Effects of Substrate Composition on Apache Trout Fry Emergence
2001; Taylor & Francis; Volume: 16; Issue: 3 Linguagem: Inglês
10.1080/02705060.2001.9663823
ISSN2156-6941
Autores Tópico(s)Water Quality and Resources Studies
ResumoABSTRACT Artificial substrates were used under laboratory conditions to assess the potential effects of fine sediment (< 2 mm) on a native southwestern (USA) salmonid. Apache trout (Oncorhynchus apache). Asynchronous, complementary field assessment of stream substrate composition was made in the White Mountains of east-central Arizona, the native range of Apache trout. Laboratory studies suggested that fry emergence was significantly reduced at 25% or greater by weight of fine sediments. Mean fine content of substrates in streams in the White Mountains ranged from 8 to 43% and averaged about 24%. Based on laboratory and field data, streams in the White Mountains region are approaching the threshold that could dramatically limit reproductive success of Apache trout. Further, a significantly greater content of optimum spawning substrate (8–32 mm) was estimated in streams emanating from the Fort Apache Indian Reservation than those in Apache Sitgreaves National Forest.
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