Compliance with Canada’s Fisheries Act: A Field Audit of Habitat Compensation Projects

Loss of fish habitat in North America has occurred at an unprecedented rate through the last century. In response, the Canadian Parliament enacted the habitat provisions of the Fisheries Act. Under these provisions, a “harmful alteration, disruption, or destruction to fish habitat” (HADD) cannot occur unless authorised by Fisheries and Oceans Canada (DFO), with legally binding compensatory habitat to offset the HADD. The guiding principle to DFO’s conservation goal is “no net loss of the productive capacity of fish habitats” (NNL). However, performance in achieving NNL has never been evaluated on a national scale. We investigated 52 habitat compensation projects across Canada to determine compliance with physical, biological, and chemical requirements of Section 35(2) Fisheries Act authorisations. Biological requirements had the lowest compliance (58%) and chemical requirements the highest (100%). Compliance with biological requirements differed among habitat categories and was poorest (19% compliance) in riparian habitats. Approximately 86% of authorisations had larger HADD and/or smaller compensation areas than authorised. The largest noncompliance in terms of habitat area occurred in riverine habitat in which HADDs were, on average, 343% larger than initially authorised. In total, 67% of compensation projects resulted in net losses of habitat area, 2% resulted in no net loss, and 31% achieved a net gain in habitat area. Interestingly, probable violations of the Fisheries Act were prevalent at half of the projects. Analyses indicated that the frequency of probable Fisheries Act violations differed among provinces. Habitat compensation to achieve NNL, as currently implemented in Canada, is at best only slowing the rate of habitat loss. In all likelihood, increasing the amount of authorised compensatory habitat in the absence of institutional changes will not reverse this trend. Improvements in monitoring and enforcement are necessary to move towards achieving Canada’s conservation goals.     

Effectiveness of Fish Habitat Compensation in Canada in Achieving No Net Loss

Fish habitat loss has been prevalent over the last century in Canada. To prevent further erosion of the resource base and ensure sustainable development, Fisheries and Oceans Canada enacted the habitat provisions of the Fisheries Act in 1976. In 1986, this was articulated by a policy that a “harmful alteration, disruption, or destruction to fish habitat” (HADD) cannot occur unless authorised with legally binding compensatory habitat to offset the HADD. Despite Canada’s progressive conservation policies, the effectiveness of compensation habitat in replicating ecosystem function has never been tested on a national scale. The effectiveness of habitat compensation projects in achieving no net loss of habitat productivity (NNL) was evaluated at 16 sites across Canada. Periphyton biomass, invertebrate density, fish biomass, and riparian vegetation density were used as indicators of habitat productivity. Approximately 63% of projects resulted in net losses in habitat productivity. These projects were characterised by mean compensation ratios (area gain:area loss) of 0.7:1. Twenty-five percent of projects achieved NNL and 12% of projects achieved a net gain in habitat productivity. These projects were characterised by mean ratios of 1.1:1 and 4.8:1, respectively. We demonstrated that artificially increasing ratios to 2:1 was not sufficient to achieve NNL for all projects. The ability to replicate ecosystem function is clearly limited. Improvements in both compensation science and institutional approaches are recommended to achieve Canada’s conservation goal.     

Understanding the Value of Local Ecological Knowledge and Practices for Habitat Restoration in Human-Altered Floodplain Systems: A Case from Bangladesh

Worldwide there is a declining trend in natural fish catch (FAO, The state of world fisheries and aquaculture. , 2002) and Bangladesh is no exception. The vast inland fisheries of Bangladesh have been declining over the years, largely a result of human alteration of the aquatic habitats arising from human interventions in the floodplain systems such as the establishment of water control structures which favor agricultural production but reduce fish habitats. It can be assumed that conventional management measures are not adequate to conserve natural fisheries and exploring alternative knowledge systems to complement existing management is warranted. This paper focuses on local ecological knowledge and several other local practices held by fishers engaging directly with floodplain ecosystems. These knowledge systems and practices may be valuable tools for understanding ecosystems processes and related changes and developing local level responses to avert negative consequences of such changes. This may help in devising alternatives to ecosystem management and the conservation of floodplain fish habitats of Bangladesh and elsewhere in the world. This study was conducted in a natural depression (locally called beel) and its surrounding floodplain system located in north central Bangladesh which has become highly degraded. The results of the study indicate that the fishers and local users of the floodplain ecosystems are rich in local ecological knowledge concerning the hydrology of the floodplains and small lakes, the habitat preferences of fish, the role of agricultural crops on fish habitats, and the impact of habitat human interventions in aquatic ecosystems. Given the apparent inadequacy of the present management regime, this article argues for an inclusion of local knowledge and practices into habitat management as a more holistic approach to floodplain habitat restoration and conservation that encourages multi-level cooperation and which builds on diversified knowledge systems.     

