Mussel Habitat Research Articles

Microplastic's Contamination in the Hemolymph and Organs (Gills and Hepatopancreas) of Perna viridis.

The issue of microplastics (MPs) has emerged as a significant concern globally, with discussions surrounding the potential environmental impact of these tiny plastic particles becoming increasingly prevalent. This study aimed to identify the concentration and characteristics of MPs in hemolymph and organs (gills and hepatopancreas) of green mussels (Perna viridis) that are frequently consumed by people in Pangkajene Kepulauan, South Sulawesi Province, Indonesia. Green mussels were collected from two different sampling sites for comparison. Screening was carried out on dispensed hemolymph and dissected organs to identify the characteristics of MPs. Surface seawater sampling was added as information on MP's characteristics from the mussel habitat. Visual observation of MP's characteristics using a stereomicroscope in laminar flow is to prevent contamination. The identification of MP's polymer type is using FTIR-ATR. The results showed that hemolymph, hepatopancreas, gills, and surface water were concentrated with MPs. Small (2-3.9cm) green mussels accumulated more MPs than medium (4-5.9cm) and large (> 6cm). MPs characteristics of fiber shape, transparent color, and size 0.1-0.5mm were dominant in all samples. A total of seven polymers of MPs were identified with polyethylene and polystyrene types most frequently found from all samples. Based on this study, green mussels are good for biomonitoring of MPs.

Mussel culture monitoring with semi-supervised machine learning on multibeam echosounder data using label spreading

High diversity seabed habitats, such as shellfish aggregations, play a significant role in marine ecosystem sustainability but are susceptible to bottom disturbance induced by anthropogenic activities. Regular monitoring of these habitats with effective mapping methods is therefore essential. Multibeam echosounder (MBES) has been widely used in recent decades for seabed characterization due to its non-destructive manner and extensive spatial coverage compared to traditional methods like bottom sampling. Nevertheless, bottom sampling remains essential to link ground truth with acoustic seabed classification. Using seabed samples and MBES measurements, machine learning techniques are commonly employed to model their relationships and generate classification maps of an extended seabed. However, limited ground truth data, resulting from constraints in regulations, budget, or time, may impede the development of robust machine learning models. To address this challenge, we applied a semi-supervised machine learning method to classify seabed sediments of a blue mussel (Mytilus edulis) cultivation area in the Oosterschelde, the Netherlands. We utilized nine boxcore samples to generate pseudo-labels on MBES data. These pseudo-labels enlarged the training data size, facilitated the training of three comprehensive machine learning algorithms (Gradient Boosting, Random Forest, and Support Vector Machine), and helped to classify the study site into mussel and non-mussel areas. We found the geomorphological and backscatter-related features to be complementary for mussel culture detection. Our classification results were demonstrated effective through expert knowledge of this cultivation area and brought insights for future research on natural mussel habitats.

Reintroduction of freshwater mussels (Bivalvia, Unionida) directly after channel dredging can serve as an effective measure in mitigation conservation

This study is based on a natural experiment carried out in the Biebrza National Park, Poland. The study site was a channel inhabited by Anodonta anatina, A. cygnea, Unio pictorum and U. tumidus. The deepening of the channel to restore ecosystem connectivity provided an opportunity to conduct this study. Mussels were collected before dredging, held in captivity for 48 h, measured, individually tagged and released post-dredging to the same 5-m channel sections they originated from. They were subsequently monitored for three consecutive years. Mussel survival remained high throughout the study, and no increased mortality in the year following reintroduction was observed. There was no growth retardation. Mussel mobility was low, with most individuals remaining in the same channel section in which they were released. Recolonisation patterns were consistent with the composition of mussel communities in adjacent unaffected habitats. Although dredging drastically changes mussel habitat, some characteristics: microclimate, water chemistry, nutrient availability and host fish can remain adequate. Our study shows that reintroducing mussels to the same site can serve as an effective mitigation conservation measure and can be preferable to translocation, particularly when carried out under time pressure with limited possibilities of assigning appropriate destination sites.

