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Articles 1 - 30 of 42
Full-Text Articles in Life Sciences
A Manual For The Analysis Of Butyltins In Environmental Samples, Michael A. Unger
A Manual For The Analysis Of Butyltins In Environmental Samples, Michael A. Unger
Reports
The Virginia Institute of Marine Science (VIMS) has developed methods for the analysis of tributyltin (TBT) in environmental samples. These methods have been published in the scientific literature where they are freely available to the public. When used by skilled analysts and supported by appropriate quality assurance and quality control procedures (QA/QC), we believe these methods, as well as other published analytical methods for TBT, can provide accurate and precise results. As in any environmental analysis, method performance is a function of the sample type, available instrumentation and skill and care taken by laboratory workers. The suitability of the data …
Simulation Of Annual Plankton Productivity Cycle In The Black Sea By A One-Dimensional Physical-Biological Model, Temel Oguz, Hugh Ducklow, Paola Malanotte-Rizzoli, Nikolai P. Nezlin, Umit Unluata
Simulation Of Annual Plankton Productivity Cycle In The Black Sea By A One-Dimensional Physical-Biological Model, Temel Oguz, Hugh Ducklow, Paola Malanotte-Rizzoli, Nikolai P. Nezlin, Umit Unluata
VIMS Articles
The annual cycle of the plankton dynamics in the central Black Sea is studied by a one-dimensional vertically resolved physical-biological upper ocean model, coupled with the Mellor-Yamada level 2.5 turbulence closure scheme. The biological model involves interactions between the inorganic nitrogen (nitrate, ammonium), phytoplankton and herbivorous zooplankton biomasses, and detritus. Given a knowledge of physical forcing, the model simulates main observed seasonal and vertical characteristic features, in particular, formation of the cold intermediate water mass and yearly evolution of the upper layer stratification, the annual cycle of production with the fall and the spring blooms, and the subsurface phytoplankton maximum …
Identification Of Pollutant Sources Contributing To Degraded Sanitary Water Quality Intaskinas Creek National Estuarine Research Reserve, Virginia, Howard Kator, Martha Rhodes
Identification Of Pollutant Sources Contributing To Degraded Sanitary Water Quality Intaskinas Creek National Estuarine Research Reserve, Virginia, Howard Kator, Martha Rhodes
Reports
No abstract provided.
Modeling The Lower Chesapeake Bay Littoral Zone & Fringing Wetlands: Modeling The Lower Chesapeake Bay Littoral Zone & Fringing Wetlands: Ecosystem Processes And Habitat Linkages.Ii. Model Sensitivity Analysis, Validation, And Estimates Of Ecosystem Processes, Christopher P. Buzzelli, Richard L. Wetzel
Modeling The Lower Chesapeake Bay Littoral Zone & Fringing Wetlands: Modeling The Lower Chesapeake Bay Littoral Zone & Fringing Wetlands: Ecosystem Processes And Habitat Linkages.Ii. Model Sensitivity Analysis, Validation, And Estimates Of Ecosystem Processes, Christopher P. Buzzelli, Richard L. Wetzel
Reports
No abstract provided.
Beneficial Uses Of Dredged Material From The Waterway On The Coast Of Virginia (Wcv), Walter I. Priest Iii, Christopher W. Frye, Janet Nestlerode, Robert J. Byrne
Beneficial Uses Of Dredged Material From The Waterway On The Coast Of Virginia (Wcv), Walter I. Priest Iii, Christopher W. Frye, Janet Nestlerode, Robert J. Byrne
Reports
No abstract provided.
