Why toxins increase in concentration at each successive tropic level ina food chain?

Answer 1

With the increase of the tropic level, there is a loss of energy. It is averaged that each organism consumes 10% of the energy from the organism that it eats. Because of this loss of energy, the animals at the higher tropic levels eat more, and hence, eat more toxins. The toxins accumulate in the fat of the animals, and just continue to increase.

Answer 2

Toxins accumulate at each successive trophic level because they are stored in the tissues of organisms and are not easily metabolized or excreted. This process is known as bioaccumulation. As predators consume multiple prey individuals, they accumulate the toxins stored in those organisms, leading to higher concentrations at each higher trophic level.