Fish Habitat Assessment Research Articles

Physical habitat modeling for river macroinvertebrate communities

Habitat models rarely consider macroinvertebrate communities as ecological targets in rivers. Available approaches mainly focus on single macroinvertebrate species, not addressing the ecological needs and functionality of the whole community.This research aimed at providing an approach to model the habitat of the macroinvertebrate communities. The study was carried out in three rivers, located in Italy and characterized by a braiding morphology, gravel riverbeds, and low flows during the summer period. The approach is based on the recently developed Flow-T index, together with a Random Forest (RF) regression, which is employed to apply the Flow-T index at the mesohabitat scale. Using different datasets gathered from field data collection and 2D hydrodynamic simulations, the model was calibrated in the Trebbia River (2019 field campaign) and validated in the Trebbia, Taro, and Enza rivers (2020 field campaign).The RF model selected 12 mesohabitat descriptors as important for the macroinvertebrate community. These descriptors belong to different frequency classes of water depth, flow velocity, substrate grain size, and connectivity to the main river channel. The cross-validation R2 coefficient (R2cv) of the training dataset was 0.71, whereas the R2 coefficient (R2test) for the validation dataset was 0.63. The agreement between the simulated results and the experimental data shows sufficient accuracy and reliability. The outcomes of the study reveal that the model can identify the ecological response of the macroinvertebrate community to possible flow regime alterations and river morphological modifications.Lastly, the proposed approach allowed to extend the MesoHABSIM methodology, widely used for the fish habitat assessment, to a different ecological target community. Further applications of the approach can be related to ecological flows design in both perennial and non-perennial rivers, including river reaches in which fish fauna is absent.

An improved 3D fish habitat assessment model based on the graph theory algorithm

With the economic development, social progress and the increase in power demand, the number of water conservancy projects has gradually increased. However, the reservoir dams inevitably lead to changes in the river connectivity and hydraulic characteristics of rivers, causing damage to fish habitats. Regulating the operation of dams to supplement the ecological flow required by fish is usually an effective way to protect river fish habitats. Based on the graph theory algorithm, we proposed an improved three-dimensional habitat model that comprehensively considered the quantity and quality of fish habitat and used it to the effect assessment of water conservancy project construction on fish habitat. The fish habitat quality evaluation indicators in this paper mainly emphasized the pivotal role of core habitat patches and the connectivity between habitat patches, namely, habitat importance index (HII) and habitat connectivity index (HCI). Then, the model was combined with the Instream Flow Incremental Methodology (IFIM) and applied to the habitat assessment of Schizothorax prenanti (S. prenanti) in the Anshunchang reach of the Dadu River. The results showed that the change trend of the habitat index curves of different water depths showed a trend of first increasing and then decreasing, but the inflection points of the curves and the habitat indexes of different water depths were different. Taking into account the bottom living habits of target fish, the most suitable flow range for S. prenanti was from 271.7 m3/s to 489.1 m3/s. Compared with previous studies, the improved three-dimensional habitat model effectively avoids simulation errors caused by ignoring habitat quality and differences in fish habits.

Suitability Assessment of Fish Habitat in a Data-Scarce River

Assessing fish habitat suitability in a data-scarce tidal river is often challenging due to the absence of continuous water quantity and quality records. This study is comprised of an intensive field study on a 42 km reach which recorded bathymetry and physical water quality parameters (pH, electroconductivity, dissolved oxygen, and total dissolved solids) testing and corresponding water levels and velocity. Frequent water sampling was carried out on 17 out of 90 locations for laboratory water quality tests. Based on this, an interpolation technique, i.e., Inverse Distance Weighted (IDW), generates a map in a Geographic Information System (GIS) environment using ArcGIS software to determine the river water quality parameters. Additionally, a hydrodynamic model study was conducted to simulate hydraulic parameters using Delft3D software followed by a water quality distribution. During validation, the Delft3D-simulated water quality could reasonably mimic most field data, and GIS featured dissolved oxygen. The overall water quality distribution showed a lower dissolved oxygen level (~3 mg/L) in the industrial zone compared to the other two zones during the study period. On the other hand, these validated hydraulic properties were applied in the Physical Habitat Simulation Model (PHABSIM) set up to conduct the hydraulic habitat suitability for Labeo rohita (Rohu fish). Thus, the validated model could represent the details of habitat suitability in the studied river for future decision support systems, and this study envisaged applying it to other similar rivers.

