Environmental Science › Ecology

Aquatic Invertebrate Ecology and Behavior

Works Count: 49136

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Description

This cluster of papers focuses on the ecological impact of freshwater mussels, particularly the invasive species, on aquatic ecosystems. It covers topics such as biodiversity loss, ecosystem engineering, conservation genetics, and the environmental impacts of unionoida and dreissenid mussels.

Keywords

Freshwater Mussels; Invasive Species; Ecosystem Engineering; Biodiversity Loss; Aquatic Invasions; Unionoida; Dreissenid Mussels; Conservation Genetics; Ecosystem Function; Environmental Impacts

Extraction of high molecular weight DNA from molluscs

1993-12-01

Birgitta Winnepenninckx , Thierry Backeljau , Rupert De Wächter

Predation and Freshwater Communities

1982-02-01

J. M. Elliott , Thomas M. Zaret

Invasive Aquatic Species of Europe. Distribution, Impacts and Management

2002-01-01

Erkki Leppäkoski , Stephan Gollasch , Sergej Olenin

Sulphate reduction and sulphur cycling in lake sediments: a review

2001-04-28

Marianne Holmer , Peter Storkholm

1. The concentration of sulphate is low in lakes and sulphur cycling has often been neglected in studies of organic matter diagenesis in lake sediments. The cycling of sulphur is, … 1. The concentration of sulphate is low in lakes and sulphur cycling has often been neglected in studies of organic matter diagenesis in lake sediments. The cycling of sulphur is, however, both spatially and temporally dynamic and strongly influences many biogeochemical reactions in sediments, such as the binding of phosphorus. This review examines the control of sulphate reduction and sulphur cycling in sediments of lakes with different trophic status. 2. The factors that control the rate of sulphate reduction have not been identified with certainty in the various environments because many factors are involved, e.g. oxygen and sulphate concentrations, temperature and organic matter availability. 3. Sulphate reduction is less significant under oligotrophic conditions, where mineralization is dominated by oxic decomposition. The supply of organic matter may not be sufficient to support sulphate reduction in the anoxic parts of sediments and, also, sulphate availability may control the rate as the concentration is generally low in oligotrophic lakes. 4. There is a potential for significant sulphate reduction in eutrophic lakes, as both the availability of organic matter and sulphate concentration are often higher than in oligotrophic lakes. Sulphate is rapidly depleted with sediment depth, however, and methanogenesis is generally the most important process in overall carbon mineralization. Sulphate reduction is generally low in acidic lakes because of low sulphate availability and reduced microbial activity. 5. It is still unclear which of the forms of sulphur deposits are the most important and under which conditions burial occurs. Sulphur deposition is controlled by the rate of sulphate reduction and reoxidation. Reoxidation of sulphides occurs rapidly through several pathways, both under oxic and anoxic conditions. Only a few studies have been able to examine the importance of reoxidation, but it is hypothesized that most of the reoxidation takes place under anoxic conditions and that disproportionation is often involved. The presence of sulphide oxidizing bacteria, benthic fauna and rooted macrophytes may substantially enhance oxic reoxidation. Deposition of sulphur is generally higher in eutrophic than in oligotrophic lakes because of a number of factors: a higher rate of sulphate reduction, enhanced sedimentation of organic sulphur and less reoxidation as a result of reduced penetration of oxygen into the sediments, a lack of faunal activity and rooted macrophytes.

Changing Perspectives on Pearly Mussels, North America's Most Imperiled Animals

2004-01-01

David L. Strayer , John Downing , Wendell R. Haag +4 more

Pearly mussels (Unionacea) are widespread, abundant, and important in freshwater ecosystems around the world. Catastrophic declines in pearly mussel populations in North America and other parts of the world have … Pearly mussels (Unionacea) are widespread, abundant, and important in freshwater ecosystems around the world. Catastrophic declines in pearly mussel populations in North America and other parts of the world have led to a flurry of research on mussel biology, ecology, and conservation. Recent research on mussel feeding, life history, spatial patterning, and declines has augmented, modified, or overturned long-held ideas about the ecology of these animals. Pearly mussel research has begun to benefit from and contribute to current ideas about suspension feeding, life-history theory, metapopulations, flow refuges, spatial patterning and its effects, and management of endangered species. At the same time, significant gaps in understanding and apparent paradoxes in pearly mussel ecology have been exposed. To conserve remaining mussel populations, scientists and managers must simultaneously and aggressively pursue both rigorous research and conservation actions.

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Are invasive species a major cause of extinctions?

2004-07-23

Jessica Gurevitch , Dianna K. Padilla

Ecological and Genetic Studies on<i>Dreissena polymorpha</i>(Pallas): a New Mollusc in the Great Lakes

1989-09-01

Paul D. N. Hebert , B. W. Muncaster , Gerry Mackie

Dreissena polymorpha, a bivalve mollusc endemic to Europe, has established a population in Lakes St. Clair and Erie, likely as a result of ballast water discharge. Allozyme studies showed that … Dreissena polymorpha, a bivalve mollusc endemic to Europe, has established a population in Lakes St. Clair and Erie, likely as a result of ballast water discharge. Allozyme studies showed that the Lake St. Clair population was polymorphic at 73.9% of the loci examined and that individual heterozygosities averaged 31.6%. This high level of genotypic diversity indicated that the population was founded from a substantial number of individuals and did not undergo a bottleneck subsequent to founding. The population is reproducing with peak densities in excess of 200 individuals∙m −2 . Juvenile settlement occurs in late July and August with veliger larvae preferentially settling on the shells of live mussels. The species appears likely to become a dominant member of the shallow water benthos throughout the lower Great Lakes.

Assessing the Effects of Climate Change on Aquatic Invasive Species

2008-06-01

Frank J. Rahel , Julian D. Olden

Abstract: Different components of global environmental change are typically studied and managed independently, although there is a growing recognition that multiple drivers often interact in complex and nonadditive ways. We … Abstract: Different components of global environmental change are typically studied and managed independently, although there is a growing recognition that multiple drivers often interact in complex and nonadditive ways. We present a conceptual framework and empirical review of the interactive effects of climate change and invasive species in freshwater ecosystems. Climate change is expected to result in warmer water temperatures, shorter duration of ice cover, altered streamflow patterns, increased salinization, and increased demand for water storage and conveyance structures. These changes will alter the pathways by which non‐native species enter aquatic systems by expanding fish‐culture facilities and water gardens to new areas and by facilitating the spread of species during floods. Climate change will influence the likelihood of new species becoming established by eliminating cold temperatures or winter hypoxia that currently prevent survival and by increasing the construction of reservoirs that serve as hotspots for invasive species. Climate change will modify the ecological impacts of invasive species by enhancing their competitive and predatory effects on native species and by increasing the virulence of some diseases. As a result of climate change, new prevention and control strategies such as barrier construction or removal efforts may be needed to control invasive species that currently have only moderate effects or that are limited by seasonally unfavorable conditions. Although most researchers focus on how climate change will increase the number and severity of invasions, some invasive coldwater species may be unable to persist under the new climate conditions. Our findings highlight the complex interactions between climate change and invasive species that will influence how aquatic ecosystems and their biota will respond to novel environmental conditions.

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Three hundred ways to assess Europe's surface waters: An almost complete overview of biological methods to implement the Water Framework Directive

2011-12-09

Sebastian Birk , W. Bonne , Ángel Borja +7 more

The functional role of burrowing bivalves in freshwater ecosystems

2001-11-01

Caryn C. Vaughn , Christine C. Hakenkamp

1. Freshwater systems are losing biodiversity at a rapid rate, yet we know little about the functional role of most of this biodiversity. The ecosystem roles of freshwater burrowing bivalves … 1. Freshwater systems are losing biodiversity at a rapid rate, yet we know little about the functional role of most of this biodiversity. The ecosystem roles of freshwater burrowing bivalves have been particularly understudied. Here we summarize what is known about the functional role of burrowing bivalves in the orders Unionoida and Veneroida in lakes and streams globally. 2. Bivalves filter phytoplankton, bacteria and particulate organic matter from the water column. Corbicula and sphaeriids also remove organic matter from the sediment by deposit feeding, as may some unionids. Filtration rate varies with bivalve species and size, temperature, particle size and concentration, and flow regime. 3. Bivalves affect nutrient dynamics in freshwater systems, through excretion as well as biodeposition of faeces and pseudofaeces. Excretion rates are both size and species dependent, are influenced by reproductive stage, and vary greatly with temperature and food availability. 4. Bioturbation of sediments through bivalve movements increases sediment water and oxygen content and releases nutrients from the sediment to the water column. The physical presence of bivalve shells creates habitat for epiphytic and epizoic organisms, and stabilizes sediment and provides refugia for benthic fauna. Biodeposition of faeces and pseudofaeces can alter the composition of benthic communities. 5. There is conflicting evidence concerning the role of resource limitation in structuring bivalve communities. Control by bivalves of primary production is most likely when their biomass is large relative to the water volume and where hydrologic residence time is long. Future studies should consider exactly what bivalves feed upon, whether feeding varies seasonally and with habitat, and whether significant overlap in diet occurs. In particular, we need a clearer picture of the importance of suspension versus deposit feeding and the potential advantages and tradeoffs between these two feeding modes. 6. In North America, native burrowing bivalves (Unionidae) are declining at a catastrophic rate. This significant loss of benthic biomass, coupled with the invasion of an exotic burrowing bivalve ( Corbicula ), may result in large alterations of ecosystem processes and functions.

