ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Publication Date: 2022-05-25
    Description: Author Posting. © Inter-Research, 2005. This article is posted here by permission of Inter-Research for personal use, not for redistribution. The definitive version was published in Marine Ecology Progress Series 295 (2005): 33-42, doi:10.3354/meps295033.
    Description: Gradients of dimethylsulfide (DMS), dimethylsulfoniopropionate (DMSP), dimethylsulfoxide (DMSO), and bacterial numbers and diversity from the surface microlayer to 500 cm depth were assessed in coastal waters surrounding the Martha’s Vineyard Coastal Observatory, Massachusetts, USA. Microlayer samples were collected with a surface skimmer: a partially submerged, rotating glass cylinder (‘drum’) that allows the collection of a thin layer of water by adherence to the drum. A depletion of DMS towards the water surface (10 cm) was found at all sampling days, with largest gradients during rough sea surface conditions. The steep gradients show that gas fluxes and transfer velocities, based on the concentration disequilibrium between the water and the atmosphere, need to be based on near surface gas concentration values. Elevated DMSP, DMSO concentrations and bacterial numbers were found at the sea surface during calm conditions. Although degassing and photo-oxidation on the skimmer will bias the microlayer data, the results indicate stratification of DMSP, DMSO and bacteria during periods of smooth sea surface conditions.
    Description: We also thank the postdoctoral scholar program at the Woods Hole Oceanographic Institution, with funding provided by the J. Seward Johnson Fund.
    Keywords: Marine sulfur ; Bacteria ; Depth profiles ; Microlayer sampling ; Coastal waters ; DMS ; DMSP ; DMSO
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2022-05-25
    Description: Author Posting. © Inter-Research, 2008. This article is posted here by permission of Inter-Research for personal use, not for redistribution. The definitive version was published in Diseases of Aquatic Organisms 81 (2008): 219-229, doi:10.3354/dao01948.
    Description: Quahog Parasite Unknown (QPX) is the cause of mass mortality events of hard clams Mercenaria mercenaria from Virginia, USA, to New Brunswick, Canada. Aquaculture areas in Massachusetts, USA, have been particularly hard hit. The parasite has been shown to be a directly infective organism, but it is unclear whether it could exist or persist outside of its clam host. We used molecular methods to examine water, sediment, seaweeds, seagrass and various invertebrates for the presence of QPX. Sites in Virginia and Massachusetts were selected based upon the incidence of QPX-induced clam die-offs, and they were monitored seasonally. QPX was detectable in almost all of our different sample types from Massachusetts, indicating that the parasite was widely distributed in the environment. Significantly more samples from Massachusetts were positive than from Virginia, and there was a seasonal pattern to the types of samples positive from Massachusetts. The data suggest that, although it may be difficult to completely eradicate QPX from the environment, it may be possible to keep the incidence of disease under control through good plot husbandry and the removal of infected and dying clams.
    Description: This work is the result of research sponsored by NOAA National Sea Grant College Program Office, Department of Commerce, under Grant No. NA16RG2273, Woods Hole Oceanographic Institution Sea Grant Project No. R/B-168.
    Keywords: Quahog Parasite Unknown ; QPX ; Environmental detection ; Remediation
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2022-05-25
    Description: Author Posting. © Inter-Research, 2006. This article is posted here by permission of Inter-Research for personal use, not for redistribution. The definitive version was published in Marine Ecology Progress Series 322 (2006): 239-248, doi:10.3354/meps322239.
    Description: Dimethylsulfoniopropionate (DMSP) synthesized by marine phytoplankton is the principal source of dimethylsulfide (DMS), an important climate-affecting gas. Prior research has demonstrated that grazing by invertebrate phytoplanktivores often affects the dynamics of DMS production from algal DMSP, but the effects of grazing by phytoplanktivorous fish have not previously been investigated. We studied the fate of algal DMSP following grazing by juvenile Atlantic menhaden Brevoortia tyrannus (13 cm fork length), which are generally viewed as the most specialized for phytoplanktivory of all postlarval fish. The menhaden were fed the dinoflagellate Prorocentrum micans, containing 1 to 2 pmol DMSP cell–1. During the first 24 h following ingestion of algal DMSP, almost none of the DMSP (ca. 1%) appeared as DMS. About 21% of ingested DMSP appeared in the water column as dissolved DMSP, peaking in concentration 9 to 11 h after feeding; in natural settings, this fraction would be poised for microbial metabolism, including potential conversion to DMS in surface waters from which outgassing to the atmosphere could occur. About 10% of ingested DMSP appeared in fecal pellets that tended to sink rapidly toward the bottom of the tanks. About 33% of ingested DMSP was deposited in the tissues of the menhaden, in particular in the red and white swimming muscles, in which we observed concentrations exceeding 0.7 µmol g–1. This final fraction could ultimately be metabolized to DMS, or it could be passed up food chains and possibly act as a taste factor in commercially important piscivores such as striped bass and bluefish. In total, our research demonstrated that at least two-thirds of the ingested DMSP ends up in tissues or feces or in solution in the ambient water in the first 24 h after feeding, and virtually none is converted to ambient DMS during that time period.
