Josef Daniel Ackerman

Josef Daniel Ackerman
University of Guelph | UOGuelph · Department of Integrative Biology

PhD

About

120
Publications
41,674
Reads
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3,961
Citations
Citations since 2016
26 Research Items
1688 Citations
2016201720182019202020212022050100150200250
2016201720182019202020212022050100150200250
2016201720182019202020212022050100150200250
2016201720182019202020212022050100150200250
Introduction
Josef Daniel Ackerman is a professor in the Department of Integrative Biology, University of Guelph. He conducts research in the broad field defined by Physical Ecology -- the interface of hydrodynamics and ecology -- which overlaps with a number of research areas in Limnology, Marine Sciences, Oceanography, Aquatic Botany, and Mollusc Ecology. Some of the research topics currently under investigation include: suspension feeding, dispersal, settlement and recruitment, particle capture, photosynthesis, abiotic pollination, hypoxia, and form-function relationships.
Additional affiliations
July 2003 - present
University of Guelph
Position
  • Professor (Full)
August 1994 - June 2003
University of Northern British Columbia
Position
  • Professor (Associate)
January 1994 - December 1994
Royal Ontario Museum
Position
  • Visiting Scientist

Publications

Publications (120)
Article
The transport of particulate matter including the gametes, larvae and propagules of reproducing organisms and other organic matter involved in nutrient/contaminant transport are important processes, yet there are few environmentally friendly methods available to examine dispersal empirically. Herein we report on the development and application of a...
Article
Freshwater unionid mussels are ecosystem engineers that are highly endangered in part because of land-use changes that have altered their habitat and negatively impacted their ecophysiology. The environmental factors that affect mussels do not act alone and may be better understood using a multiple-stressor approach. We examine how changes in water...
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Effective conservation requires that species recovery measures are informed by rigorous scientific research. For imperilled freshwater fishes and mussels in Canada, numerous research gaps exist, in part owing to the need for specialized research methods. The Canadian Freshwater Species at Risk Research Network (SARNET) was formed and identified or...
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Many aquatic processes (i.e., organism locomotion, macrophyte response to unsteady flow and mass/heat transfer) involve oscillatory or undulatory movements perpendicular to the direction of flow and perpendicular to the plane of oscillation (i.e., spanwise). The reduction of boundary layer (BL) thickness and increased turbulence have been identifie...
Article
Sediment oxygen demand (SOD) and hypolimnetic oxygen demand (HOD) drive deep-water dissolved oxygen (DO) depletion in lakes, yet these parameters can be difficult to be measure routinely. To address this issue, we present an empirical DO depletion model from time-series measurements of hypolimnetic DO and water-column temperature profiles to estima...
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We simulated bottom resuspension events in Lake Erie, using a coupled three-dimensional hydrodynamic and water quality model. Key parameters in the model, including critical bottom shear stress (τcr) and resuspension rate (α) were calibrated and validated by comparing the model output to observations. These included total suspended solid (TSS) conc...
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Climate change affects physical and biogeochemical processes in lakes. We show significant increases in surface-water temperature (~ 0.5 °C decade−1; > 0.2% year−1) and wave power (> 1% year−1; the transport of energy by waves) associated with atmospheric phenomena (Atlantic Multidecadal Oscillation and Multivariate El Niño/Southern Oscillation) in...
Article
• Increases in total suspended solids (TSS) reduce feeding and reproductive success of unionid mussels, but mussels in turbid rivers are less affected than those in clear rivers, probably due to differences in gill and palp morphology. This study was designed to determine whether the differences observed between adult mussels in populations from tu...
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Juvenile mussels enter the benthos after excysting from a fish host and settling to the bottom where they inhabit the interstitial zone in rivers. We examined the algal composition in the surface water and pore waters in different locations in a temperate river (Thames River) in Southern Ontario. Surprisingly, algal concentration (C) was ~9× higher...
