Identifying trout refuges in the Indian and Hudson Rivers in northern New York through airborne thermal infrared remote sensing

Open-File Report 2015-1078
Prepared in cooperation with New York State Department of Environmental Conservation and Rochester Institute of Technology
By: , and 

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Abstract

The locations and sizes of potential cold-water refuges for trout were examined in 2005 along a 27-kilometer segment of the Indian and Hudson Rivers in northern New York to evaluate the extent of refuges, the effects of routine flow releases from an impoundment, and how these refuges and releases might influence trout survival in reaches that otherwise would be thermally stressed. This river segment supports small populations of brook trout (Salvelinus fontinalis), brown trout (Salmo trutta), and rainbow trout (Oncorhynchus mykiss) and also receives regular releases of reservoir-surface waters to support rafting during the summer, when water temperatures in both the reservoir and the river frequently exceed thermal thresholds for trout survival. Airborne thermal infrared imaging was supplemented with continuous, in-stream temperature loggers to identify potential refuges that may be associated with tributary inflows or groundwater seeps and to define the extent to which the release flows decrease the size of existing refuges. In general, the release flows overwhelmed the refuge areas and greatly decreased the size and number of the areas. Mean water temperatures were unaffected by the releases, but small-scale heterogeneity was diminished. At a larger scale, water temperatures in the upper and lower segments of the reach were consistently warmer than in the middle segment, even during passage of release waters. The inability of remote thermal infrared images to consistently distinguish land from water (in shaded areas) and to detect groundwater seeps (away from the shallow edges of the stream) limited data analysis and the ability to identify potential thermal refuge areas.

Suggested Citation

Ernst, A.G., Baldigo, B.P., Calef, F.J., Freehafer, D.A., and Kremens, R.L., 2015, Identifying trout refuges in the Indian and Hudson Rivers in northern New York through airborne thermal infrared remote sensing: U.S. Geological Survey Open-File Report 2015–1078, 17 p., http://dx.doi.org/10.3133/ofr20151078.

ISSN: 2331-1258 (online)

Study Area

Table of Contents

  • Abstract
  • Introduction
  • Study Area
  • Methods
  • Results Discussion
  • Study Limitations
  • Summary
  • References Cited
Publication type Report
Publication Subtype USGS Numbered Series
Title Identifying trout refuges in the Indian and Hudson Rivers in northern New York through airborne thermal infrared remote sensing
Series title Open-File Report
Series number 2015-1078
DOI 10.3133/ofr20151078
Year Published 2015
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) New York Water Science Center
Description vii, 17 p.
Country United States
State New York
Other Geospatial Hudson River and Indian River, Adirondack Park
Online Only (Y/N) Y
Additional Online Files (Y/N) N
Google Analytic Metrics Metrics page
Additional publication details