Zebra mussels : biology, impacts, and control

1993-01-01

Thomas F. Nalepa , Donald W. Schloesser

Part 1 Biology: thirty years of studies of dreissena polymorpha pallas ecology in Mazurian lakes of northeastern Poland. Part 2 Morphology and physiology: the anatomy of dreissena polymorpha and the … Part 1 Biology: thirty years of studies of dreissena polymorpha pallas ecology in Mazurian lakes of northeastern Poland. Part 2 Morphology and physiology: the anatomy of dreissena polymorpha and the evolution and success of the heteromyarian form in the dreissenoida. Part 3 Impacts: the impact of dreissena polymorpha on water works operation at Monroe Michigan. Part 4 Controls: monitoring and control of dreissena polymorpha and other macrofouling bivalves in European industrial and power plant cooling water systems.

Eutrophication in peel inlet—II. Identification of critical uncertainties via generalized sensitivity analysis

1980-01-01

Robert C. Spear

Exotic Species in the Great Lakes: A History of Biotic Crises and Anthropogenic Introductions

1993-01-01

Edward L. Mills , J. H. Leach , James T. Carlton +1 more

Extinction Rates of North American Freshwater Fauna

1999-10-23

Anthony Ricciardi , Joseph B. Rasmussen

Abstract: Since 1900, 123 freshwater animal species have been recorded as extinct in North America. Hundreds of additional species of fishes, mollusks, crayfishes, and amphibians are considered imperiled. Using an … Abstract: Since 1900, 123 freshwater animal species have been recorded as extinct in North America. Hundreds of additional species of fishes, mollusks, crayfishes, and amphibians are considered imperiled. Using an exponential decay model, we derived recent and future extinction rates for North American freshwater fauna that are five times higher than those for terrestrial fauna. Assuming that imperiled freshwater species will not survive throughout the next century, our model projects a future extinction rate of 4% per decade, which suggests that North America's temperate freshwater ecosystems are being depleted of species as rapidly as tropical forests.

The nearshore phosphorus shunt: a consequence of ecosystem engineering by dreissenids in the Laurentian Great Lakes

2004-07-01

Robert E. Hecky , Ralph E.H. Smith , David R. Barton +4 more

Dreissenid mussels have been exceptionally successful invaders in North American lakes and rivers, especially in the lower Laurentian Great Lakes. As benthic filter feeders capable of attaching to hard substrates, … Dreissenid mussels have been exceptionally successful invaders in North American lakes and rivers, especially in the lower Laurentian Great Lakes. As benthic filter feeders capable of attaching to hard substrates, the magnitudes of their biomass and filtering activity in nearshore waters are without precedent. The dreissenid colonization has implications for the removal and fate of materials filtered from the water by the mussels and for the longer-term development of the nearshore benthic community and lake ecosystem. A conceptual model, the nearshore shunt, seeks to describe a fundamental redirection of nutrient and energy flow consequent to dreissenid establishment. The model explains some emergent problems in the Great Lakes, such as reemergence of Cladophora in some coastal zones while offshore P concentrations remain low, and highlights areas in need of more research. The source of particulate nutrient inputs to dreissenids and the fate of materials exported from the benthic community are critical to understanding the role of dreissenids in the lakes and assessing the applicability of current models for managing nutrients and fisheries. The nearshore shunt would require even more stringent P management for lakes strongly impacted by dreissenids to maintain nearshore water quality.

Conservation Status of Freshwater Mussels of the United States and Canada

1993-09-01

James D. Williams , Melvin L. Warren , Kevin S. Cummings +2 more

The American Fisheries Society (AFS) herein provides a list of all native freshwater mussels (families Margaritiferidae and Unionidae) in the United States and Canada. This report also provides state and … The American Fisheries Society (AFS) herein provides a list of all native freshwater mussels (families Margaritiferidae and Unionidae) in the United States and Canada. This report also provides state and provincial distributions; a comprehensive review of the conservation status of all taxa; and references on biology, conservation, and distribution of freshwater mussels. The list includes 297 native freshwater mussels, of which 213 taxa (71.7%) are considered endangered, threatened, or of special concern. Twenty-one taxa (7.1%) are listed as endangered but possibly extinct, 77 (20.6%) as endangered but extant, 43 (14.5%) as threatened, 72 (24.2%) as of special concern, 14 (4.7%) as undetermined, and only 70 (23.6%) as currently stable. The primary reasons for the decline of freshwater mussels are habitat destruction from dams, channel modification, siltation, and the introduction of nonindigenous mollusks. The high numbers of imperiled freshwater mussels in the United States and Canada, which harbor the most diverse fauna in the world, portend a trajectory toward an extinction crisis that, if unchecked, will severely impoverish one of our richest components of aquatic biodiversity.

Freshwater biomonitoring and benthic macroinvertebrates

1993-07-01

David M. Rosenberg , Vincent H. Resh

Introduction to freshwater biomonitoring and benthic macroinvertebrates-- D. M. Rosenberg and V. H. Resh A history of biological monitoring using benthic macroinvertebrates-- J. Cairns, Jr. and J. R. Pratt The … Introduction to freshwater biomonitoring and benthic macroinvertebrates-- D. M. Rosenberg and V. H. Resh A history of biological monitoring using benthic macroinvertebrates-- J. Cairns, Jr. and J. R. Pratt The literature of biomonitoring-- K. E. Marshall Freshwater biomonitoring using individual organisms, populations, and species assemblages of benthic macroinvertebrates-- R. K. Johnson, T. Weiderholm and D. M. Rosenberg Contemporary quantitative approaches to biomonitoring using benthic macroinvertebrates-- V. H. Resh and E. P. McElravy Rapid assessment approaches to biomonitoring using benthic macroinvertebrates-- V. H. Resh and J. K. Jackson Analysis and interpretation of benthic macroinvertebrate surveys-- R. H. Norris and A. Georges Monitoring freshwater benthic macroinvertebrates and benthic processes: measures for assessment of ecosystem health-- S. R. Reice and M. Wohlenberg Paleolimnological biomonitoring using freshwater benthic macroinvertebrates-- I. R. Walker toxicity studies using freshwater benthic macroinvertebrates-- A. L. Buikema, Jr. and J. Reice Voshell, Jr. Field experiments in biomonitoring-- S. D. Cooper and L. Barmuta Future directions in freshwater biomonitoring using benthic macroinvertebrates-- R. O. Brinkhurst.

Effects of Acid Rain on Freshwater Ecosystems

1988-01-08

D. W. Schindler

Acid-vulnerable areas are more numerous and widespread than believed 7 years ago. Lakes and streams in acid-vulnerable areas of northeastern North America have suffered substantial declines in acid-neutralizing capacity, the … Acid-vulnerable areas are more numerous and widespread than believed 7 years ago. Lakes and streams in acid-vulnerable areas of northeastern North America have suffered substantial declines in acid-neutralizing capacity, the worst cases resulting in biological damage. Many invertebrates are very sensitive to acidification, with some disappearing at pH values as high as 6.0. However, the recent rate of acidification of lakes is slower than once predicted, in part the result of decreases in sulfur oxide emissions. A discussion of some of the processes that have contributed to the acidification of lakes as well as those that have protected acid-sensitive freshwaters is presented. The author is in the Department of Fisheries and Oceans, Freshwater Institute, 501 University Crescent, Winnipeg, Manitoba R3T 2N6, Canada.

