The Black River is part of a
blackwater system which is nutrient-poor and more acidic than other types of freshwater ecosystems. The higher acidity is a result of vegetation decay and the subsequent release of tannins in the water. This makes for an environment that does not sustain most hardwood tree species and even slows the growth of bald cypress. Although its blackwater prevents certain organisms from flourishing in the Black River Preserve, these types of ecosystems often consist of a unique variety of fauna and flora. Within the Black River lives a rare species of fish called the Santee chub (
Cyprinella zanema). Another rare fish is the Broadtail Madtom. Although both of these species are uncommon, their current status is neither endangered nor threatened. == Ancient bald cypress ==