Benjamin H Letcher
Ben is a population ecologist focusing on stream habitats and science communication.
Biography
Education
- PhD, 1994, NC State, Zoology with statistics and modeling minor
- M.S. 1990, URI School of Oceanography, biological option
- B.S. 1985, Trinity College, Biology
Main research questions include:
Where are the fish?
- Distribution modeling
- Modeling climate refugia
What drives fish abundances?
- Long-term individual-based field studies
- State-space abundance modeling
- Integrated demographic models
How are the fish changing?
- Thermal adaptive capacity
- Estimating fitness in the wild
How are stream environments changing?
- Stream temperature statistical models
- Stream flow modeling using images
In addition, Ben is very interested in creating integrated, interactive, web-based systems to assist decision-making for natural resources. His group has created the Spatial Hydro-Ecological Decision System (‘SHEDS’ at ecosheds.org) which links databases, models and visualization tools.
- An extensive stream temperature database is at db.ecosheds.org.
- Stream temperature and Brook Trout occupancy models are at ecosheds.org
- The Interactive Catchment Explorer (‘ICE’) which facilitates exploration of complex environmental datasets and modeling results is at ice.ecosheds.org.
- Visualizations of individual tagging data from long-term studies are at pitdata.ecosheds.org.
- A stream visualization tool linking hydrographs to images is at fpe.ecosheds.org.
- A time series explorer is at tse.ecosheds.org.
Google scholar link: https://scholar.google.com/citations?user=fwgbROwAAAAJ&hl=en
Science and Products
North Atlantic-Appalachian AI/ML Capabilities
Artificial Intelligence (AI) and Machine Learning (ML) includes a broad suite of flexible data-driven empirical approaches to perform tasks that are difficult to implement using conventional methods. AI and ML harness the power of computing resources to evaluate the underlying patterns and relationships within a dataset without explicit instructions.
The North Atlantic-Appalachian AI/...
Enabling AI for citizen science in fish biology
Artificial Intelligence (AI) is revolutionizing ecology and conservation by enabling species recognition from photos and videos. Our project evaluates the capacity to expand AI for individual fish recognition for population assessment. The success of this effort would facilitate fisheries analysis at an unprecedented scale by engaging anglers and citizen scientists in imagery collection. This...
Enabling AI for citizen science in fish ecology
Artificial Intelligence (AI) is revolutionizing ecology and conservation by enabling species recognition from photos and videos. Our project evaluates the capacity to expand AI for individual fish recognition for population assessment. The success of this effort would facilitate fisheries analysis at an unprecedented scale by engaging anglers and citizen scientists in imagery collection.This...
Understanding Brook Trout Persistence in Warming Streams
Cold-water adapted Brook Trout were historically widely distributed – ranging from northern Quebec to Georgia, and from the Atlantic Ocean to Manitoba in the north, and along the Appalachian ridge in the south. However, studies show that due to factors associated with climate change, such as increased stream temperature and changing water flow, the number of streams containing Brook Trout is...
Brook Trout Population Responses to Climate Variation Across the Southeast USA
Brook trout are the only native fish from the salmon family in the southeastern United States. Despite their recreational and cultural significance, human activities, such as habitat degradation and introduction of non-native species, have led to serious declines of brook trout populations in the region. Stream temperature and flow alterations from climate change are projected to impact this...
A generic web application to visualize and understand movements of tagged animals
The goal of this project was to maximize the value of expensive animal tagging data. We developed an interactive web application to help scientists understand patterns in their own tagging datasets and to help scientists, funders and agencies communicate tagging data to decision-makers and to the general public. Interactive visualizations have emerged recently as a valuable tool for...
Brook trout vulnerability to drought: eastern component of USGS national integrated ecohydrological research and monitoring plans
There is a growing and urgent need to develop and implement innovative strategies to research, monitor, and manage freshwater resources as societal demands escalate simultaneously with climate-driven changes in water availability. Over the past several years, many regions have experienced extreme droughts, fueled by prolonged periods of reduced precipitation and exceptionally warm temperatures...
