Detection of contaminants in some typical Mediterranean fish : anisakis parasites and heavy metals

Abstract

The Mediterranean Sea is recognized for its high biodiversity but is also a hotspot for pollution. In this study, fish samples of four native marine species were collected from wild catches to determine contaminants such as Anisakis parasites and heavy metals, including nickel, lead, copper, zinc, and chromium, within local marine fish species. The detection of Anisakis parasites was performed by a visual inspection and a digestion method. Metal analysis was carried out on skin, muscle, viscera, and bones of fish, using Microwave Plasma-Atomic Emission Spectroscopy. This study demonstrated that Boops boops was the least infested species by Anisakis parasite, while Scomber colias was the most infested, with Sardinella aurita and Trachurus trachurus showing a lower infestation rate. Pearson correlation statistics revealed that infestation correlated with fish size but not with maturity or sex. Principal component analysis (PCA) demonstrated that the carnivorous species were more prone to Anisakis infestation than the omnivorous species. The maximum levels of copper, nickel, chromium, lead, and zinc content in fish tissues were 13.2 ± 0.11, 19.5 ± 0.02, 19.9 ± 0.01, 28.8 ± 0.09, and 184.87 ± 0.63 µg/g, respectively. PCA revealed that heavy metal contamination does not discriminate between fish species and sex, as opposed to tissue type and location of catch. Some metals, such as zinc and lead, seem to accumulate more in muscle rather than the other tissues. These findings indicate that Anisakis infestation and heavy metal analysis should be monitored and extended beyond the current EU requirements.