Instream Flow Incremental Methodology Research Articles

CHARACTERIZATION OF SPANISH PYRENEAN STREAM HABITAT: RELATIONSHIPS BETWEEN FISH COMMUNITIES AND THEIR HABITAT

Spanish Pyrenean streams are characterized by extreme summer drought and torrential flows during spring snowmelt and their fish communities are dominated by trout at high altitudes and by barbel in the lower reaches. The Instream Flow Incremental Methodology (IFIM) was adapted to analyse the fisheries habitat of Spanish streams. Parameters were developed that measure the particular characteristics of these streams, taking into account the habitat needs of the main developmental stages (adults, juveniles, fry and spawning) in different seasons. For this analysis ‘potential habitat’ was defined as that determined by hydraulics and geomorphological features. ‘Real habitat used’ was defined by the fish population characteristics (densities, biomass, age-structure and population dynamics). Habitat complexity was calculated as the diversity of habitats of different developmental stages and different species. Habitat conditions during summer-drought were analysed by the simulation of low flow conditions as measured by guaging stations. Habitat parameters were measured in several stream reaches and compared with the charactistics of the fish populations they supported by multivariate analysis. The results show that fish abundance increases downstream along the river continuum, indicating that the habitat carrying capacity increases downstream. The depth and rock surfaces are the main factors limiting the capacity of the stream to provide refuges. Trout populations are also influenced by submerged macrophytes. This IFIM eveluation of stream habitat was not correlated with fisheries features because factors other than hydraulics appear to limit trout population in the Pyrenean streams. Hydraulic factors may limit the fish populations during brief periods, but population recovery from these disturbances may take longer than the time available between disturbances events.

Evaluation of fish habitat in Oto river by IFIM

Recently, the request for ecological aspect in river improvement works becomes gradually stronger in order to offer higher quality of natural space to people. We adopted the Instream Flow Incremental Methodology (IFIM) to determine a conservation flow for freshwater fishes. Habitat variables (velocity, depth, and substrate) are utilized to derive a habitat suitability criteria for pale chub, dark club, and river lizard goby observed in 1994 in Oto River. And we surveyed macro-habitat variables, that are water temperature and cover (i. e. shadowed area on water surface by trees along the riverside), during the summer in 1995 to enhance the IFIM model by introducing the relation with target fishes. To apply the IFIM to a study reach, we developed a one-dimensional mathematical model for a gradually varied flow. We derived accurate and objective habitat suitability criteria between target fishes and habitat variables and found that density of fish species was related to cover according to each fish's food pattern. However, water temperature data during one day were not sufficient to explain a relation with target fishes. Variation in WUA, which shows a quantitative estimate of fish habitat, is found out to be closely related to density of target fishes and a conservation flow for pale chub in summer in Oto river is evaluated about 4m3/sec.

The Relation between Habitat Availability and the Short-Term Carrying Capacity of a Stream Reach for Smallmouth Bass

We used the behavioral carrying capacity (BCC) technique to test the assumption of the instream flow incremental methodology (IFIM) that a positive linear relation exists between available fish habitat (weighted usable area, WUA) and fish biomass for populations of smallmouth bass Micropterus dolomieu at carrying capacity. The BCC experiments were performed at various streamflows, and WUA was measured at each flow. In each BCC experiment, a section of a stream was overstocked with juvenile smallmouth bass, excess fish were trapped as they emigrated, and the remaining resident fish were collected after a 10-d period. We did not find a positive relation between WUA and BCC, and we found a negative relation between stream discharge and BCC. High BCC values recorded during low-flow experiments resulted from less upstream and downstream movement by juvenile smallmouth bass. Such behavioral changes may prevent smallmouth bass populations from being limited by habitat availability during low flows. The low-velocity nature of many warmwater streams is quite different from the high-velocity trout streams where IFIM was developed. In warmwater streams, the microhabitat variables typically used in IFIM studies (depth, velocity, substrate, and cover) may be inadequate for predicting population responses of pool-dwelling fishes to streamflow alteration.