Does drifting passage need to be linked to fish habitat assessment? Assessing environmental flow for multiple fish species with different spawning patterns with a framework integrating habitat connectivity

The use of environmental flow (e-flow) regimes has been widely implemented to improve fish habitat quality in river restoration efforts. However, e-flow designs focusing only on one key life stage (e.g., spawning) without considering potential bottlenecks in other stages (e.g., hatching) can result in little to no improvement, especially when targeting the restoration of fish with drifting eggs. Few e-flow assessments are available that closely link the spatial–temporal dependence of the hydrodynamic effect of drifting eggs on hatching habitats. Moreover, an understanding of how to allocate e-flows to achieve the best possible outcomes for biological diversity conservation is still lacking. In this study, a new framework was developed to assess e-flows, aiming to satisfy the requirements of multiple fish species with different spawning patterns concerning streamflow requirements during spawning and hatching periods. In this framework, the final weighted usable area (FWUA) was proposed by linking the spawning demand to the hydrodynamic effect of drifting eggs to assess habitat quality for fish that produce drifting eggs, and water temperature was used to guide when and how to shift from fixed to moving protection targets in allocating e-flows. Here, we used the Xiangjiaba Reservoir, located in the lower Jinsha River, as a case study to design e-flows for the conservation of multiple fish species with different spawning patterns, which was beneficial for increasing the probability of restoration success. By testing scenarios with an absence of drifting passage, the ecological base flow considering only spawning habitat appears to be lower than that considering both quality of spawning habitat and hatching passage. The ecological benefits (FWUA) generated from the ecological base flow identified by traditional models represent only 64.91% of our framework and are thus anticipated to have cascading deviant effects on ecological patterns and processes in riverine ecosystems. This underlying difference in FWUA generated due to different ecological base flows determined from traditional models and our framework, however, has been overshadowed in previous research. We highlight that the highest fish population density recovery potential will be reached at only certain ratios for both sets of habitat benefits. This work provides a tool that can help managers evaluate e-flows and compare different river restoration scenarios to protect degraded rivers or develop strategies to build resilience to climate change.

Can the Morphological Quality Index (MQI) be used to determine the ecological status of lowland rivers?

Stream assessment indices have become increasingly important in quantifying the overall status of river networks to define specific targets for restoration initiatives. Such an assessment is particularly needed in degraded environments, such as agricultural streams. Some of these evaluation tools, for instance the Qualitative Habitat Evaluation Index (QHEI), are resource intensive because they are field based. Indices that are less dependent on detailed field observations, such as the Morphological Quality Index (MQI), can provide a greater spatial coverage at a lower cost. The objectives of this study are to (1) verify whether a river's morphological quality, quantified using the MQI, can predict the fish habitat quality of a stream determined with the QHEI for eastern Canadian lowland streams, (2) compare the morphological quality, estimated solely from remotely sensed data (RMQI), to the standard MQI, (3) test whether a modified MQI (MMQI) is more appropriate than the original index for the eastern Canadian landscape when comparing with the QHEI fish habitat assessment, and (4) considering the near absence of dams in lowland eastern Canadian streams, compare an MQI where dam-related indicators are optional (MQI-OD) with the QHEI. The hydrogeomorphological and ecological conditions of 118 stream reaches, including 97 in agricultural areas, were assessed across Quebec and southern Ontario using the MQI and QHEI. Each stream was initially evaluated using remotely sensed data: 1-m LiDAR (Quebec) and 5-m DEMs (Ontario), historical aerial photography (1964–2010), and orthophotos. Field assessments were conducted to validate fish habitat and morphological data for both indices. A strong correlation was observed at the reach scale between the MQI and QHEI (r = 0.81) and MQI and RMQI (r = 0.95). Both modified MQI (MMQI and MQI-OD) showed stronger correlation than the standard MQI with the QHEI (r = 0.87), likely because the standard MQI slightly overestimates the current quality status at the habitat scale in the case of small agricultural catchments where main pressures are not always represented by artificial structures. However, because the standard MQI performs generally well in the study area, we suggest using it to ensure consistency and facilitate comparison with other regions. The results from this study demonstrate that the MQI can be used to provide an assessment of ecological (fish habitat) quality. In addition, our results indicate that a remote hydrogeomorphological assessment can be conducted to estimate the overall status of stream networks.

