Answer:
Biomagnification is the collection or accumulation of a toxic or non-toxic substance or chemical by an organism from exposure to water and food that leads to a concentration that is far more than the expected condition of exposure from equilibrium. It leads to harmful effects on the health and physiology of individual organisms.
Consuming a huge number of marine animals or fish could cause the biomagnification of harmful substances if accumulated such as mercury as it is the most significant source of ingestion-related mercury exposure in humans.