Aquatic Habitat Quality Research Articles

Anthropogenic Activities and the Quality of Aquatic Habitat with Reference to Heptachlor in Ethiope River Basin

The influences of man on the quality of aquatic habitat is indispensable, hence the distribution of heptachlor, one of the most sought pesticide in the nascent fragile Niger- Delta environment in the water, bottom sediment and Tilapia mariae in Ethiope River Basin was investigated. Samples were collected monthly from three stations, Amukpe, Igun watershed and Owah-Abe, all along the River during the dry (January-April) and wet seasons (May-August).These stations were chosen because of their close proximity to where the pesticide is regularly use except the control station. The concentration of the pesticide was analyzed using CECIL 1010 model of high performance liquid chromatography. The results revealed a higher concentration of the pesticide in surface water during the dry season, than the wet season while the reverse was the case for the bottom sediment and T. mariae which had higher concentrations during the rainy season. Spatial variations showed that the downstream stations had statistically higher concentrations in all matrices at p < 0.05. The observed concentrations of heptachlor were above the permissible limits set by Nigeria National Environment Standards and Regulation Enforcement Agency for aquatic water bodies (0.3 μg/gdw). Though, fishes and the likes may live freely in water contaminated with heptachlor, for a very long time with no health effects. However, pesticides can easily biomagnified along the trophic level, and the risk to aquatic species become greater when repeated applications occur, resulting in continual exposure to peak concentrations.

Effect of Human Induced Sediments Inflow on Habitat Quality in River Chanchaga, Minna, Nigeria

A developing nation like Nigeria should be much concern on environmental management particularly in the area of drinking water, air, soil or general ecosystem. Sediment inflow has become public concerns on aquatic life and habitat loss as well as fragmentations of biodiversity of River Chanchaga. The study assessed the effects of human induced sediment inflows on habitat quality in River Chanchaga. The inhabitant population data, rainfall data and remote sensing data were collected to determine sediment inflow and land use cover of the study area. A total of 250 people accounting for 0.5% of the total population were interviewed, making it eight per each community in thirty communities along the study area. The findings of the study revealed a significant correlation between rainfall and runoff at r = 0.991 accounting for 99% indicating strong positive relationship between them. Pearson correlation is 99% with remain 1% for other parameters like wind, institutional and industrial activities accounting for negligible percentage that are responsible for sediment inflow of River Chanchaga as depicted in Table 3. The implication of this is that the higher the mean monthly rainfall, the higher the runoff volume in River Chanchaga, which may result into subsequent increase of sediments inflow into the river. The result from the study is that land use covers have been affected by population increase, which have direct impact on soil erosion that influences sediment inflow into the study area. The study recommended that anthropogenic activities that lead to generation and transportation of huge volume of debris and sediment loads along River Chanchaga should be regulated to control or reduce aquatic habitat quality damage and to ensure making good use of aquatic resources. There should be programme to enlighten general public on implications of indiscriminant human activities that can affect habitat and water quality along the study.

Observations of Channel Change from Constructed Wood Jams on a Forested Gravel-Bed Stream

AbstractSalmonids in the Pacific Northwest face a number of threats: habit degradation, loss of habitat, overharvest, competition from hatchery fish, dams, and climate change. Wood has been shown to play a key role in many aspects of stream habitat quality; however, it is in low supply in many Pacific Northwest streams because of wood removal and timber harvest practices in riparian zones. Wood placement for restoration has the potential to benefit salmonid populations. However, common applications often fall short of producing the physical changes necessary to achieve the objectives, such as the formation of deep pools and cover. This study evaluated the hypothesis that wood jams constructed with whole-tree materials, high wood piece counts, and high wood volumes would be effective at creating instream geomorphic complexity, function, and aquatic habitat quality. Results were based on an evaluation of changes to surface sediment textures and channel morphology at eight constructed wood jams built with va...

Telemetry-Determined Habitat Use Informs Multi-Species Habitat Management in an Urban Harbour.

