Impact of environmental exposure and physiological factors on metal bioaccumulation in the liver of northern pike (Esox lucius)

U ovome smo istraživanju odredili ukupne te prvi put i citosolske koncentracije 19 elemenata u jetrama štuka (Esox lucius) s dviju postaja na rijeci Mrežnici (REF: referentna; DRT: postaja ispred nekadašnje tvornice tekstila). Koncentracije Bi, Cs, Cu, Fe, Se i Zn bile su više na DRT postaji kao znak utjecaja povijesnog onečišćenja, a Mn, Mo i Tl na REF postaji, vjerojatno uslijed utjecaja poljoprivrede, što se podudara s onečišćenjem vode i sedimenta rijeke Mrežnice. Visoka zastupljenost (>70%) u citosolskoj frakciji jetre zabilježena je za veći broj elemenata (npr., Ag, As, Bi, Cd, Cs, Cu), što upućuje na njihovu potencijalnu toksičnost. Utvrdili smo da veličina, spol i način ishrane štuka (veća ili manja zastupljenost ribe u prehrani) mogu utjecati na koncentracije nekih elemenata akumuliranih u njihovim jetrama. Koncentracije Bi, Cs i Fe bile su više u većim ribama, a Ca u manjim. Koncentracije Bi bile su više u ženkama, a Mo i Zn u mužjacima. Koncentracije As, Mn i Na bile su više u štukama sa zelenim jetrama (prehrana vjerojatno bogatija beskralješnjacima), a Bi, Cs i Fe u štukama sa žutim jetrama (prehrana vjerojatno bogatija ribama). Rezultati ovoga rada doprinose boljem poznavanju bioakumulacije metala/metaloida u jetri štuke kao značajnog bioindikatorskog organizma.Total and, for the first time, the cytosolic concentrations of 19 elements were determined in the northern pike (Esox lucius) liver from two locations at the Mrežnica River (REF: reference; DRT: in front of the former textile factory). Bismuth, Cs, Cu, Fe, Se, and Zn concentrations were higher at DRT as a sign of historical contamination impact, and Mn, Mo and Tl at REF, probably due to agricultural impact, which is consistent with water/sediment contamination of the Mrežnica River. High percentage of several elements in cytosol (>70%) (e.g., Ag, As, Bi, Cd, Cs, Cu) indicated their potential toxicity. Size, sex and diet composition (more or less fish in the food) were shawn to sometimes influence metal/metalloid accumulation in the northern pike liver. Bismuth, Cs and Fe concentrations were higher in bigger fish, Ca in smaller. Bismuth concentrations were higher in females, Mo and Zn in males. Arsenic, Mn and Na concentrations were higher in specimens with green liver (diet probably rich in invertebrates), Bi, Cs and Fe in specimens with yellow liver (diet probably rich in fish). The results of this thesis contribute to better understanding of hepatic metal/metalloid accumulation in the northern pike as an important bioindicator organism