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<br />1995]
<br />
<br />MACROINVERTEBRATES OF THE GREEN RIVER
<br />
<br />217
<br />
<br />TABLE 4, Densities of benthic invertebrates (#/m2) from the Green River, river backwater habitat, Ouray National
<br />Wildlife Refuge, Ouray, UT.
<br />
<br /> 10 July 1991 8 August 1991
<br /> # of samples # of samples
<br />Taxon Density/m2 (95% C,L.) processed Density/m2 (95% C,L.) processed
<br />Nematoda 54,872 (24,350-123,650) 5 134,183 (94,656-190,542) 5
<br />Oligochaeta 26,642 (14,622-48,495) 9 164,731 (101,881-266,728) 5
<br />Insecta
<br />Ceratopogonidae 96 (90-107) 30 461 (385-552) 30
<br />Chironomidae 31,125 (15,356-63,089) 5 22,863 (12,139--43,136) 6
<br />Early instars 8877 7301
<br />Chironomus 7032 6340
<br />Lenziella 346 1249
<br />Polypedilum 14,179 5860
<br />Procladius 461 1345
<br />Psectrocladius U5 0
<br />Tanytarsus U5 769
<br />
<br />TABLE 5. Densities of benthic invertebrates (#/m2) from the Green River, seasonally inundated wetland habitat,
<br />Ouray National Wildlife Refuge, Ouray, UT.
<br />
<br /> 10 June 1991 12 July 1991 15 August 1991
<br /> Density/m2 # of samples Density/m2 # of samples Density/m2 # of samples
<br />Taxon (95% C.L,) processed (95% c.L.) processed (95% c.L.) processed
<br />Nematoda 7133 (4534-11,266) 8 80,694 (38,595-168,713) 5 88,533 (83,125-94,784) 5
<br />Oligochaeta 4573 (3402-6141) 30 87,150 (39,242-193,547) 10 22,249 (11,930-41,494) 5
<br />Insecta
<br />Ceratopogonidae 0 30 0 14 2478 (1941-3165) 20
<br />Chironomidae 903 (895-915) 30 23,055 (13,707-38,780) 14 3977 (2816-5617) 10
<br />Early instars 96 8769 2479
<br />Ablabesmyia 0 124 0
<br />Chironomus 154 41 576
<br />Cricotopus 19 453 0
<br />Cryptochironomus 134 206 0
<br />Cryptotendipes 58 947 346
<br />Glyptotendipes 58 988 0
<br />Lenziella 115 1112 0
<br />Microtendipes 0 1029 0
<br />Paratanytarsus 231 6505 58
<br />Polypedilum 19 2388 173
<br />Procladius 0 124 58
<br />Psectrocladius 0 41 0
<br />Tanypus 0 124 173
<br />Tanytarsus 0 206 115
<br />Zavrelia 19 0 0
<br />
<br />. .
<br />
<br />"
<br />
<br />52
<br />N=-
<br />d2x2
<br />
<br />sample (in this case 0.1), and x = the mean.
<br />For our samples d was chosen to be 0.1, for an
<br />accuracy within 10% of the mean, If, after five
<br />samples were processed, N was <5 for a spe-
<br />cific taxonomic group, no more samples were
<br />processed for that group, Those taxa for which
<br />N was >5 were counted in an additional sam-
<br />ple, The mean and variance for taxa not elimi-
<br />nated were again calculated using the addi-
<br />tional sample value(s) and above formula. This
<br />
<br />were used in the following formula to estimate
<br />the number of samples to process (Elliot
<br />1977):
<br />
<br />where N = number of samples to process, 5 =
<br />variance, d = level of accuracy desired for the
<br />
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