Widespread human development has led to impairment of freshwater coastal wetlands and embayments, which provide critical and unique habitat for many freshwater fish species. This is particularly evident in the Laurentian Great Lakes, where such habitats have been severely altered over the last century as a result of industrial activities, urbanization, dredging and infilling. In Toronto Harbour, extensive restoration efforts have been directed towards improving the amount and quality of aquatic habitat, especially for fishes. To evaluate the effectiveness of this restoration work, use of the restored area by both target species and the fish community as a whole must be assessed. Individuals from four species (Common Carp, Largemouth Bass, Northern Pike and Yellow Perch) were tagged and tracked continuously for 1 year using an acoustic telemetry array in Toronto Harbour area of Lake Ontario. Daily site fidelity was estimated using a mixed-effects logistic regression model. Daily site fidelity was influenced by habitat restoration and its interactions with species and body size, as well as season and its interactions with species and body size. Daily site fidelity was higher in restored sites compared to non-restored sites for Yellow Perch and Northern Pike, but lower for Largemouth Bass and Common Carp. For all species, daily site fidelity estimates were highest during the summer and lowest during autumn. The approach used here has merit for evaluating restoration success and informing future habitat management activities. Creating diverse habitats that serve multiple functions and species are more desirable than single-function-oriented or single-species-oriented designs.

Nexus between food, energy, water, and forest ecosystems in the USA

Efforts to promote appreciation for the multifaceted contributions of forests are particularly timely because of the many threats currently faced by forests. These threats include the world’s growing population, which is projected to top 9.1 billion by 2050; global climate change; land degradation; land scarcity; and deforestation. Already, human activities have destroyed 50 % of the forests that once existed under modern climatic conditions. The US Forest Service’s research and management activities are promoting the health, productivity, and resilience of forests and grasslands by, for example, advancing agroforestry, producing and applying science and technology that integrates energy production into sustainable forest and grassland management practices, and protecting water supplies by increasing the quality of aquatic habitats, reducing erosion, and decreasing peak flows. The US Forest Service must increase public understanding and support for such efforts to restore and create healthy landscapes that will supply vital resources to future generations.

Mapping the Relative Probability of Common Toad Occurrence in Terrestrial Lowland Farm Habitat in the United Kingdom.

IntroductionThe common toad (Bufo bufo) is of increasing conservation concern in the United Kingdom (UK) due to dramatic population declines occurring in the past century. Many of these population declines coincided with reductions in both terrestrial and aquatic habitat availability and quality and have been primarily attributed to the effect of agricultural land conversion (of natural and semi-natural habitats to arable and pasture fields) and pond drainage. However, there is little evidence available to link habitat availability with common toad population declines, especially when examined at a broad landscape scale. Assessing such patterns of population declines at the landscape scale, for instance, require an understanding of how this species uses terrestrial habitat.MethodsWe intensively studied the terrestrial resource selection of a large population of common toads in Oxfordshire, England, UK. Adult common toads were fitted with passive integrated transponder (PIT) tags to allow detection in the terrestrial environment using a portable PIT antenna once toads left the pond and before going into hibernation (April/May-October 2012 and 2013). We developed a population-level resource selection function (RSF) to assess the relative probability of toad occurrence in the terrestrial environment by collecting location data for 90 recaptured toads.ResultsThe predicted relative probability of toad occurrence for this population was greatest in wooded habitat near to water bodies; relative probability of occurrence declined dramatically > 50 m from these habitats. Toads also tended to select habitat near to their breeding pond and toad occurrence was negatively related to urban environments.

Design of Restoration of Regulated Rivers Based on Bioindication

Streambeds of rivers and brooks should form the dominant features in the urbanized areas. However, the current river regulations were unilaterally focused on flood protection and riverbeds have generally the character of prismatic channel. This solution inhibits the aesthetic function of the watercourses and has the negative impacts on instream biota. Based on the results of the research that was carried out on the mountain streams of Slovakia the authors introduce the implementation of river restorations that maintain the flood protection of the area while retaining the landscaping features of the stream. The paper describes the procedure for restoring the regulated streams based on bioindication and documents the quality of aquatic habitat of regulated and natural streams in particular examples.

