What was the cause of over half of North America's fish extinctions in coastal waters,wetlands and lakes? 

A)  introduction of non-native species 
B)  excess agricultural runoff 
C)  overfishing 
D)  oil spills

Non-native Species

Species that have been introduced to an environment where they are not naturally found, often having significant impacts on native ecosystems and species.

Agricultural Runoff

Water from rain or irrigation that carries soil, pesticides, and nutrients from fields into rivers, lakes, and other water bodies.

Fish Extinctions

The complete disappearance of fish species from the planet, often as a result of human activities, environmental changes, or natural events.