9713 - Laserfiche WebLink

Home Browse Search

FALL RESUL 1S Physical Parameters During the fall of 2004, the LCR experienced several discrete monsoonal flooding events (Figure 13). In September, floods began on 19 September, peaked on 21 September at 2,160 cubic feet per second (cfs), and thereafter declined until 30 September, when another flood arrived. At Salt Camp, turbidity reached a high of 124,416 NTUs on 22 September,-and thereafter decreased to a low of 16,280 NTUs on 29 September. Turbidity increased again on 30 September (fly-out day) to 67,584 NTUs with the arrival of another flood (Figure 14). Daily afternoon water temperatures ranged between 15.3 and 19.1 DC (mean = 17.4 DC). During the October trip, the LCR ran at base flow and was blue. Although blue in color, turbidity was still declining from the sequence of flooding events experienced this fall and decreased from 61.4 NTUs on 19 October to 23.8 NTUs on 28 October (Figure 14). Daily afternoon water temperatures ranged from 17.1 to 18.3 DC (mean = 17.9 DC). Effort and Catch A total of 1 ,080 hoop net sets were completed during the September and October trips yielding 25,396 hours of fishing effort. Total CPUE for HBC in September was 0.036 fish/net-hour, and in October was 0.181 fish/net-hour (Table 10). The distribution of effort was similar among the three reaches. Fishing effort during these trips produced a catch of 3,821 fish (Table 11). The dominant species in the catch were HBC (2,778 fish; 73%) and speckled dace (644 fish; 17%). Fathead minnow comprised the dominant nonnative species (74 fish; 2%). Species Composition Observed species composition during both the September and October trips was similar, with some small differences (Figure 15). HBC comprised the largest proportion of fish caught on both trips (79% and 72%), compared to 70% and 52% on the spring trips. Speckled dace increased in proportion from 6% of the catch in September to 19% of the catch in October. The proportions of black bullhead and carp declined from 3% in September to <1 % in October. Nonnative species in order of decreasing catch included fathead minnow, black bullhead, carp, channel catfish, red shiner, plains killifish and rainbow trout. Nonnative species captured in hoop nets during September and October comprised 11.4% and 2.1 % of the catch, respectively. Length Frequencies and Catch More HBC were captured during the October trip (2,322 fish) than during the September trip (456 fish; Figure 16), likely a result of decreased turbidity in October (Figure 14). A spike of age-O fish (<100 mm) was detected in October 22