Habitat connectivity as a metric for aquatic microhabitat quality: application to Chinook salmon spawning habitat

AbstractQuality of fish habitat at the scale of a single fish, at the metre resolution, which we defined here as microhabitat, has been primarily evaluated on short reaches, and their results have been extended through long river segments with methods that do not account for connectivity, a measure of the spatial distribution of habitat patches. However, recent investigations of quality of aquatic habitat at the stream segment scale, at hundredth of metre resolution macrohabitat, indicate that the spatial distribution of aquatic habitat quality and size is an important factor at the network scale. Here, we hypothesize that aquatic habitat connectivity, quality and patch size are also important at the microhabitat scale. We test this hypothesis by modelling Chinook salmon (Oncorhynchus tshawytscha) spawning habitat in a 6‐km long reach of Bear Valley Creek (Idaho, USA) with microhabitat resolution of 1‐m square. We use two‐dimensional hydraulic numerical modelling coupled with suitability curves to predict the spatial distribution of spawning habitat quality. We quantify connectivity for each habitat patch with the ratio between the area of neighbouring patches and their squared hydrographic distances. Results from a logistic regression analysis comparing predicted with observed spawning locations indicate that habitat quality and patch size are important factors and connectivity among patches may have a secondary effect. Therefore, spatial distribution of aquatic habitat and size of habitat patches are important aspects of its quality, suggesting that composite metrics such as weighted usable area may not be sufficient in defining the condition of the river environment. Copyright © 2015 John Wiley &amp; Sons, Ltd.

Spatio-temporal patterns in water surface temperature from Landsat time series data in the Chesapeake Bay, U.S.A.

Abstract Water temperature is a key factor used to assess biogeochemical cycles and aquatic habitat quality, and is typically monitored using in situ sensors deployed on distributed piers, buoys or mobile platforms. Due to multiple, spatially and temporally varying influences on surface water temperature, (e.g., solar radiation, water depth, tidal stage, turbidity, and industrial activities) multi-temporal remote sensing observations might effectively be used to link these drivers with observations. However, while low- to moderate-resolution sensors provide temporally continuous observations, large pixel sizes have proven problematic in coastal regions where shoreline influences on pixel radiance contaminate the radiation signal leaving the water surface. To alleviate this problem, we used a dense stack of Landsat TM/ETM+ thermal imagery organized by day of year of acquisition, thus producing a climatology of water temperature. We use these data to analyze the spatial patterns of water surface temperature climatology (e.g., average maximum and minimum temperatures) for the past thirty years. We also explore the impact of power plant thermal effluent on water surface temperature climatology of the Chesapeake Bay tributaries. Finally, we divide the Landsat record into 5-year intervals, and calculate the water surface temperature climatology for each period. Trends in water surface temperature over the Landsat record were then compared against air temperature records available from coastal NOAA weather stations. The resulting data exhibit broad scale patterns, such as water surface climatology differences between the main stem of the Bay and its tributaries. The results also include the influence of urbanization and industrialization such as increases in impervious surface area and thermal effluent from power plants. Trends of increasing water surface temperature and air temperature were found for more than 92% of the Bay. While water temperature was always ~ 2–3° cooler than the air temperature, water temperature has been increasing more rapidly than air temperature in some areas, particularly in the main stem of the Bay and in the Potomac estuary. Therefore, there is a detectable impact of global change on the Chesapeake Bay in the form of an increase in water temperature, which can only partially be explained by increasing air temperatures.

Evaluation of quality of aquatic habitat on the Nitrica river

Evaluation of quality of aquatic habitat on the Nitrica river

Influence of a forest preserve on aquatic macroinvertebrates, habitat quality, and water quality in an urban stream

The use of nature areas as an effective tool for conservation of streams and their biota is a relatively unexplored option in urban stream management. Benthic macroinvertebrates and water quality in an urban stream, Poplar Creek, were monitored along a continuum within and downstream of a forest preserve in the western Chicago metropolitan area, USA. Taxa richness and a benthic macroinvertebrate index of biological integrity (MIBI) increased as the stream progressed within the preserve, but percentage of Ephemeroptera, Trichoptera, and Plecoptera (%EPT) showed no improvement. Reductions in the amount of silt substrates and increases in gravel-dominated substrate were evident at sites within the preserve. There were no improvements in water-quality measures tested although trends may have been obscured by precipitation events between sampling occasions. The benefits in stream quality attained within the forest preserve extended beyond the downstream border of the preserve and were not diminished by the presence of a railway, which bisected the stream. The nature preserve provided an opportunity for increased macroinvertebrate biodiversity, likely through local reductions in impervious surfaces and improvements in stream substrate, despite lack of evidence that it improved water quality.

