Geokemične in izotopske raziskave površinskih sedimentov in mišic čokatega voleka na izbranih lokacijah Nacionalnega parka Kornati - Hrvaška

Ilenič, Anja (author), Dolenec, Matej (mentor), Lojen, Sonja (comentor)

Nacionalni park Kornati velja za območje z minimalnim antropogenim vnosom snovi v okolje. Namen diplomskega dela je bilo določiti geokemične, mineraloške in izotopske lastnosti sedimenta in mišičnih tkiv čokatega voleka Hexaplex trunculus (Linne, 1758). Lokacije so bile izbrane glede na ocenjeno pričakovano večjo (Piškera in Vrulje), manjšo (Lojena in Mana) in najmanjšo (Klobučar) možnost antropogenega onesnaženja. Geološko zaledje lokacij pridobljenih vzorcev so kredni apnenci in dolomiti ter kvartarni nanosi kraške jerovice (terra rosse) na lokaciji Vrulje. Rentgenska difraktometrična analiza (XRD) je pokazala, da na izbranih lokacijah v recentnih morskih sedimentih prevladujejo karbonatni minerali, in sicer: kalcit, aragonit in dolomit. Kremen in ostali silikati terigenega izvora se v nekaj več odstotkih pojavljajo na lokaciji Vrulje. Z metodama rentgenske fluorescence (XRF) in masne spektrometrije z induktivno sklopljeno plazmo (ICP-MS) je bila določena vsebnost glavnih in slednih prvin ter potencialno strupenih elementov (PTE) v sedimentu. Večje vsebnosti PTE so povezane z večjo vsebnostjo glinencev in ostalih silikatov terigenega izvora na posameznih lokacijah. Koncentracije PTE ne presegajo mejnih imisijskih vrednosti za tla v Sloveniji in na Hrvaškem ter stopnje PEL („probable effect level“) in TEL („threshold effect level“). Izračunali smo stopnjo onesnaženosti, faktor obogatitve (EF) in indeks geoakumulacije (IGEO) za določene PTE glede na posamezne lokacije. Na lokaciji Vrulje so bili nekoliko višji okoljski faktorji izračunani za Cr, Cu in Zn, ki so posledica uporabe gnojil, pesticidov in kemičnih sredstev za preprečevanje korozije. Izotopske meritve sedimenta so pokazale, da so vrednosti izotopske sestave organskega ogljika (δ13CORG) v sedimentu na lokaciji Piškera (‒17,84 ‰) in Vrulje (‒18,50 ‰) glede na ostale lokacije nekoliko povišane, kar je lahko posledica prisotnosti morske trave Posidonia oceanica v sedimentu ali dotoka terigenih organskih snovi s kopnega. Vrednosti δ13CORG in δ15N v mišičnih tkivih so najbolj pozitivne na lokaciji Piškera (‒14,47 ‰, +8,87 ‰) in Vrulje (‒15,66 ‰, +10,4 ‰), kar lahko nakazuje na prisotnost pigmenta indirubina (C16H10O2N2), ki povzroča vijolično barvo, in na dejstvo, da so organizmi plenilci (Surowiec in sod., 2012). Prav tako so povišane vsebnosti izotopske sestave dušika (δ15N) najverjetneje tudi posledica nekontroliranih komunalnih odplak iz bližnje marine in vasi.

• Language: Slovenian
• Keywords: PTE, čokati volek Hexaplex trunculus (Linne, 1758), Kornati, okoljski faktorji, izotopska sestava ogljika in dušika
• Work type: Bachelor thesis/paper
• Organization: NTF - Faculty of Natural Sciences and Engineering
• Year: 2017
• PID: 20.500.12556/RUL-95579
• COBISS.SI-ID: 1354590
• Publication date in RUL: 21.09.2017

Secondary language

• Language: English
• Title: Geochemical and isotopic study of surface sediments and Banded dye-murex muscles from selected locations in the national Park Kornati - Croatia

Abstract

Kornati National Park is considered an environment with a minimal anthropogenic input. The purpose of my thesis was to determine the geochemical, mineralogical and isotopic characteristics of the sediment and muscle tissue of banded dye murex Hexaplex trunculus (Linne, 1758). The locations were selected according to the expected estimated large (Piškera in Vrulje), lower (Lojena in Mana) and minimum (Klobučar) possibility of anthropogenic pollution. Geological outskirts of selected locations represent Cretaceous limestones and dolomites, as well as Quaternary deposits of terra rossa at Vrulje. Completed method of XRD indicated that carbonate minerals such as calcite, aragonite and dolomite, prevail in recent marine sediments at the selected locations. Quartz and other terrigenous silicates occur in a few more percentages at location Vrulje. With the use X-Ray Fluorescence (XRF) and Inductively coupled plasma mass spectrometry (ICP-MS) we were able to determine the concentrations of main and trace elements, as well as the concentrations of potentially toxic elements (PTE) in the sediment. Higher PTE content is associated with a higher content of feldspars and terrestrial silicates at individual locations. PTE concentrations do not exceed the limit imission values for soil in Slovenia and Croatia, as well as the Probable effect level (PEL) and Threshold effect level (TEL). We calculated the level of pollution, enrichment factor (EF) and geoaccumulation index (IGEO) for certain PTE depending on the particular locations. At Vrulje there were slightly higher factors calculated for Cr, Cu and Zn, as a result of the use of fertilizers, pesticides and chemical assets to prevent corrosion. Isotopic measurements of the sediment have shown, that the values of isotopic composition of organic carbon (δ13CORG) at Piškera (‒17,84 ‰) and Vrulje (‒18,50 ‰) were slightly elevated as compared to other locations, which may be the result of sea grass Posidonia oceanica in the sediment or the influx of terrestrial organic matter from the land. Concentrations δ13CORG and δ15N in muscle tissue are the most positive at Piškera (‒14,47 ‰, +8,87 ‰) and Vrulje (‒15,66 ‰, +10,4 ‰), which indicate the presence of pigment indirubin (C16H10O2N2) which causes the purple colour, and the fact that the organisms are predators. The elevated content of δ15N could also be due to untreated sewage from a nearby marina and village.

• Keywords: PTE, banded dye murex Hexaplex trunculus (Linne, 1758), Kornati, environmental factors, isotopic composition of carbon and nitrogen