Energy Flow in the Salt Marsh Ecosystem of Georgia

1962-10-01

John M. Teal

Detritus Processing by Macroinvertebrates in Stream Ecosystems

1979-01-01

Norman H. Anderson , J. R. Sedell

The detritus pathway is that in which plant or animal material dies and is then attacked by microorganisms. More of the energy fixed by autotrophic organisms is probably transferred through … The detritus pathway is that in which plant or animal material dies and is then attacked by microorganisms. More of the energy fixed by autotrophic organisms is probably transferred through this route than through the grazing pathway (98). Detritus cannot be precisely defined in terms of its chemical composition or associated microorganisms. As an operational definition, Boling et al (16) defined it as all particulate (>0.45-μm particle diameter) organic matter (reduced carbon compounds) together with associated microbiota—fungi, bacteria, protozoa, and other microinvertebrates. Microbes are included as part of the detritus because the relationship between them and the organic substrate is so intimate that independence is never observed in nature; also, efficient separation techniques applicable to field-collected detritus are nonexistent. The role of detritus in aquatic ecosystems was discussed in two recent symposia (1, 109). Studies of biological decomposition are interdisciplinary in nature and were a theme of the International Biological Programs in freshwater, marine, and terrestrial projects (1). Thus, with the upsurge of interest in this topic, it is timely to review contributions, especiajly on the

A review of harmful algal blooms and their apparent global increase

1993-03-01

Gustaaf M. Hallegraeff

No abstract available. No abstract available.

Eradication revisited: dealing with exotic species

2000-08-01

Judith H. Myers , Daniel Simberloff , Armand M. Kuris +1 more

INTRODUCED SPECIES: A SIGNIFICANT COMPONENT OF HUMAN-CAUSED GLOBAL CHANGE

1997-01-01

Peter M. Vitousek , Carla M. D’Antonio , Lloyd L. Loope +2 more

Humans move species beyond their native ranges both deliberately and inadvertently, and many of these species become established and spread in their new habitat. The list of established introduced species … Humans move species beyond their native ranges both deliberately and inadvertently, and many of these species become established and spread in their new habitat. The list of established introduced species grows annually, as does the number of them that cause significant economic and ecological effects. One recent and notorious example in North America is the Eurasian zebra mussel which like many other aquatic organisms entered in the ballast water of ships, and like many others spread rapidly once it arrived. The invasion of zebra mussels is unusual in the magnitude of its economic consequences; the mussels grow and reproduce rapidly, covering river and lake bottoms and municipal and industrial water inlets. The cost of clearing blocked intake pipes has been calculated to be approximately US$2 billion (Office of Technology Assessment, 1993). Zebra mussels also alter populations of algae and the concentrations of nutrients in whole ecosystems (Caraco et al., 1997), and they are continuing to spread in rivers, lakes, and canals throughout North America. We suggest that biological invasions by notorious species like the zebra mussel, and its many less-famous counterparts, have become so widespread as to represent a significant component of global environmental change. This point has been made before (eg Elton, 1958), but is not widely appreciated, even by the global change research community or by those who study and/or work to control biological invasions. In part, this lack of appreciation reflects the fact that our perception is limited spatially it is possible to document the presence and importance of biological invasions almost anywhere, but more difficult to perceive that invasions are almost everywhere. In part, it may also reflect a narrow view of global environmental change, one that emphasizes climate change (global warming) at the expense of other, equally significant components of human-caused global change. In this paper, we place biological invasions in context with other human-caused global environmental changes; briefly describe the global extent of biological invasion; illustrate the consequences of particular invasions as they affect human health and wealth, and/or the functioning and biological diversity of natural ecosystems; discuss interactions between biological invasions and other components of global change; and describe ways that society can prevent, manage, and/or cope with invasions.

The Role of Benthic Invertebrate Species in Freshwater Ecosystems

1999-02-01

Alan P. Covich , Margaret A. Palmer , Todd A. Crowl

Small invertebrates are functionally important in many terres- Small invertebrates are functionally important in many terres-

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Animal-sediment relationships revisited: cause versus effect

1995-08-01

Paul V. R. Snelgrove , Cheryl Ann Butman

Ecological Forecasts: An Emerging Imperative

2001-07-27

James S. Clark , S. R. Carpenter , M. Craig Barber +7 more

Planning and decision-making can be improved by access to reliable forecasts of ecosystem state, ecosystem services, and natural capital. Availability of new data sets, together with progress in computation and … Planning and decision-making can be improved by access to reliable forecasts of ecosystem state, ecosystem services, and natural capital. Availability of new data sets, together with progress in computation and statistics, will increase our ability to forecast ecosystem change. An agenda that would lead toward a capacity to produce, evaluate, and communicate forecasts of critical ecosystem services requires a process that engages scientists and decision-makers. Interdisciplinary linkages are necessary because of the climate and societal controls on ecosystems, the feedbacks involving social change, and the decision-making relevance of forecasts.

Ecological Predictions and Risk Assessment for Alien Fishes in North America

2002-11-08

Cynthia S. Kolar , David M. Lodge

Methods of risk assessment for alien species, especially for nonagricultural systems, are largely qualitative. Using a generalizable risk assessment approach and statistical models of fish introductions into the Great Lakes, … Methods of risk assessment for alien species, especially for nonagricultural systems, are largely qualitative. Using a generalizable risk assessment approach and statistical models of fish introductions into the Great Lakes, North America, we developed a quantitative approach to target prevention efforts on species most likely to cause damage. Models correctly categorized established, quickly spreading, and nuisance fishes with 87 to 94% accuracy. We then identified fishes that pose a high risk to the Great Lakes if introduced from unintentional (ballast water) or intentional pathways (sport, pet, bait, and aquaculture industries).

Geographical patterns in range extension of Ponto-Caspian macroinvertebrate species in Europe

2002-07-01

A. bij de Vaate , Krzysztof Jażdżewski , Henk A. M. Ketelaars +2 more

Range extensions of aquatic Ponto-Caspian macroinvertebrate species in Europe have mainly been facilitated by the interconnection of river basins through man-made canals and intentional introductions. Three inland migration corridors can … Range extensions of aquatic Ponto-Caspian macroinvertebrate species in Europe have mainly been facilitated by the interconnection of river basins through man-made canals and intentional introductions. Three inland migration corridors can be distinguished: (i) a northern corridor: Volga [Formula: see text] Lake Beloye [Formula: see text] Lake Onega [Formula: see text] Lake Ladoga [Formula: see text] Neva [Formula: see text] Baltic Sea, (ii) a central corridor connecting the rivers Dnieper [Formula: see text] Vistula [Formula: see text] Oder [Formula: see text] Elbe [Formula: see text] Rhine, and (iii) a southern corridor connecting the Danube and Rhine rivers. Important trade harbours in Europe were connected via these corridors allowing further range extensions of macroinvertebrate species attached to a vessel's hull or in ballast water. The central corridor was the main migration route before 1992, after which the southern corridor became the most important migration route for the range expansions to the west because of the reopening of the Main-Danube Canal, connecting the Rhine and Danube basins. Especially the water level maintenance in the upper part of the canal, with water supply from the Danube basin, facilitated migration of mobile animals (e.g., crustaceans) from the Danube basin towards the Rhine basin; however, contribution of other transport mechanisms (e.g., shipping) is expected in the near future.

An ounce of prevention or a pound of cure: bioeconomic risk analysis of invasive species

2002-11-22

Brian Leung , David M. Lodge , David Finnoff +3 more

Numbers of non-indigenous species--species introduced from elsewhere - are increasing rapidly worldwide, causing both environmental and economic damage. Rigorous quantitative risk-analysis frameworks, however, for invasive species are lacking. We need … Numbers of non-indigenous species--species introduced from elsewhere - are increasing rapidly worldwide, causing both environmental and economic damage. Rigorous quantitative risk-analysis frameworks, however, for invasive species are lacking. We need to evaluate the risks posed by invasive species and quantify the relative merits of different management strategies (e.g. allocation of resources between prevention and control). We present a quantitative bioeconomic modelling framework to analyse risks from non-indigenous species to economic activity and the environment. The model identifies the optimal allocation of resources to prevention versus control, acceptable invasion risks and consequences of invasion to optimal investments (e.g. labour and capital). We apply the model to zebra mussels (Dreissena polymorpha), and show that society could benefit by spending up to US$324 000 year(-1) to prevent invasions into a single lake with a power plant. By contrast, the US Fish and Wildlife Service spent US$825 000 in 2001 to manage all aquatic invaders in all US lakes. Thus, greater investment in prevention is warranted.