Effects Of Sunlight On Bacteriophage Viability And Structure, Ke Wommack, Rt Hill, Ta Muller, Rr Colwell
Effects Of Sunlight On Bacteriophage Viability And Structure, Ke Wommack, Rt Hill, Ta Muller, Rr Colwell
VIMS Articles
Current estimates of viral abundance in natural waters rely on direct counts of virus-like particles (VLPs), using either transmission or epifluorescence microscopy. Direct counts of VLPs, while useful in studies of viral ecology, do not indicate whether the observed VLPs are capable of infection and/or replication. Rapid decay in bacteriophage viability under environmental conditions has been observed. However, it has not been firmly established whether there is a corresponding degradation of the virus particles, To address this question, viable and direct counts were carried out employing two Chesapeake Bay bacteriophages in experimental microcosms incubated for 56 h at two depths …
Abundance And Distribution Of Sea Turtles Off North Carolina, J. A. Keinath, J. A. Musick, D. E. Bernard
Abundance And Distribution Of Sea Turtles Off North Carolina, J. A. Keinath, J. A. Musick, D. E. Bernard
Reports
No abstract provided.
Effects Of Periodic Environmental Hypoxia On Predator Utilization Of Macrobenthic Infauna, Janet A. Nestlerode
Effects Of Periodic Environmental Hypoxia On Predator Utilization Of Macrobenthic Infauna, Janet A. Nestlerode
Dissertations, Theses, and Masters Projects
Hypoxia and anoxia have significant deleterious ecological effects on living resources throughout many estuarine and marine ecosystems worldwide. Brief periods of low oxygen facilitate transfer of benthic production to higher trophic levels as many benthic infaunal species have shallower sediment depth distributions during hypoxic events. A baited time-lapse camera equipped with a water quality datalogger was used to document in situ exploitation of oxygen-stressed benthic invertebrate prey organisms by mobile fish and crustacean predators during alternating normoxia-hypoxia cycles in the York River. Based on photographic and diver observations, this hypoxiainduced benthic-pelagic transfer of production is more likely to occur when …
Virginia Game Fish Tagging Program Annual Report 1995, Cm Bain Iii, John A. Lucy
Virginia Game Fish Tagging Program Annual Report 1995, Cm Bain Iii, John A. Lucy
Reports
The Virginia Came Fish tagging Program (VGFTP) was established in 1995 as an ongoing, cooperative project of the Virginia Marine Resources Commission and the Virginia Institute of Marine Science of the College of William and Mary The project is funded with revenues generated by Virginia's marine recreational fishing license.
In Situ Grazing On Plankton <10 Mu M By The Boreal Sponge Mycale Lingua, Aj Pile, Mr Patterson, Jd Witman
In Situ Grazing On Plankton <10 Mu M By The Boreal Sponge Mycale Lingua, Aj Pile, Mr Patterson, Jd Witman
VIMS Articles
Ultraplankton, heterotrophic and autotrophic plankton < 5 mu m, are the most abundant food source in the world's oceans, yet their role as a food source for macroinvertebrates is largely unexamined. We quantified in situ feeding on heterotrophic and autotrophic plankton < 10 mu m by the boreal sponge Mycale lingua using measurements that quantified sponge feeding efficiencies, pumping rates, and abundance to determine the contribution of plankton < 10 mu m to sponge carbon intake. Using dual-beam now cytometry we identified 5 populations of plankton < 10 mu m: heterotrophic bacteria, Prochlorococcus, Synechococcus-type cyanobacteria, autotrophic eucaryotes < 3 mu m, and autotrophic eucaryotes 3 to 10 mu m Mycale lingua nonselectively grazed on all types of plankton < 10 mu m. Prochlorococcus was filtered with the highest efficiency (93%), followed by Synechococcus-type cyanobacteria (89%), autotrophic eucaryotes 3 to 10 mu m (86%), heterotrophic bacteria (74%), and autotrophic eucaryotes < 3 mu m (72%). We conservatively estimate that M. lingua al naturally occurring densities can obtain 29 mg C d(-1) m(-2) feeding on plankton < 10 mu m, with 74% resulting from ultraplankton, suggesting that ultraplankton are an important overlooked component of benthic-pelagic coupling.
