Lake benthos invertebrate distribution

The distribution of benthic invertebrates is affected by physical, chemical, and biological processes. These processes interact to create distinct niches, however little research has been conducted on benthic-pelagic interactions. We investigated benthic invertebrate depth distribution in a protected Kansas reservoir with a deep metalimnetic photosynthetic community (DCM). The reservoir has a protected watershed managed by the University of Kansas, making it an ideal model for a minimally disturbed, stratified lake. Benthic samples were collected at meter depth increments and invertebrates were identified and counted. The distribution, abundance, and richness of benthic invertebrates were analyzed in conjunction with a long-term DCM data set and water quality depth profile. Richness was strongly correlated to water quality variables, and decreased with depth. Diversity (Shannon’s index) was weakly correlated with water quality variables, and was highest at the locations: surface (0m), upper thermocline (3-4m), and the majority of the DCM migration range (6-7m). Oligochaeta, nematode, and hydrachnidia abundance peaked within the DCM migration range. These suggest the groups are highly influenced by physiochemical gradients in the lake depths and either directly or indirectly using the DCM as a food source.

Bowes DDIG_Martin_Poster_v03