Great Lakes coastal fish habitat classification and assessment

Abstract Basin-scale assessment of fish habitat in Great Lakes coastal ecosystems would increase our ability to prioritize fish habitat management and restoration actions. As a first step in this direction, we identified key habitat factors associated with highest probability of occurrence for several societally and ecologically important coastal fish species as well as community metrics, using data from the Great Lakes Aquatic Habitat Framework (GLAHF), Great Lakes Environmental Indicators (GLEI) and Coastal Wetland Monitoring Program (CWMP). Secondly, we assessed whether species-specific habitat was threatened by watershed-level anthropogenic stressors. In the southern Great Lakes, key habitat factors for determining presence/absence of several species of coastal fish were chlorophyll concentrations, turbidity, and wave height, whereas in the northern ecoprovince temperature was the major habitat driver for most of the species modeled. Habitat factors best explaining fish richness and diversity were bottom slope and chlorophyll a. These models could likely be further improved with addition of high-resolution submerged macrophyte complexity data which are currently unavailable at the basin-wide scale. Proportion of invasive species was correlated primarily with increasing maximum observed inorganic turbidity and chlorophyll a. We also demonstrate that preferred habitat for several coastal species and high-diversity areas overlap with areas of high watershed stress. Great Lakes coastal wetland fish are a large contributor to ecosystem services as well as commercial and recreational fishery harvest, and scalable basin-wide habitat models developed in this study may be useful for informing management actions targeting specific species or overall coastal fish biodiversity.

The Study on Assessment of Fish Habitat in De-watered River Channel Due to Diversion-type Hydropower Station

Alteration of hydrological regime due to diversion-type hydropower station has significant impacts on the fish habitat in the de-watered river channel.This paper evaluate the alteration of hydrological regime by using the Indicators of Hydrologic Alteration (IHA) and the Range of Variability Analysis (RVA),analysis the impact on the fish habitat.The IHA&RVA analysis suggests that the construction of diversion-type hydropower hydrological seriously effectshydrological alterations of downstream and damages the fish habitat. Instream flow and hydrogragh study should be developed urgently.

Impacts of river bank stabilization using riprap on fish habitat in two contrasting environments

AbstractRiverbank stabilization using rock riprap is commonly used for protecting road and bridge structures from fluvial erosion. However, little is known about how streams adjust to such perturbation or how this can affect fish habitat in different fluvial environments, particularly for non‐salmonid species in small streams. The objective of this study is to assess impacts of riprap on fish habitat quantity and quality through a pairwise comparison of 27 stabilized and non‐stabilized stream reaches in two physiographic regions, the Saint Lawrence Lowlands and the Appalachian highlands of Montérégie‐Est (Quebec, Canada). Both quantitative (Hydro‐morphological Index of Diversity, HMID) and qualitative (Qualitative Habitat Evaluation Index, QHEI) fish habitat assessment techniques are applied in order to compare results between methods. For each stream reach depth and velocity were measured to calculate HMID. In‐stream cover (woody debris, overhanging vegetation, undercut banks, aquatic macrophytes) and habitat units (pools, riffles, runs, glides) were also documented and used to determine QHEI. Results show that overall bank stabilization using riprap at bridge and stream crossings alters fish habitat characteristics. Loss of in‐stream covers and riparian vegetation lower QHEI scores at stabilized reaches, especially in more pristine Appalachian streams, but has less impact on already altered straightened Lowlands streams. In this latter context, some positive alterations of fish habitat were observed in riprapped reaches due to the coarsening of the substrate and an induced increase of slope. The two metrics (HMID and QHEI) revealed similar differences between stabilized and non‐stabilized sites for Lowlands sites, but their level of agreement was much less in the Appalachian streams, suggesting caution when interpreting habitat quality results based on a single metric. Copyright © 2016 John Wiley & Sons, Ltd.