The Role Of Epibenthic Predators In Structuring Marine Soft-Bottom Communities Along An Estuarine Gradient, Rochelle D. Seitz
The Role Of Epibenthic Predators In Structuring Marine Soft-Bottom Communities Along An Estuarine Gradient, Rochelle D. Seitz
Dissertations, Theses, and Masters Projects
A unifying theory of community regulation in soft-bottom systems remains elusive, despite extensive field studies on factors controlling community structure. Here, I have (1) reviewed models of community regulation, (2) examined the role of predation in controlling benthic diversity along a salinity gradient, (3) examined effects of predation upon an abundant bivalve, Macoma balthica, and (4) revised a model of community regulation in an estuarine soft-bottom system. The Menge and Sutherland (MS) "consumer stress model" posits that consumers feed ineffectively in harsh environments, and the importance of physical disturbance, competition and predation varies with recruitment, environmental conditions, and trophic position. …
Growth Of Bacterioplankton And Consumption Of Dissolved Organic Carbon In The Sargasso Sea, C. A. Carlson, H. W. Ducklow
Growth Of Bacterioplankton And Consumption Of Dissolved Organic Carbon In The Sargasso Sea, C. A. Carlson, H. W. Ducklow
VIMS Articles
Lability of the bulk dissolved organic carbon (DOG) pool and the amount available to bacterioplankton on short time scales (hours to days) were examined in oligotrophic Sargasso Sea water (near Bermuda). We examined bacterial growth and DOC utilization using seawater culture methodology in combination with measurements of bacterial abundance, cell volume, and DOC. Bulk DOC concentrations were determined by high temperature combustion (HTC) analysis, which proved to be a sensitive method for detecting small changes in natural concentration of DOG. Measurable bacterial growth and DOC utilization only occurred in unamended cultures when initial DDC concentrations were greater than observed in …
Mucus Entrapment Of Particles By A Suspension-Feeding Tilapia (Pisces: Cichlidae), S. Laurie Sanderson, Michael C. Stebar, K. Lara Ackermann, Samuel H. Jones, Ioannis E. Batjakas, Les Kaufman
Mucus Entrapment Of Particles By A Suspension-Feeding Tilapia (Pisces: Cichlidae), S. Laurie Sanderson, Michael C. Stebar, K. Lara Ackermann, Samuel H. Jones, Ioannis E. Batjakas, Les Kaufman
Arts & Sciences Articles
A miniature fiberoptic endoscope was used to observe the processes of particle encounter and retention inside the buccopharyngeal cavity of suspension-feeding tilapia. Small particles (38 µm to 1.0 mm in diameter) were trapped in strands and aggregates of mucus, which usually slid posteriorly on the ceratobranchials of arches IIV towards the esophagus while the fish pumped water through the buccopharyngeal cavity. During stage 1 of periodic reversals of water flow inside the buccopharynx, mucus-bound particles usually lifted off the arch surfaces and travelled a short distance in an anterior or anterodorsal direction. During stage 2 of a reversal, the mucus …
Epizootiology Of Perkinsus Marinus Disease Of Oysters In Chesapeake Bay, With Emphasis On Data Since 1985, Eugene Burreson, Lisa M. Ragone Calvo
Epizootiology Of Perkinsus Marinus Disease Of Oysters In Chesapeake Bay, With Emphasis On Data Since 1985, Eugene Burreson, Lisa M. Ragone Calvo
VIMS Articles