Model development for the assessment of terrestrial and aquatic habitat quality in conservation planning

There is a growing pressure of human activities on natural habitats, which leads to biodiversity losses. To mitigate the impact of human activities, environmental policies are developed and implemented, but their effects are commonly not well understood because of the lack of tools to predict the effects of conservation policies on habitat quality and/or diversity. We present a straightforward model for the simultaneous assessment of terrestrial and aquatic habitat quality in river basins as a function of land use and anthropogenic threats to habitat that could be applied under different management scenarios to help understand the trade-offs of conservation actions. We modify the InVEST model for the assessment of terrestrial habitat quality and extend it to freshwater habitats. We assess the reliability of the model in a severely impaired basin by comparing modeled results to observed terrestrial and aquatic biodiversity data. Estimated habitat quality is significantly correlated with observed terrestrial vascular plant richness (R2=0.76) and diversity of aquatic macroinvertebrates (R2=0.34), as well as with ecosystem functions such as in-stream phosphorus retention (R2=0.45). After that, we analyze different scenarios to assess the suitability of the model to inform changes in habitat quality under different conservation strategies. We believe that the developed model can be useful to assess potential levels of biodiversity, and to support conservation planning given its capacity to forecast the effects of management actions in river basins.

Détermination du potentiel d’accueil de la Loutre d’Europe (Lutra lutra) par secteur géographique en France métropolitaine

Determination of potential habitat suitability for the European Otter (Lutra lutra) in geographical sectors of metropolitan France. After a long period of decline, the European Otter is now in the process of recolonizing the French territory. In order to facilitate its expansion, one of the objectives of the National Action Plan is to define and locate the habitat suitability for this mustelid in France. For each river subsector we gathered all available information about the factors (availability and quality of aquatic habitat, availability of food resources, human disturbances and general characteristics of the ecosystem) essential to the presence of the otter in order to create a Maxent model. According to this model, 30 % of the sub-sectors in metropolitan France are unlikely to offer favourable habitats for the Otter, 68 % should contain favourable habitats and 2 % could be considered as very favourable for the settling of European otters.

Caracterizacion fisica, quimica e hidromorfologica de los rios altoandinos tropicales de Ecuador y Peru

To understand the physical, chemical and hydromorphological variability of tropical highland Andean rivers (2000 m.a.s.l.), 123 localities in eight river basins in Ecuador and Peru were sampled. The sites were selected according to their latitude, altitude, and impairment degree. The samples were taken between October 2007 and October 2008 coinciding with the dry season at both countries. In each locality both, physical and chemical (i.e., temperature, dissolved oxygen, conductivity, phosphates, nitrites, nitrates, ammonia, etc.) and hydromorphological (i.e., altitude, riparian quality index (QBR), degree of vegetal cover in the stream zone, riparian cover structure and quality, naturalness of the stream channel, aquatic habitat quality index (IHF), substrate composition, rapids frequency, elements of heterogeneity) variables were measured. At regional level (between basins), the mineralization, the hydromorphological features and the aquatic habitat heterogeneity were the most important factors explaining environmental variability. Meanwhile the temperature dissolved, oxygen and habitat heterogeneity parameters were shown to be relevant in the altitudinal gradient, while the mineralization was it in the latitudinal gradient. The importance of each factor is related to the spatial scale studied (site, basin, region). However, the altitude and variables changing with it, as temperature and dissolved oxygen, shown similar patterns regardless of the latitudinal location of the basin.