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Alien species in fresh waters: ecological effects, interactions with other stressors, and prospects for the future

2010-01-01

David L. Strayer

Summary 1. Biological invasions are numerous in fresh waters around the world. At least hundreds of freshwater species have been moved outside of their native ranges by vectors such as … Summary 1. Biological invasions are numerous in fresh waters around the world. At least hundreds of freshwater species have been moved outside of their native ranges by vectors such as ballast water, canals, deliberate introductions, and releases from aquaria, gardens, and bait buckets. As a result, many bodies of fresh water now contain dozens of alien species. 2. Invasions are highly nonrandom with respect to the taxonomic identity and biological traits of the invaders, the ecological characteristics of the ecosystems that are invaded, and the geographical location of the ecosystems that supply and receive the invaders. 3. Some invaders have had deep and pervasive effects on the ecosystems that they invade. Classes of ecologically important invaders in fresh waters include molluscs that are primary consumers and disrupt the food web from its base, fishes that disrupt the food web from its apex or centre, decapods that act as powerful omnivores, aquatic plants that have strong engineering effects and affect the quality and quantity of primary production, and diseases, which probably have been underestimated as an ecological force. 4. The number of alien species in freshwater ecosystems will increase in the future as new aliens are moved outside of their native ranges by humans, and as established aliens fill their potential ranges. Alien species create “no‐analogue” ecosystems that will be difficult to manage in the future. We may be able to reduce future impacts of invaders by making more serious efforts to prevent new invasions and manage existing invaders. 5. Thematic implications : interactions between alien species and other contemporary stressors of freshwater ecosystems are strong and varied. Because disturbance is generally thought to favour invasions, stressed ecosystems may be especially susceptible to invasions, as are highly artificial ecosystems. In turn, alien species can strongly alter the hydrology, biogeochemical cycling, and biotic composition of invaded ecosystems, and thus modulate the effects of other stressors. In general, interactions between alien species and other stressors are poorly studied.

The Global Decline of Nonmarine Mollusks

2004-01-01

Charles Lydeard , Robert H. Cowie , Winston F. Ponder +7 more

Invertebrate species represent more than 99% of animal diversity; however, they receive much less publicity and attract disproportionately minor research effort relative to vertebrates. Nonmarine mollusks (i.e., terrestrial and freshwater) … Invertebrate species represent more than 99% of animal diversity; however, they receive much less publicity and attract disproportionately minor research effort relative to vertebrates. Nonmarine mollusks (i.e., terrestrial and freshwater) are one of the most diverse and imperiled groups of animals, although not many people other than a few specialists who study the group seem to be aware of their plight. Nonmarine mollusks include a number of phylogenetically disparate lineages and species-rich assemblages that represent two molluscan classes, Bivalvia (clams and mussels) and Gastropoda (snails, slugs, and limpets). In this article we provide an overview of global nonmarine molluscan biodiversity and conservation status, including several case studies documenting the diversity and global decline of nonmarine mollusks. We conclude with a discussion of the roles that mollusks and malacologists should play in conservation, including research, conservation management strategies, and education and outreach.

Dispersal and emerging ecological impacts of Ponto-Caspian species in the Laurentian Great Lakes

2002-07-01

Henry A. Vanderploeg , Thomas F. Nalepa , David J. Jude +5 more

We describe, explain, and "predict" dispersal and ecosystem impacts of six Ponto-Caspian endemic species that recently invaded the Great Lakes via ballast water. The zebra mussel, Dreissena polymorpha, and quagga … We describe, explain, and "predict" dispersal and ecosystem impacts of six Ponto-Caspian endemic species that recently invaded the Great Lakes via ballast water. The zebra mussel, Dreissena polymorpha, and quagga mussel, Dreissena bugensis, continue to colonize hard and soft substrates of the Great Lakes and are changing ecosystem function through mechanisms of ecosystem engineering (increased water clarity and reef building), fouling native mussels, high particle filtration rate with selective rejection of colonial cyanobacteria in pseudofeces, alteration of nutrient ratios, and facilitation of the rapid spread of their Ponto-Caspian associates, the benthic amphipod Echinogammarus ischnus and the round goby, Neogobius melanostomus, which feeds on zebra mussels. The tubenose goby,Proterorhinus marmoratus, which does not feed on zebra mussels, has not spread rapidly. Impacts of these benthic invaders vary with site: in some shallow areas, habitat changes and the Dreissena [Formula: see text] round goby [Formula: see text] piscivore food chain have improved conditions for certain native game fishes and waterfowl; in offshore waters, Dreissena is competing for settling algae with the native amphipod Diporeia spp., which are disappearing to the detriment of the native deep-water fish community. The predatory cladoceran Cercopagis pengoi may compete with small fishes for zooplankton and increase food-chain length.

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Mollusks as ecosystem engineers: the role of shell production in aquatic habitats

2003-04-01

Jorge L. Gutiérrez , Clive G. Jones , David L. Strayer +1 more

Mollusk shells are abundant, persistent, ubiquitous physical structures in aquatic habitats. Using an ecosystem engineering perspective, we identify general roles of mollusk shell production in aquatic ecosystems. Shells are substrata … Mollusk shells are abundant, persistent, ubiquitous physical structures in aquatic habitats. Using an ecosystem engineering perspective, we identify general roles of mollusk shell production in aquatic ecosystems. Shells are substrata for attachment of epibionts, provide refuges from predation, physical or physiological stress, and control transport of solutes and particles in the benthic environment. Changes in availability of these resources caused by shell production have important consequences for other organisms. Colonization of shelled habitat depends on individual shell traits and spatial arrangement of shells, which determine access of organisms to resources and the degree to which biotic or abiotic forces are modulated. Shell production will increase species richness at the landscape level if shells create resources that are not otherwise available and species are present that use these resources. Changes in the availability of resources caused by shells and the resulting effects on other organisms have both positive and negative feedbacks to these engineers. Positive feedbacks appear to be most frequently mediated by changes in resource availability, whereas negative feedbacks appear to be most frequently mediated by organisms. Given the diversity of species that depend upon resources controlled by shells and rapid changes in global shell production that are occurring due to human activities, we suggest that shell producers should not be neglected as a targets of conservation, restoration and habitat management.

The Monopolization Hypothesis and the dispersal–gene flow paradox in aquatic organisms

2002-06-01

Luc De Meester , África Gómez , Beth Okamura +1 more

Dispersal in Freshwater Invertebrates

2001-11-01

David T. Bilton , Joanna R. Freeland , Beth Okamura

▪ Abstract Movement between discrete habitat patches can present significant challenges to organisms. Freshwater invertebrates achieve dispersal using a variety of mechanisms that can be broadly categorized as active or … ▪ Abstract Movement between discrete habitat patches can present significant challenges to organisms. Freshwater invertebrates achieve dispersal using a variety of mechanisms that can be broadly categorized as active or passive, and which have important consequences for processes of colonization, gene flow, and evolutionary divergence. Apart from flight in adult freshwater insects, active dispersal appears relatively uncommon. Passive dispersal may occur through transport by animal vectors or wind, often involving a specific desiccation-resistant stage in the life cycle. Dispersal in freshwater taxa is difficult to study directly, and rare but biologically significant dispersal events may remain undetected. Increased use of molecular markers has provided considerable insight into the frequency of dispersal in freshwater invertebrates, particularly for groups such as crustaceans and bryozoans that disperse passively through the transport of desiccation-resistant propagules. The establishment of propagule banks in sediment promotes dispersal in time and may be particularly important for passive dispersers by allowing temporal escape from unfavorable conditions. Patterns that apply to dispersal in freshwater invertebrates can be readily extended to other freshwater taxa, since common challenges arise from the colonization of isolated aquatic systems.

The Biology of Streams and Rivers

1998-11-26

Paul S. Giller , Björn Malmqvist

Abstract Although they constitute less than 1% of the world's water, freshwaters play a vital role in life on Earth. Running water, or lotic, habitats comprise a tiny proportion of … Abstract Although they constitute less than 1% of the world's water, freshwaters play a vital role in life on Earth. Running water, or lotic, habitats comprise a tiny proportion of these freshwaters, yet they offer important resources and are rich and complex environments. This book provides an essential introduction to the biology and ecology of lotic habitats, and their constituent organisms. Rarely has the breadth and complexity of all aspects of the biology of streams and rivers been dealt with in a single volume. The aim of this book is to delve into the rich and growing literature, and to provide an up-to-date introduction to stream and river biology. It begins by outlining the factors that make running water habitats unique, and describing the many different water-course systems. The authors then outline the range of living organisms in lotic habitats, and the environmental adaptations they exhibit. They discuss population, community, and ecosystem patterns and processes, such as energy flow, nutrient cycling, migration, food webs, and community structure. Each chapter includes practical information on simple studies and experiments for students to try. The book finishes with a discussion of applied issues surrounding water use, pollution, species diversity, and conservation of this fascinating and immensely important habitat.

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Fresh-Water Invertebrates of the United States

1979-09-01

Lewis Berner , Robert W. Pennak

Animal–sediment relationships

2012-10-12

Through interviews and classroom observations, this study investigated the academic helpseeking and interactions of high school girls with their computer science classmates.This study investigated these behaviors in both a private … Through interviews and classroom observations, this study investigated the academic helpseeking and interactions of high school girls with their computer science classmates.This study investigated these behaviors in both a private school and a public school setting.The study explored five aspects of this help-seeking interaction: a) females as a gender minority in computer science, b) determinants of peer interaction, c) teacher versus peer assistance, d) factors detracting from willingness to assist peers, and e) preference for group interaction.A key finding in this study was that physical proximity was an important determinant of help-seeking behaviors in a high school computer lab.Another finding was that girls in the sample studied often asked their peers for help even when they preferred the teacher's help and believed that the teacher was more knowledgeable.One particularly counter-intuitive finding in this study was that most girls preferred to work individually in a setting in which there was already substantial peer interaction.One implication of this study is that teachers should be wary of applying the general finding that girls prefer group work to every girl in the class and should instead respect the preference of the individual.If the findings obtained in this study are found in other settings, then a recommendation might be that in order to maximize help-seeking, talented programming students should be evenly distributed throughout the classroom.

