Accumulation of Metals in the Tissues of Three Spined Stickelback (Gasterosteus aculeatus) from Natural Fresh Waters

Three spined sticklebacks (Gasterosteus aculeatus) were sampled from five different watercourses in Flanders (Belgium). Concentrations of cadmium, lead, copper, and zinc were measured in water, sediment, food, and fish tissues. Considered as food was the taxonomic groups of macroinvertebrates predominately present in the stomach of the sticklebacks at the different sites. Analyzed tissues were gill, liver, and muscle. To determine the relative importance of the different uptake routes, multiple linear regression models were constructed. Accumulated metal levels in the tissues were related to metal levels in sediment, water, and food. Generally, the amount of variation in accumulated metal levels that could be explained by these models was limited, with coefficients of determination not exceeding 0.57. Cadmium levels in the three tissues were solely related to levels in invertebrates. The same was true for copper in liver. In the other cases the tissue levels could be related only to sediment and/or water levels. Depending on the metal, levels were highest in gill or in liver. In all cases lowest metal levels were measured in muscle.