Yazar "Karadede-Akin H." seçeneğine göre listele

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  • [ X ]
    Öğe
    Bioaccumulation of cadmium by nile tilapia Oreochromis niloticus (L.) in the presence of green algae Cladophora glomerata (L.) kutz
    (2009) Unlu E.; Karadede-Akin H.; Akturk M.N.; Yanar M.
    Accumulation of cadmium (Cd) was determined in the muscle and gill tissues of Nile tilapia Oreochromis niloticus (L.) exposed to sublethal concentrations of Cd (0.1 and 1.0 mg/L) under laboratory conditions for 15 and 30 days, in the absence or presence of green algae Cladophora glomerata (L.) Kutz. Results showed that muscles, irrespective of treatments, accumulated less Cd than gills. Cd accumulation significantly increased in both the tissues in treatment groups as compared to control groups (p<0.05), except in muscle of fish exposed to 0.1 mg/L Cd for 15 days (p>0.05). Presence of green algae did not influence accumulation of Cd in muscle. But Cd accumulation was significantly reduced in gills, in the presence of green algae, in all treatments groups, except in 0.1 mg/L Cd exposure for 15 days. In the presence of green algae, the reduced Cd accumulation in gills might be due to its uptake from the medium by the algae.
  • [ X ]
    Öğe
    Seasonal variations of heavy metals in water, sediments, pondweed (P. pectinatus L) and freshwa-ter fish (C. c. umbla) of lake hazar (Elaziğ-Turkey)
    (2009) Karadede-Akin H.
    In this study concentrations of heavy metals, such as, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn were determined in water, sediment, sago pondweed (Pot?mogeton pectinatus L.) and muscle, liver and gill of freshwater fish (Capoeta capoeta umbla) collected seasonally from three selected sites of Hazar Lake. The heavy metal concentrations ob- tained from water samples were low. Among the metals, the highest concentrations in water samples were found for Fe. In the sediment samples, the highest concentration was recorded for Mn and the lowest for Pb in all seasons and sites. The metal concentrations determined in sago pond- weed varied seasonally. The highest levels of Fe, Mn and Zn values in sago pondweed were in spring. Heavy metal concentrations varied significantly depending on the type of the tissue and season. The highest metal concentrations were found in liver, followed by gill and muscle. Heavy metal levels in tissues of freshwater fish C. c. umbla were increased in summer and winter, while were decreased in autumn and spring. The present study shows that precau- tions need to be taken in Hazar Lake in order to prevent heavy metal pollution that can occur in the future.