scholarly journals River-Wide Habitat Availability for Fish Habitat Guilds: Implications for In-Stream Flow Protection

Water ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1132 ◽  
Author(s):  
Jonathan Spurgeon ◽  
Mark Pegg ◽  
Piotr Parasiewicz ◽  
Joe Rogers

The variation in river discharge alters habitat heterogeneity with implications for the distribution of fish species with different habitat requirements. Assessments of habitat availability following changes in river discharge are difficult to apply at broad spatial scales and with relevance to multiple species. We used a MesoHABSIM modeling approach to quantify river-wide changes in habitat availability for five fish habitat guilds under three river discharge levels along the Niobrara River, NE, USA. We used a time-series of river discharge (1958–2010) to create uniform continuous under-threshold habitat duration curves that identified habitat conditions that may result in periods of stress for fish communities along the Niobrara River. Habitat availability for each fish habitat guild was dependent on river discharge and location along the river. Habitat availability for fish habitat guilds ranged from 5% to 49% of the total channel area suggesting habitat availability may, at times, be limited. We provide river discharge guidelines for bioperiods that limit the frequency and duration of stressful habitat conditions. Understanding interactions between river discharge and habitat availability through time and at river-wide scales may aid in managing for ecological integrity by including protection of river discharge variability to support multiple fish habitat guilds.

Geology ◽  
2021 ◽  
Author(s):  
Joel S. Scheingross ◽  
Michael P. Lamb

Waterfall plunge pools experience cycles of sediment aggradation and scour that modulate bedrock erosion, habitat availability, and hazard potential. We calculate sediment flux divergence to evaluate the conditions under which pools deposit and scour sediment by comparing the sediment transport capacities of waterfall plunge pools (Qsc_pool) and their adjacent river reaches (Qsc_river). Results show that pools fill with sediment at low river discharge because the waterfall jet is not strong enough to transport the supplied sediment load out of the pool. As discharge increases, the waterfall jet strengthens, allowing pools to transport sediment at greater rates than in adjacent river reaches. This causes sediment scour from pools and bar building at the downstream pool boundary. While pools may be partially emptied of sediment at modest discharge, floods with recurrence intervals >10 yr are typically required for pools to scour to bedrock. These results allow new constraints on paleodischarge estimates made from sediment deposited in plunge pool bars and suggest that bedrock erosion at waterfalls with plunge pools occurs during larger floods than in river reaches lacking waterfalls.


2020 ◽  
Vol 96 (5) ◽  
Author(s):  
Jonas J Lembrechts ◽  
L Broeders ◽  
J De Gruyter ◽  
D Radujković ◽  
I Ramirez-Rojas ◽  
...  

ABSTRACT Creating accurate habitat suitability and distribution models (HSDMs) for soil microbiota is far more challenging than for aboveground organism groups. In this perspective paper, we propose a conceptual framework that addresses several of the critical issues holding back further applications. Most importantly, we tackle the mismatch between the broadscale, long-term averages of environmental variables traditionally used, and the environment as experienced by soil microbiota themselves. We suggest using nested sampling designs across environmental gradients and objectively integrating spatially hierarchic heterogeneity as covariates in HSDMs. Second, to incorporate the crucial role of taxa co-occurrence as driver of soil microbial distributions, we promote the use of joint species distribution models, a class of models that jointly analyze multiple species’ distributions, quantifying both species-specific environmental responses (i.e. the environmental niche) and covariance among species (i.e. biotic interactions). Our approach allows incorporating the environmental niche and its associated distribution across multiple spatial scales. The proposed framework facilitates the inclusion of the true relationships between soil organisms and their abiotic and biotic environments in distribution models, which is crucial to improve predictions of soil microbial redistributions as a result of global change.