One‐dimensional and two‐dimensional hydrodynamic modeling derived flow properties: impacts on aquatic habitat quality predictions

AbstractStudies of the effects of hydrodynamic model dimensionality on simulated flow properties and derived quantities such as aquatic habitat quality are limited. It is important to close this knowledge gap especially now that entire river networks can be mapped at the microhabitat scale due to the advent of point‐cloud techniques. This study compares flow properties, such as depth and velocity, and aquatic habitat quality predicted from pseudo‐2D and fully 2D hydrodynamic modeling. The models are supported by high‐resolution, point‐cloud derived bathymetries, from which close‐spaced cross‐sections were extracted for the 1D modeling, of three morphologically and hydraulically different river systems. These systems range from small low‐gradient meandering pool–riffle to large steep confined plane‐bed rivers. We test the effects of 1D and 2D models on predicted hydraulic variables at cross‐sections and over the full bathymetry to quantify the differences due to model dimensionality and those from interpolation. Results show that streambed features, whose size is smaller than cross‐sectional spacing, chiefly determine the different results of 1D and 2D modeling whereas flow discharge, stream size, morphological complexity and model grid sizes have secondary effects on flow properties and habitat quality for a given species and life stage predicted from 1D and 2D modeling. In general, the differences in hydraulic variables are larger in the bathymetric than in the cross‐sectional analysis, which suggests that some errors are introduced from interpolation of spatially disaggregated simulated variables with a 1D model, instead of model dimensionality 1D or 2D. Flow property differences are larger for velocity than for water surface elevation and depth. Differences in weighted usable area (WUA) derived from 1D and 2D modeling are relatively small for low‐gradient meandering pool–riffle systems, but the differences in the spatial distribution of microhabitats can be considerable although clusters of same habitat quality are spatially comparable. Copyright © 2014 John Wiley &amp; Sons, Ltd.

Linking Stream Sediment Deposition and Aquatic Habitat Quality in Pearl Mussel Streams: Implications for Conservation

AbstractThe introduction of fine sediments into streams is considered to have a major effect on habitat quality affecting the reproduction of sensitive species such as unionid mussels and salmonid fishes. To date, there is a lack of information on the magnitude and spatio‐temporal resolution of sediment introduction.This study aimed to quantify the spatio‐temporal deposition of fine sediments in headwater streams in relation to the status of Margaritifera margaritifera and Salmo trutta. Fine sediment deposition was linked to physicochemical conditions of the adjacent streambed.The mean observed deposition of fine sediments over the study period was 3.4 kg m−2 month−1 with a high spatio‐temporal variation ranging from &lt;0.01 to 20.3 kg m−2 month−1. Discharge had the strongest influence on deposition rates.Mean differences in redox potential between free‐flowing water and the interstitial zone were 90 mV. The spatio‐temporal variability of physicochemical parameters increased with degree of degradation. High‐quality reaches had more constant conditions.Our results indicate that monitoring of sediment quality and deposition in streams has to comprise several time points and study reaches, or should at least be conducted during periods with the most adverse habitat conditions, to allow valid assessments of habitat quality. In streams with increased fine sediment deposition, in‐stream restoration measures are insufficient for the enhancement of pearl mussel habitats as a result of rapid clogging of interstitial pores. Only integrative catchment management based on detailed habitat analysis can ensure sufficient habitat quality for species sensitive to siltation. Copyright © 2014 John Wiley &amp; Sons, Ltd.

A flood risk assessment for the City of Chilliwack on the Fraser River, British Columbia, Canada

ABSTRACTFlood hazard management in Canada is predicated on an event of arbitrary return period – the ‘design flood’, which on the Fraser River is the flood of record, with an estimated return period of 500 years. Recent studies have demonstrated that the existing dikes will not contain design flood levels, in a location where the potential consequences of flooding have increased exponentially during the past century. This suggests that a hazard-based approach is questionable for effective flood management. A pilot flood risk assessment was completed for the City of Chilliwack, 80 km east of Vancouver. We assessed direct and indirect economic losses for three hypothetical dike breach scenarios for flood return periods from 100 to 1000 years. We estimate that total losses would exceed CND $1 billion (€720 million) for the flood scenarios examined, not including intangibles such as emotional and cultural losses, environmental contamination, or changes in the quality and abundance of aquatic and terrestrial habitat. The study concludes with recommendations that would lead to a risk-based decision-making framework for flood mitigation design and emergency preparedness.