Article
Rivers often transport phytoplankton to coastal embayments and introduce nutrients that can enrich coastal plankton communities. We investigated the effects of the Nottawasaga River on the nearshore (i.e. within 500 μm of shore) phytoplankton composition along a 10‐km transect of Nottawasaga Bay, Lake Huron in 2015 and 2016. Imaging flow cytometry...
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Hypoxia, defined as dissolved oxygen (DO) < 2 mg/L, in the central basin of Lake Erie has been studied since the mid‐1900s. Even so, spatial patterns of hypoxia, and episodic hypoxia in nearshore areas where drinking water plant intakes are located, are not well characterized owing to limited observations and short‐term dynamics. We evaluated a phy...
Article
The feeding of three co-occurring freshwater mussel species Ptychobranchus fasciolaris, Quadrula quadrula and Potamilus alatus) of differing conservation status on river water from their collection site was examined under static and ecologically relevant flow conditions using three characteristics of the suspended river seston from a turbid river (...
Article
Unionid mussels from clear‐water rivers are often found in turbid waters in which their feeding and reproductive efficiency should be impaired. We examined the feeding response of Lampsilis siliquoidea from a clear and turbid river in response to increased concentrations of total suspended solids (TSS) and water velocity in a funnel chamber and a r...
Article
Unionid mussels are important constituents of aquatic systems that are affected by anthropogenic changes in hydrology and concomitant increases in suspended solids, yet little is known about the effects of flow on their suspension feeding. We examined the clearance rates (CRs) of four species of freshwater mussels (Lampsilis siliquoidea, Lampsilis...
Article
• Increases in total suspended solids (TSS) in rivers have likely contributed to the decline in unionid mussel population sizes as feeding and reproduction are reduced at high TSS concentrations. Surprisingly, however, unionids are often found in turbid rivers. We predicted that clay‐sized particles, which comprise > 80% of river seston (particles...
Article
Particle capture is important for ecological processes in aquatic and terrestrial ecosystems. The current model is based on a stationary collector for which predictions about capture efficiency (η; flux of captured particles ∶ flux of particles) are based on the collector flow environment (i.e., collector Reynolds number, Rec; inertial force ∶ visc...
Article
We examined the effect of TSS concentration on the clearance rates (CR) of newly transformed juvenile and adult Lampsilis fasciola, L. siliquoidea, Ligumia nasuta, and Villosa iris, as increased total suspended solids (TSS) are thought to interfere with feeding processes. Mussel CR were measured in aerated (or swirled for juveniles) chambers at TSS...
Article
Benthic suspension feeders such as dreissenid mussels (Dreissena polymorpha and D. rostriformis bugensis) are often found in remarkably dense aggregations (i.e. > 105 mussels m− 2), which is surprising, given their high clearance rates and limited mixing within the benthic boundary layer. Results from flow visualization in flow chamber experiments...
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Despite their role as ecosystem engineers, which is in large part a consequence of their suspension feeding activities, the early life history of unionid mussels is not well understood. We examined the suspension feeding rates (i.e., clearance rates, CR) of recently metamorphosed juvenile Lampsilis siliquoidea (1–4 week old), Lampsilis fasciola (1–...
Data
Species specific values for the model of glochidia loss versus juvenile mussels produced
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We investigated whether Neogobius melanostomus, an invader of biodiversity 'hot-spots' in the Laurentian Great Lakes region, facilitates or inhibits unionid mussel recruitment by serving as a host or sink for their parasitic larvae (glochidia). Infestation and metamorphosis rates of four mussel species with at-risk (conservation) status (Epioblasma...
Article
Stream-habitat assessment for evaluation of restoration projects requires the examination of many parameters, both watershed-scale and reach-scale, to incorporate the complex non-linear effects of geomorphic, riparian, watershed and hydrologic factors on aquatic ecosystems. Rapid geomorphic assessment tools used by many jurisdictions to assess natu...
Article
Bottom roughness can influence gamete and larval transport in benthic organisms. For example the ratio of the roughness spacing (λ) and roughness height (k) determines the type of roughness flow regime created in two dimensional (2D) flows: λ/k < 8 results in skimming flow; λ/k ∼ 8 results in wake interference flow; and λ/k > 8 results in isolated...
