Simplification of natural habitats is a growing global concern demanding that ecologists better understand how habitat heterogeneity influences the structure and functioning of ecosystems. While there is extensive evidence that physical habitat heterogeneity affects the structure of biotic communities (i.e., organismal abundance, distribution, diversity, etc.), ecologists know little about how ...

The critical domain size problem determines the size of the region of habitat needed to ensure population persistence. In this paper we address the critical domain size problem for seasonally fluctuating stream environments and determine how large a reach of suitable stream habitat is needed to ensure population persistence of a stream-dwelling species. Two key factors, not typically found in c...

Patterns of habitat use by fish assemblages in two chalk streams in southern England were examined to identify species preferences with respect to major habitat gradients. Both study sites, although differing in some physical habitat characteristics, mainly channel width, water temperature and instream cover, could be arranged similarly along a continuum extending from erosional to depositional...

Terminal restriction fragment length polymorphism and 16S rRNA gene sequencing were used to explore the community composition of bacterial communities in biofilms on sediments (epipssamon) and rocks (epilithon) in stream reaches that drain watersheds with contrasting lithologies in the Noatak National Preserve, Alaska. Bacterial community composition varied primarily by stream habitat and secon...

The fish assemblage structure was analyzed in the streams of Kumaon Himalaya of Uttarkhand State, India. Seven sites were sampled by using different fishing gears during Jan, 2007 to December 2008. The physical features like stream habitat, stream classifications, fish assemblage at different sites, habitat preference and riparian vegetations were registered for each site. In the present invest...

Stream-dwelling species in the U.S. southern Appalachian Mountains region are particularly vulnerable to climate change and acidification. The objectives of this study were to quantify the spatial extent of contemporary suitable habitat for acid- and thermally sensitive aquatic species and to forecast future habitat loss resulting from expected temperature increases on national forest lands in ...

A fish survey in 35 stream reaches (from 1st to 3rd order) with physicochemical and habitat assessment in the São José dos Dourados system, southeastern Brazil, was conducted. Most of the basin land cover (77.4%) is used for pasture. From the sampled stream reaches, 24 were of good physicochemical quality, 10 of fair quality, and only one of poor quality. A habitat assessment showed that 10 str...

In order to minimize the impacts on fish of human activities such as logging, agriculture, and urbanization, managers must understand and be able to accurately monitor how these activities affect fish habitat. Specifically, it is necessary to understand what habitat factors are affected, what habitat factors are limiting to fish abundance, how these factors interact with each other and which ar...

—We describe and demonstrate the Unit Characteristic Method (UCM) as a means by which measurements of habitat from typical stream surveys can be used to estimate the capacity of a stream to rear juvenile steelhead Oncorhynchus mykiss. Channel unit features of importance include surface area by unit type, depth, substrate, and cover. The influence of a stream’s primary productivity is represente...

—Stream restoration has accelerated in the Midwestern United States during the past decade, but the effects of restoration on stream biota are rarely evaluated. From 1997 to 2000, we studied the responses in fish communities to the attempted restoration of two channelized streams (Juday Creek and Potato Creek) in northwestern Indiana, each of which received two new meanders to a 1-km reach of s...