    Description: Financial support came from Michigan State University (R.W.H. sabbatical) and National Science Foundation, Division of Ocean Sciences Grant nos. OCE-9411497 and OCE-9102532.
    Keywords: Dimethylsulfide ; Dimethylsulfoniopropionate ; Menhaden ; DMS ; DMSP ; Brevoortia tyrannus ; Taste factor ; Phytoplanktivory
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2022-05-25
    Description: Author Posting. © Inter-Research, 2007. This article is posted here by permission of Inter-Research for personal use, not for redistribution. The definitive version was published in Marine Ecology Progress Series 343 (2007): 131-140, doi:10.3354/meps06825.
    Description: Dimethylsulfoniopropionate (DMSP) synthesized by marine phytoplankton is the principal source of dimethylsulfide (DMS), an important climate-affecting gas. Grazing by small zooplankton on phytoplankton often accelerates DMS production from algal DMSP. The effects of grazing by benthic suspension feeders, such as bivalve molluscs, however, have not been studied, even though their populations sometimes process a sizable fraction of local phytoplankton production. We fed Tetraselmis sp. Strain UW474 (27 to 42 fmol DMSP cell–1) to adult mussels Mytilus edulis and scallops Argopecten irradians and studied the fate of the algal DMSP during the 24 h following ingestion. Almost none of the ingested DMSP reappeared in the environment as DMS or DMSP; the amount that appeared in the ambient water as DMS was 〈1% of that ingested, and the sum total that appeared either as fecal DMSP (which microbes might convert to DMS) or in the water as DMS or DMSP was ≤3 to 4% of that ingested. In the short term, therefore, thriving bivalve populations probably strongly reduce the rate of DMS formation (direct or indirect) from local algal DMSP, in contrast to zooplankton populations. Ingested DMSP is likely accumulated in the bodies of mussels and scallops. However, although we have weak evidence of partial accumulation in scallop gastrointestinal tissue, we were unable to document accumulation in mussels because of high variability and statistical nonnormality in their naturally occurring DMSP content. In total, we showed that in the 24 h following feeding, mussels and scallops do not facilitate ambient DMS formation from algal DMSP and evidently sequester most of the algal DMSP they ingest.
    Description: Financial support came from Michigan State University (R.W.H. sabbatical) and the US National Science Foundation, grants OCE-9411497 and OCE-9102532.
    Keywords: Dimethylsulfide ; DMS ; Dimethylsulfoniopropionate ; DMSP ; Bivalves ; Mussels ; Scallops ; Mytilus edulis ; Argopecten irradians ; Phytoplanktivory
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Publication Date: 2022-05-26
    Description: Author Posting. © Inter-Research, 2006. This article is posted here by permission of Inter-Research for personal use, not for redistribution. The definitive version was published in Marine Ecology Progress Series 310 (2006): 263-270, doi:10.3354/meps310263.
    Description: The longfin squid Loligo pealeii is distributed widely in the NW Atlantic and is the target of a major fishery. A previous electrophoretic study of L. pealeii was unable to prove genetic differentiation, and the fishery has been managed as a single unit stock. We tested for population structure using 5 microsatellite loci. In early summer (June), when the squids had migrated inshore to spawn, we distinguished 4 genetically distinct stocks between Delaware and Cape Cod (ca. 490 km); a 5th genetic stock occurred in Nova Scotia and a 6th in the northern Gulf of Mexico. One of the summer inshore stocks did not show genetic differentiation from 2 of the winter offshore populations. We suggest that squids from summer locations overwinter in offshore canyons and that winter offshore fishing may affect multiple stocks of the inshore fishery. In spring, squids may segregate by genetic stock as they undertake their inshore migration, indicating an underlying mechanism of subpopulation recognition.
