Going Cray Cray with the Crawdaddies: Influences of water quality and site conditions on the diversity and abundance of crayfish communities in northern New York

Abstract

Freshwater crayfish are a group of macroinvertebrate omnivores that serve as a prey species for fish and birds. They are under threat with changing climates, and greater research on their distribution patterns across different habitats is needed to establish a necessary conservation strategy. Key factors which determine the presence of crayfish species are water velocity, water quality, over story, and substrate composition. Relatively limited research has successfully established a link between crayfish species and the water quality metrics. We predicted that fewer crayfish species and lesser abundance would be found in the lentic sites. In fall 2024, we placed 5 to 23 minnow and turtle traps in lotic (Little Ausable River) and lentic (Barracks Golf Course) sites for 24 hours. Crayfish captured were examined for parasites, in addition to being weighed and measured. Specimens were photographed, marked on the carapace with a permanent marker, and immediately released. Two species of crayfish were identified, one unique to each site, Faxonius immunis at the lentic ponds and Cambarus robustus at the lotic river. Additionally, greater crayfish abundance occurred at the lentic site. Water quality tests showed similar average pH (7.91, 8.02) and conductivity (198, 210) ranges between the lentic and lotic sites, respectively. Little Ausable River trapping site velocities ranged between 42.5 m3/s to 1.181 m3/s, which likely affected the crayfish population. Crayfish were on average smaller at the lentic versus the lotic sites, potentially as a function of predation, water quality, and available resources. By establishing a better understanding of the distribution of crayfish types of wetlands, more effective conservation strategies can be implemented for declining native species in North America.