Modeling lamprey distribution using flow, geomorphology, and elevation in a terminal lake system.

Area of Science:

• Ecology
• Conservation Biology
• Geospatial Analysis

Background:

• Lampreys are ecologically vital but understudied fishes, with several species facing endangerment.
• Key data gaps in distribution and habitat exist, particularly in arid/semi-arid aquatic ecosystems.
• Species distribution models (SDMs) are crucial for conservation but can be impaired by spatial autocorrelation and scale mismatches in stream networks.

Purpose of the Study:

• To examine factors influencing the distribution of two lamprey species in the Goose Lake Basin across multiple spatial scales.
• To develop an accurate, basin-wide species distribution model (SDM) for imperiled lamprey populations.
• To improve understanding of ecological relationships and inform conservation strategies for native fishes.

Main Methods:

• Integrated fish presence-absence data with publicly available geospatial habitat variables.
• Employed logistic regression models and a spatial stream network (SSN) approach to account for spatial autocorrelation.
• Compared multiple sample grains for slope and sinuosity (250-1000 m) and elevation scales (site and watershed) to address scale mismatches.

Main Results:

• Flow, slope, and sinuosity (at 1000 m grain) and watershed-scale elevation were significant predictors of lamprey presence.
• Non-spatial models predicted presence in sinuous, low-gradient streams.
• Spatial models, incorporating spatial dependencies, predicted contiguous high-probability areas near known presences.

Conclusions:

• Ecological relationships were elucidated, and an accurate basin-wide SDM was produced.
• Accounting for spatial relationships across multiple scales improved both prediction and inference.
• Developing efficient modeling strategies for hierarchical stream ecosystems aids native fish conservation, including lampreys.