Since 1987 Perkinsus marinus has been the most important pathogen of the eastern oyster, Crassostrea virginica, in Chesapeake Bay because of its widespread distribution and persistence in low salinity areas. The pathogen became established on all oyster beds in the Chesapeake Bay as a result of natural spread during the consecutive drought years from 1985 to 1988 or by movement of infected oysters during the same period. Elevated salinities resulting from drought conditions and concomitant warm winters allowed P. marinus to proliferate in what were historically low salinity areas. Oyster mortality was high on most beds and landings of market …
Characterization Of Soft-Bottom Benthic Habitats Of The Aland Islands, Northern Baltic Sea, E Bonsdorff, R. J. Diaz, R Rosenberg, A Norkko
Characterization Of Soft-Bottom Benthic Habitats Of The Aland Islands, Northern Baltic Sea, E Bonsdorff, R. J. Diaz, R Rosenberg, A Norkko
VIMS Articles
Sediment surface and profile imaging (SPI) was used in combination with grab sampling of sediment (sediment type, organic content, benthic infauna) and hydrography (temperature, oxygen saturation of bottom water) to analyze and describe the soft-bottom benthic habitats of the Aland archipelago (60 degrees 00' to 60 degrees 30' N, 19 degrees 30' to 20 degrees 30' E) in the northern Baltic Sea. The SPI analysis covered 42 stations (5 to 263 m depth), from inner sheltered bays to open coastal waters, with varying sediment types (soft mud with high organic content to sandy substrates with low organic content; loss on …
Propagation And In Vitro Studies Of Perkinsus Marinus, Jerome F. Lapeyre
Propagation And In Vitro Studies Of Perkinsus Marinus, Jerome F. Lapeyre
VIMS Articles
The development of continuous cultures of Perkinsus marinus (Apicomplexa) is a major breakthrough that will lead to a better understanding of this deadly oyster pathogen. More than 10 P. marinus isolates are currently in continuous cultures. Culture media used to propagate P. marinus range from media designed for the culture of mammalian cells to protein-free chemically defined media. Continuous cultures of P. marinus can be initiated from a variety of infected oyster tissues or from isolated hypnospores (i.e., the enlarged stage of P. marinus from oyster tissue incubated in Ray's fluid thioglycollate medium). P. marinus cells adapt well to culture …
Effects Of Predation On Zostera Marina L. Seed Abundance, James R. Fishman, R J. Orth
Effects Of Predation On Zostera Marina L. Seed Abundance, James R. Fishman, R J. Orth
VIMS Articles
Predator effects on Zostera marina L. seed abundance were studied in the York River, VA, USA, using enclosure and exclosure caging experiments. Seeds were placed in cages in two concurrent experiments. The first experiment was a predator exclosure experiment to test the effects of excluding predators, using a full predator exclosure cage, a partial exclosure top-only cage, a partial exclosure side-only cage and uncaged plots. The second experiment was a predator enclosure experiment, using two highly abundant macro-benthic predators in the Chesapeake Bay: the decapod crustacean Callinectes sapidus Rathbun and the sciaenid fish Micropogonias undulatus L. Additionally, two-week long trials …
Status Of Stock Assessment Knowledge Used To Manage Important Virginia Finfish Species, Virginia Marine Resources Commission, Virginia Institute Of Marine Science
Status Of Stock Assessment Knowledge Used To Manage Important Virginia Finfish Species, Virginia Marine Resources Commission, Virginia Institute Of Marine Science
Reports
No abstract provided.
