Table 4.2 Mean abundance, (standard error), and percent of total abundance for all common species at the NAV 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)
Polypedilum sp.(3.99%)                3.56(0.96)                               Gastropoda sp.(3.76%)                 5.76(4.92)                           Oligochaete sp.(29.7%)                14.04(2.85)
Procladius sp.(7.08%)                    6.32(1.21)                               Procladius sp.(3.02%)                  4.62(1.17)                           Marenzellaria virdis(62.61%)        29.6(11.79)
Oligochaete sp.(63.59%)               56.8(9.37)                               Oligochaete sp.(71.2%)                109(19.31)
Ostracoda sp.(3.4%)                      3.04(1.24)                               Tubificidae sp.(10.36%)                15.86(15.86)
Marenzellaria virdis(8.78%)          7.84(4.64)  

Taxa                        1999                        mean(stderr)        Taxa                        2000                        mean(stderr)
Coelotanypus sp.(3.47%)                           2.12(0.7)        Oligochaete sp.(8.92%)                            6.85(2.92)
Oligochaete sp.(8.34%)                             5.08(2.11)       Tubificoides heterochaetus(51.76%)    39.75(10.63)
Tubificoides heterochaetus(17.72%)    41.23(12.21)       Malacoceros vanderhorsti(6.27%)       4.8(4.8)
                                                                                                Marenzellaria virdis(21.16%)                16.25(7.67)