Pollution Indicators and HAB-Associated Halophilic Bacteria Alongside Harmful Cyanobacteria in the Largest Mussel Cultivation Area in Greece

Abstract

Taking into consideration the essential contribution of Mytilus galloprovincialis farming, it is of rising importance to add knowledge regarding bacterial species occurrence in water samples from aquaculture zones from the point of view of both the organism and public health. In the present study, we investigated the bacterial community existing in water samples from six Mytilus galloprovincialis aquaculture areas in the Thermaikos gulf, northern Greece, that may provoke toxicity in aquatic organisms and humans and may indicate environmental pollution in mussel production as well as algal blooms. Bacterial species were identified molecularly by sequencing of a partial 16s rRNA segment and were analyzed phylogenetically for the confirmation of the bacterial taxonomy. The results obtained revealed the presence of four bacterial genera (Halomonas sp., Planococcus sp., Sulfitobacter sp., and Synechocystis sp.). Members of the Halomonas and Sulfitobacter genera have been isolated from highly polluted sites, Planococcus bacteria have been identified in samples derived directly from plastic debris, and Synechocystis bacteria are in line with microcystin detection. In this context, the monitoring of the bacteria community in mussel aquaculture water samples from the Thermaikos gulf, the largest mussel cultivation area in Greece, represents an indicator of water pollution, microplastics presence, algal blooms, and toxin presence.

Are Marine Heatwaves Responsible for Mortalities of Farmed Mytilus galloprovincialis? A Pathophysiological Analysis of Marteilia Infected Mussels from Thermaikos Gulf, Greece

“…Concerning bivalve farming in Greece, Thermaikos Gulf is the culture site with the highest productivity of mussels, representing 90% of the total mussel production, while 80% is exported to other European countries [ 50 ]. However, in 2020 and 2021, reinforced by the COVID-19 pandemic situation that delayed harvesting, mass mortality events in Greek mussels farms resulted in the collapse of productivity, reaching 100% loss of the production in northern Greece’s farms.…”

Seasonal Dynamics of Marine Bacterial Communities in Aquaculture Farms: The case of the Northern Ionian Coastal Ecosystem (Mediterranean Sea)

“…To this end, mass amplicon-based sequencing has revolutionized the field of microbial ecology and provided valuable information on the phylogenetic diversity in aquatic ecosystems [18][19][20]. The assessment of bacterial diversity and the respective interactions in aquaculture systems can be achieved by next-generation sequencing (NGS) technologies, particularly with the use of 16S rRNA gene amplicon sequencing [21,22]. This technology has been effectively used to study the temporal dynamics of marine microbial communities in aquaculture farms [23], identify the presence of potential pathogens [24,25], and assess the impact of environmental stressors, such as climate change, mainly in ecosystems like the Mediterranean Sea where large variations in future temperature levels are expected [26].…”

Aquaponics as a Promising Strategy to Mitigate Impacts of Climate Change on Rainbow Trout Culture

“…The ecological crisis and the disruption of the ecological balance of aquatic ecosystems are the main and primary issues negatively influencing both marine and freshwater basins, as well as their inhabitants [ 1 ]. They derive from a major impact of climate change, causing alterations in a combination of abiotic factors, such as increased temperatures, rainfall reduction, oxygen availability, and pollution [ 2 ]. In this context, temperature, nutrient availability, and oxygen distribution in water levels tend to become a major challenge for global aquaculture [ 1 , 3 ].…”