The composition and distribution of freshwater fish in 691 Massachusetts streams (1,430 samples statewide) surveyed during 1969-1987 were documented. White sucker (Catostomus commersoni) was the most ubiquitous species, while blacknose dace (Rhinichthys atratulus) and brook trout (Salvelinus fontinalis) were the most abundantly represented. Brown trout (Salmo trutta) appear well-distributed in contrast to historical records. A classification system for wadeable-sized streams in Massachusetts was developed using exploratory, multivariate statistics to identify repeated patterns of stream structure and function, based on the relationship between measured habitat variables and stream fish species assemblages, with particular emphasis on reproducing trout populations. The ordination technique of detrended correspondence analysis provided a portrayal of stream fish species relative to their distributional pattern along environmental gradients statewide. This analysis, in correspondence with established physiographic regions and documented limits of fish species distribution, facilitated the delineation of three fish faunal regions in Massachusetts, encompassing the Berkshire-Valley, Central-Upland, and Coastal-Lowland areas of the state. Cluster analysis of stream gradient and summer water temperature measures, followed by discriminant analysis, led to the development of a six-class thermal-gradient model which effectively classified 79 percent of a test-data set, on the basis of discrimination between optimal (reproducing) trout and non-trout streams. Stratified by fish faunal region, analysis of fish-group structure within predicted stream habitat classes were investigated, relative to determinants of stream habitat degradation. Fish species assemblages in Massachusetts' smaller, wadeable streams differ along an environmental gradient from the western Berkshire highlands to the eastern Coastal seaboard. Within the limits of fish species biogeography, a similar gradient is operative within any given drainage system as well. However, this gradient is not necessarily continuous, but varies primarily in response to abiotic factors of the environment, which then serve to regulate fish species occurrence. This system for classifying streams along an environmental continuum of chemico-physical conditions, serves as an initial macrohabitat "templet" upon which to base further evaluation of environmental impacts on stream ecosystem structure and function. It will also be used to manage the Commonwealth's lotic environments by ecological resource category, leading to implementation of a statewide wild trout management program.
| Identifer | oai:union.ndltd.org:UMASS/oai:scholarworks.umass.edu:dissertations-2600 |
| Date | 01 January 1989 |
| Creators | Halliwell, David Bishop |
| Publisher | ScholarWorks@UMass Amherst |
| Source Sets | University of Massachusetts, Amherst |
| Language | English |
| Detected Language | English |
| Type | text |
| Source | Doctoral Dissertations Available from Proquest |
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