Assessing Zebra Mussels’ Impact on Fishway Efficiency: McNary Lock and Dam Case Study

The Columbia River Basin faces a threat from the potential invasion of zebra mussels (Dreissena polymorpha), notorious for their ability to attach to various substrates, including concrete, which is common in fishway construction. Extensive mussel colonization within fishways may affect fish passage by altering flow patterns or creating physical barriers, leading to increased travel times, or potentially preventing passage altogether. Many factors affect mussel habitat suitability including vectors of dispersal, water parameters, and various hydrodynamic quantities, such as water depth, velocity, and turbulence. The objective of this study is to assess the potential for zebra mussels to attach to fishway surfaces and form colonies in the McNary Lock and Dam Oregon-shore fishway and evaluate the potential impact of this infestation on the fishway’s efficiency. A computational fluid dynamics (CFD) model of the McNary Oregon-shore fishway was developed using the open-source code OpenFOAM, with the two-phase solver interFoam. Mesh quality is critical to obtain a reliable solution, so the numerical mesh was refined near the free surface and all solid surfaces to properly capture the complex flow patterns and free surface location. The simulation results for the 6-year average flow rate showed good agreement with the measured water column depth over each weir. Regions susceptible to mussel infestation were identified, and an analysis was performed to determine the mussel’s preference to colonize as a function of the depth-averaged velocity, water depth, and wall shear stress. Habitat suitability criteria were applied to the output of the hydraulic variables from the CFD solution and provided insight into the potential impact on the fishway efficiency. Details on the mesh construction, model setup, and numerical results are presented and discussed.

The response of epibenthic molluscan assemblages associated with Mytilus galloprovincialis beds to natural- and human-induced changes: Structure and small-scale spatiotemporal variability

Mussel beds are species-rich and diversified biogenic habitats for associated assemblages, playing important ecological roles and contributing significantly to local littoral invertebrate biodiversity. The community structure and seasonal patterns of molluscan assemblages associated with rocky-intertidal mussel Mytilus galloprovincialis beds along NW Atlantic coast of Morocco were investigated. Sampling was conducted at reference and contaminated stations in three distant coastal areas over a 4-season sampling period (between August 2018 and May 2019). We tested the hypothesis that the biogenic mussel habitats in areas experiencing different environmental conditions along the shore would support different associated molluscan assemblages under human-induced and natural changes at small spatial and temporal scales. A total of 6371 specimens comprising 28 taxa were identified and encompassing four trophic groups (carnivores, detritivores/deposivores, micrograzers and suspensivores). Micrograzers predominated, followed by carnivores, with gastropods being the numerically dominant taxa accounting for 79 % of total abundance. Steromphala pennanti emerged as the most abundant and frequent species, across almost all seasons and stations contributing to 31 % of total abundance. Significant seasonal variations were observed in species richness and Shannon-Wiener’s index (ANOVA, p<0.05), with the highest values recorded at the most polluted stations during cold/wet periods, and the lowest at the cleanest stations during hot/warm periods. Furthermore, the ANOVA analyses unveiled a significant spatiotemporal variation in abundance, emphasizing the dynamic nature of molluscan assemblages in response to environmental conditions and seasonal changes. The multivariate structure of associated molluscan assemblages (PERMANOVA analysis) differed significantly among stations and seasons, highlighting clear geographical and seasonal effects. Gastropod species, including Acanthochitona fascicularis, Lepidochitona cinerea, Nucella lapillus, Patella ulyssiponensis, P. vulgata, Phorcus lineatus, P. sauciatus, and Steromphala pennanti, were identified as the most contributive species to the dissimilarity of molluscan assemblage structure among stations throughout seasons (SIMPER analysis). Based on the canonical correspondence analysis results, salinity, water temperature, nutrient concentrations, sediment granulometry and total organic matter were identified as the key factors driving changes in the molluscan community structure. This study underscores the ecological importance of habitat-forming mussels as ecosystem engineers and biodiversity enhancers in shallow coastal waters along the Moroccan Atlantic coast.

Sounding out horse mussel sediment thickness: an integrated data approach

Horse mussel beds are listed as a Priority Marine Feature (PMF) in Scotland for their influence in the creation of diverse benthic communities and provision of ecosystem services. In Scotland, horse mussel beds are also recognised for their importance in marine carbon sequestration. Unfortunately, there is a paucity of data on horse mussel bed carbon stocks and sediment thickness. There are also significant financial and logistical barriers with which to address these data gaps. This study investigates the robustness of Sub-Bottom Profiling (SBP) as a cost-effective method to quantify horse mussel sediment thickness across a landscape. Integrating SBP and Drop-Down Video (DDV) data, this study also details an integrated approach to investigate the links between horse mussel habitat condition and sediment thickness. With the addition of abiotic data, this study uses Structural Equation Modelling (SEM) to elucidate key relationships between abiotic factors, biotic variables, and sediment thickness. There is a significant positive correlation of horse mussel habitat condition and sediment thickness. Average horse mussel total sediment thickness, across all measures of habitat condition, was 1.37m. These findings substantially increase previous estimates of horse mussel sediment thickness, and potential value to climate change mitigation through blue carbon frameworks. This study highlights the importance of both abiotic and biotic factors on marine carbon sediment quantification.

