Aquaponics Post #2
Energy diagram:
What do you predict about the quantity of energy the producers take in compared to the quantity of energy that goes out?
The producers will likely take in roughly the same amount of energy that they send back out into the system. The energy used by the producers for respiration and other cellular processes is roughly equal to the energy emitted by the producers via photosynthesis and other cellular processes; the mint plants will absorb energy through nitrates, which are vital nutrients, and then release energy through catabolic reactions like cellular respiration.
What do you predict about the quantity of energy the consumers take in compared to the quantity of energy that goes out?
We predict that the input and output of energy to/from the consumers (the goldfish) will be approximately equal. In a closed system, equilibrium is maintained by the outputs and inputs of energy from both the producers (mint plants, bacteria) and the consumers (goldfish); the energy used by the fish for respiration and the energy leaving the fish in the form of chemical energy in waste (ammonia) will likely be roughly equal. However, there is a caveat in that most of the energy leaving the fish is only released upon the breakdown of ammonia to nitrites and nitrates by bacteria. In addition, the goldfish themselves would not absorb as much energy as the mint plants would, because only about 10% of energy is passed to the next trophic level in an ecosystem; the mint plants and goldfish likely absorb as much energy as they emit, but that energy level is not uniform between the mint and the fish.
What do you think are various ways that producers and consumers could lose energy?
Producers-- the mint plants-- could lose energy by water leaving their stomata and by the breakdown of nutrients for energy, such as in glycolysis. Consumers-- the goldfish-- could lose energy through metabolic processes, especially thermoregulation and heat, as well as respiration. They also temporarily lose energy through waste excreted, until the chemical energy in the waste is released through the bacterial breakdown of ammonia into nitrates.
How could you estimate the amount of energy lost through these various pathways?
Energy loss in producers-- the mint plants-- could be estimated by approximating the net productivity. This is calculated by subtracting all the energy that was used in cellular respiration (released as heat) from the gross productivity. Energy loss in consumers-- the goldfish-- could be estimated by approximating heat loss from waste, urine, and gill excretions. Lost energy is replenished through goldfish pellets containing required fats, carbohydrates, and protein for the goldfishs' diet.