Naslov
Microbiological quality of seawater in two marinas at Split area

Autori
Jozić, Slaven ; Vrdoljak Tomaš, Ana ; Šolić, Mladen ; Šantić, Danijela

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, prošireni sažetak, znanstveni

Izvornik
THIRD International Congress Age of New Economy and New Jobs - Blue Economy and Blue Innovation / Russo, Andrea ; Jozić, Slaven ; Vrdoljak Tomaš, Ana ; Raguž, Željka ; Škare, Zorana - Split : Healthy City, 2021, 35-37

ISBN
978-953-7678-13-5

Skup
3rd International Congress, Age of New Economy and New Jobs: Blue Economy and Blue Innovation

Mjesto i datum
Split, Hrvatska, 10.10.2021. - 12.10.2021

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
small port, monitoring, quality of seawater, Escherichia coli, intestinal enterococci

Sažetak
Responsible managing of marine ports in the Adriatic Sea is of utmost importance to address environmental issues. Most of these ports are small ports, supporting different activities such as boat services, fishing, sports, tourism and recreation. They play an important role in the community, not only economic but also social and environmental. As places where a large number of different activities meet, that can potentially have a negative impact on the environment, thus coordinated and responsible management is very important. A relatively large number of ports and port berths in two countries with the longest Adriatic coast, Italy and Croatia, combined with growing nautical tourism, makes this semi-closed sea very vulnerable to potential negative effect to its well-preserved environment. Microbiological contamination is just one of the possible consequences of irresponsible management of ports and boats they host and service. Although the microbiological quality of seawater in ports is not regulated by legislation, the possibility of introducing periodic or regular controls should be considered for several reasons: • This would help the local authorities and community to have an insight into how the port owner/concessionaire manages the port, • This would help the port owner/concessionaire to have an insight into whether port users are behaving responsibly, • This would help concessionaires of neighbouring beaches to ensure better protection of bathers’ health. To assess the potential impact of small ports on the microbiological quality of seawater in the port themselves and adjacent areas, we established the monitoring program in two small ports (marinas) in the area of Split, marina Špinut and marina Strožanac. Marina Špinut is located in the north of Split, under the hill of Marjan and next to the protected forest park Marjan. Marina has about 950 berths of which 350 for small boats less than 6 m, and the remaining for boats 6-15 m. Due to its location in semi-closed Kaštela bay and the proximity to adjacent beach Prva voda, the marina presents a potential risk for pollution of the area. Marina Strožanac is located in the south of Podstrana, next to the mouth of the river Žrnovnica. Marina has approximately 320 berths for different boat sizes. Since on both sides of the marina there are very popular and frequented public beaches, it is very important to monitor its potential negative impact on these beaches. Monitoring was carried out for two years, from April 2019 to February 2021. Sampling was organized once a month by collecting seawater samples for the determination of indicator bacteria, Escherichia coli and intestinal enterococci. Both indicator bacteria were determined by membrane filtration method, ISO 7899-2:2000 for intestinal enterococci and alternative, temperature modified ISO 9308-1:2014 method for E. coli. All samples were collected from 30 cm depth, at 6 sampling sites in both marinas, with one additional reference site at both areas. At the beach next to the marina Špinut and at both beaches (western and eastern) next to the marina Strožanac two sampling sites per beach were also included in monitoring to assess the potential effect of marina water on the beach water quality. Additionally, we analysed riverine water to assess potential faecal material load from Žrnovnica River. Since there are no legal criteria and standards for water quality in marinas, water quality was assessed following Croatian national regulation for coastal bathing water quality, using 90th and 95th percentile values of both indicator bacteria. When analysing the data obtained during two bathing seasons (May-September), all sites in the marina Špinut were of excellent quality. When included the data obtained during the whole year, five of six sites were excellent and one site was of good quality. No negative impact of the marina to the adjacent beach and area was recorded. Seawater quality in the marina Strožanac was excellent at five and good at one site during the bathing season. When included the data obtained during the whole year, four of six sites were excellent and two sites were of good quality. Seawater quality at two sites at the western beach, which is between the marina and the mouth of river Žrnovnica, was poor, both during the season and throughout the year. By analysing riverine water, the river was confirmed as the main source of faecal contamination of the area. The additional source of faecal material contributing to the contamination of the water is seagull droppings since huge numbers of seagulls gather at the area of the mouth of the river. As a result, no negative impact of the marina on the surrounding area was recorded, but on the contrary, the water from the river and river mouth had a negative impact on the water in the marina and the beach between the river mouth and marina. Thanks to the favourable direction of sea currents, no negative impact of contaminated water on the quality of bathing water at the eastern beach was found. Two monitored marinas in the Split area showed at least good quality of seawater, with a dominant number of sites with excellent quality. Anyhow, seawater in both marinas met the set requirements, to be of at least good quality.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

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