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In wind pollination, the release of pollen from anthers into airflows determines the quantity and timing of pollen available for pollination. Despite the ecological and evolutionary importance of pollen release, wind-stamen interactions are poorly understood, as are the specific forces that deliver pollen grains into airflows. We present empirical...
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Premise of research. Angiosperms possess pollen dispersal units (PDUs) of varying size, from monads (single grains) to aggregates containing thousands of grains. It has been suggested that the degree of aggregation is related to the dispersal agent (in particular, animals vs. wind), but aggregation has rarely been measured, and its correlation with...
Article
The offshore regions of large temperate lakes are characterized by strong summer temperature stratification that limits vertical mass flux, and enables near-inertial internal wave motions. Here, we investigate the contribution of near-inertial baroclinic velocity shear on enhancing the vertical transport of dissolved oxygen (DO) through the thermoc...
Article
Full-text available
Benthic suspension feeders play significant roles in aquatic ecosystems, but the influences of abiotic, especially hydrodynamic, factors on many of their activities remain largely unknown. This is especially true for freshwater unionid mussels, which are important inhabitants of rivers and lakes, often forming multispecies assemblages in the former...
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The factors influencing the habitat requirements and dispersal of juvenile Unionidae (unionids) between post-larval detachment from a fish host and burrowing into the substratum are largely unknown, although bed shear stress (τw) has been proposed as a critical factor. We used a laboratory wall jet apparatus to manipulate τw experimentally to exami...
Chapter
Full-text available
Dreissenid mussels are benthic invertebrates that remain relatively sedentary on the bottom of lakes and rivers except for their early-life history that involves broadcast spawning and a planktotrophic larval stage. This chapter focuses on the interaction of dreissenids with their fluid environment, which is responsible for essential biological pro...
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Larval transport and settlement in benthic invertebrates is theorised to be influenced by bottom roughness and the hydrodynamic forces that roughness generates near the bed. This study of freshwater Dreissena spp. bivalves examined the transport and suspension of pediveliger larvae and larval models in a laboratory flow chamber and larval settlemen...
Article
[1] The examination of hypoxia in the hypolimnion of large lakes traditionally focuses on the assessment of its spatial and temporal extent and its effect on water quality. In Lake Erie, hypoxia typically occurs between July and October in the central basin; however, there is considerable interannual variability both spatially and temporally. The p...
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External fertilization in broadcast-spawning benthic invertebrates has been hypothesized to be influenced by hydrodynamic forces in the near-bed region of aquatic systems. This study examined how the fertilization success of two freshwater mussels (Dreissena polymorpha and D. bugensis) examined in a laboratory flow chamber and in Lake Erie was infl...
Article
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Simple transport models predict that the distance organisms drift downstream in rivers is determined by their settling velocity (w s), the release height (z r), and the stream velocity (U). Unfortunately, empirical evidence is lacking on whether and how factors such as w s affect mussel larvae dispersion in rivers under natural turbulent conditions...
Article
Approximately 10 percent of plant species rely on wind for pollination (anemophily). These include many taxa of economic importance: e.g. cultigens such as wheat and maize; species like grasses and ragweed that trigger allergies; and the conifers, our most important species for the forest industry in the mid- latitudes. It has often been assumed th...
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Purpose – The dynamics of organizational change related to environmental sustainability on university campuses are examined in this article. Whereas case studies of campus sustainability efforts tend to classify leadership as either “top‐down” or “bottom‐up”, this classification neglects consideration of the leadership roles of the institutional “m...
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Juvenile unionid mussels disperse in the water column after detachment from their host fish. The settling velocity (ws) of juvenile mussels is an important component of their dispersion in the water column but has not been measured for unionid mussels. The goal of our study was to measure the ws of juvenile mussels in the laboratory and to examine...
Article
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Many broadcast-spawning benthic invertebrates are subject to sperm limitation yet achieve high population densities, as for example dreissenid mussels (Dreissena polymorpha and Dreisssena bugensis) that were introduced into the Laurentian Great Lakes. The question remains whether biological or ecological/physical mechanisms reduce sperm limitation....
