Lake shorelines are ecotones with high diversity and productivity, but are also zones of intense
human activity. In comparison to other aquatic habitats, less is known of lake shorelines, their
connections to other lake habitats, and how shorelines are affected by human activities. Focusing
on lakes and reservoirs of the Sierra Nevada ecoregion (CA/NV), this research provides a better
understanding of the lake habitats and nearshore benthic macroinvertebrate communities.
The first study (Chapter 2) assessed the nearshore littoral benthic macroinvertebrate
communities at the regional extent. Benthic community structure in the littoral zone was
considered in relation to broad-scale categories of subregion and lake type. The results indicate
that these categories are associated with nearshore benthic community structure, but they also
suggest the influence of local-scale factors.
The second study (Chapter 3) examined how lake habitat composition (mesohabitat,
riparian land cover, catchment land cover and trophic status) varied among lake types and
subregions and how they were associated with macroinvertebrate community patterns. I found
that mesohabitat composition did not differ among lake types nor subregions, but similar to the
nearshore benthos, riparian land cover did differ among lake types. Trophic status was found to
correlate with mean abundance.
The third study (Chapter 4) examined within-lake spatial and temporal distribution of
nearshore benthos in a subset of Sierra Nevada lakes with natural basins; interannual
compositional differences, between lentic and lotic habitats, and the effect of plot size were
addressed. There was little annual variation in composition, lentic and lotic habitats had distinct
communities, and increasing the plot size did not provide a substantial benefit.
Within the broader context of lake shoreline research, the results of this work suggest that
with intentional habitat stratification, appropriate sampling methodology and taxonomic focus,
benthic macroinvertebrates can serve as a first tier prioritizing step at the regional extent. The
work also supports that benthic macroinvertebrates have the potential to serve as bioindicators of
lake-scale change due to littoral or riparian modification in regions such as the Sierra Nevada.
The knowledge gained from this research will assist in further regional lake assessment and
research.