Empirical modelling of maximum weekly average stream temperature in British Columbia, Canada, to support assessment of fish habitat suitability

The objective of this study was to characterize the spatial variability of stream thermal regimes in British Columbia, Canada, with the specific goal of developing a predictive model to assist in provincial-scale assessment of fish habitat. It is part of a broader study to develop an approach to support the designation of “Temperature Sensitive Streams”, particularly in relation to the potential effects of forest harvesting and climate change. Stream temperature data were collected from researchers, consultants and government agencies. After checking for data quality, the annual maximum of a seven-day running average of mean daily water temperature (MWAT) was extracted for each station-year. A multiple regression model for the mean MWAT for each station was fitted for stations having basin areas between 1 and 104 km2. Predictor variables included the logarithm of catchment area, normal July–August air temperature for the location, the square root of the percentage of glacier cover in the catchment, the square root of the percentage of lake cover in the catchment, the mean catchment elevation, channel slope, a coefficient related to intensity of the mean annual flood, and the deviation of July–August air temperature during the monitoring year(s) from the average during a reference period. Model coefficients were consistent with the physical processes known to govern stream temperature. The standard deviation of prediction errors from a 10-fold cross-validation was 2.1°C. Lack of information on riparian shading is a likely source of a significant portion of the prediction error. The model can be used to provide an initial prediction of stream temperature regime for fish habitat assessment, as well as to provide first-order estimates of the sensitivity of MWAT to climatic warming and glacier retreat.

Accuracy of Stream Habitat Interpolations Across Spatial Scales

Stream habitat data are often collected across spatial scales because relationships among habitat, species occurrence, and management plans are linked at multiple spatial scales. Unfortunately, scale is often a factor limiting insight gained from spatial analysis of stream habitat data. Considerable cost is often expended to collect data at several spatial scales to provide accurate evaluation of spatial relationships in streams. To address utility of single scale set of stream habitat data used at varying scales, we examined the influence that data scaling had on accuracy of natural neighbor predictions of depth, flow, and benthic substrate. To achieve this goal, we measured two streams at gridded resolution of 0.33 × 0.33 meter cell size over a combined area of 934 m2 to create a baseline for natural neighbor interpolated maps at 12 incremental scales ranging from a raster cell size of 0.11 m2 to 16 m2. Analysis of predictive maps showed a logarithmic linear decay pattern in RMSE values in interpolation accuracy for variables as resolution of data used to interpolate study areas became coarser. Proportional accuracy of interpolated models (r2) decreased, but it was maintained up to 78% as interpolation scale moved from 0.11 m2 to 16 m2. Results indicated that accuracy retention was suitable for assessment and management purposes at various scales different from the data collection scale. Our study is relevant to spatial modeling, fish habitat assessment, and stream habitat management because it highlights the potential of using a single dataset to fulfill analysis needs rather than investing considerable cost to develop several scaled datasets

Assessment of hydraulic fish habitat condition using integrated toolkit: a case study of the Geum river basin, Republic of Korea

Artificial changes of rivers, including construction and operation of dams, inevitably lead to physical and ecological changes throughout waterways and their floodplains. In this study, a conceptual model coupled with integrated numerical modeling is presented for hydraulic fish habitat assessment of the Geum River basin, Republic of Korea. Based on the major events which might have affected the ecological system, a conceptual model was formulated to guide desktop and field studies, modeling and scenario evaluations. The result of hydraulic fish habitat assessment indicated that the construction of the Daecheong Multipurpose Dam (DMD) in the Geum River basin has altered flow magnitudes and reduced the river's flow variability. Changes are evident in the magnitude of medium and small flows and the river experiences increased low flows during the dry season. Black shiner, an endangered fish species in Korea, was selected and analyzed to explore relationships between flow regime change by dams and changes to its preferred habitats. As a result, fewer sensitive riffle-benthic species were observed in the reaches downstream of DMD due to the reduction of suitable habitat conditions such as riffle-pool sequences. The proposed conceptual model and integrated toolkit would allow river managers to isolate the physical and biological effects associated with dam operation and could be useful for developing river management strategies.