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PROCEEDINGS OF THE MALACOLOGICAL SOCIETY OF LONDON

1902-04-01

Martin Fountain Woodward

Journal Article PROCEEDINGS OF THE MALACOLOGICAL SOCIETY OF LONDON Get access MARTIN FOUNTAIN WOODWARD MARTIN FOUNTAIN WOODWARD Search for other works by this author on: Oxford Academic Google Scholar Journal … Journal Article PROCEEDINGS OF THE MALACOLOGICAL SOCIETY OF LONDON Get access MARTIN FOUNTAIN WOODWARD MARTIN FOUNTAIN WOODWARD Search for other works by this author on: Oxford Academic Google Scholar Journal of Molluscan Studies, Volume 5, Issue 1, April 1902, Pages 1–7, https://doi.org/10.1093/oxfordjournals.mollus.a065930 Published: 01 April 1902 Article history Received: 08 November 1901 Published: 01 April 1902

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Freshwater Invertebrates of the United States

1979-04-01

Robert P. Higgins , Robert W. Pennak

Freshwater Biomonitoring and Benthic Macroinvertebrates

1994-11-01

D. M. Harper , D. A. Rosenberg , V. H. Resh

Freshwater Snails Of Africa And Their Medical Importance

1994-05-26

David S. Brown

The first half of this book is primarily a systematic survey of the snails, beginning with glossaries, keys for identification to genera and a checklist of species. This is followed … The first half of this book is primarily a systematic survey of the snails, beginning with glossaries, keys for identification to genera and a checklist of species. This is followed by a synopsis of species, with brief notes on ecology, distribution and parasites. Relationships are then described between snails and schistosomes and with other paras

Ecology and classification of North American freshwater invertebrates

2001-09-01

Naturalis Biodiversity Center (NL) - Porifera

2024-01-01

J. Goud , Bram Van Der Bijl , Jeroen Creuwels

Database contains specimen records from the Porifera collection of the Naturalis Biodiversity Center (Leiden, Netherlands). These specimens originate from the collections of the National Museum of Natural History (RMNH; Rijksmuseum … Database contains specimen records from the Porifera collection of the Naturalis Biodiversity Center (Leiden, Netherlands). These specimens originate from the collections of the National Museum of Natural History (RMNH; Rijksmuseum voor Natuurlijke Historie), later National Museum of Natural History, Naturalis in Leiden and of the former Zoological Museum Amsterdam (ZMA). On request more information can be provided.

Meiobenthology: the microscopic motile fauna of aquatic sediments

2009-05-01

Olav Giere

to Meiobenthology.- The Biotope: Factors and Study Methods.- Sampling and Processing Meiofauna.- Biological Characteristics of Meiofauna.- Meiofauna Taxa: A Systematic Account.- Evolutionary and Phylogenetic Effects in Meiobenthology.- Patterns of Meiofauna … to Meiobenthology.- The Biotope: Factors and Study Methods.- Sampling and Processing Meiofauna.- Biological Characteristics of Meiofauna.- Meiofauna Taxa: A Systematic Account.- Evolutionary and Phylogenetic Effects in Meiobenthology.- Patterns of Meiofauna Distribution.- Meiofauna from Selected Biotopes and Regions.- Synecological Perspectives in Meiobenthology.- Retrospect on Meiobenthology and Outlook on New Approaches and Future Research.

Modelling growth and population parameters of the invasive gastropod Rapana venosa (Muricidae) in the Black Sea using statolith-based ageing

2025-06-24

Nuri Başusta , Ömerhan Dürrani , Levent Bat +3 more | Fisheries Science

Temporal variation in macroinvertebrate assemblage structure in the Ohio River, USA

2025-06-24

Esther Atutey , Mark Pyron | Hydrobiologia

Evidence on the Occurrence of Airbreathing Snail, Laemodonta punctigera (H. Adams and A. Adams, 1854) (Gastropoda: Ellobiidae) from India

2025-06-23

Prasad Chandra Tudu , S. Balakrishnan , Aditya Kapil Valiveti +1 more | Thalassas An International Journal of Marine Sciences

CERNUELLA VIRGATA (DA COSTA, 1778) (MOLLUSCA, GEOMITRIDAE) – AN ADVENTIVE SPECIES IN TURKMENISTAN

2025-06-23

Евгений Викторович Шиков , M. Miheeva | Ekosistemy

Cernuella virgata (Da Costa, 1778) has been recorded for the first time in Turkmenistan. The species inhabits Ashgabat and its suburbs: Bikrova and Berzengi. The natural range of C. virgata … Cernuella virgata (Da Costa, 1778) has been recorded for the first time in Turkmenistan. The species inhabits Ashgabat and its suburbs: Bikrova and Berzengi. The natural range of C. virgata includes the western Mediterranean, the British Isles, Crimea and the vicinity of Novorossiysk. The authors hypothesize that C. virgata was introduced from Europe in the 1990s, when a substantial number of seedlings were imported along with soil for urban landscaping projects. All biotopes inhabited by C. virgata are located along roads and near residential buildings, both in single-story and multi-story areas. The snails are predominantly found in grassy environments. In Europe, C. virgata lives in open steppes, so it is commonly called the steppe snail. In Turkmenistan, C. virgata resides in afforestation areas, under the shade of trees and in irrigated vegetable gardens. Ecological changes are attributed due to the peculiarities of the arid continental climate of the semi-desert zone of Turkmenistan. Reproduction of this species occurs in spring and autumn, with a lifespan until complete shell development and sexual maturity ranging from two to six years, depending on the moisture levels of the habitats due to irrigation. During the summer heat, these snails ascend tree trunks and hide in the cracks of the bark. The general parameters of the shells and reproductive system correspond to the descriptions of C. virgata from Western European countries, with shell heights ranging from 8.6 to14.2 mm; shell widths from 12.5 to 19.2 mm, and the number of whorls from 4.6 to 6.25. The ecological adaptations of C. virgata in Turkmenistan demonstrate the species’ considerable capacity to acclimatize to new conditions, which makes it possible for it to spread to other anthropogenic biotopes in Asian countries.

Population genetic dynamics of the Ivory Snail (Babylonia areolata): Insights from coastal waters of Vietnam for conservation and aquaculture

2025-06-23

Sang Vu , Sarifah Aini , Angkasa Putra +7 more | Research Square (Research Square)

<title>Abstract</title> The ivory snail <italic>Babylonia areolata</italic> has experienced a significant population decline in marine ecosystem due to the overharvesting, habitat loss, and climate change. Despite its ecological significance and commercial … <title>Abstract</title> The ivory snail <italic>Babylonia areolata</italic> has experienced a significant population decline in marine ecosystem due to the overharvesting, habitat loss, and climate change. Despite its ecological significance and commercial value, the population genetic studies on this gastropod remain limited. This study provides the first genetic insight into <italic>B. areolata</italic> based on 105 newly generated mitochondrial cytochrome c oxidase subunit I (<italic>COI</italic>) gene sequences collected from Vietnam. The analysis revealed the lowest interspecific genetic distance (11.2%) between <italic>B. areolata</italic> and <italic>Babylonia borneensis</italic>, and the highest (18.5%) with <italic>Babylonia zeylanica</italic>. The Bayesian and Maximum-likelihood phylogenetic analyses showed <italic>B. areolata</italic> as a distinct monophyletic lineage, while species delimitation methods recovered multiple operational taxonomic units, suggesting the potential presence of cryptic diversity. The low inter-population divergence (0.2–0.3%) further indicated a high level of genetic connectivity among <italic>B. areolata</italic> populations across coastal waters of Thailand, Vietnam, and China. The haplotype network analysis revealed 26 haplotypes, including a dominant central haplotype, supporting the hypothesis that larval dispersal and regional ocean currents have shaped gene flow of <italic>B. areolata</italic>. Additionally, the presence of several unique haplotypes in the study regions may reflect historical geological events and demographic isolation, which likely shaped the distinct populations of <italic>B. areolata</italic>, especially in enclosed coastal areas like Cam Ranh Bay in central Vietnam. These findings underscore the importance of molecular tools in elucidating population structure and offer critical insights for the conservation and sustainable aquaculture of <italic>B. areolata</italic> in Southeast and East Asia.

