This model simulates the growth of carp in an aquaculture pond, both with respect to production and environmental effects.
Both the anabolism and fasting catabolism functions contain elements of allometry, through the m and n exponents that reduce the ration per unit body weight as the animal grows bigger.
The 'S' term provides a growth adjustment with respect to the number of fish, so implicitly adds competition (for food, oxygen, space, etc).
Carp are mainly cultivated in Asia and Europe, and contribute to the world food supply.
Aquaculture currently produces sixty million tonnes of fish and shellfish every year. In May 2013, aquaculture production overtook wild fisheries for human consumption.
This paradigm shift last occurred in the Neolithic period, ten thousand years ago, when agriculture displaced hunter-gatherers as a source of human food.
Aquaculture is here to stay, and wild fish capture (fishing) will never again exceed cultivation.
Recreational fishing will remain a human activity, just as hunting still is, after ten thousand years - but it won't be a major source of food from the seas.
The best way to preserve wild fish is not to fish them.