A Retrospective Time Series Analysis Of Oyster, Crassostrea Virginica, Recruitment (1946-1993), Herbert Austin, David Evans, Dexter Haven
A Retrospective Time Series Analysis Of Oyster, Crassostrea Virginica, Recruitment (1946-1993), Herbert Austin, David Evans, Dexter Haven
VIMS Articles
Temporal patterns of eastern oyster, Crassostrea virginica (Gmelin 1791), spatfall in the Virginia tributary rivers to the Chesapeake Bay showed a decline in all rivers from 1946 through the early 1970s, with a subsequent leveling off. The decline was most severe in the James and less so moving north to the York and Rappahannock Rivers; it was least severe in the Potomac River. Yearling patterns generally mirrored the spat. Cluster analyses grouped the bars naturally by up- and downriver spatfall patterns. They also clustered this way when between-river comparisons were made. Spatfall showed a significant cross-correlation with yearlings a year …
A Comparison Of Crassostrea Gigas And Crassostrea Virginica: Effects Of Temperature And Salinity On Susceptibility To The Protozoan Parasite, Perkinsus Marinus, Fu-Lin C. Chu, Aswani Volety, G Constantin
A Comparison Of Crassostrea Gigas And Crassostrea Virginica: Effects Of Temperature And Salinity On Susceptibility To The Protozoan Parasite, Perkinsus Marinus, Fu-Lin C. Chu, Aswani Volety, G Constantin
VIMS Articles
The susceptibility of diploid and triploid (2N and 3N) Crassostrea gigas to Perkinsus marinus was compared, in the laboratory, with that of Crassostrea virginica al three test temperatures (10, 15, and 25 degrees C) at 20-22 ppt and at three test salinities (3, 10, and 20 ppt) at a temperature of 19-22 degrees C. Experimental oysters were challenged twice with freshly isolated P, marinus meronts, after acclimation to test temperatures and salinities. Although infection prevalence and intensity increased with temperature (p = 0.0001) and salinity in P. marinus-challenged oysters of both oyster species: they were highest in C. virginica groups. …
Foreword, Frank O. Perkins
History Of Perkinsus Marinus, A Pathogen Of Oysters In Chesapeake Bay 1950-1984, Jd Andrews
History Of Perkinsus Marinus, A Pathogen Of Oysters In Chesapeake Bay 1950-1984, Jd Andrews
VIMS Articles
The pathogen Perkinsus marinus (Dermo) was discovered in Chesapeake Bay in 1950. It was already widely distributed in the Bay and caused annual mortality below the mouth of the Rappahannock River. Annual mortality in trayed oysters at the Virginia Institute of Marine Science (VIMS) varied annually from 24% to 57% at this most favorable site for the disease. Over 2 million bushels of seed oysters from the James River public beds were transplanted annually to private beds in 4 major growing areas. These were Hampton Roads, lower Bay proper, Mobjack Bay at mouth of York River, and the Rappahannock River. …
Laboratory Investigations Of Susceptibility, Infectivity, And Transmission Of Perkinsus Marinus In Oysters, Fu-Lin C. Chu
Laboratory Investigations Of Susceptibility, Infectivity, And Transmission Of Perkinsus Marinus In Oysters, Fu-Lin C. Chu
VIMS Articles
The protozoan parasite, Perkinsus marinus (Dermo), has caused significant mortality in the eastern oyster, Crassostrea virginica, along the east coast of the United States and the Gulf of Mexico, since the 1950s. Because of its current expanded distribution and increased abundance, P. marinus is now considered more prevalent in the mid-Atlantic waters and the Chesapeake Bay in particular, than another protozoan pathogen, Haplosporidium nelsoni (MSX). The susceptibility, infectivity/pathogenicity, and transmission of P. marinus in eastern oysters were investigated in numerous laboratory studies, The influence of environmental factors such as temperature, salinity, and pollution on the interaction between the host oyster …
The Structure Of Perkinsus Marinus (Mackin, Owen And Collier, 1950) Levine, 1978 With Comments On Taxonomy And Phylogeny Of Perkinsus Spp., Frank O. Perkins
The Structure Of Perkinsus Marinus (Mackin, Owen And Collier, 1950) Levine, 1978 With Comments On Taxonomy And Phylogeny Of Perkinsus Spp., Frank O. Perkins
VIMS Articles
