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-Open Water Community-- water column invertebrates Invertebrates were sampled in five-open water.communities• M3, M7, M8, M14, and M18. This community type had.the second highest number of water column invertebrates L-1. Data-for the first three sample periods are presented in Figure 33a, and the. last three sample.-periods in Figure 33b. Cladocera in the-open-water had low densities at-all stations -for the first sample period, 16 June (not apparent at all stations-due to graph scale). Cladocera numbers increased. over the next two sample periods of 1 July and 17 July. ..The greatest Cladocera densities- were found on 17 July at station M3 with 131 individuals per liter. The last three sample periods (Figure 33b) showed a decline in Cladocera numbers at all stations.. Stations M14-and M18 on the-last sample date'had very low numbers of Cladocera which is not apparent on the .graph due to graph scale. Copepoda-also had low densities at-all stations during the -first sample period. .The second sample period. showed increases at all, stations, with M8 showing the greatest density for all open water stations for the sample season with 188 Copepoda per liter. Numbers-generally declined through: the remainder of the, season with the exception of station M3-which reached its seasonal high of 57 Copepoda-per liter. ,. Chironomid had relatively low densities, or-were absent from ` the water column in the open water community. The highest densities were occurred during the last sample period of 18 October with 0.31 per liter at station M18. Insects other than chironomids were rare or absent at all stations through the sample period. Highest numbers were seen on 30 July and-13 August with-nearly 0.05 per liter-present. Other invertebrates again were rare through all sample dates with only one occurrence on 1 July at station M14. 57