Kanno Y.,University of Connecticut |
Vokoun J.C.,University of Connecticut |
Beauchene M.,Bureau of Water Protection and Land Reuse
Ecological Indicators | Year: 2010
Biological indicators based on fish assemblage characteristics are used to assess stream condition worldwide. Fish-based bioassessment poses challenges in Southern New England, the USA, due to the effects of within-watershed thermal gradients on fish assemblage types, low regional species richness, and lack of minimally disturbed sites. Dual multi-metric indices (MMI) of biological condition were developed for wadeable streams based on fish assemblage characteristics sampled across watershed landscapes with varying levels of human disturbance. A coldwater MMI was developed using streams with drainage area of ≤15 km2, and a mixed-water MMI for streams with drainage areas of >15 km2. For each MMI development, candidate metrics represented by ecological classes were sequentially tested by metric range, within-year precision, correlation with stream size, responsiveness to landscape-level human disturbances, and redundancy. Resultant coldwater and mixed-water MMI were composed of 5 and 7 metrics, respectively. Stream sites tended to score similarly when the two MMI were applied to transitional sites, i.e., drainage areas of 5-40 km2. However, some sites received high scores from the mixed-water MMI and intermediate scores from the coldwater MMI. It was thus difficult to ascertain high-quality mixed-water streams from potential coldwater streams which currently support mixed-water assemblages due to ecological degradation. High-quality coldwater streams were restricted to stream sites with drainage areas ≤15 km2. The newly developed fish-based MMI will serve as a useful management tool and the dual-MMI development approach may be applicable to other regions with thermal gradients that transition from coldwater to warmwater within watersheds. © 2009 Elsevier Ltd. All rights reserved.
Barrett J.,University of Connecticut |
Rose J.M.,National Oceanic and Atmospheric Administration |
Pagach J.,Bureau of Water Protection and Land Reuse |
Pagach J.,Connecticut College |
And 2 more authors.
Ecological Indicators | Year: 2015
Numerous coastal and estuarine management programs around the world are developing strategies for climate change and priorities for climate change adaptation. A multi-state work group collaborated with scientists, researchers, resource managers and non-governmental organizations to develop a monitoring program that would provide warning of climate change impacts to the Long Island Sound estuarine and coastal ecosystems. The goal of this program was to facilitate timely management decisions and adaptation responses to climate change impacts. A novel approach is described for strategic planning that combines available regional-scale predictions and climate drivers (top down) with local monitoring information (bottom up) to identify candidate sentinels of climate change. Using this approach, 37 candidate sentinels of climate change were identified as well as a suite of core abiotic parameters that are drivers of environmental change. A process for prioritizing sentinels was developed and identified six of high priority for inclusion in pilot-scale monitoring programs. A monitoring strategy and an online sentinel data clearinghouse were developed. The work and processes presented here are meant to serve as a guide to other coastal and estuarine management programs seeking to establish a targeted monitoring program for climate change and to provide a set of "lessons learned." © 2015 Elsevier Ltd. All rights reserved.
Bellucci C.J.,Bureau of Water Protection and Land Reuse |
Becker M.,Bureau of Water Protection and Land Reuse |
Beauchene M.,Bureau of Water Protection and Land Reuse
Northeastern Naturalist | Year: 2011
Water quality programs in Connecticut and nationally have focused on restoring impaired waters, while modest attention has been allocated to healthy watersheds in the least disturbed condition. The objective of our study was to document the geographic location of least disturbed streams in Connecticut, describe the aquatic biota from these systems, and describe important environmental variables that may help explain the distribution of these biota. We used geographic information systems to select drainage basins by their natural attributes and by eliminating anthropogenic stressor variables in order to best approximate a least disturbed watershed condition in Connecticut. We then sampled the fish and macroinvertebrate communities, water chemistry, and associated GIS-derived watershed attributes to determine the variables that best described the sampled biota. We identified 30 least disturbed streams that had drainage areas <29 km 2, whose stream order ranged from 14, and that contained <4% total impervious cover in the upstream watershed. Least disturbed streams were generally located in three geographic areas of the statenorthwest Connecticut, northeast Connecticut, and the central Connecticut valleyand were absent from the southern coast of Connecticut and southwestern Connecticut. Cluster analysis and nonmetric multidimensional scaling of macroinvertebrate taxa in the Orders Ephemeroptera, Plecoptera, and Trichoptera showed 3 macroinvertebrate stream classes, with 12 significant indicator species (P < 0.05). Drainage area, water temperature, alkalinity, hardness, chloride, ammonia, total nitrogen (TN), and total phosphorus (TP) may explain some of the differences in taxa between macroinvertebrate stream classes. Cluster analysis and nonmetric multidimensional scaling of fish species also showed three fish stream classes, with 9 significant indicator species (P < 0.05). Drainage area, stratified drift, dam density, water temperature, total suspended solids, alkalinity, hardness, ammonia, TN, and TP may explain some of the differences in species between fish stream classes. Ninety percent of the least disturbed streams sampled contained Salvelinus fontinalis (Brook Trout), which can be considered a sentinel fish species for small, least disturbed streams in Connecticut.