    Description: We acknowledge funding from WHOI Sea Grant NA16RG2273, the Massachusetts Environmental Trust (#98-04), and the Sholley Foundation.
    Keywords: Fisheries ; Spawning migration ; Microsatellites ; Population structure ; Population recognition ; Null alleles
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2022-05-26
    Description: Author Posting. © Inter-Research, 2006. This article is posted here by permission of Inter-Research for personal use, not for redistribution. The definitive version was published in Diseases of Aquatic Organisms 72 (2006): 45-52, doi:10.3354/dao072045.
    Description: Quahog Parasite Unknown (QPX) is a thraustochytrid pathogen responsible for catastrophic mortalities of the northern quahog (hard clam) Mercenaria mercenaria. A real-time quantitative polymerase chain reaction (qPCR) assay was developed to assist research efforts on QPX ecology and pathology. Sensitivity of the assay was evaluated with serial dilutions of QPX-cultured cells to determine the lowest concentration of DNA that remained detectable in both the presence and absence of extraneous environmental substances. QPX cells were quantified before DNA extraction to calibrate standard curves to cell counts. Based on our results, the qPCR assay is able to quantify QPX within the range of 1 to several thousand organisms per reaction. Specificity of the assay was assessed by testing 29 thraustochytrid-like protists isolated from suspension-feeding bivalves from China, Oregon, Maryland, and Virginia. Application of the assay was demonstrated with positive qPCR results from naturally contaminated environmental samples including marine aggregates (i.e. marine snow), clam pseudofeces, and inflammatory nodules from infected clams. This quantitative assay for QPX will provide a valuable tool for characterizing QPX parasite abundances in coastal environments and for improving clam disease diagnostics.
    Description: This research was funded in part by NSF-NIH Ecology of Infectious Disease Grant (No. 0429018) to R.S. and a grant to R.S. and S.B.R. from the County of Barnstable, Massachusetts.
    Keywords: Quahog Parasite Unknown ; QPX ; Thraustochytrids ; Mercenaria mercenaria ; Real-time PCR ; Histology ; Marine aggregates ; Pseudofeces ; Clams
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Publication Date: 2022-05-26
    Description: Author Posting. © Inter-Research, 2006. This article is posted here by permission of Inter-Research for personal use, not for redistribution. The definitive version was published in Diseases of Aquatic Organisms 70 (2006): 115-122, doi:10.3354/dao070115.
    Description: Quahog Parasite Unknown (QPX) is a significant cause of hard clam Mercenaria mercenaria mortality along the northeast coast of the United States. It infects both wild and cultured clams, often annually in plots that are heavily farmed. Subclinically infected clams can be identified by histological examination of the mantle tissue, but there is currently no method available to monitor the presence of QPX in the environment. Here, we report on a polymerase chain reaction (PCR)-based method that will facilitate the detection of QPX in natural samples and seed clams. With our method, between 10 and 100 QPX cells can be detected in 1 l of water, 1 g of sediment and 100 mg of clam tissue. Denaturing gradient gel electrophoresis (DGGE) is used to establish whether the PCR products are the same as those in the control QPX culture. We used the method to screen 100 seed clams of 15 mm, and found that 10 to 12% of the clams were positive for the presence of the QPX organism. This method represents a reliable and sensitive procedure for screening both environmental samples and potentially contaminated small clams.
    Description: Quahog Parasite Unknown (QPX) is a significant cause of hard clam Mercenaria mercenaria mortality along the northeast coast of the United States. It infects both wild and cultured clams, often annually in plots that are heavily farmed. Subclinically infected clams can be identified by histological examination of the mantle tissue, but there is currently no method available to monitor the presence of QPX in the environment. Here, we report on a polymerase chain reaction (PCR)-based method that will facilitate the detection of QPX in natural samples and seed clams. With our method, between 10 and 100 QPX cells can be detected in 1 l of water, 1 g of sediment and 100 mg of clam tissue. Denaturing gradient gel electrophoresis (DGGE) is used to establish whether the PCR products are the same as those in the control QPX culture. We used the method to screen 100 seed clams of 15 mm, and found that 10 to 12% of the clams were positive for the presence of the QPX organism. This method represents a reliable and sensitive procedure for screening both environmental samples and potentially contaminated small clams.
    Keywords: Quahog Parasite Unknown ; Detection limit ; Seed clams ; SSU rDNA
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...