Research conducted in southeast Alaska suggests that karst stream systems play a significant role in the productivity of downstream aquatic habitat. The research indicates that karst can increase fish productivity in the following ways:

• the leaching of calcium carbonate from bedrock has important buffering effects on acidic streams,
• the groundwater associated with karst results in cool, even stream temperatures throughout the year,
• the storage capacity in karst stream systems buffers seasonal flow rates to produce lower peak flows and higher low flow periods,
• karst streams tend to supply more nutrients and encourage more algae and moss growth,
• aquatic insect populations within karst streams are larger and more diverse,
• karst stream systems provide more protective sites for fish to rest, breed, and avoid predators. (Photo by J. Marc.)

In addition, karst aquifers contribute to human water supplies in many parts of the world. Although relatively little is known about BC's karst groundwater systems, it is likely that they too play an important role in some community watersheds.

The subsurface drainage systems of karst lack many of the natural cleansing and filtering mechanisms of surface streams. As a result, harmful substances or materials introduced into karst waters have the potential to seriously affect karst environments, human water supplies, and important fish-rearing streams.