Notes: Utility of Depth and Velocity Preferences for Predicting Steelhead Parr Distribution at Different Flows

Abstract We tested an assumption of the instream flow incremental methodology that depth and velocity preferences are independent of streamflows. We had previously developed depth and velocity preferences (P[d] and P[v]) for juvenile (parr) steelhead Oncorhynchus mykiss at 0.86 m3/s in Morse Creek, Washington, and found parr distributed in microhabitats with higher combined depth–velocity preference (P[dv] = P[d] × P[v]) at a similar flow (0.69 m3/s). In the present study, we evaluated the relationship between fish distribution and combined depth–velocity preference using an independent data set from a higher flow (2.41 m3/s) in the adjacent stream segment. Most steelhead parr were distributed in microhabitats with high P[dv], consistent with distribution at 0.69 m3/s and significantly different than expected if fish distribution were independent of habitat preference (chi-square, P < 0.02). These results suggest that depth and velocity preferences are independent of flow.

Two-Dimensional Hydrodynamic Modeling: A Neglected Tool in the Instream Flow Incremental Methodology

Abstract The instream flow incremental methodology (IFIM) needs to be improved to more reliably predict the effects of altering fish habitat. Two-dimensional (2-D) hydrodynamic modeling with moving boundaries by the finite element approach overcomes may limitations related to classical physical habitat simulation modeling (mostly 1-D). Some of its most important properties are: the spatial resolution of the model can be adapted to the scale of individual fish habitats and to the spatial variability of field data; the areas frequently uncovered because of flow regime are correctly taken into account through the drying–wetting capability; and the flow resistance variables are more accurate in 2-D because they can be specified as functions of the local substrate conditions or lateral shear stresses. This approach is illustrated by a study of the habitat of juvenile Atlantic salmon Salmo salar of the Moisie River (Quebec) where a water diversion has been planned. The results of simulations carried out at two ...

Modelling the effect of groundwater abstraction on salmonid habitat availability in the river Allen, Dorset, England

AbstractThe River Allen in Dorset, England is regarded as a classic example of a chalk stream and historically has a reputation as a high quality trout and salmon fishery. Since 1946 the Allen has been subject to groundwater abstraction from chalk boreholes situated close to the stream. Significant reductions in salmonid populations in recent years prompted the National Rivers Authority Wessex (now South Western) Region to initiate detailed hydrological, biological and fisheries studies to investigate the perceived problem. As part of these studies the Institute of Hydrology was commissioned to investigate the effect of the historical groundwater abstraction regime on the availability of physical habitat for life stages of trout and salmon (Johnson et al., 1993).The modelling procedure used the instream flow incremental methodology (IFIM) (Bovee, 1982), which was implemented using the physical habitat simulation (PHABSIM) model (Milhous et al., 1984). Outputs from PHABSIM hydraulic models were combined with habitat suitability data for life stages of trout and salmon to develop habitat (weighted usable area) versus discharge relationships. Habitat suitability indices were developed by the National Rivers Authority Wessex Region by snorkelling and wading in a number of chalk streams similar in character to the Allen.To assess the impact of groundwater abstraction on the temporal variation of habitat availability, weighted usable area versus discharge relationships were combined with a 20 year time series of mean monthly historical and ‘naturalized’ flows. The resulting time series of historical and naturalized weighted usable areas were analysed using a standard duration curve program to demonstrate the effect of the abstraction on the availability of habitat for each species life stage considered.

Microhabitat use by freshwater mussels and recommendations for determining their instream flow needs

AbstractA conventional application of the instream flow incremental methodology (IFIM) assumes that target organisms have specific microhabitat preferences and the ability to move to areas of suitable hydraulic conditions in response to changes in stream discharge. We investigated the use of the IFIM for determining the instream flow needs of a diverse mussel assemblage in Horse Lick Creek, a fourth‐order stream in the upper Cumberland River drainage in Kentucky. We determined habitat availability by measuring water depth, velocity and substrate at 60 cm intervals along 23 transects during low, medium and high flows. The distribution of mussels within the study site was highly contagious. Although habitat suitability curves developed from data collected on 2004 mussels indicated a clear preference for particular hydraulic conditions, the limited mobility of mussels in the coarse substrate of Horse Lick Creek implies that these curves are flow‐conditional—that is, mussels appear to prefer different hydraulic conditions at different stream discharges. Consequently, these curves are of limited value for determining conservation flows for mussels. Nonetheless, water depth and velocity were important factors limiting the distribution of mussels during base flow periods. Similarly, substrate characteristics were of limited value in defining mussel distributions; unfractured bedrock excluded mussels from portions of the study site, but mussels did not utilize all areas with preferred substrate. Because the larvae (glochidia) of mussels in Horse Lick Creek are obligate parasites on fish, data were also collected on habitat preferences of the host fishes. These data were incorporated in the physical habitat simulation system (PHABSIM) to determine the relationship between the availability of host fish habitat and stream discharge during periods of glochidia release and juvenile settlement.Unlike simple hydraulic variables, complex hydraulic characteristics such as shear stress were significantly correlated with mussel abundance for flows ranging from 0.03 to 2.18 m3 s−1. This range encompasses most flows during the period of juvenile settlement. We suggest that the high shear stress in some portions of the study site is a major factor limiting mussel recruitment. The lack of a significant correlation between mussel abundance and shear stress at high flow (9.35 m3 s−1) resulted from a variable relationship between shear stress and discharge among transects due to channel morphology. The higher shear stresses at most transects over mussel beds during a discharge of 9.35 m3 s−1 suggests that spates occurring during or shortly after juvenile settlement may result in a loss of juveniles.The unique life history and limited mobility of mussels necessitates a more complicated procedure than generally used for fish and other macroinvertebrates for determining conservation flows. Specifically, we recommend an approach that incorporates concepts of hydraulic stream ecology with the more common practice of modelling only simple hydraulic variables in habitat simulations. Estimating the complex hydraulic key characteristics can be performed with minimal effort through the selection of appropriate subroutines with PHABSIM. This approach may also be suitable for simulating habitat of other sessile organisms.

