Oceanographic characteristics of the Adriatic Sea – Support to secondary HAOP spread through natural dispersal

Abstract

Vessels, specifically ballast water and hull fouling, are a major vector for the introduction of non-indigenous species (NIS) in European seas. The Mediterranean is one of the world's marine regions where their invasion is heaviest. The shallow Adriatic basin is a highly sensitive area that is already experiencing its consequences. The secondary spread of NIS over a wider area through natural dispersion is a complex process that depends on a wide range of oceanographic factors. This work analysed the dataset of the BALMAS project, in whose framework twelve ports in the Adriatic Sea were subjected to a Port Baseline Survey (PBS), to estimate the natural spread of NIS organisms from their port of arrival to the wider Adriatic basin. Its findings indicate that the prevailing water circulation patterns facilitate the natural dispersal of harmful aquatic organisms and pathogens (HAOP).

Impacts of Atmospheric and Anthropogenic Factors on Microbiological Pollution of the Recreational Coastal Beaches Neighboring Shipping Ports

“…In contrast, only in 2019 could microbiological load from the port of Pula have affected the surrounding area of the port, when the impacted bathing sites were in close proximity to the entrance of the Bay (not shown). This assumption corroborates the cyclonic circulation pattern along the Adriatic coast, passing northward along the entrance to the port of Pula and the predominant easterly winds facilitating waters to leave the port (sensu the Pula Bay) [39]. It is also in line with the fact that in 2018 and 2019, the number of tourists was rather similar, excluding this factor from imposing any effect.…”

“…Particularly in 2009–2015 and 2019, microbiological pollution from the port may have affected water quality in the surrounding area, as sites rated below average quality are located in close proximity to the port. During the summer period, a westward circulation pattern along the northern coast of the Rijeka Bay where the port of Rijeka is located, along with the predominant impact of easterly winds, facilitates the waters to leave both basins of the port of Rijeka, as the openings of both basins are at their west side [ 39 ]. The circulation along the northern and western coast of the Rijeka Bay is cyclonic (counterclockwise) and therefore favors water circulation along the coast, where the bathing sites are located, toward the open sea, where waters ultimately enter the open cyclonic circulation of the Adriatic Sea.…”

Non-native species in the north Gulf of Aqaba (Red Sea) revealed from environmental DNA

“…Although maritime traffic could explain the relative abundance of NIS in the three studied locations, other explanations are possible. NIS may have arrived in other areas within the Red Sea and move to the north of the Gulf of Aqaba by unaided ways, like secondary dispersal drifting with currents and maritime tides (Kraus et al, 2019;Wood et al, 2021). Rafting on floating marine litter (Rech et al, 2018;Fernandez et al, 2022) cannot be excluded either as a way of secondary dispersal, because the most littered Hahashmal beach was the most biopolluted (but it is the closest to the commercial port; thus, it is not possible to distinguish between the two factors).…”

Ballast Water Management in Ports: Monitoring, Early Warning and Response Measures to Prevent Biodiversity Loss and Risks to Human Health

“…The spread of organisms from the port to the surrounding area by currents and the circulation of water masses has already been documented [185][186][187]. People eating seafood could come into direct contact with human pathogens or toxic species, especially during the bathing season, as organisms can spread from the port to nearby beaches [188].…”