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A Remote‐Sensing, GIS‐Based Approach to Identify, Characterize, and Model Spawning Habitat for Fall‐Run Chum Salmon in a Sub‐Arctic, Glacially Fed River
Author(s) -
Wirth Lisa,
Rosenberger Amanda,
Prakash Anupma,
Gens Rudiger,
Margraf F. Joseph,
Hamazaki Toshihide
Publication year - 2012
Publication title -
transactions of the american fisheries society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.696
H-Index - 86
eISSN - 1548-8659
pISSN - 0002-8487
DOI - 10.1080/00028487.2012.692348
Subject(s) - habitat , environmental science , overwintering , arctic , fish migration , remote sensing , oncorhynchus , fishery , physical geography , ecology , geography , oceanography , geology , fish <actinopterygii> , biology
At northern limits of a species’ distribution, fish habitat requirements are often linked to thermal preferences, and the presence of overwintering habitat. However, logistical challenges and hydrologic processes typical of glacial systems could compromize the identification of these habitats, particularly in large river environments. Our goal was to identify and characterize spawning habitat for fall‐run chum salmon Oncorhynchus keta and model habitat selection from spatial distributions of tagged individuals in the Tanana River, Alaska using an approach that combined ground surveys with remote sensing. Models included braiding, sinuosity, ice‐free water surface area (indicating groundwater influence), and persistent ice‐free water (i.e., consistent presence of ice‐free water for a 12‐year period according to satellite imagery). Candidate models containing persistent ice‐free water were selected as most likely, highlighting the utility of remote sensing for monitoring and identifying salmon habitat in remote areas. A combination of ground and remote surveys revealed spatial and temporal thermal characteristics of these habitats that could have strong biological implications. Persistent ice‐free sites identified using synthetic aperture radar appear to serve as core areas for spawning fall chum salmon, and the importance of stability through time suggests a legacy of successful reproductive effort for this homing species. These features would not be captured with a one‐visit traditional survey but rather required remote‐sensing monitoring of the sites through time.