56 ENVIRONMENTAL ENGINEERTNG
Figure 4-1. A typical terrestrial ecosystem. The numbers refer to trophic level above
the autotrophic, and the arrows show progressive loss of energy. (Source: Turk, A.
et al., Environmental Science. Philadelphia: W.B. Saunders, 1974.)quickly after the storm flow abates, so the invertebrates do not starve. In contrast, the
deep oceanic ecosystem is extraordinarily fragile, not resilient, and not resistant to
environmental disturbances. This must be considered before the oceans are used as
waste repositories.
Although inland waters (streams, lakes, wetlands, etc.) tend to be fairly resi-
lient ecosystems, they are certainly not totally immune to destruction by outside