The biggest threat to marine mammals in our oceans isn’t predators, it’s pollution. Pollution from land as well as toxic chemicals and PCB’s are having detrimental effects on marine mammal populations. In 2016, a killer whale was found stranded and dead on the Aisle of Tiree in Scotland with possibly the highest amount of PCB’s and toxins ever recorded. This shows that the pollution problem in our oceans isn’t getting better, it is getting worse. Lulu, an adult killer whale was entangled in a creel rope, but blubber analysis revealed that she had high levels of toxins in her body. This high level of toxins was effecting her health and reproductive fitness before her death and the level of PCBs in her body were over 100 times higher than the average toxins currently being found in marine mammals. PCBs were used for years in electrical equipment, but were banned in the 1980s due to their effect on the environment and wildlife. The chemicals do not break down and have been shown to cause immune deficiencies and cancers in people and wildlife. Killer whales are large predators and high levels of toxins can build up in their systems and over time this can cause them to become infertile as well as very sick. This is just a huge reminder that how we treat the environment now can have such a huge effect on our planet’s future. PCBs have been banned for years, but they will never disappear and now they are accumulating in our oceans and are a huge threat to our marine life. Every person can make a difference to help our oceans. If everyone can take the time to recycle, reuse and reduce their use of plastics, it can help our oceans for years to come. Killer whales are apex predators and have a huge effect on our oceanic food webs. By keeping pollutants out of our oceans, we can help keep marine life populations healthy for the future.
Written By: Stefanie Schmidt
Edited By: Winnie Shih