Geology topics

Pete Cadmus

Publications and source records attributed to Pete Cadmus.

3 recordsLinked to original sources

USGS2025

Sinoatrial contracaeciasis in Johnny Darters ( Etheostoma nigrum ) and Plains Topminnow ( Fundulus sciadicus ) from the South Platte drainage, Colorado

Intra-sinoatrial nematodes were incidentally recognized in wild-caught Colorado Johnny Darters ( Etheostoma nigrum , JD) in 2020–2021 and in Colorado Plains Topminnow ( Fundulus sciadicus , PTM) in 2023-2024. PTM and JD were evaluated histologically. Nematodes dissected from PTM were used for morphologic evaluation and molecular identification. The first and second internal transcribed spacers (ITS1 and ITS2) of ribosomal DNA were sequenced. Sinoatrial nematodes were found in two of 1232 JD (0.2%) and nine of 110 PTM (8.2%). Worms caused dilation or aneurysm of the sinus venosus. One JD had severe sinus venosus phlebitis. Morphologic, histologic and molecular features were diagnostic for Contracaecum spp. This is the first identification of larval Contracaecum in PTM, the first record of an intravascular nematode in this species, and the first documentation of vascular localization of Contracaecum larvae in JD. Vascular pathology could result in increased susceptibility to predation and favour the completion of the nematode life cycle. Parasites could become detrimental to population survival, especially those that are stressed by ecological and anthropogenic factors.

Colorado↗

USGS2022

Integrated assessment of chemical and biological recovery after diversion and treatment of acid mine drainage in a Rocky Mountain stream

Responses of stream ecosystems to gradual reductions in metal loading following remediation or restoration activities have been well documented in the literature. However, much less is known about how these systems respond to the immediate or more rapid elimination of metal inputs. Construction of a water treatment plant on the North Fork of Clear Creek (NFCC; CO, USA), a US Environmental Protection Agency Superfund site, captured, diverted, and treated the two major point-source inputs of acid mine drainage (AMD) and provided an opportunity to investigate immediate improvements in water quality. We conducted a 9-year study that included intensive within- and among-year monitoring of receiving-stream chemistry and benthic communities before and after construction of the treatment plant. Results showed a 64%–86% decrease in metal concentrations within months at the most contaminated sites. Benthic communities responded with increased abundance and diversity, but downstream stations remained impaired relative to reference conditions, with significantly lower taxonomic richness represented by a few dominant taxa (i.e., Baetis sp., Hydropsyche sp., Simulium sp., Orthocladiinae). Elevated metal concentrations from apparent residual sources, and relatively high conductivity from contributing major ions not removed during the treatment process, are likely limiting downstream recovery. Our study demonstrates that direct AMD treatment can rapidly improve water quality and benefit aquatic life, but effectiveness is limited, in part, to the extent that inputs of metals are captured and treated. Consideration should also be given to the effects of elevated major ion concentrations from the treated effluent not removed during the lime treatment process. Continued chemical and biological monitoring will be needed to quantify the NFCC recovery trajectory and to inform future remediation strategies.

Colorado↗

USGS2016

Low-cost floating emergence net and bottle trap: Comparison of two designs

Sampling emergent aquatic insects is of interest to many freshwater ecologists. Many quantitative emergence traps require the use of aspiration for collection. However, aspiration is infeasible in studies with large amounts of replication that is often required in large biomonitoring projects. We designed an economic, collapsible pyramid-shaped floating emergence trap with an external collection bottle that avoids the need for aspiration. This design was compared experimentally to a design of similar dimensions that relied on aspiration to ensure comparable results. The pyramid-shaped design captured twice as many total emerging insects. When a preservative was used in bottle collectors, >95% of the emergent abundance was collected in the bottle. When no preservative was used, >81% of the total insects were collected from the bottle. In addition to capturing fewer emergent insects, the traps that required aspiration took significantly longer to sample. Large studies and studies sampling remote locations could benefit from the economical construction, speed of sampling, and capture efficiency.

Journal of Freshwater Ecology↗