinc and Copper have toxic effects on A. urmiana and A. franciscana. Although the resistance of both of them was high, but A. urmiana was more endure than A. franciscana. It is, suggested that the two Artemia species might have adopted a strategy to speed up growth and reproduce before metal pollution can cause death for them. Also, this study indicated that Zinc was less toxic than Copper for the two species investigated