2017 ◽  
Vol 21 (11) ◽  
pp. 5763-5780 ◽  
Author(s):  
Rui Rivaes ◽  
Isabel Boavida ◽  
José M. Santos ◽  
António N. Pinheiro ◽  
Teresa Ferreira

Abstract. Environmental flows remain biased toward the traditional biological group of fish species. Consequently, these flows ignore the inter-annual flow variability that rules species with longer lifecycles and therefore disregard the long-term perspective of the riverine ecosystem. We analyzed the importance of considering riparian requirements for the long-term efficiency of environmental flows. For that analysis, we modeled the riparian vegetation development for a decade facing different environmental flows in two case studies. Next, we assessed the corresponding fish habitat availability of three common fish species in each of the resulting riparian landscape scenarios. Modeling results demonstrated that the environmental flows disregarding riparian vegetation requirements promoted riparian degradation, particularly vegetation encroachment. Such circumstance altered the hydraulic characteristics of the river channel where flow depths and velocities underwent local changes of up to 10 cm and 40 cm s−1, respectively. Accordingly, after a decade of this flow regime, the available habitat area for the considered fish species experienced modifications of up to 110 % when compared to the natural habitat. In turn, environmental flows regarding riparian vegetation requirements were able to maintain riparian vegetation near natural standards, thereby preserving the hydraulic characteristics of the river channel and sustaining the fish habitat close to the natural condition. As a result, fish habitat availability never changed more than 17 % from the natural habitat.


2015 ◽  
Vol 11 (1) ◽  
pp. 20140930 ◽  
Author(s):  
Martin J. P. Sullivan ◽  
Stuart E. Newson ◽  
James W. Pearce-Higgins

A long-standing aim of ecologists is to understand the processes involved in regulating populations. One such mechanism is the buffer effect, where lower quality habitats are increasingly used as a species reaches higher population densities, with a resultant average reduction in fecundity and survival limiting population growth. Although the buffer effect has been demonstrated in populations of a number of species, a test of its importance in influencing population growth rates of multiple species across large spatial scales is lacking. Here, we use habitat-specific population trends for 85 bird species from long-term national monitoring data (the UK Breeding Bird Survey) to examine its generality. We find that both patterns of population change and changes in habitat preference are consistent with the predictions of the buffer effect, providing support for its widespread operation.


2014 ◽  
Vol 36 (3) ◽  
pp. 221-230
Author(s):  
Jin-Hong Jung ◽  
Ji-Young Park ◽  
Young-Han Yoon ◽  
Hyun-Man Lim ◽  
Weon-Jae Kim

Author(s):  
Ganiyu Titilope Oyerinde ◽  
Agnide E. Lawin ◽  
Oluwafemi E. Adeyeri

Abstract The Niger basin have experienced historical drought episodes and floods in recent times. Reliable hydrological modelling has been hampered by missing values in daily river discharge data. We assessed the potential of using the Multivariate Imputation by Chained Equations (MICE) to estimate both continuous and discontinuous daily missing data across different spatial scales in the Niger basin. The study was conducted on 22 discharge stations that have missing data ranging from 2% to 70%. Four efficiency metrics were used to determine the effectiveness of MICE. The Flow Duration Curves (FDC) of observed and filled data were compared to determine how MICE captured the discharge patterns. Mann-Kendall, Modified Mann-Kendall, Pettit and Sen's Slope were used to assess the complete discharge trends using the gap-filled data. Results shows that MICE near perfectly filled the missing discharge data with Nash-Sutcliffe Efficiency (NSE) range of 0.94–0.99 for the calibration (1992–1994) period. Good fits were obtained between FDC of observed and gap-filled data in all considered stations. All the catchments showed significantly increasing discharge trend since 1990s after gap filling. Consequently, the use of MICE in handling missing data challenges across spatial scales in the Niger basin was proposed.


2015 ◽  
Vol 17 (1) ◽  
pp. 15-28
Author(s):  
Joana Sender ◽  
Weronika Maślanko

Abstract The aim of the study was a hydromorphological valorisation of the river valley in the Roztocze region using the British method - River Habitat Survey (RHS). As a result of field research two numerical indicators HMS (Habitat Modification Score) and HQA (Habitat Quality Assessment) were identified and purity water classes were defined. The river did not fulfil the requirements of the Water Framework Directive, because its state was defined as poor and moderate. On the base of physical and chemical parameters, in the majority of water studied the watercourses were classified to the first class of purity. Only in one segment waters were below the first class, or even out of class.


