| Summary: | Grant/Contract No: C07-33 Sampling and Gear Effort We conducted monthly fish sampling on Thompson Lake from 7-30-07 thru 11-30-07 (excluding September) using a multiple gear approach (Table 1). Sampling consisted of 9 electrofishing runs (15 minutes each), 12 fyke net sets (24 hours each), 12 mini-fyke net sets (24 hours each), and 25 minnow trap sets (24 hours each) at shoreline or pseudo-shoreline (used for shoreline gear) sites. Additionally, 2 tandem fyke net sets (24 hours each), 2 tandem mini-fyke net sets (24 hours each), 1 trammel net (1.5 hour set) and 1 experimental gill net set (1.5 hour set) were deployed at open water sites. Trammel and gill net sets were discontinued due to fouling by filamentous algae. All gears were fished with protocols set by Gutreuter et al. (1995) used for the Long Term Resource Monitoring Program. Total Fish Catch Numbers We collected a total of 1,290 fish representing 8 species and 3 families from Thompson Lake in 2007. Overall, catches were dominated by centrarchids. Largemouth bass (Micropterus salmoides) dominated the catch with 1,158 fish comprising 89.8 % of the total catch. Largemouth bass were followed by 100 black crappie (Pomoxis nigromaculatus) (7.8 %), 19 bluegill (Lepomis macrochirus ) (1.5 %), 5 pumpkinseed (L.gibbosus) (0.4 %), 5 bowfin (Amia calva) (0.4 %), 1 common carp (Cyprinus carpio) (0.1 %), 1 warmouth (L. gulosus ) (0.1 %), and 1 white crappie (P. annularis) (0.1 %). (Table 2) Electrofishing Mean Catch-per-Unit Effort (CPUE) We collected 5 fish species while electrofishing, which comprised 67.4 % of the total catch by all gears. Largemouth bass dominated the catch with 376 fish per hour of electrofishing, followed by 7 black crappie per hour, 2 bluegill per hour, and < 1 each of common carp and white crappie per hour. Bowfin, pumpkinseed, and warmouth were not collected by electrofishing. Catch rates of different fish species varied by gear, but largemouth bass dominated the catches in all gears (Table 3, 4). The only non-native fish species captured was an individual common carp. The individual common carp was removed from the fish community of Thompson Lake. 2 Submersed and Emergent Aquatic Vegetation Presence/Absence Submersed and emergent aquatic vegetation sampling was limited to visual presence/absence observations to ensure low levels of disturbance during the first year of restoration. Aquatic vegetation observed in Thompson Lake included various duck weed species (Lemnaceae), American pondweed (Potamogeton nodosus), curlyleaf pondweed (Potamogeton crispus), sago pondweed (Potamogeton pectinatus), horned pondweed (Zannichellia palustris), coontail (Ceratophyllum demersum), American elodea (Elodea canadensis), common arrowhead (Sagittaria latifolia), and Eurasian water milfoil (Myriophyllum spicatum). Curlyleaf pondweed and Eurasian water milfoil were the only non-native species of aquatic vegetation observed. INHS Technical Report Prepared for The Nature Conservancy
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