Final answer:
Large predatory fish as secondary or tertiary consumers receive significantly less energy due to energy loss at each trophic level in the food chain, leading to a small energy amount available at these higher levels.
Step-by-step explanation:
Large predatory fish that are classified as secondary or tertiary consumers fall within higher trophic levels in the food chain. Being a secondary consumer typically means preying on primary consumers, which are herbivores that consume primary producers such as plants and phytoplankton. As a tertiary consumer, a fish would be a carnivore that eats other carnivores, thus feeding at an even higher trophic level.
The concept of trophic levels is based on energy transfer through the ecosystem. Energy is lost at each level due mainly to the second law of thermodynamics dictating that energy conversions are not perfectly efficient, and a lot of energy is dissipated as heat. According to the energy pyramid, only about 10% of the energy from each trophic level is passed on to the next, which means that tertiary consumers like large predatory fish receive significantly less energy compared to organisms at the bottom of the food chain.
Therefore, large predatory fish have a limited amount of energy available to them because they are at the top trophic levels, and the energy that originates from primary producers has been significantly reduced through the various levels of the food chain.