Spatial-Scale Effects on Relative Importance of Physical Habitat Predictors of Stream Health

A common theme in recent landscape studies is the comparison of riparian and watershed land use as predictors of stream health. The objective of this study was to compare the performance of reach-scale habitat and remotely assessed watershed-scale habitat as predictors of stream health over varying spatial extents. Stream health was measured with scores on a fish index of biotic integrity (IBI) using data from 95 stream reaches in the Eastern Corn Belt Plain (ECBP) ecoregion of Indiana. Watersheds hierarchically nested within the ecoregion were used to regroup sampling locations to represent varying spatial extents. Reach habitat was represented by metrics of a qualitative habitat evaluation index, whereas watershed variables were represented by riparian forest, geomorphology, and hydrologic indices. The importance of reach- versus watershed-scale variables was measured by multiple regression model adjusted-R² and best subset comparisons in the general linear statistical framework. Watershed models had adjusted-R² ranging from 0.25 to 0.93 and reach models had adjusted-R² ranging from 0.09 to 0.86. Better-fitting models were associated with smaller spatial extents. Watershed models explained about 15% more variation in IBI scores than reach models on average. Variety of surficial geology contributed to decline in model predictive power. Results should be interpreted bearing in mind that reach habitat was qualitatively measured and only fish assemblages were used to measure stream health. Riparian forest and length-slope (LS) factor were the most important watershed-scale variables and mostly positively correlated with IBI scores, whereas substrate and riffle-pool quality were the important reach-scale variables in the ECBP.     

Flow‐Biology Relationships Based on Fish Habitat Guilds in North Carolina

The health of freshwater biota is dependent on streamflow, yet identification of the flow regimes required to maintain ecological integrity remains challenging to states in the United States seeking to establish ecological flows. We tested the relationship between decreases in streamflow and Shannon‐Weaver diversity index of fish species for four flow‐based habitat guilds: riffle, riffle‐run, pool‐run, and pool in North Carolina. We found species that prefer shallow habitats, such as riffles and riffle‐runs were the most sensitive to decreases in streamflow; whereas no significant relationships were found for pool or pool‐run species. The sensitivity to decreases in streamflow was greatest during summer and fall, when streams are naturally lower. When all fish habitat guilds were included in the assessment of flow‐biology relationships, there were no significant relationships to decreases in streamflow. As the sensitivity of fish to reductions in streamflow is not constant across habitat guilds, combining all fish species together for flow‐biology analyses may greatly underestimate the response of fish species to decreases in flow and should be acknowledged when establishing ecological flows.     

FORUM: Restoration of Stream Habitats in the Western United States: Restoration as Reexpression of Habitat Capacity

/ Ecological restoration is increasingly invoked as a tool for the maintenance and regeneration of biodiversity. Yet the conceptual foundations and assumptions underlying many restoration management activities are frequently unclear or unstated. Unforeseen, undesirable consequences of restoration activities may emerge as a result. A general conceptual framework for restoration is needed to better accommodate dynamic habitat systems and evolving biota in restoration strategies. A preliminary framework for stream habitat restoration emphasizing stream habitat-biota development is proposed. As developing systems, streams and stream biota exhibit temporal behaviors that change with stream environments. Underlying the dynamic development of streams is potential capacity. Streams express this capacity as an array of habitats over time and across the landscape. Human land uses in the western United States have rapidly altered aquatic habitats and the processes that shape habitat. As a result, the diversity of native fishes and their habitats has been suppressed. Restoration is fundamentally about allowing stream systems to reexpress their capacities. Several steps are provided to guide stream restoration activities. Key tasks include: identification of the historic patterns of habitat development; identification of developmental constraints; relief of those constraints; classification of sensitive, critical, or refuge habitats; protection of the developmental diversity that remains; and monitoring of biotic responses to habitat development. KEY WORDS: Stream habitat; Stream biota; System capacity; System development; Restoration; Classification     

A Review of Habitat Connectivity Research for Pacific Salmon in Marine,Estuary, and Freshwater Environments

