Evaluation of the health of Mediterranean mussels (Mytilus galloprovincialis Lamarck, 1819) distributed in the Çanakkale strait, Turkey.

The observation of mortality in Mediterranean mussels (Mytilus galloprovincialis) distributed in the Çanakkale Strait in recent years was influential in developing the research question for this study. In this study, the presence of bacteria (Vibrio spp.) and parasites (Marteilia spp. and Haplosporidium spp.) in mussels collected from Kumkale, Kepez, and Umurbey stations in the Çanakkale Strait was investigated seasonally. Microbiological findings, histopathology, oxidative stress enzymes and their gene expressions, lipid peroxidation, lysosomal membrane stability, and changes in haemolymph were examined. In summer samples, both the defence system and the extent of damage were higher in gill tissue. In winter samples, enzyme activities and lipid peroxidation were found to be predominantly higher in digestive gland tissues. Histological examinations and Hemacolor staining revealed the presence of protozoan cysts, and for bacterial examination, molecular analysis performed after culturing revealed the presence of 7 Vibrio species. While the total numbers of heterotrophic bacteria detected in all samples were at acceptable levels, the predominance of Vibrio spp. numbers among the total heterotrophic bacteria detected in almost all samples were noteworthy. The total hemocyte count was calculated as 5.810(4)±0.58 (cells/mm3) in winter and 7.210(4)±1.03 (cells/mm3) in summer. These factors are considered to be possible causes of mussel mortality.

Mass mortality in endangered fan mussels Pinna nobilis (Linnaeus 1758) caused by co-infection of Haplosporidium pinnae and multiple Vibrio infection in Çanakkale Strait, Turkey.

PURPOSE: Pinna nobilis (fan mussel) is one of the most important endemic bivalve molluscs in the Mediterranean and mass mortality events were observed in these mussels in recent years. In this study, we report mass mortalities caused by Haplosporidium pinnae, which has been spreading in the Mediterranean for 3 years, and reached the Çanakkale Strait, which is the entrance of the Marmara and the Black Sea. MATERIAL AND METHODS: Field observations during sampling and subsequent histopathological, biochemical, genetic, and microbiological analyses were carried out. RESULTS: These analyses showed that H. pinnae infection spread among the natural beds of P. nobilis, causing severe tissue damage and oxidative stress. Our phylogenetic analyses suggested that the parasite spread through the Mediterranean much faster than thought. The results showed that vibriosis originating from Vibrio coralliilyticus, Vibrio tubiashii, Vibrio mediterranei, and Vibrio hispanicus, acted together with H. pinnae in infected individuals and caused death. CONCLUSION: It is highly probable that the spread of H. pinnae to the Sea of Marmara and the Black Sea may occur earlier than expected, and it was concluded that mass deaths were caused by co-infection with H. pinnae and a geographically specific marine pathogen that can infect P. nobilis populations.

Depuration Times of Donax trunculus and Tapes decussatus.

The present study was performed to determine the depuration time and ability of Donax trunculus (Wedge Clam) and Tapes decussatus (Carpet Shell) contaminated with Escherichia coli, Salmonella enterica subsp. enterica serovar Typhimurium and Vibrio parahaemolyticus. Clams were contaminated with each bacterium at the level of 7.0 - 8.0 Log10 cfu/g. After contamination, clams were analyzed every 3 h in the first 24 h time period and every 6 h until the 72nd hour. During the depuration process of both clams, the level of bacteria decreased quickly to 40% of initial load in the first 12 h. The results of this study indicate that the depuration time of carpet shells for all bacteria is 66 h. The depuration process of the wedge clam was different from the carpet shell; S. typhimurium and E. coli can be depurated in 66 and 78 h, respectively, while V. parahaemolyticus was present after 72 h at the level of 1.7 Log10 cfu/g.

Depuration Times of Donax trunculus and Tapes decussatus

The present study was performed to determine the depuration time and ability of Donax trunculus (Wedge Clam) and Tapes decussatus (Carpet Shell) contaminated with Escherichia coli, Salmonella enterica subsp. enterica serovar Typhimurium and Vibrio parahaemolyticus. Clams were contaminated with each bacterium at the level of 7.0 - 8.0 Log10 cfu/g. After contamination, clams were analyzed every 3 h in the first 24 h time period and every 6 h until the 72nd hour. During the depuration process of both clams, the level of bacteria decreased quickly to 40% of initial load in the first 12 h. The results of this study indicate that the depuration time of carpet shells for all bacteria is 66 h. The depuration process of the wedge clam was different from the carpet shell; S. typhimurium and E. coli can be depurated in 66 and 78 h, respectively, while V. parahaemolyticus was present after 72 h at the level of 1.7 Log10 cfu/g.

Proximate and elemental composition of Chamelea gallina from the southern coast of the Marmara Sea (Turkey).

The venerid clam Chamelea gallina is a popular and economic foodstuff around the Mediterranean countries especially in Italy, Spain, and France. The aim of this study is to evaluate the nutritional quality of striped venus of Southern Marmara. Samples were harvested seasonally at five stations and analyzed to determine meat yield, proximate, and elemental composition. According to the results, meat yield ranged from 20.24% to 29.94%. Means of water, protein, lipid, and ash content were 67%, 10.12%, 2.57%, and 1.66%, respectively. The mean concentrations (mg/kg wet weight) of elements in tissues are as follows: B: 2.37-4.24; Cr: 0-0.76; Co: 0-0.43; Cu: 0.71-5.30; Mn: 0.30-5.94; Zn: 13.08-77.76; Ni: 0-1.22; Fe: 2.46-114.22; Al: 1.23-75.49; Pb: 0.18-3.24; Ba: 0.66-15.97; Cd: 0.04-0.69. Among the reported metal levels, only Pb and Zn in two stations exceeded the maximum critical concentrations enforced by Turkish legislation and European Commission. Therefore, we report that striped venus from Southern Marmara Sea, in general, are safe for human consumption; nonetheless, Pb and Zn levels should be closely monitored in the future.