Climate change forecasts for eastern salmonids
Small streams in forests are likely to see dramatic shifts as global climate change influences air temperature and rain patterns. We have already seen warmer stream temperatures as air temperatures increase in summer in the Northeastern US. The intensity and duration of floods and droughts are also expected to magnify as future rain patterns shift. This project will evaluate how stream...
The West Brook Story
Natural systems, like rivers and streams, are remarkably complex, with many interacting parts. Data visualization tools make understanding and communicating complex ecological processes easier. Effective visualizations help users learn about patterns in data and how models work. Interactive visualizations are particularly useful, as they let users explore data and develop a personal...
Fish Ecology
Our goal is to identify the factors that govern population dynamics. Emphasis is on an integrative approach, combining field and laboratory studies to provide data for mathematical models of ecological and evolutionary dynamics. We focus on the fish that live in streams; how environmental variation, barriers to movement, and landscape characteristics influence changes in abundance over time...
Predicting Climate-Induced Expansions of Invasive Fish in the Pacific Northwest: Implications for Climate Adaptation of Native Salmon and Trout
The headwaters of the Columbia River Basin in the Northern Rocky Mountains region is widely recognized as a stronghold for native fish, containing some of the last remaining connected cold-water habitats for species such as the threatened bull trout and native westslope cutthroat trout. However, as temperatures rise, non-native invasive fish species could be poised to prosper in the region as...
Modeling species response to environmental change: development of integrated, scalable Bayesian models of population persistence
Estimating species response to environmental change is a key challenge for ecologists and a core mission of the USGS. Effective forecasting of species response requires models that are detailed enough to capture critical processes and at the same time general enough to allow broad application. This tradeoff is difficult to reconcile with most existing methods. We propose to extend and combine...
Cohort strength and body size in co-occurring salmonids in a small stream network: Variation in space and time
Trout and salmon commonly coexist in stream networks. Exploring similarities and differences among species can help explain coexistence and invasive ability. Here, we describe spatial distribution, cohort strengths and size-at-age of three co-occurring species in a small stream network. Spatial distributions varied dramatically among species;...
Letcher, Benjamin; Nislow, Keith H.; O'Donnell, Matthew; Whiteley, Andrew R.; Coombs, Jason A.; Dubreuil, Todd L. An interactive data visualization framework for exploring geospatial environmental datasets and model predictions
With the rise of large-scale environmental models comes new challenges for how we best utilize this information in research, management and decision making. Interactive data visualizations can make large and complex datasets easier to access and explore, which can lead to knowledge discovery, hypothesis formation and improved understanding. Here,...
Walker, Jeffrey D; Letcher, Benjamin; Rodgers, Kirk D.; Muhlfeld, Clint C.; D'Angelo, Vincent S. Evaluation of genetic structuring within GIS‐derived Brook Trout management units
Delineation of management units across broad spatial scales can help to visualize population structuring and identify conservation opportunities. Geographical information system (GIS) approaches can be useful for developing broad‐scale management units, especially when paired with field data that can validate the GIS‐based delineations. Genetic...
Nathan, Lucas R; Kanno, Y.; Letcher, Benjamin; Welsh, Amy B.; Whiteley, Andrew R.; Vokoun, Jason C. Climate‐change refugia: Biodiversity in the slow lane
Climate‐change adaptation focuses on conducting and translating research to minimize the dire impacts of anthropogenic climate change, including threats to biodiversity and human welfare. One adaptation strategy is to focus conservation on climate‐change refugia (that is, areas relatively buffered from contemporary climate change over time that...
Morelli, Toni Lyn; Barrows, Cameron W.; Ramirez, Aaron R.; Cartwright, Jennifer M.; Ackerly, David D.; Eaves, Tatiana D.; Ebersole, Joseph L.; Krawchuk, Meg A.; Letcher, Benjamin; Mahalovich, Mary Frances; Meigs, Garrett; Michalak, Julia; Millar, Constance I.; Quinones, Rebecca M.; Stralberg, Diana; Thorne, James H. Managing climate refugia for freshwater fishes under an expanding human footprint
Within the context of climate adaptation, the concept of climate refugia has emerged as a framework for addressing future threats to freshwater fish populations. We evaluated recent climate‐refugia management associated with water use and landscape modification by comparing efforts in the US states of Oregon and Massachusetts, for which there are...
