Table 1. δ15N values for other trophic levels and fish species in the four study reservoirs. Note that phyto- and zoo-plankton samples were bulk samples and likely represent a range of taxa.
| δ15N | Blue River Reservoir | Fall Creek Reservoir | Hills Creek Reservoir | Lookout Point Reservoir |
|---|---|---|---|---|
| Phytoplankton | 0.44 (n = 2) | 0.77 (n = 6) | 0.74 (n = 5) | 0.29 (n = 4) |
| Zooplankton | 0.01 (n = 3) | 1.46 (n = 3) | 1.17 (n = 3) | * |
| Chironomidae (aquatic macroinvertebrate) | 0.28 (n = 1) | 2.05 (n = 3) | 2.15 (n = 4) | 0.73 (n = 1) |
| Bluegill (Lepomis macrochirus) | 4.27 (n = 9) | 4.97 (n = 12) | 5.76 (n = 10) | 5.16 (n = 8) |
| Brown Bullhead (Ameiurus nebulosus) | Not detected | 6.58 (n = 6) | 7.69 (n = 5) | 6.27 (n = 12) |
| Chinook Salmon (Oncorhynchus tshawytscha) | Not present | 6.08 (n = 49) | 7.23 (n = 71) | 7.97 (n = 29) |
| Largemouth Bass (Micropterus salmoides) < 150 mm | 5.29 (n = 5) | 5.19 (n = 15) | 6.16 (n = 11) | 6.68 (n = 6) |
| Largemouth Bass (Micropterus salmoides) > 150 mm | 8.60 (n = 7) | 6.61 (n = 18) | 8.94 (n = 20) | 8.77 (n = 20) |
| Rainbow Trout (Oncorhynchus mykiss) < 150 mm | 4.88 (n = 2) | 5.12 (n = 1) | 6.57 (n = 9) | 6.94 (n = 3) |
| Rainbow Trout (Oncorhynchus mykiss) > 150 mm | 7.88 (n = 14) | 6.36 (n = 12) | 7.42 (n = 9) | 7.56 (n = 14) |
| Yellow Bullhead (Ameiurus natalis) | Not detected | 6.64 (n = 18) | 7.19 (n = 4) | 6.97 (n = 10) |
Mean δ15N values and sample sizes (n) for other trophic levels and fish species in the four study reservoirs. Data represent either whole organisms (plankton and macroinvertebrates) or individual fin clips (fishes). The riverbed draining treatment reservoir is highlighted in bold.
*Bulk zooplankton were not collected for Lookout Point but the mean δ15N for Daphniidae was 1.56 (n = 7).