Pollution

Humans depend on nature to dispose of our waste products. As a result, our oceans, rivers, lakes, air and lands have become repositories for society’s industrial and personal waste.

The incredible volumes of pollution currently being dumped into the environment overwhelm the Earth’s capacities to absorb, transform or break down these materials. Some materials take thousands of years to decay, and may become more toxic as they decompose, resulting in long-term environmental damage.

Pollutants dumped into the environment don’t just disappear, or remain suspended in air and water:they enter the tissues of the living things. The pollutants are then passed up the through the food chain and increase in toxicity, a process known as bioaccumulation.

Bioaccumulation is painfully evident in Beluga whale populations in the St.Lawrence River, where levels of PCBs, mercury, lead and DDT in the whales are at extreme levels. Because beluga whales are a top predator on the food chain, they collect the toxins from all the organisms that they eat. Sadly, these toxins are passed down to the next generation when females release these toxins to their young in-utero and through their milk. This high level of toxicity is having a significant impact on St. Lawrence beluga populations through an increase in diseases such as cancer.

Man-made pollutants can have devastating impacts on living creatures of all shapes and sizes. But amphibians are often the first creatures to show signs of stress from pollution. Scientists have found that commonly used chemicals such as pesticides, herbicides and fertilizers are decimating frog populations. The reduced abundance and diversity of frog species are a warning signal about the impacts of pollution.

To learn more:

• AmphibiaWeb – Worldwide Amphibian Declines
• Environment Canada - Tracking Key Environmental Issues
• FrogWatch Canada