Ebersole, Joseph L.; Quinones, Rebecca M.; Clements, Shaun; Letcher, Benjamin How repeatable is CTmax within individual brook trout over short- and long-time intervals?
As stream temperatures increase due to factors such as heated runoff from impervious surfaces, deforestation, and climate change, fish species adapted to cold water streams are forced to move to more suitable habitat, acclimate or adapt to increased thermal regimes, or die. To estimate the potential for adaptation, a (within individual) repeatable...
O'Donnell, Matthew J.; Regish, Amy M.; McCormick, Stephen D.; Letcher, Benjamin H. Daily estimates reveal fine-scale temporal and spatial variation in fish survival across a stream network
Environmental drivers of population vital rates, such as temperature and precipitation, often vary at short time scales, and these fluctuations can have important impacts on population dynamics. However, relationships between survival and environmental conditions are typically modeled at coarse temporal scales, ignoring the role of daily...
Childress, Evan S.; Nislow, Keith; Whiteley, Andrew R.; O'Donnell, Matthew; Letcher, Benjamin Atlantic Salmon (Salmo salar) climate scenario planning pilot report
Scenario planning is a structured process that embraces uncertainty and explores plausible alternative future conditions under different assumptions to help manage risk and prioritize actions ( Schwartz 1996, Peterson et al. 2003). It has been used by a variety of organizations to explore and help prepare for the future, lends itself well to...
Borggaard, Diane; Dick, Dori; Star, Jonathan; Alexander, Mike; Bernier, M.; Collins, Matt; Damon-Randall, Kelly; Dudley, Robert; Roger Griffis, Roger; Hayes, Sean; Johnson, Mike; Kircheis, Dan; Kocik, John; Letcher, Benjamin; Mantua, Nate; Morrison, Wendy; Nislow, Keith; Saba, Vince; Saunders, R.; Sheehan, Tim; Staudinger, Michelle D. Survival and density of a dominant fish species across a gradient of urbanization in North Carolina tidal creeks
Development in the southeastern U.S. coastal plain generates the need for a better understanding of how demographics (survival and abundance) of estuarine nekton respond to urbanization. Apparent survival and density of the dominant Atlantic coast salt marsh fish, Fundulus heteroclitus, were estimated in four North Carolina tidal creeks using a...
Rudershausen, Paul J; Hightower, Joseph E; Buckel, Jeffery A; O'Donnell, Matthew J.; Dubreuil, Todd; Letcher, Benjamin H. State-space analysis of power to detect regional brook trout population trends over time
Threats to aquatic biodiversity are expressed at broad spatial scales, but identifying regional trends in abundance is challenging owing to variable sampling designs, and temporal and spatial variation in abundance. We compiled a regional dataset of brook trout Salvelinus fontinalis counts across their southern range representing 326 sites from...
Pregler, Kasey C.; Hanks, R. Daniel; Childress, Evan S.; Hitt, Nathaniel P.; Hocking, Daniel J.; Letcher, Benjamin H.; Kanno, Yoichiro A geostatistical state‐space model of animal densities for stream networks
Population dynamics are often correlated in space and time due to correlations in environmental drivers as well as synchrony induced by individual dispersal. Many statistical analyses of populations ignore potential autocorrelations and assume that survey methods (distance and time between samples) eliminate these correlations, allowing samples to...
Hocking, Daniel J.; Thorson, James T.; O'Neil, Kyle; Letcher, Benjamin H. The S.O. Conte Anadromous Fish Research Center--a model for progress
No abstract available.
Castro-Santos, Theodore R.; Haro, Alexander J.; Letcher, Benjamin H.; McCormick, Stephen D.
Ecosheds.org
LSC Conte Anadrmous Fish Laboratory is currently involved in https://ecosheds.org.