Application and Testing of Bioassessment Protocols on Lakes in New Jersey - 1998
Creators: name: McIntyre, Dennis
name: Tholen, Dan
name: McNew, Don
name: Lewis, Phil
name: Kurtenbach, Jim
Publisher: name: No Publisher Supplied
Year: 1998

description: The overall objective for this work assignment was to develop biological criteria for New Jersey lakes using macroinvertebrate data collected from the sublittoral zone of 72 New Jersey lakes. Other tasks included the analysis of sediment grain size from samples collected from the 72 lakes, identification of the benthic macroinvertebrates collected from the sublittoral zone of the 72 lakes, the identification of the benthic macroinvertebrates collected from the littoral zorie of the 72 lakes, and the identification of the sedimented diatoms collected from the 72 lakes. The development of the multi-metric index described in this report used only the macroinvertebrate data collected from the sublittoral zone. The macroinvertebrate data from the littoral zone and the sedimented diatom data were not available at the time of the index development. These data may be considered for use in a multi-assemblage index for the New Jersey lakes.An initial step in the development of a multi-metric index was to select a classification system that explains the variability in the community data. A physiographic classification system was not usee! because the majority of the reference lakes in the study were located in two of the four regions (the Valley and Ridge region and the New Jersey Highland region). An examination of the macroinvertebrate data by non-metric multidimensional scaling (NMOS) did not reveal any distinct groupings of lakes. The evaluation of a classification system focused on three environmental variables, sediment size, lake size and conductivity, uf which different analytical procedures such as NMDS, rank correlation, nonparametric analysis of variance and two factor analysis of variance (using tr;msformed data) produced somewhat different results. The results of the NMDS, rank correlation and nonparametric ANOVA analyses of the reference lakes indicated lake size is best suited for a classification system to explain the differences in the sublittoral macroinvertebrate community followed by percent sand and conductivity. The results of the two factor ANOV A indicated that sediment size (percent sand) also explained the variability in the macroinvertebrate data and it showed a significant differences between the reference and potentially impaired lakes. Metrics were selected for both the lake size and sediment size classification systems. The same six core metrics were selected for both systems from a list of 12 candidate metrics based on the ANOV A results and visual inspection of the box and whisker plots. The primary evaluation criterion for selection was a metrics ability it detect impairment. Four of the six core metrics were related to the two dominant groups found in the New Jersey lakes, oligochaetes and dipterans. A scoring system was proposed based on the six core metrics for a two class sediment size classification, sandy lakes and muck lakes and for a two class lake size classification, large lakes and small lakes. The sediment size classification was the recommended system because it relates directly to the sublittoral habitat to which the macroinvertebrates were collected from. From an ecological perspective, it would follow that the structure and function of the sublittoral macroinvertebrate community would be closely associated with the characteristics of the sediment.