Computer Models for Quantifying the Hydro‐Ecology of British Rivers

ABSTRACTIn recent years, the use of models and scoring surveys for assessing the environmental impacts associated with river‐engineering works has increased. This paper discusses the circumstances in which modelling may be needed, and gives details of some of the models currently in use and under development. River corridor surveys, HABSCORE, RIVPACS (River Invertebrate Prediction and Classification System), SERCON (System for Evaluating Rivers for Conservation) and QUASAR (Quality Simulation Along Rivers) are described, and more detailed information is given on the IFIM (Instream Flow Incremental Methodology using PHABSIM), the physical habitat simulation approach being tested for the National Rivers Authority and the Ministry of Agriculture, Fisheries and Food.

White Sturgeon Spawning and Rearing Habitat in the Lower Columbia River

Abstract Estimates of spawning habitat for white sturgeons Acipenser transmontanus in the tailraces of the four dams on the lower 470 km of the Columbia River were obtained by using the Physical Habitat Simulation System of the U.S. Fish and Wildlife Service's Instream Flow Incremental Methodology to identify areas with suitable water depths, water velocities, and substrates. Rearing habitat throughout the lower Columbia River was assessed by using a geographic information system to identify areas with suitable water depths and substrates. The lowering of spring and summer river discharges from hydropower system operation reduces the availability of spawning habitat for white sturgeons. The four dam tailraces in the study area differ in the amount and quality of spawning habitat available at various discharges; the differences are due to channel morphology. The three impoundments and the free-flowing Columbia River downstream from Bonneville Dam provide extensive areas that are physically suitable for rea...

Determination of ecologically acceptable flows in rivers with seasonal changes in the density of macrophyte

AbstractThe Instream Flow Incremental Methodology (IFIM) is a procedure that has been applied to the rivers of many countries to determine the relationship between discharge and a measure of the physical habitat area available to aquatic species. PHABSIM is a software package that is used to perform the calculations required for the IFIM procedure. Published data on instream macrophyte growth in chalk streams are used here to test the seasonal effects of plant growth in a hypothetical channel. The results show how these effects can significantly distort PHABSIM results. The predicted weighted useable area can differ by as much as 34% depending on the season used for the principal calibration of the Water Surface Profile module (WSP) of PHABSIM. An algorithm is proposed for use with PHABSIM which allows the effects of changes in macrophyte biomass to be included.

Habitat selection by rainbow trout Oncorhynchus mykiss in a California stream: implications for the Instream Flow Incremental Methodology

AbstractWe quantified microhabitat selection of rainbow trout (Oncorhynchus mykiss) at 2 flows (low= 1.13 m3. s−1 and high =4.95 m3. s−1) in the Pit River, California. Flows were controlled by an upstream dam and habitat availability was similar during 4 sampling periods at low flow and 2 periods at high flow. A principal components analysis reduced 6 microhabitat variables to 3 new variables that explained 80% of the observed variance. The 3 components loaded heavily on velocity variables, depth variables and substrate. Microhabitat selection generally differed among macrohabitats (i. e., pools, runs, and riffles). Rainbow trout selected different microhabitats at high flow relative to low flow in response to the availability of deeper, faster water. At low flow, depth and velocity selection were positively correlated with seasonal temperature change for adults but not juveniles. Rainbow trout apparently sought shelter in interstitial spaces in the substrate of runs and riffles during the day in early winter. Generally, large rainbow trout were observed in pools, intermediate‐sized fish in runs, and small trout in riffles. The largest fish occurred in slow, deep areas of pools, where they moved slowly without orientation to flow and were not observed feeding, whereas small fish generally faced upstream and fed in all habitat types. Foraging forays were directed up in the water column at velocities similar to the mean water column velocities at holding positions. Rainbow trout were the most abundant species in 76% of the population survey stations. Other species that might have influenced microhabitat selection by rainbow trout were uncommon.

