Application of Calcified Structures in Fish as Indicators of Metal Exposure in Freshwater Ecosystems

Although there are common and well-established bioindicator organisms tissues, is still a need for reliable sensitive bioindicators in aquatic environments. In the present pilot study, calcified structures fish were applied as indicators of metal exposure combination with commonly used soft tissues intestinal parasites, therefore comprising short- long-term indicators. Patterns accumulation distribution (muscle, liver) hard (scales, otoliths) brown trout (Salmo trutta Linnaeus, 1758) their acanthocephalans (Dentitruncus truttae Sinzar, 1955), from Krka River influenced by industrial municipal wastewaters estimated compared. Most elements had higher levels acanthocephalans, scales liver than muscle otoliths, possibly reflecting differences uptake routes, tissue function metabolic activity. Despite recorded contents, all reflected environmental conditions similar way, indicating most contaminated rather reference site. Acanthocephalans confirmed due to effective capacity, while provided extended temporal information on exposure. Wastewater impact was evidenced moderate pollution pointed but also disturbances importance continuous monitoring protective actions.