Abstract | Kvaliteta morskog okoliša važan je javnozdravstveni problem. Brodovi, kako bi poboljšali stabilnost prilikom iskrcaja tereta, uvlače morsku vodu (balast), koju potom ispuštaju u luci ukrcaja tereta. Pri tome, osim tereta, transportiraju i mikroorganizme koji se nastanjuju u novim staništima. Cilj ovog istraživanja bio je ispitati mikrobiološko opterećenje najveće hrvatske pomorske luke Rijeka, u vodenom stupcu i sedimentu, te procijeniti utjecaj luke na mikrobiološko onečišćenje okolnog rekreacijskog područja.
Istraživanje je provedeno u okviru projekta ProtectAs, u razdoblju od 10. mjeseca 2020. godine do 9. mjeseca 2021. godine, na 3 lokacije u luci Rijeka: JPG 28, RI bwB i RI bwS. Ukupno je ispitan 63 uzoraka, 51 uzorak morske vode te 12 uzoraka sedimenta. Također, analizirani su podaci iz nacionalnog monitoringa kakvoće mora za kupanje za sezonu kupanja 2021., na 29 lokacija (292 uzorka) u rekreativnom području u blizini luke Rijeka (16 istočno i 13 zapadno od luke Rijeka). Prema Pravilniku o upravljanju i nadzoru balastnih voda (NN 128/2012) ispitani su mikrobiološki pokazatelji Escherichia coli, crijevni enterokoki te Vibrio cholerae (O1 i O139). Kao dodatni pokazatelji kakvoće ispitani su sljedeći mikroorganizmi: Clostidium perfinges, Pseudomonas aeruginosa, Salmonella spp., Shigella spp., Vibrio spp. te Legionella spp. Vodeni stupac najopterećeniji je fekalnim bakterijama u hladnijem razdoblju godine, a sediment u ljetnoj sezoni. Vodeni stupac opterećeniji je koliformnim bakterijama, dok su više koncentracije UBB, C. perfringens i P. aeruginosa zabilježene su u sedimentu. Koncentracije E. coli 10 puta je veća u vodenom stupcu, u odnosu na sediment, a koncentracija crijevnih enterokoka je 1,5 puta veća u sedimentu u odnosu na vodeni stupac. Vrste roda Vibrio dokazane su u 25,5 % uzoraka (u najvećoj mjeri V. alginolyticus u 13,7 %), a V. cholere O1 i O139 nisu dokazani u ni jednom ispitanom uzorku. Prisutnost Salmonella spp. dokazana je u 5,9 % uzoraka. Mikrobiološki najopterećenija lokacija bila je RI bwS (vodeni stupac i sediment). Najveće opterećenje E. coli i crijevnim enterokokima, uz najniži salinitet, zabilježeno je na zapadnoj obali užeg područja oko luke Rijeka. Rezultati istraživanja ukazuju na prostorne i sezonske varijacije fekalnog onečišćenja u luci Rijeka, u vodenom stupcu i sedimentu. Uz balastne vode, na kvalitetu morskog okoliša moguće utječu i mikrobiološki opterećeni donosi slatkih voda. Luka Rijeka predstavlja moguće žarište onečišćenja za okolno rekreacijsko područje. |
Abstract (english) | The quality of the marine environment is an important public health issue. Ships, in order to improve stability during cargo unloading, take in seawater (ballast), which they then discharge at the cargo loading port. In doing so, they transport not only cargo but also microorganisms that settle in new habitats. The aim of this research was to examine the microbiological load of Croatia's largest maritime port, Rijeka, in the water column and sediment, and to assess the port's impact on the microbiological pollution of the surrounding recreational area.
The research was conducted within the ProtectAs project, from October 2020 to September 2021, at three locations in the port of Rijeka: JPG 28, RI bwB, and RI bwS. A total of 63 samples were tested, including 51 seawater samples and 12 sediment samples. Additionally, data from the national monitoring of bathing water quality for the 2021 bathing season were analyzed at 29 locations (292 samples) in the recreational area near the port of Rijeka (16 to the east and 13 to the west of the port of Rijeka). According to the Regulation on the Management and Control of Ballast Waters (NN 128/2012), the following microbiological indicators were tested: Escherichia coli, intestinal enterococci, and Vibrio cholerae (O1 and O139). As additional quality indicators, the following microorganisms were tested: Clostridium perfringens, Pseudomonas aeruginosa, Salmonella spp., Shigella spp., Vibrio spp., and Legionella spp. The water column was most burdened with fecal bacteria during the colder period of the year, while the sediment was more contaminated in the summer season. The water column was more burdened with coliform bacteria, while higher concentrations of UBB, C. perfringens, and P. aeruginosa were recorded in the sediment. The concentration of E. coli was 10 times higher in the water column compared to the sediment, while the concentration of intestinal enterococci was 1.5 times higher in the sediment compared to the water column. Vibrio species were detected in 25.5% of the samples (most notably V. alginolyticus in 13.7%), while V. cholerae O1 and O139 were not detected in any tested sample. The presence of Salmonella spp. was confirmed in 5.9% of the samples. The most microbiologically burdened location was RI bwS (water column and sediment). The highest load of E. coli and intestinal enterococci, along with the lowest salinity, was recorded on the western coast of the narrow area around the port of Rijeka. The research results indicate spatial and seasonal variations in fecal contamination in the port of Rijeka, in both the water column and sediment. Besides ballast waters, microbiologically burdened freshwater inflows may also impact the quality of the marine environment. The port of Rijeka represents a potential hotspot of pollution for the surrounding recreational area. |