Development and analysis of a Target Fish Community model to assess the biological integrity of the Lamprey Designated River, New Hampshire, and to identify indicator fish species for a MesoHABSIM model

As part of a Protected Instream Flow (PISF) study, the Northeast Instream Habitat Program (NEIHP) and Rushing Rivers Institute conducted an assessment of instream habitat under multiple flow conditions within a Designated segment of the Lamprey River, New Hampshire. Within that study a habitat simulation model, MesoHABSIM (Parasiewicz 2001), was used to determine the relationship between instream flow conditions and habitat availability for selected fish species. The analysis entailed the use of multivariate statistics to establish physical habitat characteristics associated with habitat suitability for individual fish species (or species groups). The purpose of that analysis is to provide a means of identifying areas of suitable habitat for select fish species and to assess changes in the sizes and availability of those areas with regard to changes in stream flow conditions. As a component of that PISF study, a Target Fish Community (TFC) model was created to identify the native fluvial fish species considered as indicator species for the MesoHABSIM modeling process. Information from the TFC was used to assess the biological integrity of the Designated segment of the Lamprey River based on a comparative evaluation of the compositions of species and species groups within the TFC and the existing fish community of the Designated River. The TFC development and analysis processes consisted of multiple steps: First, a list of species expected or with the potential to occur within the study area is compiled and classified based on habitat use, and pollution and thermal regime tolerances. Next, a group of rivers (or river segments) having geomorphic and zoogeographic characteristics similar to those of the Lamprey Designated River are selected as potential references using Geographic Information System (GIS) software. This list of rivers is then filtered based on ecological condition, habitat quality, and the availability of fish collection data to remove those possessing impacted conditions or lacking adequate fish data. The remaining rivers were considered the best available reference rivers for the Lamprey River study area. Existing fish collection data from the reference rivers were subjected to a weighted-ranking procedure to calculate the composition and proportions of fish species within the TFC (Bain and Meixler 2000). Finally, the TFC model was compared to recent fish data collected within the Lamprey Designated River to assess the biological integrity of the study area based on the current condition of the existing fish community. Overall the Designated River exhibited a fish community that was highly similar to the TFC. A comparative evaluation of the two communities using the percent model affinity approach (Novak and Bode 1992) yielded a 71% affinity index value. Major differences between the two communities were illustrated by an under-abundance of cold-water species and an over-abundance of warm-water species. Additionally, minor differences were revealed by a lower proportion of fluvial specialist species and a greater proportion of macrohabitat generalist species within the existing fish community than the expected TFC proportions. The analysis suggests that the Lamprey Designated River may be affected by macrohabitat conditions conducive to supporting warm-water, macrohabitat generalist species and limiting fluvial specialist species and cold-water species. Based on the overall similarity of the existing fish community to the TFC, the biological integrity of the Designated River appears to be relatively un-impaired. However, the differences between the two communities are indicative of the effects of man-made dams and impoundments present within the Designated River. Lamprey Target Fish Community Report 21 June 2007 Page 1 of 36 Introduction Target Fish Community (TFC) models have been utilized within instream flow related studies on multiple rivers in Southern New England since Bain and Meixler’s initial development and application of the methodology on the Quinebaug River (2000). Successful applications of the approach to assess the status of native fish communities on the Quinebaug, Ipswich, Assabet, Charles, Housatonic, Pomperaug, Souhegan, and Eightmile Rivers (Bain and Meixler 2000, Lang et al. 2001, Armstrong et al. 2001, Parker et al. 2004, Meixler 2005, Kearns et al. 2005, Legros 2007a, Legros 2007b, Parasiewicz et al. 2007) have proven the effectiveness of TFC models as fish community assessment tools. These practical applications illustrate the ability of TFC models to assess the biological integrity of streams using an inference approach based on the biological requirements of fish species (or species groups) and a comparison of their compositions within a TFC and the existing fish community of a study stream (or stream segment). The increasing use and acceptance of this methodology, and similar methods, are indicative of the significance of using fish communities to assess the biological integrity of aquatic systems (Karr 1981, Fausch et al. 1990, Hughes 1995, Halliwell et al. 1999). The past success and recognized importance of the TFC approach has led to its adoption by the Commonwealth of Massachusetts and State of New Hampshire as a component of their water resources policy development processes regarding Protected Instream Flows (PISF). As a component of a PISF study commissioned by the New Hampshire Department of Environmental Services (NHDES), a TFC was developed to assess the biological integrity of the Designated segment of the Lamprey River and identify indicator fish species for a MesoHABSIM model (Parasiewicz 2001). Development of the TFC was dependent upon the use of fish data from several ecologically healthy Reference River sites that are geomorphically and zoogeographically similar to the Designated segment of the Lamprey River. Defining the model was an interactive process that required direct input from local fisheries experts to assure that the species compositions of the proposed fish community model were conducive to management objectives for the Designated River and consistent with the fish fauna expected to occur within this area. Reference River fisheries data used to calculate the TFC model were provided by various agencies and organizations. This report presents the Target Fish Community model developed for the Lamprey Designated River. The development and calculation processes are described in detail, the resulting community is given, and a comparative analysis identifying deviations between the expected (TFC) and existing fish community assemblages is illustrated and explained. Potential reasons for such deviations, related to the biological integrity of the study area, are then suggested using an inference-based approach. Inferences are attained based on similarities (or differences) in the compositions and proportions of individual fish species and species groups (with regard to habitat use, pollution tolerance and thermal regime classification guilds) between the expected and existing fish communities. The indicator fish species selected for training of the 1 Determination of the zoogeographic similarity of areas, or Ecoregions, is based on an analysis of geology, physiography, vegetation, climate, soils, land use, wildlife and hydrology (Omernik 1987). Lamprey Target Fish Community Report 21 June 2007 Page 2 of 36 MesoHABSIM model developed for the Lamprey River PISF study are identified from the TFC.