Long‐term conservation planning for diadromous fishes would benefit from a better understanding of both the role of connectivity among environments and habitat variability in the expression of life‐history diversity. Most of the scientific knowledge on habitat fragmentation and connectivity has been developed in terrestrial systems in the discipline of landscape ecology. Research on habitat connectivity in aquatic systems (e.g., salmonid research that spans the spectrum of habitats from freshwater to the sea) is uncommon and largely focused on barriers to fish passage. Here, we present a review of the literature characterizing current research patterns on habitat connectivity within and among environments for Pacific salmon. We found this topic is still incipient: the literature is dominated by studies of freshwaters, with few articles focusing on habitat needs in estuary and marine systems. Pan‐environment studies are rare, pointing to a gap in our understanding of complex habitat relationships that might be significant in the development of long‐term conservation and restoration plans for Pacific salmon, particularly in light of the potential impact of climate change.     

Habitat Assessment of Non-Wadeable Rivers in Michigan

Habitat evaluation of wadeable streams based on accepted protocols provides a rapid and widely used adjunct to biological assessment. However, little effort has been devoted to habitat evaluation in non-wadeable rivers, where it is likely that protocols will differ and field logistics will be more challenging. We developed and tested a non-wadeable habitat index (NWHI) for rivers of Michigan, where non-wadeable rivers were defined as those of order ≥5, drainage area ≥1600 km², mainstem lengths ≥100 km, and mean annual discharge ≥15 m³/s. This identified 22 candidate rivers that ranged in length from 103 to 825 km and in drainage area from 1620 to 16,860 km². We measured 171 individual habitat variables over 2-km reaches at 35 locations on 14 rivers during 2000–2002, where mean wetted width was found to range from 32 to 185 m and mean thalweg depth from 0.8 to 8.3 m. We used correlation and principal components analysis to reduce the number of variables, and examined the spatial pattern of retained variables to exclude any that appeared to reflect spatial location rather than reach condition, resulting in 12 variables to be considered in the habitat index. The proposed NWHI included seven variables: riparian width, large woody debris, aquatic vegetation, bottom deposition, bank stability, thalweg substrate, and off-channel habitat. These variables were included because of their statistical association with independently derived measures of human disturbance in the riparian zone and the catchment, and because they are considered important in other habitat protocols or to the ecology of large rivers. Five variables were excluded because they were primarily related to river size rather than anthropogenic disturbance. This index correlated strongly with indices of disturbance based on the riparian (adjusted R² = 0.62) and the catchment (adjusted R² = 0.50), and distinguished the 35 river reaches into the categories of poor (2), fair (19), good (13), and excellent (1). Habitat variables retained in the NWHI differ from several used in wadeable streams, and place greater emphasis on known characteristic features of larger rivers.     

Critical Factors and Evaluation Criteria for Habitat Translocation

Habitat translocation is the process of moving soils or substrates with their vegetation and any animals that remain associated with them in order to rescue or salvage habitats that would be lost due to changes in land use, or to restore biodiversity to damaged, degraded or newly created sites. Critical factors are similarity in the environmental context of the donor and receptor sites, the translocation technique, and habitat management of the translocated habitat. These critical factors should be taken into account in such a way that the risk of unwanted changes to a habitat due to translocation is reduced to a level that takes account of its nature conservation value. Long-term habitat management and monitoring schemes need to be implemented fully to obtain the biodiversity benefits of translocation. Evaluation of the degree of success or failure against the original aims of the translocation project over a defined period of time requires objective criteria and repeatable measurements that can be confirmed independently of the project team. Codes of best practice covering guidelines and standards for habitat translocation are required which will benefit both business and industry and the planning and regulatory authorities.     

Morphodynamic Effects on the Habitat of Juvenile Cyprinids (<Emphasis Type="Italic">Chondrostoma nasus</Emphasis>) in a Restored Austrian Lowland River

