Goiter-Like Changes in the Thyroid Gland of Mass Stranded Striped Dolphins (Stenella coeruleoalba)

Abstract

Seven striped dolphins (Stenella coeruleoalba) were found dead， stranded on Gogo island， Ehime， Japan in March 2003. A post-mortem examination of six of the seven adult dolphins demonstrated severe congestive edema of the lung. No signs of bruising or other trauma were observed. The possible causes of the mass stranding were not identified. Cystic enlargement of the follicles of the thyroid gland with an accumulation of abundant colloid were observed in two animals : these findings were consistent with goiter. An analysis of organohalogens in blubber showed a similar pattern of accumulation of organohalogens in marine mammals in Japan. In addition，high levels of organohalogens were detected.