What percentage of energy is passed down from algae to the small fish?

Typically, only about 10% of the energy from algae is passed on to small fish in a food chain. This is due to the energy transfer inefficiency, where a significant portion of energy is lost through metabolic processes and as heat. Consequently, the remaining 90% is not available for the next trophic level. This phenomenon is part of the broader ecological principle known as the "10% rule."