A novel, inexpensive, and adaptable system for the simultaneous measurement of valve movements and cardiac activity in bivalves

2025-06-22

James E. Vereycken , David C. Aldridge | Environmental Technology

Guarding aquatic resources from degradation is vital. Organismal behavioural biomonitoring enables facile broad-spectrum toxicity detection, with distinct strengths over traditional water-quality sensing. Bivalve molluscs make ideal biomonitors, using alterations within … Guarding aquatic resources from degradation is vital. Organismal behavioural biomonitoring enables facile broad-spectrum toxicity detection, with distinct strengths over traditional water-quality sensing. Bivalve molluscs make ideal biomonitors, using alterations within two behaviours, valve movements and cardiac activity. Commercial systems monitoring these are costly, and often inflexible, whilst published methods typically lack broad suitability or requisite detail, or necessitate expertise; widespread application can be hindered, especially in the Global South and remote locations, despite the benefits for water monitoring. Furthermore, integration of both behaviours in systems is uncommon, despite probable gains in informativeness and sensitivity. Therefore, in the current work, a novel prototype set-up to simultaneously monitor valve movements and cardiac activity in multiple specimens was designed, constructed, and demonstrated. Employing popular, sophisticated, and robust technological approaches, the system caters for many bivalves (sessile/mobile, freshwater/marine). Reproducible, inexpensive, and uncomplicated, the low-power system centres around a Raspberry Pi (3B+) microcontroller, compatible with manifold open-source software. Monitoring eight unfixed animals for approximately £200 (during 2020), the system is adaptable for specimen numbers, type/rate of data capture, and operational conditions/environment. It is also scalable; miniaturisation and economies of scale should reduce the size and cost of a single set-up, making wider deployment of multiple systems, and larger cohorts, increasingly feasible. In providing extensive detail, the current work encourages further application of such monitoring capability. Widespread deployment or biomonitoring networks could revolutionise water management, improving protection of aquatic ecosystems and human health. Such ecological understanding aids bivalve conservation, of particular benefit to declining freshwater species.

Hybridisation primes population invasiveness under environmental change

2025-06-20

Ross N. Cuthbert | Journal of Animal Ecology

Abstract Research Highlight : Jermacz, Ł., Podwysocki, K., Desiderato, A., Bącela‐Spychalska, K., Rewicz, T., Szczerkowska, E., Augustyniak, M., Gjoni, V., & Kobak, J. (2025). The same species, not the same … Abstract Research Highlight : Jermacz, Ł., Podwysocki, K., Desiderato, A., Bącela‐Spychalska, K., Rewicz, T., Szczerkowska, E., Augustyniak, M., Gjoni, V., & Kobak, J. (2025). The same species, not the same invader: Metabolic responses of genetically distinct invasive populations of Dikerogammarus villosus (Sowinsky, 1894) and their intraspecific hybrid to environmental stresses. Journal of Animal Ecology , in press. Biological invasions are a major global environmental change that has contributed to most anthropogenic extinction events while costing trillions. Invasiveness and impact assessments are often done at the species level; however, there is growing recognition that intraspecific population‐level differences can be profound, especially in response to environmental gradients. Jermacz et al. (2025) employ a series of experiments to compare physiological responses between two populations of a high‐impact invasive amphipod, the ‘killer shrimp’ Dikerogammarus villosus , under stresses associated with climate change. Moreover, they assess the performance of intraspecific hybrids between the populations, which are expected to converge in future along their separate invasion routes from the Ponto‐Caspian region. The main finding in their study is that—alongside differences in physiological performance between the two populations—their intraspecific hybrids exhibit significant performance advantages under environmental stress. The increased genetic diversity and phenotypic capacity afforded through hybridisation between distinct invasive populations could be a mechanism that bolsters invasion success under climate change. These findings have implications for fundamentally understanding and practically managing invasive populations in changing environments.

Исследование реки Ехегис в целях гидробиологического мониторинга

2025-06-19

Marine Dallakyan , Ж.Г. Мкртчян , Э.В. Епремян +3 more | Ecosystem Transformation

С 2011 г. ведутся работы по улучшению системы управления водными ресурсами Армении, в результате которых территория республики разделена на шесть территорий управления речными бассейнами и основана государственная система гидробиологического мониторинга, … С 2011 г. ведутся работы по улучшению системы управления водными ресурсами Армении, в результате которых территория республики разделена на шесть территорий управления речными бассейнами и основана государственная система гидробиологического мониторинга, требующая регулярного исследования экологического состояния поверхностных водных объектов. Данная работа посвящена оценке изменений в сообществе донных макробеспозвоночных в бассейне реки Ехегис спустя десятилетие после первоначальных исследований. Результаты показывают более высокое таксономическое разнообразие по сравнению с 2012 г., однако существенных изменений в общем экологическом состоянии не выявлено. Это подтверждает возможность дальнейшего использования упрощенного мультиметрического индекса, разработанного для управления Араратским речным бассейном. В то же время необходимы дополнительные исследования видового состава донных макробеспозвоночных для повышения эффективности индекса. Due to initiated in 2011 improvements in the water management system of Armenia, six Basin Management Areas were created and hydrobiological monitoring was introduced. It requires regular investigations of ecological status of surface water bodies. The current research aims to study the changes in the assemblage of benthic macroinvertebrates in the basin of the Yeghegis River ten years after the baseline studies. The results show higher taxonomic diversity for this basin in comparison with 2012. However, significant changes in its overall ecological status have not been revealed. This proves the assumption that existing multimetric index can be still used for the Ararat Basin Management Area, but further investigations of species structure of benthic macroinvertebrates are necessary to improve its performance.

Assessing muskrat predation on a freshwater mussel assemblage in a southeastern United States river

2025-06-18

Barry Hicks , Augustin C. Engman , Jeronimo G. Da Silva Neto +3 more | Food Webs

Integrative taxonomy confirms the synonymy of three springsnail species (Hydrobiidae: Pyrgulopsis)

2025-06-17

Kathryn E. Perez , Megan Solis , Michelle Flores +1 more | European Journal of Taxonomy

The small, spring-dwelling snails, Pyrgulopsis Call &#38; Pilsbry, 1886, form a diverse radiation in Western North America. In this study, we examine the validity of three species of Pyrgulopsis, Pyrgulopsis … The small, spring-dwelling snails, Pyrgulopsis Call &#38; Pilsbry, 1886, form a diverse radiation in Western North America. In this study, we examine the validity of three species of Pyrgulopsis, Pyrgulopsis pilsbryana (Baily &#38; Baily, 1952), P. nonaria Hershler, 1998, and P. transversa Hershler, 1998. These three species of Pyrgulopsis are found primarily in Utah, with ranges extending into Idaho, Wyoming, and Nevada. They were originally diagnosed primarily on the number and position of penial glands, but subsequent examination with mitochondrial DNA data suggested they should be synonymized. Here, we incorporate additional mitochondrial and nuclear DNA data, increased geographic sampling, and quantify some stated differences in shell and radula morphology. We test the utility of penial ornamentation and other anatomical features used to distinguish these species. We found that the shell shape and radula features measured tend to be unique to each local population, not species-specific distinguishing features. Further, we found the diagnostic features used to erect the three focal species are not associated with phylogenetic relationships. Therefore, we present a synonymy of the three focal species under the name with priority, P. pilsbryana.

Effects of flooding on aquatic macroinvertebrate assemblage structure on a connected and disconnected regulated river floodplain

2025-06-16

Patricia L. S. Wooden , William E. Kelso , Michael D. Kaller | Hydrobiologia

Local environmental conditions and loss of river–lake connection shape the ecological uniqueness of molluscan assemblages

2025-06-16

Lei Ren , Peng Zheng , Jorge García‐Girón +2 more | Hydrobiologia

New Species and Old Semaphoronts: Updating Taxonomic Knowledge of Kempnyia Klapálek, 1914 (Plecoptera: Perlidae) with an Integrative Approach

2025-06-13

Lucas Henrique de Almeida , Rodrigo Braga Gastaldo , Frederico Falcão Salles +1 more | Diversity

Kempnyia Klapálek, 1914 (Plecoptera: Perlidae) is the only genus within its family endemic to Brazil, being present in the Atlantic Forest and sections of the Cerrado. Taxonomic knowledge of the … Kempnyia Klapálek, 1914 (Plecoptera: Perlidae) is the only genus within its family endemic to Brazil, being present in the Atlantic Forest and sections of the Cerrado. Taxonomic knowledge of the genus is incomplete, especially for nymphs. An integrative approach to the description of species and semaphoronts is essential for further studies. We describe a new species of Kempnyia based on morphological and molecular data, associate and describe the nymphs of both the new species and Kempnyia umbrina Froehlich, 1988, as well as expand its distribution and correct past mistakes in identification of K. umbrina. Specimens were identified morphologically and sequenced for the barcode region of the cytochrome oxidase subunit I (COI) mitochondrial gene, resulting in eight new sequences for three species of the genus. Both morphological and molecular analyses revealed a new species, Kempnyia krenaki sp. nov. Its nymph and that of K. umbrina are also described. With our additions, the number of known Kempnyia species rises to 41, of which 26 have COI sequences available in GenBank. Although only 11 nymphs have been associated and described for the genus so far, as the Kempnyia sequence database continues to grow, studies associating and describing nymphs will become more common, gradually reducing the Haeckelian deficit.

