Adult female European perch (Perca fluviatilis) from the Baltic Sea show no evidence of thiamine deficiency

Deficiency of thiamine (vitamin B1) has been demonstrated in several species in the northern hemisphere and is suggested as a cause for declining populations. European perch from the Baltic Sea show negative temporal trends for several health biomarkers and poor recruitment of unknown cause. In this study, thiamine status of perch liver from the Baltic Sea was studied with emphasis on seasonal variation. During spring the thiamine concentration increased, reached a higher level during the summer and then decreased again during autumn. Despite this variation the thiamine concentration was always sufficient in the perch liver. These results indicate that direct thiamine deficiency is an unlikely explanation for the health effects observed in adult female perch from the Baltic Sea.