Article
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In streams, hydrodynamic forces may influence food web structure by limiting the spatial distribution or diversity of primary consumers. To examine the spatial relationships between organisms and physical drivers, we measured distributions of local bed shear stress (τw), periphyton, and herbivorous invertebrates (larvae of the mayfly Epeorus longim...
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Unionid mussels are highly imperiled and the survival of their local populations is linked to the availability and dispersal potential of their host fish. We examined the displacement distance of logperch (Percina caprodes), which are obligate host fish for endangered snuffbox mussels (Epioblasma triquetra), to determine the dispersal potential by...
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A wall jet is presented as a novel means of measuring the attachment strength of zebra mussels. Attachment strength was inferred from a fluid detachment parameter (DP), defined as the nominal wall shear stress at the detachment site × mussel length2. DP varied significantly on natural and artificial substrates: in tests with 288 Dreissena bugensis...
Article
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Fluid dynamic forces were found to significantly affect the ability of freshwater dreissenid mussels (Dreissena polymorpha and Dreissena bugensis) to clear plankton. Tests conducted in a flow chamber at <1 cm·s-1 were consistent with published clearance rates from standard tests involving unstirred containers (i.e., 60-70 mL· mussel-1·h-1 for 11-mm...
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Physiological techniques were used to separate two related Dreissena species initially established by electrophoretic and morphological characteristics (May and Marsden. 1992. Can. J. Fish. Aquat. Sci. 49: 1501–1506). Samples of zebra mussels (Dreissena polymorpha) and "quagga" mussels (provisionally either Dreissena polymorpha andrusovi or Dreisse...
Article
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Freshwater unionid mussels are among the most endangered groups of organisms in the world. They develop indirectly via a host, usually a fish, and this dependence appears to limit the reproduction and distribution of freshwater mussels. Epioblasma torulosa rangiana and Lampsilis fasciola are 2 endangered species in Canada. Epioblasma t. rangiana ha...
Article
1. Freshwater unionid mussels are a highly imperilled group. Their dispersal abilities depend on the availability and the movement of host fish on which their parasitic mussel larvae develop. 2. We examined the relationship between the dispersal abilities of unionid mussels and their conservation status on a regional (SW Ontario) scale and their di...
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The near-bed hydraulic environment inhabited by torrential stream fauna was characterized by recording velocity profiles, near-bed velocities, and local wall shear stresses over the upper surface of boulders (or stones) in a mountain stream located in eastern British Columbia. Velocity profiles regularly deviated from a semi-logarithmic shape, and...
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The ecological and economic impacts of the introduced zebra mussel (Dreissena polymorpha (Pallas)) have been due in part to a life history that is conserved with marine bivalves but unique among the indigenous freshwater fauna. There are a number of life history events in D. polymorpha that follow external fertilization and embryology. The first is...
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Mechanical investigations of biological materials are becoming increasingly important in the study of organismic and evolutionary ecology. Such studies help to explain how and why organisms evolve and exist today, and address some questions of scale (e.g., how big can a tree or mammal grow?). These ideas and questions often intrigue biology student...
Article
The present study examined the effect of dissolved organic carbon (DOC), both added and inherent, on Cu toxicity in glochidia, the larvae of freshwater mussels. Using incremental additions of natural DOC concentrate and reconstituted water, a series of acute copper toxicity tests were conducted. An increase in DOC from 0.7 to 4.4 mg  C/L resulted i...
Article
We examined the dispersal of larvae (glochidia) of a common unionid mussel species, Actinonaias ligamentina, which need to attach to a host fish in order to develop into juveniles, in a lowland river (Sydenham River, Ontario, Canada). Generally, the decline in the number of glochidia captured with distance from release was best described by an inve...
Article
We examined the dispersal of larvae (glochidia) of a common unionid mussel species, Actinonaias ligamentina, which need to attach to a host fish in order to develop into juveniles, in a lowland river (Sydenham River, Ontario, Canada). Generally, the decline in the number of glochidia captured with distance from release was best described by an inve...