Predicting Microdistributions of Steelhead (Oncorhynchus mykiss) Parr from Depth and Velocity Preference Criteria: Test of an Assumption of the Instream Flow Incremental Methodology

We tested an assumption of the Physical Habitat Simulation of the Instream Flow Incremental Methodology (IFIM) that fish select microhabitats based on the quality of one or several hydraulic conditions. We developed preference curves for juvenile steelhead (Oncorhynchus mykiss) in Morse Creek, Washington, USA, that accounted for availability of depths and velocities and their utilization by steelhead parr. To allow comparison of intervals among preference curves from different studies, we developed preference indices. We then evaluated the relationship between steelhead parr density and preference or preference indices for depth, velocity, and depth and velocity combined using an independent data set from a different year and an adjacent location in Morse Creek; these indices reflected observed densities of steelhead parr. There was a significant rank correlation between steelhead parr density and preferences or preference indices of steelhead parr for velocity alone and for depth and velocity combined, but not for depth alone. Steelhead parr strongly avoided habitat in which depth preference was 0.0, but velocity preference appeared to influence use of habitat where depth preference was not 0.0. Steelhead parr avoided cells with low preference indices and preferred cells with high preference indices. These relationships support an assumption of the IFIM.

Application and testing of a procedure to evaluate transferability of habitat suitability criteria

AbstractA procedure designed to test the transferability of habitat suitability criteria was evaluated in the Cache la Poudre River, Colorado. Habitat suitability criteria were developed for active adult and juvenile rainbow trout in the South Platte River, Colorado. These criteria were tested by comparing microhabitat use predicted from the criteria with observed microhabitat use by adult rainbow trout in the Cache la Poudre River. A one‐sided X2 test, using counts of occupied and unoccupied cells in each suitability classification, was used to test for non‐random selection for optimum habitat use over usable habitat and for suitable over unsuitable habitat. Criteria for adult rainbow trout were judged to be transferable to the Cache la Poudre River, but juvenile criteria (applied to adults) were not transferable. Random subsampling of occupied and unoccupied cells was conducted to determine the effect of sample size on the reliability of the test procedure. The incidence of type I and type II errors increased rapidly as the sample size was reduced below 55 occupied and 200 unoccupied cells. Recommended modifications to the procedure included the adoption of a systematic or randomized sampling design and direct measurement of microhabitat variables. With these modifications, the procedure is economical, simple and reliable. Use of the procedure as a quality assurance device in routine applications of the instream flow incremental methodology was encouraged.

Conceptual model for quantifying pre‐smolt production from flow‐dependent physical habitat and water temperature

AbstractA conceptual model has been developed to test river regulation concepts by linking physical habitat and water temperature with salmonid population and production in cold water streams. Work is in progress to examine numerous questions as part of flow evaluation and habitat restoration programmes in the Trinity River of California and elsewhere. For instance, how much change in pre‐smolt chinook salmon (Oncorhynchus tshawytscha) production in the Trinity River would result from a different annual instream allocation (i.e. up or down from 271 × 106 m3 released in the late 1980s) and how much change in pre‐smolt production would result from a different release pattern (i.e. different from the 8.5 m3 s−1 year‐round release). The conceptual model is being used to: design, integrate and improve young‐of‐year population data collection efforts; test hypotheses that physical habitat significantly influences movement, growth and mortality of salmonid fishes; and analyse the relative severity of limiting factors during each life stage. The conceptual model, in conjunction with previously developed tools in the Instream Flow Incremental Methodology, should provide the means to more effectively manage a fishery resource below a regulated reservoir and to provide positive feedback to planning of annual reservoir operations.