Probable Extirpation of Anodonta vescoiana in Iraq: A Case Study of Unionid Displacement by Sinanodonta woodiana

2025-06-12

Murtada D. Naser , Amaal Yasser , Juergen Geist +2 more | Diversity

Conservation of ecologically important freshwater mussels is high on the international agenda, but there is only limited knowledge about the status of rare unionid species in arid and semi-arid areas … Conservation of ecologically important freshwater mussels is high on the international agenda, but there is only limited knowledge about the status of rare unionid species in arid and semi-arid areas which are particularly vulnerable. One such example concerns Anodonta vescoiana which was recognized as one of the few endemic species of unionid mussels from Iraq and was restricted to the marshes of southern Mesopotamia and its connected river systems. The last confirmed report of A. vescoiana was in 2009 from the Al-Ezz River. We conducted extensive field surveys during the years 2021 and 2022 at approximately 20 freshwater sites, but we failed to observe any live or dead specimens, suggesting a probable extirpation or severe decline. In contrast, we documented the invasive Sinanodonta woodiana at numerous sites across the Tigris–Euphrates basin including the Al-Ezz River. This documentation of S. woodiana indicates successful establishment of the species and colonization of freshwater systems modified by anthropogenic practices, which include alterations of hydrological dynamics and ecological conditions. Here, we compile existing evidence of the global ecological impacts and development of S. woodiana invasion, while also highlighting Iraq as an important example of the displacement of native unionid mussel species by invasive alien unionids. We assessed the factors that contributed to the disappearance of A. vescoiana in Iraq including biological competition (with S. woodiana), salinity stress, habitat fragmentation, and pollution. The time window to act and prevent the further decline of rare unionid species in Iraq, as well as other arid and semi-arid areas which face similar threats, is short. Urgent actions include systematic monitoring to identify remnant populations, implementing biosecurity policies (for fisheries or habitats), and restoration (of habitats) to secure the long-term persistence of remaining unionid diversity.

Biology and Conservation of Moxostoma spp. Occurring in Canada with Emphasis on the Copper Redhorse (M. hubbsi, Legendre 1952), an Endemic Species on an Extinction Trajectory

2025-06-12

Nathalie R. Le François , Charles Drouin-Johnson , Hugo C. Marchand +2 more | Conservation

Freshwater fishes are one of the most threatened animal taxa in North America. In Canada, roughly 30% of the occurring species are currently listed and under protection, including redhorses. This … Freshwater fishes are one of the most threatened animal taxa in North America. In Canada, roughly 30% of the occurring species are currently listed and under protection, including redhorses. This review covers Moxostoma spp. ecology, biology, conservation efforts, and highlights challenges to galvanize actions and outcomes through research. The threats to their survival are strongly associated to increasing anthropogenic pressures, superimposed by climate change effects. In Canada, recovery plans for the copper and the black redhorse, and a management plan for the river redhorse, are operational. The recovery strategy for the copper redhorse relies on stocking campaigns of 0+ juveniles, which was exclusively based on artificial breeding of captured wild broodstock. A conservation aquaculture program that includes genetic diversity and adaptation considerations was recently initiated, and the areas of refinement identified are the following: broodstock and early-life rearing protocols and environmental and physical enrichment protocols to improve juveniles’ post-release fitness. Research through the prism of conservation physiology is proposed in the identification welfare and health bioindicators and adaptability/response to climatic change. Concurrently, aquatic ecosystem protection/restoration, control of invasive species, eDNA detection/telemetry tracking, and post-release monitoring efforts should also be reinforced.

Passage denied: The potential of dispersal barriers to limit the spread of aquatic invasive species through shipping canals

2025-06-04

Julius Gorenz , Melina Klarl , Stefan Nehring +2 more | Journal of Environmental Management

Environmental Pollution and Biological Invasions Threaten Native Freshwater Infaunal Bivalves in the Guandu River Basin, Southeast Brazil

2025-06-03

Nathália Rodrigues , Igor Christo Miyahira , Antonio J. S. Rodrigues +2 more | Limnological Review

Freshwater bivalves play essential ecological roles in ecosystems, but they are among the most threatened fauna worldwide. Despite receiving industrial and domestic wastes, the Guandu River is the main source … Freshwater bivalves play essential ecological roles in ecosystems, but they are among the most threatened fauna worldwide. Despite receiving industrial and domestic wastes, the Guandu River is the main source of drinking water for more than nine million people in the Rio de Janeiro metropolitan region. This study aimed to assess how infaunal bivalves respond to water and sediment quality in the Guandu River basin. Samples were collected at 10 sites across reservoirs, lotic, and lentic systems during cold–dry and warm–rainy seasons. Four bivalves were identified: Anodontites trapesialis, Diplodon ellipticus, Corbicula fluminea (non-native), and C. largillierti (non-native). Native species were restricted to two lentic sites at Guandu Lagoon, with the poorest environmental quality, significantly affected by high chlorophyll a and ammonia in the water. In contrast, C. fluminea was widely distributed and more abundant in the basin but restricted to less degraded sites, suggesting a lower tolerance to environmental pollution. Multivariate analyses indicated significant differences in environmental conditions and species–environment correlation. The non-native species spread and poor environmental quality threaten native bivalves in the Guandu River basin, leading them to a local extinction risk. Results highlight the need for effective management and conservation actions to protect biodiversity in tropical river basins.

Effects of Large Bivalve <scp><i>Cristaria plicata</i></scp> on Phytoplankton Size Composition and Water Quality: A Mesocosm Case Study

2025-06-01

Zhe Zhu , Hui Jin , Mingming Zhu +7 more | Aquatic Conservation Marine and Freshwater Ecosystems

ABSTRACT As ecosystem engineers, bivalves play a key role in nutrient cycling, water quality and phytoplankton composition in aquatic ecosystems. However, the effect of different species of bivalves on phytoplankton … ABSTRACT As ecosystem engineers, bivalves play a key role in nutrient cycling, water quality and phytoplankton composition in aquatic ecosystems. However, the effect of different species of bivalves on phytoplankton composition and water quality may vary due to size‐selective feeding as small bivalves generally prefer smaller particles than large bivalves. A 70‐day outdoor experiment was carried out in mesocosms with and without a large bivalve Cristaria plicata (13.90 ± 0.27 cm) to test the hypothesis that the bivalve C. plicata decrease microphytoplankton (> 20 μm) more than nano‐ (2–20 μm) and picophytoplankton (0.2–2 μm) thereby changing the phytoplankton composition. Nitrogen, phosphorus, total suspended solids (TSS), organic suspended solids (OSS), benthic algal biomass and light intensity at the sediment surface were monitored. Three size groups of phytoplankton (microphytoplankton, nanophytoplankton, picophytoplankton), and abundance of cladocerans and rotifers were also measured. We found that the bivalve decreased the concentrations of total nitrogen (TN), TSS and OSS, but not total phosphorus (TP); increased light intensity and increased benthic algal biomass. Contrary to our hypothesis, we did not find decreased microphytoplankton biomass in the mesocosm with bivalves. However, bivalves reduced nanophytoplankton and picophytoplankton thus changing the phytoplankton composition towards larger rather than smaller phytoplankton groups. In addition, the abundance of rotifers, but not cladocerans was decreased in the bivalve mesocosms. Our results showed that the large bivalve C. plicata can decrease the phytoplankton biomass thereby improving water quality, but have limited effects on larger phytoplankton.