At the Sulm River, an Austrian lowland river, an ecologically orientated flood protection project was carried out from 1998-2000. Habitat modeling over a subsequent 3-year monitoring program (2001-2003) helped assess the effects of river bed embankment and of initiating a new meander by constructing a side channel and allowing self-developing side erosion. Hydrodynamic and physical habitat models were combined with fish-ecological methods. The results show a strong influence of riverbed dynamics on the habitat quality and quantity for the juvenile age classes (0+, 1+, 2+) of nase (Chondrostoma nasus), a key fish species of the Sulm River. The morphological conditions modified by floods changed significantly and decreased the amount of weighted usable areas. The primary factor was river bed aggradation, especially along the inner bend of the meander. This was a consequence of the reduced sediment transport capacity due to channel widening in the modeling area. The higher flow velocities and shallower depths, combined with the steeper bank angle, reduced the Weighted Useable Areas (WUAs) of habitats for juvenile nase. The modeling results were evaluated by combining results of mesohabitat-fishing surveys and habitat quality assessments. Both, the modeling and the fishing results demonstrated a reduced suitability of the habitats after the morphological modifications, but the situation was still improved compared to the pre-restoration conditions at the Sulm River.     

The need for constructing endangered fish habitats that conform to climate-driven flow changes in a western U.S. river

Warmwater fish habitat in the San Juan River of the southwestern United States has been reduced by over 30% as a result of water depletion, reservoir inundation, and cold-water dam releases combined with drought-related changes in hydrology. This reduction and a suite of other factors have contributed to declines in native fish populations including the federally endangered Colorado Pikeminnow (Ptychocheilus lucius) and Razorback Sucker (Xyrauchen texanus). Conservation efforts for these species include determining flow needs; protecting, managing, and augmenting habitats; and stocking hatchery fish. But the young of stocked fish have low survival due largely to a paucity of nursery habitat not being reformed and maintained under current conditions. Flow recommendations for Navajo Dam releases designed to mimic the river's natural hydrograph have not been met due to water shortages, and the desired outcomes of increased channel complexity and enhanced fish habitat have not been observed. Forecasted hydrology that includes ongoing drought shows that achieving the flow targets through further dam reoperations is unlikely. Mechanical construction of early life-stage habitats is a highly recommended complement to flow management for offsetting the effects of flow reduction and habitat loss. Habitats with features that are effective and resilient under a range of flows are important in counterbalancing the effects of climate change.     

Bottomfast Ice Mapping and the Measurement of Ice Thickness on Tundra Lakes Using C‐Band Synthetic Aperture Radar Remote Sensing1

Abstract: Industrial activity in Canada’s north is increasing, placing demands on the use of water from lakes to build ice roads. Winter water withdrawal from these lakes has the potential to impact overwintering fish. Removal of water from small lakes can decrease oxygen and habitat available to fish. To address this issue, a protocol has been developed by the Department of Fisheries and Oceans outlining water withdrawal thresholds. Bathymetric surveys are the traditional method to determine lake depth, but are costly given the remoteness of northern lakes. This paper investigates the use of satellite C‐band synthetic aperture radar (SAR) remote sensing technology as a potential alternative or complement to traditional survey methods. Previous research has shown that a SAR can detect the transition from grounded to floating ice on lakes, or if a lake is completely frozen. Grounded ice has a dark signature while floating ice appears very bright in contrast. Similar results were observed for the datasets acquired in the study area. This suggests that lakes that freeze completely to the bottom can be identified using SAR. Such water bodies would not be viable fish overwintering habitat and can therefore be used as water sources without thresholds necessary. However, attempts to accurately calculate the depth of the ice at the grounded‐floating ice boundary using bathymetric profiles acquired in the summer and lake ice thickness measurements from a reference lake near Inuvik proved to be unreliable.     

Impacts to Water Quality and Fish Habitat Associated with Maintaining Natural Channels for Flood Control

A field investigation conducted on Boulder Creek in Boulder, Colorado evaluated impacts of flood control maintenance activities on flood conveyance, water quality, and fish habitat. Thirty-nine transects were monitored at one control site and two maintenance sites over a period of eight months. Each site was visited on more than 50 occasions in order to characterize pre- and post-maintenance conditions, and to monitor maintenance activities. Measurements along the transects included substrate composition, flow depth, velocity, and elevation. Reach-average values were assigned to variables such as in-stream vegetation, streambank stability, and woody vegetation before and after maintenance. Water temperature, dissolved oxygen, pH, specific conductance, and turbidity were sampled, and habitat suitability indices were developed pre- and post-maintenance for seven indicator fish species. Water quality impacts during maintenance consisted of high turbidity levels (> 400 NTU), which returned to background levels (0.1–15 NTU) overnight, as well as changes in mean temperature and pH. Alteration of physical channel characteristics as a result of maintenance had limited effects on habitat quality for four of seven fish species, but caused improvements in habitat quality for three fish species. The main implications of this study for floodplain management are that: (1) Flood control maintenance practices can be in direct conflict with water quality and fish habitat objectives, and should be carefully designed and implemented by an interdisciplinary team. (2) Physical habitat for some fish species can be improved as well as reduced by maintenance activities. Habitat suitability curves may be useful tools for evaluating limiting factors of the habitat and for identifying opportunities for habitat improvements as part of maintenance.     