Distribution Analysis of Green Mussels (Perna viridis) in Banyuurip Village, Ujung Pangkah District, Gresik Regency

The aim of the research was to determine the Distribution analysis of Perna viridis diversity based on the suitability map for green mussel cultivation, analysis of community perceptions and the condition of water bodies. Perna viridis aquaculture is suitable for the waters of Banyuurip village based on the variables of sea depth, sea surface temperature, chlorophyll a concentration, and substrate radiance data. Heavy metal content of Pb is located and distributed in polluted areas. It was found that the potential for green mussel aquaculture is greater in warm water habitats, i.e. closer to the coast. In addition, the northeast was identified as a suitable habitat for green mussels. The mid-ocean area in the north-west is of low suitability due to the lack of substrate and chlorophyll. Analysis of community attitudes and behaviour showed that people remain enthusiastic about green mussel farming, although green mussel shell waste remains an environmental problem. Heavy metal analysis of green mussel samples showed that green mussels are still safe for consumption. Therefore, the main conclusion is that the habitat of Perna viridis in the waters of Banyuurip Village still has potential for cultivation, but the waters must be free from pollution.

Distinct reservoir surface elevation patterns characterize quagga mussel habitat suitability

Distinct reservoir surface elevation patterns characterize quagga mussel habitat suitability

Survey of freshwater mussels using high‐resolution acoustic imaging sonar and deep learning‐based object detection in Lake Izunuma, Japan

Abstract The use of traditional in situ methods for underwater surveys to map freshwater mussel habitats is limited by challenges such as water transparency, depth and high labour demands. In this study, adaptive resolution imaging sonar (ARIS) was applied to monitor mussel distribution and abundance. In contrast to conventional quadrat surveys, this acoustic survey is non‐invasive and enables direct observation of mussels to allow their survival status to be determined in turbid water. ARIS produces high‐quality acoustic images that facilitate the creation of a distribution map for broader‐scale monitoring, especially if paired with deep learning methods such as the YOLOv4 algorithm for automatic mussel detection and classification. ARIS was successfully applied to surveying over 2000 m2 of Lake Izunuma in Miyagi, Japan. In one site, a high mussel abundance of ~0.6 individuals/m2 was detected, while other sites had low densities. The detection model achieved a mean average precision of 0.97. The survey results were used to generate a distribution map of living mussels. This study illustrates the feasibility of using an acoustic video camera with an open‐source deep learning algorithm to monitor mussels and other benthos in turbid water.

Simulating larval dispersal across the distribution of the New Zealand green-lipped mussel: insights into connectivity and source-sink dynamics

Information about population connectivity, including the rates and routes of larval transport as well as source-sink dynamics, is important for the sustainable management of harvested species. For marine species whose primary mode of dispersal is transport during the pelagic larval stage, biophysical modelling of larval dispersal represents a valuable tool that is not subject to some of the same limitations as genetic connectivity analyses. In particular, a model that encompasses the entire distribution of a species can provide novel insights by identifying potentially important source populations or stepping-stone sites from which molecular samples may not be available. This study employed a Lagrangian particle-tracking model to simulate larval releases from all potential mussel habitats along ~15000 km of coastline for an endemic New Zealand bivalve, the green-lipped mussel. A northern and a southern cluster with a break near Cook Strait were identified, confirming the structure reported by earlier genetic analyses and a previous biophysical modelling study. The present study revealed, for the first time, that connectivity between the 2 clusters is largely asymmetrical, with more particle transport from the south to the north. Because this study simulated spawning events across the entire distribution of the species, several previously unknown source populations and stepping-stone populations were identified. These findings highlight the utility of a multidisciplinary approach to understanding marine connectivity and provide evidence for new strategies, including the protection of source and stepping-stone populations, to sustainably manage this endemic species.

