|
|
Perfluorované látky ve vodním životním prostředí
TLAČILOVÁ, Hana
Perfluorinated and polyfluorinated substances (PFAS) are synthetic compounds with a wide range of applications due to their specific properties. PFAS are highly stable substances not subject to biochemical, chemical, thermal, or photochemical degradation. They are in most cases persistent and bioaccumulative. This work deals with detecting the occurrence of 33 PFAS representatives in benthos, juvenile fish, muscle samples of adult fish, and water using POCIS passive samplers. The 27 sites selected for sampling were profiles operated by the CHMI for surface water monitoring, located on some of the major rivers of the Czech Republic The obtained samples were analyzed using high-resolution mass spectrometry with high-performance liquid chromatography (HPLC-HESI-HRPS). The concentrations of the monitored substances were evaluated using TraceFinder 3.3 software (Thermo Fisher Scientific, USA). The analysis detected 13 PFASs out of the 33 monitored substances, namely PFOS, FOSA, PFDoA, FHpPA, H4PFUnA, PFBS, PFHxS, PFTeDA, PFTrDA, PFHpS, 6:2FTS and PFHpA. At the Ohře - Želina site, the highest concentrations were measured in juvenile fish samples, with total PFAS concentrations reaching up to 887.7 ng×g-1, specifically 620 ng×g-1 PFHxS, 260 ng×g-1 PFOS and 7.7 ng×g-1 PFTrDA, and in benthic samples, with total PFAS concentrations of 147 ng×g-1, specifically 120 ng×g-1 PFHxS and 27 ng×g-1 PFOS. The highest concentration in the muscle samples was measured at the Elbe - Obříství site, 200 ng×g-1 sum PFAS. In the POCIS samples, the highest sum PFAS was estimated at the Elbe - Litoměřice site, with a concentration of 29 ng×g-1. The results of the analyses demonstrated the necessity of combining multiple sample types to obtain the vast range of captured compounds.
|
|
|
Diet of Eurasian otter (Lutra lutra) in relation to the stocking of brown trout (Salmo trutta m. fario) and grayling (Thymallus thymallus)
Lyach, Roman ; Čech, Martin (advisor) ; Poledník, Lukáš (referee)
This study aimed to evaluate otter predation on stocked trout and grayling. The diet composition of piscivorous Eurasian otters (Lutra lutra) was studied on the stream Chotýšanka in central Bohemia using spraint (otter faeces) analysis during one winter period (90 days). Stocking took place mostly in the second half of 2005. Around 5000 hatchery-reared brown trouts (Salmo trutta m. fario) of size about 10 cm, 600 graylings (Thymallus thymallus) of the same size and 480 rainbow trouts (Oncorhynchus mykiss) of size about 30 cm were stocked into the stream. Spraints were collected in December 2005 and January 2006. We found and identified 1531 fish in the spraints. The primary food source of otters was fish (almost 85 % of biomass). The main fish prey was small - sized, below 20 g in weight and 13 cm in length. The bulk of otter's diet consisted of less - valued species, especially the gudgeon (Gobio gobio). Other frequently consumed fish species were the European chub (Squalius cephalus), the common carp (Cyprinus carpio), the European perch (Perca fluviatilis), the brown trout and the rainbow trout. Consumption of stocked brown trout was 1,80 %, while cosumption of stocked rainbow trout was 10,90 % of biomass. Otters in this area consumed about 723 - 1446 brown trouts and 72 - 144 rainbow trouts...
|
|
|
Diet of Eurasian otter (Lutra lutra) in relation to the stocking of brown trout (Salmo trutta m. fario) and grayling (Thymallus thymallus)
Lyach, Roman ; Čech, Martin (advisor) ; Poledník, Lukáš (referee)
This study aimed to evaluate otter predation on stocked trout and grayling. The diet composition of piscivorous Eurasian otters (Lutra lutra) was studied on the stream Chotýšanka in central Bohemia using spraint (otter faeces) analysis during one winter period (90 days). Stocking took place mostly in the second half of 2005. Around 5000 hatchery-reared brown trouts (Salmo trutta m. fario) of size about 10 cm, 600 graylings (Thymallus thymallus) of the same size and 480 rainbow trouts (Oncorhynchus mykiss) of size about 30 cm were stocked into the stream. Spraints were collected in December 2005 and January 2006. We found and identified 1531 fish in the spraints. The primary food source of otters was fish (almost 85 % of biomass). The main fish prey was small - sized, below 20 g in weight and 13 cm in length. The bulk of otter's diet consisted of less - valued species, especially the gudgeon (Gobio gobio). Other frequently consumed fish species were the European chub (Squalius cephalus), the common carp (Cyprinus carpio), the European perch (Perca fluviatilis), the brown trout and the rainbow trout. Consumption of stocked brown trout was 1,80 %, while cosumption of stocked rainbow trout was 10,90 % of biomass. Otters in this area consumed about 723 - 1446 brown trouts and 72 - 144 rainbow trouts...
|
guest ::