A description of the structure of the Crassostrea virginica pathogen Perkinsus marinus is provided from observations at the light and transmission electron microscope levels of detail and includes cellular multiplication (palintomy) in the host and zoosporulation in estuarine water as well as observations of cells in axenic culture. The description is primarily a review of previously published information; however, new information is provided on development of walled outgrowths from hypnospores derived from fluid thioglycollate medium treatment of infected host tissue. The protoplast within the outgrowths subdivides to yield small unicells which escape into the ambient water, or the protoplast emerges …
Zostera Marina (Eelgrass) Growth And Survival Along A Gradient Of Nutrients And Turbidity In The Lower Chesapeake Bay, Ken Moore, Ha Neckles, R J. Orth
Zostera Marina (Eelgrass) Growth And Survival Along A Gradient Of Nutrients And Turbidity In The Lower Chesapeake Bay, Ken Moore, Ha Neckles, R J. Orth
VIMS Articles
Survival of transplanted Zostera marina L. (eelgrass), Z. marina growth, and environmental conditions were studied concurrently at a number of sites in a southwestern tributary of the Chesapeake Bay to elucidate the factors limiting macrophyte distribution in this region. Consistent differences in survival of the transplants were observed, with no long-term survival at any of the sites that were formerly vegetated with this species but that currently remain unvegetated. Therefore, the current distribution of Z. marina likely represents the extent of suitable environmental conditions in the region, and the lack of recovery into historically vegetated sites is not solely due …
Utilization And Turnover Of Labile Dissolved Organic Matter By Bacterial Heterotrophs In Eastern North Pacific Surface Waters, J Cherrier, Je Bauer, Erm Druffel
Utilization And Turnover Of Labile Dissolved Organic Matter By Bacterial Heterotrophs In Eastern North Pacific Surface Waters, J Cherrier, Je Bauer, Erm Druffel
VIMS Articles
Seawater incubation experiments were conducted in June and October 1992 to examine bacterial utilization of labile dissolved organic matter (DOM) in open ocean surface waters of the eastern North Pacific. Natural plankton extract-DOM (PE-DOM) and selected model compounds were added to seawater samples to evaluate bacterial utilization and respiration rates relative to bacterial carbon production rates for the various amendments. PE-DOM always stimulated bacterial production and DOM utilization, and the primary nitrogen source supporting this bacterial production was dissolved organic nitrogen (DON). Utilization of DON during exponential growth was balanced by the production of ammonium for samples amended with PE-DOM. …
Non-Structural Carbohydrate Reserves Of Eelgrass Zostera Marina, Mk Burke, Wc Dennison, Ka Moore
Non-Structural Carbohydrate Reserves Of Eelgrass Zostera Marina, Mk Burke, Wc Dennison, Ka Moore
VIMS Articles
The high minimum Light requirement of eelgrass Zostera marina L. suggests that this species has difficulty in maintaining a positive carbon balance except under high light conditions. The carbon balance of Z. marina can be studied by following seasonal changes in non-structural carbohydrate (NSC) reserves, however, little is known about the seasonal variation in NSC reserves in seagrasses or the influence of shading on NSC reserve content and distribution. Seasonal changes in eelgrass NSC reserves were measured in a shallow coastal lagoon, Chincoteague Bay, Maryland/Virginia, USA, near the southern edge of this species' distributional range. Concentrations of sugar varied seasonally …
Seasonal Variability Of Particulate Organic Radiocarbon In The Northeast Pacific Ocean, Ellen R.M. Druffel, James E. Bauer, Peter M. Williams, Shelia Griffin, David Wolgast
Seasonal Variability Of Particulate Organic Radiocarbon In The Northeast Pacific Ocean, Ellen R.M. Druffel, James E. Bauer, Peter M. Williams, Shelia Griffin, David Wolgast
VIMS Articles