Lowland Floodplain Rivers: Geomorphological Perspectives

Modelling Channel Migration and Floodplain Sedimentation in Meandering Streams Estimation of the Fractal Dimension of Terrain from Lake Size Distributions Investigating Contemporary Rates of Floodplain Sedimentation Influence of Farm Management and Drainage on Leaching of Nitrate from Former Floodlands in a Lowland Clay Catchment Floodplain Assessment for Restoration and Conservation: Application of the Instream Flow Incremental Methodology to Assess Ecological Flow Requirements in a British Lowland River.

Models of the Abundance of Large Brown Trout in New Zealand Rivers

Multiple-regression models of the abundance of brown trout Salmo trutta larger than 200 mm total length were developed from combinations of hydrological, catchment (89 sites), physical (59 sites), water quality, and benthic invertebrate biomass (43 sites) variables in New Zealand rivers. Three hydrological and catchment variables explained 44.4% of the variation in trout abundance, and benthic invertebrate biomass alone explained almost 45%. Together, invertebrate biomass and weighted usable area (WUA) for adult brown trout drift-feeding habitat explained 64.4% of the variation in trout abundance. These two variables, representing the food and space available to trout, appeared to be the major determinants of trout abundance, with winter water temperature acting as an overriding factor. Instream cover was also an important factor, whereas lakes, land development, site elevation, and river gradient were of lesser importance. Water quality (within the ranges measured) and presence of rainbow trout Oncorhynchus mykiss were not significant. The model best suited to the application of the instream flow incremental methodology (IFIM) explained 87.7% of the variation in brown trout abundance at 59 sites. Two variables were calculated with flow data: WUA for food production at median flow and WUA for adult brown trout drift-feeding habitat at mean annual low flow. Other variables within the model either did not vary with flow or varied little. This study demonstrates that WUA is an important determinant of adult brown trout abundance, refuting one of the major criticisms of IFIM.

Habitat Criteria for Rearing Steelhead: A Comparison of Site-Specific and Standard Curves for Use in the Instream Flow Incremental Methodology

Abstract Habitat utilization curves developed for fry and juveniles of steelhead Oncorhynchus mykiss in Big Creek, a small stream of moderate to high gradient in California, were compared with three standard habitat utilization curves. Comparisons were made of the amount of weighted usable area generated by the curves from the instream flow incremental methodology computer program. The narrower range of usable habitat in Big Creek resulted in utilization curves with ranges narrower than those of the standard utilization curves and with much less weighted usable area for fry and juvenile steelhead at all flows above 3.0 ft3/S. Stream width, depth, flow, gradient, substrate particle size, pool : riffle ratio, seasonal hydrography, and other habitat characteristics should be compared before habitat utilization curves from one stream are applied to another.

Evaluation of the Instream Flow Incremental Methodology by U.S. Fish and Wildlife Service Field Users

Abstract This paper summarizes results of a survey conducted in 1988 of 57 U.S. Fish and Wildlife Service field offices. The purpose was to document opinions of biologists experienced in applying the Instream Flow Incremental Methodology (IFIM). Responses were received from 35 offices where 616 IFIM applications were reported. The existence of six monitoring studies designed to evaluate the adequacy of flows provided at sites was confirmed. The two principal categories reported as stumbling blocks to the successful application of IFIM were beliefs that the methodology is technically too simplistic or that it is too complex to apply. Recommendations receiving the highest scores for future initiatives to enhance IFIM use were (1) training and workshops for field biologists; and (2) improving suitability index (SI) curves and computer models, and evaluating the relationship of weighted useable area (WUA) to fish responses. The authors concur that emphasis for research should be on addressing technical concer...

The utility and applicability of the in-stream flow incremental methodology (IFIM) for Australian lotic environments

(1991). The utility and applicability of the in-stream flow incremental methodology (IFIM) for Australian lotic environments. SIL Proceedings, 1922-2010: Vol. 24, No. 4, pp. 2559-2559.

Variability of results from the use of PHABSIM in estimating habitat area

AbstractThe estimation of the area of a stream reach suitable as habitat for an aquatic species by the Instream Flow Incremental Methodology is described. An important component of the methodology is PHABSIM, which is a collection of computer programs whereby useable stream area is computed as a function of discharge. This comprises a variety of options for both hydraulic and habitat simulation. A single data set is used to calculate the useable area at one discharge for three life stages of brown trout, using various options in habitat simulation. The results are shown to vary greatly according to the particular combination of options selected, so unless calculations are founded on biologically realistic assumptions the potential within PHABSIM for the „fudging”︁ of results is considerable.