Effects of Bioengineered Streambank Stabilization on Bank Habitat and Macroinvertebrates in Urban Streams

Non-structural streambank stabilization, or bioengineering, is a common stream restoration practice used to slow streambank erosion, but its ecological effects have rarely been assessed. We surveyed bank habitat and sampled bank macroinvertebrates at four bioengineered sites, an unrestored site, and a comparatively less-impacted reference site in the urban Peachtree-Nancy Creek catchment in Atlanta, GA, USA. The amount of organic bank habitat (wood and roots) was much higher at the reference site and three of the bioengineered sites than at the unrestored site or the other bioengineered site, where a very different bioengineering technique was used (“joint planting”). At all sites, we saw a high abundance of pollution-tolerant taxa, especially chironomids and oligochaetes, and a low richness and diversity of the bank macroinvertebrate community. Total biomass, insect biomass, and non-chironomid insect biomass were highest at the reference site and two of the bioengineered sites (p < 0.05). Higher biomass and abundance were found on organic habitats (wood and roots) versus inorganic habitats (mud, sand, and rock) across all sites. Percent organic bank habitat at each site proved to be strongly positively correlated with many factors, including taxon richness, total biomass, and shredder biomass. These results suggest that bioengineered bank stabilization can have positive effects on bank habitat and macroinvertebrate communities in urban streams, but it cannot completely mitigate the impacts of urbanization.     

Marine Habitat Classification for Ecosystem-Based Management: A Proposed Hierarchical Framework

Creating a habitat classification and mapping system for marine and coastal ecosystems is a daunting challenge due to the complex array of habitats that shift on various spatial and temporal scales. To meet this challenge, several countries have, or are developing, national classification systems and mapping protocols for marine habitats. To be effectively applied by scientists and managers it is essential that classification systems be comprehensive and incorporate pertinent physical, geological, biological, and anthropogenic habitat characteristics. Current systems tend to provide over-simplified conceptual structures that do not capture biological habitat complexity, marginalize anthropogenic features, and remain largely untested at finer scales. We propose a multi-scale hierarchical framework with a particular focus on finer scale habitat classification levels and conceptual schematics to guide habitat studies and management decisions. A case study using published data is included to compare the proposed framework with existing schemes. The example demonstrates how the proposed framework’s inclusion of user-defined variables, a combined top-down and bottom-up approach, and multi-scale hierarchical organization can facilitate examination of marine habitats and inform management decisions.     

Habitat evaluation of wild Amur tiger (Panthera tigris altaica) and conservation priority setting in north-eastern China

The Amur Tiger (Panthera tigris altaica) is one of the world’s most endangered species. Recently, habitat fragmentation, food scarcity and human hunting have drastically reduced the population size and distribution areas of Amur tigers in the wild, leaving them on the verge of extinction. Presently, they are only found in the north-eastern part of China. In this study, we developed a reference framework using methods and technologies of analytic hierarchy process (AHP), remote sensing (RS), geographic information system (GIS), GAP analysis and Natural Break (Jenks) classification to evaluate the habitat and to set the conservation priorities for Amur tigers in eastern areas of Heilongjiang and Jilin Provinces of northeast China. We proposed a Habitat Suitability Index (HSI) incorporating 7 factors covering natural conditions and human disturbance. Based on the HSI values, the suitability was classified into five levels from the most to not suitable. Finally, according to results of GAP analysis, we identified six conservation priorities and designed a conservation landscape incorporating four new nature reserves, enlarging two existing ones, and creating four linkages for Amur tigers in northeast China. The case study showed that the core habitats (the most suitable and highly suitable habitats) identified for Amur tigers covered 35,547 km², accounting for approximately 26.71% of the total study area (1,33,093 km²). However, existing nature reserves protected only (7124 km² or) 20.04% of the identified core habitats. Thus, enlargement of current reserves is necessary and urgent for the tiger’s conservation and restoration. Moreover, the establishment of wildlife corridors linking core habitats will provide an efficient reserve network for tiger conservation to maintain the evolutionary potential of Amur tigers facing environmental changes.     

