Hi John. Welcome to Permies.
I have often thought that if aquatic systems were augmented with natural plant and animal filtration (filter-feeders, for instance, and heavy-feeding riparian tree guilds and reed and marsh grass systems), a sustainable harvest might be made of what is effectively an overabundance of nutrients.
If supplementary stages and physical filters are used in conjunction, such as myco-booms and the riverene equivalent of inter-tidal
biochar gabion installations, these could set the infrastructural stage for water-based large-scale aquaponics, even just raft-based systems, at first, and working up to sustainably-designed and operated vertical river-culture plant and animal food systems.
This kind of industry (I hesitate to use the word, but what else do you call a whole sector of business?) would essentially use as its feedstock the excess nutrients that cause such problems as algal blooms that eutrophy
water systems and toxify waterways. If lack of oxygen were an issue, it would be no problem for a sustainable food system to mechanically oxygenate the water upstream of its operations, enhancing excess nutrient uptake and system output, both.
And if this kind of operation had a mandate to act as positive filtration on its part of the river system or part of the Everglades, such that water exiting the system was cleaner than that entering it, there would be positive feedback throughout natural and human systems downstream.
I really like this idea. It applies to all river systems, to one extent or another.
-CK
A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects.
-Robert A. Heinlein