We present Delta(14)C measurements of particulate organic carbon (POC) collected on four cruises at our time series site (station M) in the northeast Pacific Ocean. We observe a large gradient with depth in the suspended POC Delta(14)C values (124-160 parts per thousand). These profiles display lower Delta(14)C values (by 20-30 parts per thousand) in samples between 2500 m and the bottom during June 1992 and July 1993 than those during February and October 1992. Values of Delta(14)C in sinking POC from deep-moored sediment trap collections suggest a semiannual trend that displays lower overall Delta(14)C in material collected during periods of …
Effects Of Sand-Mining On Benthic Communities And Resource Value : Thimble Shoal, Lower Chesapeake Bay, Linda C. Schaffner, Michele A. Horvath, Carl H. Hobbs Iii
Effects Of Sand-Mining On Benthic Communities And Resource Value : Thimble Shoal, Lower Chesapeake Bay, Linda C. Schaffner, Michele A. Horvath, Carl H. Hobbs Iii
Reports
In August 1990 the City of Hampton placed approximately 276,000 cubic yards of sand from a designated borrow site on Thimble Shoal onto Buck:roe Beach for beach restoration. The Buck:roe reserve identified by Kimball et al. (1989) contains large quantities of beach quality material and is located less then 2.5 km offshore of Buck:roe Beach. In early 1989 a small section (330 m by 240 m) located in 5 m of water was delineated and permitted for dredging. This project represents the first instance of permitted, sand-mining activities for beach nourishment in the lower bay. Although the impacts of the …
The Role Of Microbial Food Webs In Benthic-Pelagic Coupling In Freshwater And Marine Ecosystems, Adele J. Pile
The Role Of Microbial Food Webs In Benthic-Pelagic Coupling In Freshwater And Marine Ecosystems, Adele J. Pile
Dissertations, Theses, and Masters Projects
A majority of carbon in freshwater and marine ecosystems is in the form of ultraplankton, heterotrophic and autotrophic plankton &<&5 &\mu&m including heterotrophic bacteria, Prochlorococcus, cyanobacteria, and autotrophic eucaryotes. However, ultraplankton and subsequently microbial food webs have yet to be incorporated into models of benthic-pelagic coupling despite the preponderance of macroinvertebrates with the capacity to feed on ultraplankton. I have examined the role of microbial food webs in benthic-pelagic coupling in three ecosystems: Lake Baikal, Siberia, Russia; Gulf of Maine, Northwest Atlantic Ocean; and Conch Reef, Florida Keys, USA. Using sponges as a model organism and in situ measurements, I have quantified (1) suspension feeding on ultraplankton and (2) release of dissolved inorganic nitrogen (DIN) and phosphorus (DIP) resulting in direct evidence that benthic macroinvertebrates do occupy the level of primary consumer within the microbial food web. Dual-beam flow cytometry was employed to quantified sponge suspension feeding on five types of ultraplankton: heterotrophic bacteria, Synechococcus-type cyanobacteria, autotrophic picoplankton &<&3 &\mu&m, autotrophic eucaryotes 3-10 &\mu&m, and in marine ecosystems Prochlorococcus. Grazing by the freshwater sponges Baikalospongia intermedia and B. bacilliferia and the boreal marine sponge, Mycale lingua, was unselective for all types of ultraplankton with efficiencies ranging from 63-99%. This is the first time that grazing on Synechococcus-type cyanobacteria and Prochlorococcus by macroinvertebrates has been quantified in freshwater and marine ecosystems. Conversely, the coral reef sponges Ircinia felix and I. strobilina release significant amounts of DIN and DIP as a result of grazing on procaryotic plankton. Using a general model for organism-mediated fluxes, it is conservatively estimated that through active suspension feeding sponges in Lake Baikal retain 1.97 g C day&\sp{lcub}-1{rcub}& m&\sp{lcub}-2{rcub}& and M. lingua retains 29 mg C day&\sp{lcub}-1{rcub}& m&\sp{lcub}-2{rcub}& while at Conch Reef sponges released 204 &\mu&mol DIN day&\sp{lcub}-1{rcub}& m&\sp{lcub}-2{rcub}& and 48 &\mu&mol DIP day&\sp{lcub}-1{rcub}& m&\sp{lcub}-2{rcub}&. A majority of the carbon retained at all three locations was from procaryotic cell types suggesting that ultraplankton are an important overlooked component of benthic-pelagic coupling.