Assessing Potential Habitat for Freshwater Mussels by Transferring a Habitat Suitability Model within the Ozark Ecoregion, Missouri

Habitat suitability models for freshwater mussels can inform conservation of these imperiled animals. Riverscape-scale hydrogeomorphic variables were previously used to predict suitable mussel habitat in the Meramec River basin, Missouri. We evaluated transferability of the Meramec River habitat suitability model to the Gasconade and Little Black rivers, in the Ozark Highlands ecoregion, Missouri. The best-fit models relied on transferring and adapting the original modeling framework to better represent the unique habitat characteristics of each river. Mussel bed occurrence in both rivers was associated with reaches that were classified as pools. Mussel beds in the Gasconade River were also associated with laterally stable reaches adjacent to small bluffs, distant from gravel bars, and with higher stream power indices. Mussel beds in the Little Black River were associated with reaches with higher surface water availability during low-flow conditions, lower stream power indices, and bluffs located downstream. Our results show that existing habitat models can be transferred to other streams with similar environmental conditions, but differences in watershed characteristics can affect transferability.

Fish ecology and sediment conditions in freshwater pearl mussel (M. margaritifera) habitats

Stable, healthy populations of locally adapted brown trout (Salmo trutta) are crucial for the reproduction of the freshwater pearl mussel (Margaritifera margaritifera), as they serve as host fish in its life cycle. In the Interreg project Malšemuschel at the river Maltsch/Malše the hydro-morphology and sediment conditions were analysed regarding their influence on the biocoenoses of rhithral waters on granitic bedrock. In this paper, the fish fauna is highlighted in particular. It could be shown that sand on the one hand and finer fractions on the other impair watercourses and their fish fauna in different ways. While an increase in fine sediments (clay, silt) causes shifts in species compositions and leads to a steady decrease in abundances, sand rather influences the hydromorphology by reducing pools, flattening out the river bed and covering structures. Thus, sand seems to more directly influence the biomass and to cause a sharp deterioration of the fish fauna when a certain threshold is exceeded. Furthermore, it could be shown that brown trout populations are strongly related to the presence of natural structures e.g. large boulders or riparian vegetation.

Assessing the potential for restoring freshwater mussels to urban streams

Abstract Field trials were conducted to assess the potential for stocking native unionid mussels in urban streams of the Chesapeake Bay catchment. Juvenile, hatchery‐raised mussels were placed in enclosures at five urban streams (two restored and three unrestored) and two nearby rural streams. Adult mussels were translocated to two restored urban streams. Mussel growth and survivorship were assessed at the stream sites and for individuals maintained at hatchery ponds. At all sites, water quality conditions were generally suitable for mussels with respect to temperature, pH, and dissolved oxygen. Food resources, as indicated by the quantity and quality of suspended and benthic particulate matter, were higher among rural sites and lower in unrestored urban streams. Positive growth rates were observed at all sites, among both juveniles (caged) and translocated adults. Mussel fatty acid profiles were generally similar among sites, except for docosahexaenoic acid (DHA), which was lower among stocked mussels relative to mussels maintained at the hatchery. Among the unrestored urban streams, the frequent occurrence of high discharge events resulted in burial and downstream loss of enclosures. At restored urban streams and rural streams, the washout effects were less severe. Apart from washout effects, mortality, as indicated by the presence of dead mussels, was low (&lt;10%). Overall, rural and restored urban streams provided suitable conditions for stocking native mussels, whereas in unrestored urban streams, bed and bank instability during high discharge events resulted in a high attrition of mussels. Conservation efforts may be aided by the consideration of mussel habitat needs in the design of stream restoration projects. The inclusion of mussel stocking efforts in urban stream restoration projects has the potential to facilitate stream recovery, expand and bring greater attention to mussel conservation efforts, and garner public support for the preservation of stream health in urban areas.

Taxonomic Reassessment of Freshwater Mussels from the Western Balkans Reveals an Overlooked but Critical Refugium and Defines Conservation Priorities

Freshwater mussels are an endangered group of animals, especially in the water bodies of Central and Western Europe. Conservation priorities were established for many endangered freshwater mussel species in the last decade. Here, we present new data on a cryptic refugium of freshwater mussels in the Western Balkans. Two species, Anodonta exulcerata Porro, 1838 and Unio elongatulus Pfeiffer, 1825, were discovered in Montenegro for the first time. The phylogenetic position and taxonomic status of freshwater mussel species from Montenegro were studied by means of an integrative approach, combining morphological data and COI gene sequences. Unio carneus Küster, 1854 stat. rev. represents a species with a restricted range, which is endemic to the Western Balkans. A viable population of Microcondylaea bonellii (Férussac, 1827) was discovered in the Zeta River. This species was not mentioned in Montenegro since the 1900s. A significant level of genetic diversity was revealed for the studied species. In the Skadar Lake basin, freshwater mussels from diverse ecological groups were discovered. Rheophilic species of freshwater mussels may represent ancient lineages, which need special conservation planning. Conservation priorities should be aimed at the protection of freshwater mussel habitats on the Balkan Peninsula.