Modeling the effects of pulsed versus chronic sand inputs on salmonid spawning habitat in a low‐gradient gravel‐bed river

ABSTRACTIt is widely recognized that high supplies of fine sediment, largely sand, can negatively impact the aquatic habitat quality of gravel‐bed rivers, but effects of the style of input (chronic vs. pulsed) have not been examined quantitatively. We hypothesize that a continuous (i.e. chronic) supply of sand will be more detrimental to the quality of aquatic habitat than an instantaneous sand pulse equal to the integrated volume of the chronic supply. We investigate this issue by applying a two‐dimensional numerical model to a 1 km long reach of prime salmonid spawning habitat in central Idaho. Results show that in both supply scenarios, sand moves through the study reach as bed load, and that both the movement and depth of sand on the streambed mirrors the hydrograph of this snowmelt‐dominated river. Predictions indicate greater and more persistent mortality of salmonid embryos under chronic supplies than pulse inputs, supporting our hypothesis. However, predicted mortality varies both with salmonid species and location of spawning. We found that the greatest impacts occur closer to the location of the sand input under both supply scenarios. Results also suggest that reach‐scale morphology may modulate the impact of sand loads, and that under conditions of high sand loading climate‐related increases in flow magnitude could increase embryo mortality through sand deposition, rather than streambed scour. Copyright © 2013 John Wiley &amp; Sons, Ltd.

Quantifying the importance of daily stream water temperature fluctuations on the hyporheic thermal regime: Implication for dissolved oxygen dynamics

• We model the heat transport in the hyporheic zone by using a Lagrangian approach. • We examine the role of the stream water temperature on hyporheic thermal regime . • We examine the role of hyporheic thermal regime on dissolved oxygen (DO) kinetics. • Via a thermal Damköhler number we relate stream morphology and temperature signal. • We show the impact of temperature variation on the evolution of DO concentration. Water temperature is a primary driver of aquatic organism migration, drift, growth and metabolism in both stream and hyporheic zone. Here, we focus on the role of the naturally occurring daily stream water temperature oscillations on the hyporheic thermal regime and on dissolved oxygen (DO) dynamics within the hyporheic zone. We choose DO as target dissolved element because of its importance for aquatic habitat quality and its role in controlling biogeochemical reactions and pool-riffle morphology as bed form because of its ubiquity and ecological relevance. To address the first objective, we introduce a new thermal Damköhler number, Da T , which is the ratio between the median residence time of stream water and the time scale of daily amplitude attenuation of water temperature within the hyporheic zone. Application of the model to a wide range of pool-riffle dimensions shows the dependence of hyporheic water temperature distribution on hyporheic residence time. The latter is a function of the interaction between stream flow and bed form morphology. Our results show that Da T increases with stream size indicating that large streams have more thermally stable hyporheic zones than small streams. To address the second objective, we analytically solve the heat and dissolved oxygen transport equations through the streambed sediment with isotropic and homogeneous hydraulic properties by means of a Lagrangian approach, under the hypothesis that transverse dispersion can be neglected and the DO reaction rate is temperature dependant. We apply these coupled transport models to characterize the distribution of DO concentrations within the hyporheic zone. This analysis shows a relation between the patterns of water temperature and of DO concentrations with important feedbacks on the life and metabolism of aquatic organisms; as well as on the reaction rates, which control the biogeochemical processes within the streambed sediment. We analyze the effects of temperature variations on the kinetics of DO assuming constant and periodic fluctuations of DO concentrations in the stream water. Our results show that for streams with pool and riffle morphology, the latter effect is more important than that of temperature dependent reaction rates.

Using watershed function as the leading indicator for water quality

Diffuse nonpoint source (NPS) pollutants, such as sediment, nitrogen, phosphorus, and pathogens, have become the primary cause of water quality impairments in the United States of America. Resource management agencies in the USA are expanding the use of tools for the assessment of ecosystem function in water quality programs to control NPS pollution to meet US Clean Water Act objectives. Assessing the ecosystem function of upland and riparian areas provides the context for monitoring data that can improve the targeting of best management practices for NPS pollution, and be a leading (early) indicator for more timely decisions about aquatic habitat and water quality. Assessment of watershed function can be applied to prioritizing resources, developing indicators, monitoring aquatic habitat and water quality, and implementing adaptive management plans to restore degraded ecosystems that are producing NPS pollution. This paper presents three examples of progress in the institutionalization of this approach to water quality programs for sustainable and healthy watersheds that affect federal, state, tribal, and private landowners. Future work should refine the approach by evaluating the benefits, costs, and effectiveness of the use of watershed function in water quality programs.