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Explora: Environment
and Resource Trace elements in Mediterranean mussels

urban development. The Mar Piccolo and Mar Grande sites subjected to the highest levels of contamination,
basins (Gulf of Taranto, Italy) have particularly faced cadmium concentrations ranged from approximately
pollution issues. Despite this, mussel farming remains a 5 µg/g to 10 µg/g (dry weight), and lead concentrations
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vital economic activity in the region. An investigation ranged from approximately 4 µg/g to 8 µg/g (dry weight).
using mussel populations was carried out over a 2-year The authors concluded that the concentrations of these
period (1999 – 2000) to understand trace element elements in soft tissues exceeded the acceptable levels
bioaccumulation and potential health risks. The CI was for human consumption, and these values are considered
used to identify the reproductive cycles of the organisms. unacceptable by Turkish legal standards. 58
As expected, trace element concentrations were highest Table 4 summarizes the mean levels (without standard
in late winter to early spring, coinciding with the end of deviations) of selected trace elements measured in wild
the reproductive cycle. Seasonal variations in element or transplanted mussels along the coasts of Greece,
levels were observed, likely influenced by reproductive according to the original investigations. 59-61 Since 1993,
activity and environmental factors. In general, the levels the bioavailability of chromium, copper, and iron has been
of most of the measured trace elements were similar to investigated in mussels from a marine area adjacent to a
those found along other Italian coasts; however, high ferro-nickel smelting plant (North Evoikos Gulf, Greece).
levels of iron (approaching approximately 1000 µg/g [dry Results showed higher levels of chromium (over 30 µg/g
weight]) and lead (exceeding 4 µg/g [dry weight]), were [dry weight]) and iron (up to about 1500 µg/g [dry weight])
measured in mussels, reflecting the anthropic pressure in in mussel tissues from the sampling sites near the smelting
the investigated area. plant or the dumping site of the metalliferous slag, while
The Aegean Sea is another significant part of the levels of copper and zinc were very similar to those found
Mediterranean experiencing widespread pollution. in reference organisms. 59
The development of densely populated areas (Athens, Such high bioavailability persists over time, as
Thessaloniki, and Iraklion in Greece; Istanbul and Izmir in evidenced by a subsequent study conducted in the same
Turkey), coupled with industrial and extraction activities, area (Larymna, Evoikos Gulf, Greece) with wild mussels
has led to the substantial release of various contaminants and a transplanted population. Specifically, chromium
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into the environment. Moreover, intense maritime traffic and iron levels in 2006 showed only a minimal decrease in
connecting the numerous islands in the Aegean Sea largely wild mussels, suggesting the presence of chronic pollution
contributes to the spread of contamination. Several studies in the study area (Table 4). Very similar concentrations were
have recently investigated the bioavailability of various trace also measured in organisms transplanted over a period of
elements in mussel tissues from various locations along the 6 months, further confirming the ongoing bioavailability
Turkish Aegean coastline. 56,57 The results indicated that the of these elements. Furthermore, nickel also showed very
highest levels of trace element contamination, especially high levels – about 20 µg/g (dry weight) in wild mussels
chromium and lead (exceeding 4 µg/g [dry weight]) and and even 50 µg/g (dry weight) in those transplanted for
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zinc (approaching about 350 µg/g [dry weight]) in mussel 6 months – confirming the significant impact of the
tissues, were found in Gokova Bay. This contamination industrial activity present in the area.
was attributed to local geological factors and the presence Finally, Strogyloudi et al. investigated the spatial and
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of coal-fired power plants. Edremit Bay exhibited the temporal variability of cadmium, chromium, copper, iron,
highest levels of lead due to nearby mining activities, manganese, nickel, and zinc in M. galloprovincialis from
while Izmir and other areas showed relatively low levels Elefsis bay (Saronikos gulf, Greece) (Table 4). Higher
of trace element contamination. In addition, a general concentrations of trace elements were recorded in mussels
increased bioavailability of cadmium, chromium, mercury, inhabiting industrial locations (steelworks and shipyards),
manganese, nickel, and lead was observed in transplanted suggesting an elevated bioavailability in the investigated
mussels in Nemrut Bay (Turkey), suggesting the role of area. The pattern of temporal variation of trace elements
industrial contamination of the investigated area. 57 in mussel tissues was similar across stations, regardless of
The Sea of Marmara is also subjected to widespread concentration levels, with higher values during the winter–
pollution. Istanbul, the largest city in Europe by spring season and lower values during the summer–
population, is undoubtedly a source of urban and industrial autumn period, confirming the influence of natural and
contamination, while the Bosphorus Strait is characterized physiological fluctuations due to the biological cycle of the
by intense maritime traffic. A study conducted between organisms.
2003 and 2004 highlighted highly variable levels of On the other hand, Elefsis Bay is characterized by
cadmium and lead in mussel tissues. For instance, at the the presence of mineral deposits that could naturally

Volume 2 Issue 2 (2025) 12 doi: 10.36922/eer.8078