Application of GIS modelling to quantify fish habitats in lakes

AbstractQuantitative measures of fish habitat in lakes and impoundments have seldom been proposed. The availability of Geographic Information Systems (GIS), however, now provides a means for researchers to assess fish habitat on a whole‐lake scale. GIS modelling was used in this study to quantify the impacts of stratification on the amount and distribution of brown trout (Salmo trutta) habitat in a large reservoir in Victoria, Australia. Species‐specific temperature and dissolved oxygen tolerance ranges for brown trout were applied to the hydrological profile and lake bathymetry. The model predicted that brown trout habitat was reduced by 82% in the summer, and the model was validated with position data from acoustically tagged adult brown trout. This study demonstrated that a quantifiable assessment of fish habitat on a whole‐lake spatial scale can be made. It also could be applied to a range of fish species, with applications in ecosystem monitoring and fisheries management.

Digital video surveys of abalone ( Haliotis sp.) stocks by commercial fishers in Western Australia

An evaluation of a digital video survey programme (DVI surveys) to provide cost-effective stock assessment information for Haliotid (abalone) fisheries was undertaken. Cost effectiveness was achieved by using commercial abalone industry divers to collect abundance and length–frequency data from remote locations using a custom designed video survey unit. Production of training DVD/video, training regimes, and a comprehensive suite of experimental tests on two abalone species ( Haliotis laevigata; Haliotis roei) were utilised to achieve this outcome. Estimates of density and size–frequency of the populations of interest were achieved (0.5–1.0 m −2 for H. laevigata; 6–18 m −2 for H. roei), and appeared reasonable in comparison with existing studies. Although results were not be used as a basis for management decisions due to their preliminary nature, they provided evidence of the potential usefulness of the method for detecting change at the population level. Importantly, the DVI surveys performed favorably against a traditional area-based survey technique, providing the same level of precision in abundance estimation of recruited H. laevigata (greenlip abalone), for 40% of the sampling effort and costs. Overall, this work has expanded the role of DVI surveys as applied to fish and fish habitat assessment, however the abundance and size estimates generated by DVI surveys need to be primarily considered as relative indices, useful for detecting trends over time, provided that the selectivity and sampling issues have appropriately considered.

Successes and failures of acoustics in the measurement of environmental impacts

The use of hydroacoustics has grown in response to the need for more accurate information to manage fisheries. Parallel to its increasing importance to fisheries management has been the expansion of its use for environmental impact assessment. Applications of acoustic technology to estimate the vulnerability of fish to entrainment by cooling water intakes, irrigation drawdown, and turbine operations at hydroelectric dams have led to operational and engineering methods to minimize harmful effects on fish populations. In addition to reducing detrimental effects, the use of acoustics to estimate fish densities before and after underwater blasting operations has led to increasing work windows for bridge and harbor construction. The recent application of acoustics to measure nuisance growths of aquatic macrophytes in shallow, freshwater lakes is leading to techniques for quantitative assessment of fish habitat, which will be equal if not more important to environmental impact evaluations and fisheries management in the future. Successful applications of hydroacoustics to environmental impact assessment are primarily attributed to the researchers having the ingenuity to overcome common biological and engineering limitations, whereas, the failures are not.

Assessment of Fish Habitat in Streams: Goals, Constraints, and a New Technique

Abstract Resolution of conflicts between forestry and fisheries requires assessment of stream habitat quality so that stream reaches of vulnerable or critical habitat may be avoided or protected. Assessment of stream habitats potentially involves a large number of stream features. Designers of stream survey techniques must choose a subset of these features based on logistical constraints of field work and intended use of the survey data. A new survey technique, developed for use in southeast Alaska, is described. The technique involves diagrammatic mapping of stream features, including water velocity/depth categories, spawning gravel, and several kinds of fish cover.