Subject
Big Bend National Park (Tex.) Environmental conditions
2
Rio Grande (Colo.-Mexico and Tex.) Environmental conditions
2
Riparian animals
2
Stream animals
2
Amistad National Recreation Area (Tex.)
1
Droughts Environmental aspects
1
Fish communities
1
Fish populations
1
Freshwater fishes
1
Freshwater fishes Effect of water quality on
1
Invertebrate populations
1
Stream invertebrates Effect of water quality on
1
Water quality
1
Water quality biological assessment
1