2014 ◽  
Vol 5 (2) ◽  
pp. 198-207 ◽  
Author(s):  
Jeremy A. Baumgardt ◽  
Joel D. Sauder ◽  
Kerry L. Nicholson

Abstract Numerous forest birds benefit from woodpecker presence or have similar habitat requirements. Monitoring populations of forest woodpeckers can be useful for management decisions regarding these and other forest species. Usefulness of monitoring efforts depends on methods used and the quality of resulting parameter estimates. Estimating the proportion of area occupied by a species can be an attractive and affordable alternative to abundance or survival estimates. The purpose of this study was to assess the distribution and area of occupancy for pileated woodpeckers (Drycopus pileatus) and American three-toed woodpeckers (Picoides dorsalis) in north-central Idaho, and to compare occupancy estimates using silent point counts, playback surveys, and playback surveys that incorporated estimates of detection probability (p). We used a hierarchical multiscale framework that allowed estimation of occupancy at two spatial scales and applied a removal design such that repeat visits to sampling stations was not necessary to estimate p. The initial naïve estimate of occupancy (using presence–absence data) for pileated woodpecker was 0.39, which increased to 0.59 using playback surveys. The corrected estimate of occupancy at the 1-km2 unit scale was 0.70. The naïve estimates of occupancy for American three-toed woodpeckers using silent point counts and playback surveys were 0.14 and 0.34, respectively. The unbiased estimate of occupancy at the 1-km2 unit scale was 0.71. Detection probabilities are known to vary spatially and temporally for numerous reasons. Thus, comparisons of naïve estimates of occupancy to monitor forest woodpeckers would be imprudent and could lead to poor management decisions. We recommend incorporating detection probability for monitoring wildlife species and show how this can be done within a single sampling framework for species that utilize the landscape at disparate scales.


<em>Abstract</em>.—Mangroves are widely understood to be important habitats for fisheries, supporting resident fish, crustacean, and mollusk populations as well as acting as nursery grounds for species that are targeted by offshore fisheries. There is, however, a lack of quantitative data on fisheries that operate in and around mangroves. We carried out a systematic search to gather data on mangrove fisheries from the scientific literature. We filtered the 4,358 studies returned by the search based on their title and abstract and extracted data from 169 of these. Despite the abundance of literature on mangrove fisheries, we were unable to build a data set of comparable, quantitative data of sufficient size to support numerical modeling approaches. In part, this is due to the variety of mangrove fisheries, which range from small-scale subsistence fishing for mollusks and crabs to large-scale industrialized prawn trawling. This is compounded by the broad range of reporting methods and metrics encountered in the literature. We make a number of recommendations to guide the future reporting of mangrove fisheries to allow for better quantification and comparison of fisheries values at large spatial scales.


Author(s):  
Bernadette Pinel-Alloul ◽  
Alain Patoine ◽  
Jérôme Marty

This review provides a Canadian perspective on freshwater zooplankton diversity and ecology across scales and systems. It aims at describing how zooplankton is a source of biodiversity in forms and functions, a key component of plankton food web, a model for ecological theories and a sentinel for monitoring lake ecological integrity and function facing environmental changes and anthropogenic stressors. These objectives are addressed across a continuum of spatial scales and ecosystem types. Zooplankton communities demonstrated a wide range of responses to anthropogenic disturbances across scales and systems due to interactions with watershed biogeochemistry and climate. This review supports the Multiple Forces hypothesis where forcing by abiotic factors have a primordial role at global scale over Canadian ecoregions, and at regional scale in the Boreal ecozones. In contrast, forcing by biotic factors is more influential at local scale, in resort and urban regions. Future research challenge will be to combine all new concepts and approaches in a holistic perspective to examine the response of freshwater zooplankton to multiple environmental changes and anthropogenic stressors.


Sign in / Sign up

Export Citation Format

Share Document