Landscape‐Scale Responses of Freshwater Biodiversity to Connectivity and Stressors

2025-06-01

Craig Wilkie , Alan Law , Stephen J. Thackeray +7 more | Global Ecology and Biogeography

ABSTRACT Aim There is compelling evidence that drivers and patterns of biodiversity and ecosystem functioning vary across multiple spatial scales, from global to regional, landscape and patch. However, macroecological processes … ABSTRACT Aim There is compelling evidence that drivers and patterns of biodiversity and ecosystem functioning vary across multiple spatial scales, from global to regional, landscape and patch. However, macroecological processes impacting freshwater biodiversity are poorly understood compared to marine and terrestrial ecosystems. Despite step changes in data availability, we have a fragmented view beyond the local scale of how hydrological and landscape connectivity interact with ecosystem stressors to shape freshwater biodiversity and functioning. While macroecological patterns can vary substantially among taxonomic groups, previous studies have focussed on individual habitat types, sites or taxonomic groups within landscapes, hindering direct comparisons. We present a cross‐landscape, multi‐species analysis of the interactive effects of landscape and hydrological connectivity and stressors on standing freshwater quality and the diversity of several major freshwater taxonomic groups. Location Great Britain (United Kingdom). Time Period 2000–2016. Major Taxa Studied Phytoplankton chlorophyll‐ a , macrophytes, molluscs, Coleoptera, Odonata, fish and birds. Methods Using random forests and generalised additive modelling, we quantified the interactive effects of landscape and hydrological connectivity and stressors on water quality (phytoplankton chlorophyll‐ a ) and the diversity of selected taxa in standing freshwaters. Results We found evidence of connectivity changing from positive to negative relationships with biotic responses with increasing human‐induced stress levels. Some species groups showed the inverse, reflecting complexities of modelling at large, cross‐landscape scales. Almost all responses were affected by stress or connectivity, often interacting and with non‐linear relationships. Main Conclusions Patterns in stressor‐connectivity interactions differed across taxa, but were important in shaping 6 of 8 biotic responses. This emphasises the need for taxon‐specific analyses to resolve freshwater ecological responses to stressors, connectivity, and their interactions. Our results also highlight that connectivity effects must be integrated in landscape‐scale, evidence‐led decision‐making, designed to reduce impacts of stressors on water quality and biodiversity.

Mind the gap: flow recession mortality of the river mussel Alathyria jacksoni revealed from acoustic detection gaps

2025-05-31

Jerom R. Stocks , Stephanie L. McCaffrey | Animal Biotelemetry

Silence of the clams: health status of Mya arenaria clams in the Saguenay–St. Lawrence Marine Park

2025-05-30

François Gagné , C. André , Edith Lacroix +2 more | Academia Biology

The cumulative effects of pollution of intertidal clam populations should be investigated to ensure the sustainable perennity of our resources. The purpose of this study was to examine the health … The cumulative effects of pollution of intertidal clam populations should be investigated to ensure the sustainable perennity of our resources. The purpose of this study was to examine the health status of intertidal clams and tissue levels of essential and non-essential elements at sites under anthropogenic stress. Clams were collected at two anthropized sites, a St. Lawrence Estuary (SLE) beluga high-residency area and reference site in the Saguenay–St. Lawrence Marine Park (Québec, Canada). Clam health status was determined by the condition factor (CF: wet weight/shell length ratio), growth index (GI: shell length/age), air survival time and weight loss index (WLI). Elemental analysis was also performed in soft tissues. The data revealed that clams from at least one of the harbor/marina sites had reduced CF, GI and WLI. Air survival time was not affected at the anthropized sites but was significantly higher at the St. Lawrence Estuary beluga high-residency area. The clams were contaminated by Ag, Al, Cd, Cu, Hg and V, with a decrease in essential cations (K, Ca, Mg) suggesting altered osmoregulation. Although the individual metals in tissues were not found at harmful concentrations based on reported data, the combined effects of non-essential elements could not be excluded. More research will be needed to better understand the cumulative effects of various stressors, such as low salinity, algal toxins and elemental composition, on clam health status.

The history of commercial freshwater mussel harvest in southern Ontario: a short-lived fishery with long-lasting consequences

2025-05-29

Cherie W. Morris , Todd J. Morris | The Canadian Field-Naturalist

Freshwater mussels (Bivalvia: Unionidae) have long been an important aquatic resource for humans, and North America’sIndigenous nations have harvested them for over 10 000 years. European exploitation began in the … Freshwater mussels (Bivalvia: Unionidae) have long been an important aquatic resource for humans, and North America’sIndigenous nations have harvested them for over 10 000 years. European exploitation began in the latter half of the 19th century, initially focussing on the collection of pearls and later shifting to the manufacture of buttons at the onset of the 20th century. By 1911, Canadian pearl button factories operated in Windsor, Berlin (now Kitchener), and Trenton, Ontario, and, by 1921, Ontario shell was being exported to factories in the United States. The Canadian harvest did not last long and ended by the mid-1940s as resources dwindled because of overexploitation, pollution, and industrial shifts to other raw materials for buttons (e.g., plastics). Annual river-specific harvest ranged from ~ 66 to 110 tonnes with a maximum of 291 tonnes (~1.1–4.4 million animals) collected at Dunnville on the lower Grand River in 1915. Although detailed collection information is lacking, species such as Mucket (Actinonaias ligamentina), Threeridge (Amblema plicata), and Round Pigtoe (Pleurobema sintoxia, now listed federally as Endangered) were targetted, while Purple Wartyback (Cyclonaias tuberculata, also now Endangered) was discarded (i.e., killed). Commercial harvests typically targetted adults, because they provided the desired quantity and type of material, resulting in death. Recent studies have shown that this type of directed mortality can have the greatest impact on the long-term persistence of these populations and, although the specific impacts of the historical harvest cannot be determined, it is likely that these harvests contributed to the current state of imperilment of this fauna.

A functional morphological classification for North American freshwater mussels: associations between morphology and environmental parameters across spatial scales

2025-05-29

Irene Sánchez González , Garrett W. Hopper , Jamie R. Bucholz +2 more | Biological reviews/Biological reviews of the Cambridge Philosophical Society

ABSTRACT Trait‐based approaches have emerged as a general framework that translates species‐specific knowledge to understand the processes driving patterns of diversity and distributions. Morphological traits are relatively easy to measure … ABSTRACT Trait‐based approaches have emerged as a general framework that translates species‐specific knowledge to understand the processes driving patterns of diversity and distributions. Morphological traits are relatively easy to measure and can provide information on organism–environment interactions and community structure due to their close linkage to ecological function and habitat partitioning. Freshwater mussels (Family: Unionidae) are a diverse (~360 North American species) and endangered group of organisms. Mussels display great interspecific morphological variation potentially yielding broad ecological implications. We aimed to modify quantitively an existing shell morphological classification system by combining size, shape, and sculpturing data using a robust data set of 1362 individuals representing 64 species spanning a broad cross section of the diverse North American freshwater mussel fauna. Using multivariate techniques, we classified species into morphological classes based on trait similarities hypothesized to explain species distributions and habitat associations. We then tested how well the classification system predicted trait–environment relationships using quantitative mussel survey data with paired environmental data collected at three spatial scales [river (km), reach (40–150 m), patch (0.25 m 2 )]. Mussel species clustered into six different morphological classes based on sculpturing, shape, and body size traits. We found associations between morphological classes and environmental parameters at each spatial scale. The modified classification explained more variation in community distribution as predicted by abiotic variables than previous frameworks. Our study underscores the value of morphological traits in predicting species distributions and understanding mechanisms of community assembly and we provide a foundation for fellow researchers to expand our morphological classification. This knowledge has significant implications for mussel conservation and management, as it helps identify suitable habitats that can guide reintroduction strategies through incorporating multiple spatial scales, a broad representation of species and geographical distribution and a wide suite of morphological traits.

Macrobenthos and morpho-sedimentary recovery dynamics in areas following aggregate extraction cessation

2025-05-28

Laura Fuster López , Koen Degrendele , Marc Roche +4 more | Marine Pollution Bulletin

On the importance and practical conservation of nongame fishes

2025-05-28

Niall G. Clancy , Frank J. Rahel , Brandon K. Peoples +6 more | Fisheries

ABSTRACT Fisheries management has historically focused conservation efforts on game or sport species. However, most species are nongame—those not traditionally captured for sport or harvest in countries where recreational fisheries … ABSTRACT Fisheries management has historically focused conservation efforts on game or sport species. However, most species are nongame—those not traditionally captured for sport or harvest in countries where recreational fisheries predominate. Greater conservation of nongame species could help ensure that population declines do not go unnoticed. Unfortunately, fisheries managers already manage complex ecosystems with limited resources, and they frequently are directed to focus on game fishes. However, game fish populations can also be tightly coupled to nongame fishes, so nongame management can sometimes also benefit game species. We reviewed functional roles of freshwater nongame fishes and suggest categories that may be especially important for conservation. Of note, nongame fishes are more imperiled than game fishes and fill largely distinct functional roles. These roles include food-web impacts, ecosystem engineering, and mussel hosting. Management priorities could include nongame piscivores and species with high biomass, especially herbivores, nest builders, and imperiled mussel hosts. We provide practical options for including nongame fishes in current management, many of which require little additional funding. These include recognizing when sport fish funding and conservation can also benefit nongame species, whole-community sampling at some monitoring locations, collecting catch data for select species observed during game fish surveys, embracing environmental DNA sampling, and making presence–absence record keeping the default option.