Fish have always been an integral part of the Tahoe’s aquatic systems. Fish play in important role in the food webs of the Region’s lakes and streams, and fishing is socially important activity. There are two key aquatic environments that support fish in the Lake Tahoe Basin: lakes and streams. These two ecosystems are dynamic in space and time. Combined, lakes and streams provide fish with necessary elements such as water, cover, and spawning and nursery habitat. Both environments play an important role in sustaining fish populations and some fish species use both lake and stream environments in different stages of their life cycles. The combination of chemical, biological, temperature, and physical characteristics of lakes and streams influence the suitability of these environments to sustain different fish populations. Likewise, the physical and biological integrity of the surrounding landscape plays an important role in sustaining aquatic habitats important to fish. Accordingly, degradation of lake and stream habitat and the surrounding landscape can reduce the sustainability of Tahoe’s fishery.
The goal of TRPA adopted threshold standards for fisheries resources is to improve aquatic habitat important for the growth, reproduction, and perpetuation of existing and threatened fish resources in the Lake Tahoe Basin (TRPA 1982a). TRPA has adopted one numerical standard (stream habitat condition), one management standard without a numeric target (instream flow), one management standard with a numeric target (lake habitat), and two policy statements (instream flow and Lahontan cutthroat trout) (Table 7-1). There are four indicator reporting categories in the fisheries threshold category: lake habitat, stream habitat, instream flow, and Lahontan cutthroat trout.