Biodiversity associated with restored small-scale mussel habitats has restoration decision implications

The global loss of marine ecosystem engineers has caused an unprecedented decline in biodiversity. Although wild shellfish habitats have been shown to support biodiverse ecosystems, little is known about how biodiversity is altered by restored shellfish habitats, particularly mussels. To explore the biodiversity response to restored mussel habitats we deposited mussels on the seafloor in 1.5 × 1.5 m plots across a gradient of benthic environments. To understand a holistic community response, this study looks at the response of three faunal classifications over 1 year: infauna, epifauna, and pelagic fauna, compared with adjacent control plots (no mussels). The restored mussel habitats recorded 42 times more demersal fish than control areas, while macroalgae and mobile benthic invertebrates had over a twofold increase in abundance. Overall, the addition of mussels to the seafloor resulted in a general reduction of infaunal abundance and biodiversity, but an increase in epifaunal and pelagic faunal abundances, specifically from those species that benefit from benthic habitat complexity and an increase in food availability. From a management perspective, we highlight location-specific differences to consider for future restoration efforts, including environmental conditions and potential observed factors such as nearby sources of species, particularly predators, and relevant demersal fish ranges. Ultimately, measuring biodiversity responses in small-scale studies will serve as a valuable guide for larger scale restoration efforts and this study recommends considerations to enhance biodiversity outcomes in restored mussel habitats.

A novel multivariate ecological approach to modeling freshwater mussel habitats verified by ground truthing

A novel multivariate ecological approach to modeling freshwater mussel habitats verified by ground truthing

Long-term monitoring reveals unprecedented stability of a vent mussel assemblage on the Mid-Atlantic Ridge

Understanding scales and drivers of ecological variability is essential to a full understanding of ecosystem functioning. At remote deep-sea hydrothermal vents, infra-annual dynamics remain poorly described. This study aims to characterise the factors that drive the dynamics of a vent faunal assemblage dominated by Bathymodiolus azoricus mussels from infra-daily to monthly time steps. We analysed a 7-year time series of images and environmental data collected at a depth of 1695 m at the base of the active Eiffel Tower edifice in the Lucky Strike vent field (Mid-Atlantic Ridge). Using images acquired by the TEMPO ecological module connected to the EMSO-Azores observatory, we assessed the dynamics of key species inhabiting the faunal assemblage in relation to changes in environmental conditions monitored daily.Our results show that habitat conditions were generally stable over the 7-year period, with small-scale variability related to tidal periodicity and local temperature anomalies. Likewise, the mussel and zoanthid assemblages exhibited remarkable stability. Changes in fluid exposure and substratum instability induced decimetre-scale movements of the mussel assemblage. Microbial mats displayed infra-annual changes characterised by aperiodic growth and decline. Their development patterns could not be entirely attributed to environmental conditions, because other factors, including biotic interactions, appeared to be involved. The crab population preferentially occupied the mussel habitat, but no predation was observed. Scales of variation and driving factors were compared with those governing intertidal zones. The outcomes question the assumption that vent fauna experience extreme and highly variable conditions. On the MAR, mussel assemblages appear to experience relatively stable and mild environmental conditions compared with their coastal counterparts.

Prediction of potential freshwater pearl mussel habitat aids in discovery of a large population of Margaritifera laevis in Iturup Island, Russia

Abstract Freshwater pearl mussels (family Margaritiferidae) are sensitive to human impact and environmental changes. Large declines in their abundance have prompted studies of distribution and estimations of population densities. Iturup Island, a part of Kuril Islands, Russia, is considered to be within the distribution area of freshwater pearl mussels, but this information is based on only two specimens collected several decades ago. Detailed survey of the island is challenging as most of its territory is nearly impassable. A preliminary analysis of island rivers was carried out prior to the surveys to discover potential freshwater pearl mussel habitats. Based on previous experience from European Russia, freshwater pearl mussel habitat was expected to occur in rivers flowing out of lowland lakes. Live individuals of Margaritifera laevis were found during surveys in one river together with the unionid Beringiana beringiana, which were also found in two other rivers where the predicted habitat occurred. Based on prediction and surveys, the occurrence of freshwater pearl mussels in other rivers of Iturup Island is unlikely. Pearl mussels were concentrated in a small section of the Zmeika River with a population of about 100,000 mussels. Present threats to the population include overharvest of host fish masou salmon (Oncorhynchus masou). Surveys using similar methods can help to reveal unknown freshwater mussel populations on other Kuril Islands and on the mainland.

