Preprints

Biological invasions are transforming ecosystems worldwide, yet the genomic bases enabling certain species to dominate new environments remain poorly understood. Phragmites australis, a widespread wetland grass with invasive and native subspecies co-occurring in North America, provides a powerful system to investigate genomic mechanisms of invasiveness. We generated independent...

Segregated variation between populations is a fundamental evolutionary process leading to parasite specialization, yet the resulting impacts on infection heterogeneity within populations are theoretically and empirically understudied. We asked whether the distribution of host susceptibility to infection within populations carries the signatures of geographic structure from pathogen local

Algal blooms represent ecosystem state shifts that degrade drinking water, restrict recreation, threaten public health, and lower property values. Detecting blooms in advance on management relevant timescales of days to weeks can support proactive intervention. Early warning statistics derived from indicator time series offer a framework for detecting state shifts, but the use of lake...

This cruise report describes work from leg three of the NOAA American Samoa Abyssal Mapping effort, OPR-T900-KR-26. Leg one preceded this effort and collected ship-based acoustic data. Leg two collected autonomous underwater vehicle (AUV) data and began before, continued contemporaneously, and finished subsequently to leg three. The USGS field activity number assigned to this expedition...

A comprehensive understanding of life history is vital to successful species conservation and management. When different life history stages are accompanied by considerable morphological or cryptic variation, such as the egg and larval phases exhibited by most fishes, genomic tools are essential for identifying species so that early-life ecology questions can be studied. Genotyping-in...

Floating photovoltaic (FPV) arrays alter the methane (CH4) cycling dynamics of waterbodies on which they are deployed. Here, we investigated dissolved CH4 dynamics and associated CH4 cycling microbial communities (methanogens and methanotrophs) in the second year of FPV deployment (70% aerial coverage) in experimental ponds. We found that bottom-water CH4 concentrations were twice as...

This study presents historical estimates and future projections of net infiltration (potential recharge), actual evapotranspiration (ET), surface runoff, and related water budget components across Minnesota using the USGS Soil Water Balance model, version 2 (SWB). The model was calibrated to streamflow and actual ET observations from 2000–2022, achieving an overall r² of 0.973 with a...

The U.S. Geological Survey, as part of the Arkansas Groundwater Initiative, developed forecast scenarios using previously calibrated MODFLOW 6 groundwater models that focused on the Cache and Grand Prairie Critical Groundwater Areas to assess the impact of future climate and water management strategies on the Mississippi River Valley alluvial aquifer. A Soil Water Balance model was used...

Rapid shifts between droughts and floods, termed hydrological whiplash, challenge water management, yet their timing and drivers remain poorly understood at continental scales. While drought-to-flood (DtF) transitions have received growing attention, flood-to-drought (FtD) transitions — though rarer — pose distinct operational challenges that are less well characterized. These wet-to-dry...

Invasion genetics presents a classic paradox: how do species successfully spread despite severe population bottlenecks? The brown treesnake (Boiga irregularis) in Guam represents a striking example of this phenomenon, having been introduced with only a handful of individuals. We show that the population endured an extreme bottleneck, with roughly half of the genome exhibiting runs of...

Communication regarding the mission of the U.S. Geological Survey (USGS) Cooperative Research Units Program (CRU) can take many forms, yet clear and concise messaging for various audiences is critical to highlight program accomplishments and increase visibility. Before the work described in this report, CRU did not have a communication strategy; therefore, CRU leadership supported a...

The endangered Columbia Basin pygmy rabbit (CBPR) faces multiple threats, particularly increasing risk of larger and more intense wildfires due to climate change, emerging disease, and sagebrush habitat loss due to agriculture and development. Through the use of conservation breeding, the CBPR wild population grew from a low of 16 individuals captured in 2001 to over 100 individuals in...