329

 In south Florida approximately 53% of the total area

 is freshwater wetlands. The collective area of all the

 ponds is only 10% of the total area, near the end of the

 dry season. The total contraction increases fish density

 approximately 25 times over what it was in the total area

 of freshwater wetlands.

 At the study site in Corkscrew marsh, fish habitat was

reduced from approximately 80 ha (the area of attraction,

Figure 40), first to 4 ha, then to 0.2 ha, which represents

a concentration of 400 times. The maximum measured density

of fish did not indicate this great a concentration,

probably because the large standing stock of predatory fish

cropped the prey fish as they moved into the pond. The

maximum measured density of prey fish at Corkscrew was 13.6

g/sq-m, which represented a concentration factor of

approximately 34 for the fish produced in the marsh.

 Odum (Odum and Odum, 1976) recently postulated that

the work a given form of energy can do is related to its

"energy quality," and that the energy quality of a material

or organism is the total energy of all types that went into

its formation, which is the same thing as its "replacement

cost." Figure 82 gives energy circuit diagrams of the Wood

Stork food chain used to calculate the Wood Stork's energy

quality. The upper diagram shows the average quantity of

the energy flows necessary to support one day's growth in a

nestling Wood Stork. The lower diagram puts the energy

flows on a "per kcal growth" basis. The sun energy (in