Increased sediment deposition triggered by climate change impacts freshwater pearl mussel habitats and metapopulations

Abstract The freshwater pearl mussel Margaritifera margaritifera is a benthic organism sensitive to hydrological regime alterations and habitat degradation driven by excessive fine bed material deposit (FBMD). Both issues are potentially exacerbated by climate change. Understanding how climate change affects future mussel habitats and the dispersal among them (dependent on the brown trout as fish host) can support the planning of effective conservation actions. To project the impacts of climate change on the mussel, a semi‐mechanistic modelling cascade was implemented for the Aist catchment in Austria (630 km2), including a hydrological model, a hydraulic model, Random Forest Models for FBMD accumulation risk and Species Distribution Models. Two climate change models (RCPs 4.5 and 8.5) for two future horizons (2060 and 2090) were considered. A graph‐based assessment of the structural connectivity was used to measure the probability of successful dispersal. Results show a reduction of peak discharge that cascades into a widespread reduction in shear stresses during high flow. The mussel's habitats, defined by hydraulics (i.e. patches with low shear stresses during high flow), are predicted to be stable over the simulated scenarios. The pressure of FBMDs over the delineated habitat patches is predicted to increase in the future due to the reduced stream transport capacity, reducing up to 25% of the available patches in 2090 for RCP 8.5. Consequently, the mussel's dispersal probability decreases to 44.3%–75.6% of the maximum theoretical value, with the highest drops for short dispersal distances, impacting metapopulation dynamics. Synthesis and applications. The widespread issue of fine sediment deposition in the streambed will be exacerbated for those catchments where climate change reduces the stream transport capacity. The impacts on the freshwater pearl mussel include habitat loss due to the formation of a new unsuitable substrate, and a decrease in the potential dispersal among the residual habitats. Thus, conservation plans that aim to protect the mussel in the future should focus on the mitigation of fine bed material deposits, prioritizing those subreaches that offer the highest potential for preserving connectivity among suitable habitats.

A review and evaluation of the effects of hydrodynamic variables on freshwater mussel communities

Abstract Riverine species are governed by the physical (i.e. hydrodynamic) forces generated by flowing water. Freshwater species are also disproportionately imperilled compared to terrestrial and marine species in large part due to widespread anthropogenic alteration of the natural flow regimes to which organisms are adapted. Sedentary species such as freshwater mussels (Bivalvia: Unionoida) are especially vulnerable because they are unable to move quickly in response to novel flow patterns created by impoundments and water withdrawals. We evaluated the effects of hydrodynamic variables on mussel communities. We reviewed the literature to synthesise the relationships between three categories of hydrodynamic variables (hydrologic, simple hydraulic, and complex hydraulic) and mussel community parameters. We evaluated which variables are most useful in predicting mussel presence, abundance, and species richness, provided recommendations to help standardise their use in characterising mussel habitat and reviewed the reciprocal influence of mussels on hydraulic forces at the sediment–water interface. Hydrologic variables such as stream size and anthropogenic flow alteration were useful in predicting basin‐ and landscape‐scale changes in mussel communities. At finer scales, complex hydraulic variables—mainly shear stress and Reynolds number—were more useful at predicting mussel community responses. Simple hydraulic variables (flow velocity, depth, discharge) had mixed success as predictors of mussel community parameters and are likely to be indirectly correlated to mussel responses because they are used to calculate more complex variables. More emphasis should be placed on species‐ and basin‐specific responses of freshwater mussels when considering the effects of the hydrologic regime on mussels, with an eye towards sustainable water management (e.g. flow restoration, environmental flows). Simple hydraulic variables should be assessed across the range of discharge at a site, in combination with channel and substrate characteristics. This allows the calculation of complex hydraulic variables that may be more directly limiting to mussel communities. Mussels also alter near‐bed hydraulic characteristics, resulting in feedbacks between mussel community parameters and local hydraulic variable s. Researchers should consider that mussel beds have a reciprocal influence on near‐bed flow characteristics and should continue to explore the effects of such ecological engineering for possible interspecific facilitation benefits between mussel species.