Chapter
Full-text available
Turbulent flow over rough boundaries is a common occurrence in nature and the subject of much interest in a range of disciplines. It has long been recognized that the geometry of the boundary (or surface) dictates the flow and turbulence structure on a mean and instantaneous time scale. However, the mechanisms linking flow characteristics to roughn...
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Hydrodynamic models of mass transport assume that diffusive processes next to the surface limit transport and that there are no biological and chemical processes that control the supply and demand of the scalar. The validity of these assumptions was examined by measuring the momentum boundary layer (via particle image velocimetry) and the concentra...
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The round goby (Neogobius melanostomus) first invaded North America in 1990 when it was discovered in the St. Clair River. Despite more than 15years of potential invasion, many Great Lakes’ lotic systems remained uninvaded. Recently, we captured the round goby from several Great Lakes tributaries known as species-at-risk hotspots. With a combinatio...
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Invasive macrophyte species are generally associated with negative ecological impacts. However, the physiological and morphological characteristics that successfully allow macrophytes to establish in new ecosystems have yet to be determined. In organisms, such as terrestrial angiosperms, algae, and corals morphology, surface area to volume ratio, a...
Article
The assessment of the potential impact of waterborne contaminants on imperilled freshwater mussels is needed. Acute copper toxicity was assessed in a standardized soft water (hardness 40-48 mg CaCO(3)equivalents L(-1)) using the larvae (glochidia) from three common and six (Canadian) endangered mussel species. The resulting 24h EC50s ranged from 7...
Article
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The reintroduction of endangered species is a potentially useful conservation strategy, which in the case of freshwater unionid mussels, must be preceded by the successful laboratory rearing of juvenile mussels on their host fishes. However, an understanding of the genetic and environmental implications of reintroductions of artificially propagated...
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The effect of stream riparian condition on invertebrate drift was examined in headwater streams of the Torpy River in north-central British Columbia, Canada. Forest harvesting provided the opportunity to examine drift within control streams (i.e., within intact forest), streams with 10 m foliated reserve strips, streams with 10 m defoliated riparia...
Chapter
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A discussion of sexual reproduction in seagrasses should begin with an examination of their origin and include a comparison with their closest freshwater relatives (i.e. the comparative method). There were no marine plants until angiosperms colonized marine coastal waters sometime in the Cretaceous, which is the earliest date of seagrass fossils (i...
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The biology of aquatic organisms determines the maximum rates of physiological processes, but the mass transport of nutrients determines the nominal rates at which these processes occur. Maximum O2 flux(Pmax) at 17.1 mmol m–3 CO2was higher for the leaves of the freshwater macrophyte Vallisneria spiralis [Pmax=0.013±0.001 mmol m–2 s–1 (gchla+bm–2)–1...
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Juvenile red sea urchins, Strongylocentrotus franciscanus, aggregate under adult conspecifics, whereas sympatric juvenile green sea urchins, Strongylocentrotus droebachiensis, are typically more solitary and dispersed. Neither the potential advantage of juvenile sheltering nor the differences in post-settlement behavior between the two species has...
Article
The mass transfer of scalar quantities (e.g., O2 and nutrients) in aquatic environments is an important and complex process involving diffusion and advection. In a flowing environment, concentration boundary layers (CBL) occur above the surfaces of organisms when they are a sink or source of scalars. In this study, we used an O2 microsensor to prof...
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The extent of stratification and vertical mixing in the water column (7-11 m deep) was investigated over an offshore reef in the western basin of Lake Erie. Measurements reveal that the vertical transport of oxygen and heat is controlled by the complex interaction of several physical mechanisms. Generally, when the wind speed (W) was >7 m·s-1 and t...
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The importance of stratification and vertical mixing was investigated in the western basin of Lake Erie. The measurements reveal that the vertical transport of oxygen and heat is controlled by the complex interaction of several physical mechanisms. Wind speeds greater than 7 m.s-1 and cooler air than water temperatures, led generally to a well-mixe...