Biological magnification, also known as biomagnification, is the process by which certain substances, such as heavy metals, pesticides, or other toxins, become more concentrated in the tissues of organisms as they move up the food chain.

This occurs because these substances are not metabolized or excreted by the organisms that consume them, and instead, they are stored in the tissues of the organisms. As a result, the concentration of these substances increases as they move up the food chain, with apex predators at the top of the food chain accumulating the highest concentrations.

This phenomenon can have negative impacts on ecosystems and human health. For example, if a toxic substance is released into the environment, it can be taken up by small organisms such as plankton, which are then eaten by larger fish, which are in turn eaten by even larger fish. By the time the toxic substance reaches a top predator such as a shark, its concentration can be many times higher than in the original source. This can result in serious health problems for the predator and potentially for humans who consume it.