Abstract

Nickel was observed at elevated levels in skin of humpback, fin, and sperm whales biopsied in the Gulf of Maine and the Gulf of Mexico. Nickel is a lustrous metal with many uses, including textile dyes, electroplating baths, batteries, and catalysts. It is a known carcinogen and is readily absorbed via inhalation, ingestion and percutaneous absorption. As such, it is important to understand the biological impact of these elevated levels. Between July and November of 2010, we biopsied 6 humpbacks and 2 fin whales from the Gulf of Maine, and 43 sperm whales from the Gulf of Mexico after the Deepwater Horizon exploded and released 200 million gallons of oil into the Gulf. Nickel levels in the two fin whales were observed to be 7.71 and 19.78 ppm, and the average level in humpbacks was 19.75 ppm. In sperm whales from the Gulf of Mexico (post oil spill), nickel was found at an average of 15.5 ppm. Both of these areas are known to have lots of boat traffic. In comparison, the global average of nickel in sperm whales was reported to be 2.31 ppm from a sample size of approximately 500 individuals. Also, five bowhead whales showed an average nickel level of 0.052 ppm; these whales were sampled from the coast of Barrow, Alaska - an area with very little boat traffic. These data demonstrate the extreme elevation of nickel in whales from this study. In order to understand the impact of nickel at these levels, we are using cytotoxicity and clastogenicity techniques in skin fibroblast cells from each of these whales. Our results show concentration dependent cytotoxicity; fin whales show higher sensitivity to nickel than either humpback or sperm whales. This is the first and only study looking at the toxicity of nickel in whales. The data indicate that nickel is a health concern for whales living in areas with heavy boat traffic. More research needs to be done on the potential sources of nickel and exposure routes for the whales.