Effects of Flooding and Tamarisk Removal on Habitat for Sensitive Fish Species in the San Rafael River,Utah: Implications for Fish Habitat Enhancement and Future Restoration Efforts

Tamarisk removal is a widespread restoration practice on rivers in the southwestern USA, but impacts of removal on fish habitat have rarely been investigated. We examined whether tamarisk removal, in combination with a large spring flood, had the potential to improve fish habitat on the San Rafael River in southeastern Utah. We quantified habitat complexity and the distribution of wood accumulation in a tamarisk removal site (treated) and a non-removal site (untreated) in 2010, 1 year prior to a large magnitude and long-duration spring flood. We used aerial imagery to analyze river changes in the treated and untreated sites. Areas of channel movement were significantly larger in the treated site compared to the untreated site, primarily because of geomorphic characteristics of the channel, including higher sinuosity and the presence of an ephemeral tributary. However, results suggest that tamarisk removal on the outside of meander bends, where it grows directly on the channel margins, can promote increased channel movement. Prior to the flood, wood accumulations were concentrated in sections of channel where tamarisk had been removed. Pools, riffles, and backwaters occurred more frequently within 30 m upstream and downstream of wood accumulations compared to areas within 30 m of random points. Pools associated with wood accumulations were also significantly larger and deeper than those associated with random points. These results suggest that the combination of tamarisk removal and wood input can increase the potential for channel movement during spring floods thereby diversifying river habitat and improving conditions for native fish.     

Assessing and Prioritizing Ecological Communities for Monitoring in a Regional Habitat Conservation Plan

In nature reserves and habitat conservation areas, monitoring is required to determine if reserves are meeting their goals for preserving species, ecological communities, and ecosystems. Increasingly, reserves are established to protect multiple species and communities, each with their own conservation goals and objectives. As resources are always inadequate to monitor all components, criteria must be applied to prioritize both species and communities for monitoring and management. While methods for prioritizing species based on endangerment or risk have been established, approaches to prioritizing ecological communities for monitoring are not well developed, despite a long-standing emphasis on communities as target elements in reserve design. We established guidelines based on four criteria derived from basic principles of conservation and landscape ecology--extent, representativeness, fragmentation, and endangerment--to prioritize communities in the San Diego Multiple Species Conservation Plan (MSCP). The MSCP was one of the first multiple-species habitat conservation areas established in California, USA, and it has a complex spatial configuration because of the patterns of surrounding land use, which are largely urbanized. In this case study, high priority communities for monitoring include coastal sage scrub (high endangerment, underrepresented within the reserve relative to the region, and moderately fragmented), freshwater wetlands, and coastal habitats (both have high fragmentation, moderate endangerment and representativeness, and low areal extent). This framework may be useful to other conservation planners and land managers for prioritizing the most significant and at-risk communities for monitoring.     

Spectrally Driven Classification of High Spatial Resolution,Hyperspectral Imagery: A Tool for Mapping In-Stream Habitat

Streams represent an essential component of functional ecosystems and serve as sensitive indicators of disturbance. Accurate mapping and monitoring of these features is therefore critical, and this study explored the potential to characterize aquatic habitat with remotely sensed data. High spatial resolution, hyperspectral imagery of the Lamar River, Wyoming, USA, was used to examine the relationship between spectrally defined classes and field-mapped habitats. Advantages of this approach included enhanced depiction of fine-scale heterogeneity and improved portrayal of gradational zones between adjacent features. Certain habitat types delineated in the field were strongly associated with specific image classes, but most included areas of diverse spectral character; spatially buffering the field map polygons strengthened this association. Canonical discriminant analysis (CDA) indicated that the ratio of the variability among groups to that within a group was an order of magnitude greater for spectrally defined image classes (20.84) than for field-mapped habitat types (1.82), suggesting that unsupervised image classification might more effectively categorize the fluvial environment. CDA results also suggested that shortwave-infrared wavelengths were valuable for distinguishing various in-stream habitats. Although hyperspectral stream classification seemed capable of identifying more features than previously recognized, the technique also suggested that the intrinsic complexity of the Lamar River would preclude its subdivision into a discrete number of classes. Establishing physically based linkages between observed spectral patterns and ecologically relevant channel characteristics will require additional research, but hyperspectral stream classification could provide novel insight into fluvial systems while emerging as a potentially powerful tool for resource management.