Toxic substances accumulate in the highest concentrations as they move up the food chain. Orca Whales, being the top predator in their environment, are more affected by pollutants than other sea creatures. Examinations of stranded killer whales have shown extremely high concentrations of lead, mercury and poly-chlorinated hydrocarbons (PCBs). These levels may be high enough to affect reproduction, immune function and endocrine function in the animals, resulting in their declining populations. These toxins are the result of abandoned marine toxic waste dumps and industrial and human refuse pollution into the oceans.
The following pictures may be difficult to look at, but if we are to protect cetaceans, we must be aware of the dangers that they face, from humans with which they share their habitat!