| Abstract | U ovom radu opisane su zajednice foraminifera u sedimentima jezgara
uzorkovanih gravitacijskim korerom na 13 postaja iz područja srednjeg i južnog Jadrana te
Šibenskog zaljeva s dubina između 38 m i 1200 m. S obzirom na sastav i abundanciju
foraminiferskih vrsta definirane su dvije asocijacije. Eilohedra vitrea – Turborotalita
quinqueloba asocijacija s dva biotopa, Turborotalita quinqueloba – Globocassidulina
subglobosa biotop i Eilohedra vitrea biotop, te Turborotalita quinqueloba asocijacija.
Sedimenti s većim udjelom sitnijih čestica bogatiji su organskom tvari i imaju manji udio
epifaunalnih vrsta, a u takvim okolišima/zajednicama dominantne vrste su Eilohedra vitrea
i Cassidulina laevigata. Indeksi raznolikosti konstantni su duž jezgre, a manji su u
jezgrama s veće dubine mora. U sedimentima s postaja dubljih od 100 m, u istraženim
poduzorcima, najbrojnija je Turborotalita quinqueloba, relativno mala planktonska vrsta,
tipični predstavnik zajednice iz hladnih mora. U sedimentima srednjeg i južnog Jadrana
elementi Mg, Al, Fe, Be, V, Cr, Sc, Co, Ni, Cu, Ti, Zn, Rb, Zr, Sb, Cs, Ba, Tl, Th su
terigenog porijekla, a moguće je da postoji antropogeni unos Pb, Cd, Ag, Se i U u području
Šibenskog zaljeva. Maseni udjeli Mn i Mo u sedimentima pod utjecajem su redoks uvjeta
unutar jezgara te je raspodjela ovih elemenata duž jezgre povezana sa vertikalnim redoks
profilima. Raspodjela foraminifera u srednjem i južnom Jadranu nije povezana s
rapodjelom istraženih elemenata u sedimentima, a razlike u izmjerenim masenim udjelima
nemaju utjecaj na sastav i raznolikost zajednice |
| Abstract (english) | The present study investigated foraminiferal assemblages in sediment cores
collected in the area of the Central and Southern Adriatic. Sediment samples were
collected with a gravity corer, at 13 stations at sampling depths ranging from 38 m to 1200
m. Considering the composition and abundance of foraminiferal species, two associations
were defined. Eilohedra vitrea – Turborotalita quinqueloba association with two biotopes,
Turborotalita quinqueloba – Globocassidulina subglobosa biotope and Eilohedra vitrea
biotope, and Turborotalita quinqueloba association. Fine grained sediments are associated
with higher fine particle share have higher organic matter content and lower abundance of
epifaunal species. Eilohedra vitrea and Cassidulina laevigata are dominant in such
environments/assemblages. Diversity indices decrease with sea depth, while they remain
constant across the core. Turborotalita quinqueloba, a relatively small planktonic species
belonging to cold-water assemblages, prevails in sediments from studied subsamples at
stations located at 100 m of water depth or deeper. Analyzed elements Mg, Al, Fe, Be, V,
Cr, Sc, Co, Ni, Cu, Ti, Zn, Rb, Zr, Sb, Cs, Ba, Tl, and Th in sediment sampled in Central
and Southern Adriatic Sea are most likely of terrigenous origin, whereas Pb, Cd, Ag, Se
and U are most likely anthropogenically enriched in sediments in the Šibenik bay.
Concentrations of Mn and Mo in sediments are influenced by redox conditions through the
cores. Distribution of foraminifera in the Central and Southern Adriatic Sea is not related
to concentrations and distribution of studied elements. Furthermore, changes in abundances
of studied elements do not affect composition or diversities of studied foraminiferal
assemblages. |
