Laserfiche WebLink
RESULTS AND DISCUSSION <br />• <br />The distribution and occurrence of aquatic macroinvertebrate taxa <br />collected a.t three stations in the Williams Fork River are shown in <br />Tab 1e 1. In addition mean density (No./ft.2), percent relative abundance <br />(xRA) and total taxa of aquatic macroinvertebrates are presented in <br />Tables 2 through 4. A total of 44 taxa was collected from the three <br />sampling stations. Station 3 recorded t~.e greatest number (32) of taxa, <br />whereas the fewest number (29) were collected at Station 2. <br />Caddisflies (Trichoptera) and mayflies (Ephemeroptera) were the <br />most abundant groups at all stations. Hayflies comprised 2~.Sx, 21.1x, <br />and 32.Ox of the total macroinvertebrate densities at stations 1, 2 and <br />3, respectively, while caddisflies represented 44.2x, 67.6%, and 46.4,x, <br />I• of the total numbers at stations 1, 2 and 3, respectively. Mayflies <br />were dominated by Baetis spp. at station 2 (33.7 organisms/it2 or 9. 7°„ <br />relative abundance) and station 3 (74.5 organisms/ft.2 or 24.9x relative <br />abundance). In contrast, the dominant mayflies at station 1 included <br />Heptagenia sp. (10.7 organisms.ft.2 or 8.6x relative abundance) and <br />Bae[is spp. (8.O organisms/ft.2 or 6.6x relative abundance). The only <br />other numerically important mayfly ac the three stations (representing <br />more than 5x of the total macroinvertebrate density) was Rithogena sp., <br />which represented 1.2x relative abundance or 24.8 organisms/ft.2. <br />ilembers of the family Hydropsychidae dominated the caddisfly fauna. <br />The species Hydropsyche sp. B dominated this group at all stations by <br />comprising 21.9X relative abundance (or 27.2 organisms/ft.2), 41.8x <br />• relative abundance (or 144.7 organisms/ft.2) and 24x relative abundance <br />2 <br />~ (or 71.7 organisms/ft. ) at stations 1, 2 and 3 respectively. Cheumatopsyce <br />sp. was the subdominant caddisfly at all stations comprising 13.5x <br />5 <br />