Table 4.1  Mean abundance, (standard error), and percent of total abundance for all common species at the NCF6 station, by year.  Common taxa are defined as those species comprising 3% or more of the total abundance at a station on any given year.  Percent abundance is given in parentheses.

Taxa                                        1996                mean (stderr)                   Taxa                        1997                mean (stderr)                   Taxa                        1998                mean (stderr)
Amphipod sp.(3.13%)                              0.44(0.3)                                Bivalvia sp.(9.96%)                     1.02(0.31)                           Chironomid sp.(6.90%)                0.52(0.42)
Gammarus mucronatus(3.6%)                 0.52(0.28)                              Oligochaete sp.(22.88%)            2.38(0.98)                           Polypedilum sp.(12.32%)             0.93(0.43)
Gammarus palustris(8.24%)                    1.16(0.71)                               Marenzellaria virdis(36.53%)     3.81(1.33)                           Procladius sp.(3.45%)                  0.26(0.19)
Chironomid sp.(15.34%)                          2.16(1.25)                                                                                                                                 Oligochaete sp.(17.73%)              1.33(0.7)
Polypedilum sp.(10.23%)                        1.44(1.10)                                                                                                                                  Marenzellaria virdis(17.24%)       1.3(0.59)
Procladius sp.(9.38%)                             1.32(0.54)                                                                                                                                 Polydora socialis(12.32%)           0.93(0.43)
Cyathura sp.(5.11%)                                 0.72(0.29)                                                                                                                                Spio pettiboneae(6.4%)                0.48(0.48)
Oligochaete sp.(13.64%)                         1.92(0.52)
Marenzellaria virdis(11.65%)                  1.64(0.99)
Tanaidacea sp.(3.13)                                0.44(0.25)

 
Taxa                                        1999                mean (stderr)                   Taxa                        2000                mean (stderr)
Gastropoda sp.(4.61%)                             2.36(1.14)                             Gastropoda sp.(11.0%)                   1.8(0.89)
Insect pupa(12.32)                                     1.6(0.95)                               Hydrobia sp.(4.59%)                       0.75(0.45)
Oligochaete sp.(3.44%)                             1.76(0.74)                             Cladotanytarsus sp.(22.63)            3.7(1.96)
Boccardiella sp A(47.54%)                       24.32(23.87)                         Coelotanypus sp.(3.06%)               0.5(0.4)
Polydora socialis(16.81%)                        8.6(7.55)                               Polypedilum sp.(10.4%)                  1.7(0.56)
Polydora sp.(3.83%)                                  1.96(1.56)                             Oligochaete sp.(3.67%)                   0.6(0.34)
                                                                                                                   Tubificidae sp.(5.5%)                      0.9(0.44)
                                                                                                                   Marenzellaria virdis(6.12%)            1.0(0.43)