Johanna Laybourn-Parry 2014-11-04 tabular digitial data McMurdo Dry Valleys LTER McMurdo Dry Valleys LTER 10.6073/pasta/6730f95313c8e49ae0fd496af73b5a12 https://mcm.lternet.edu/content/microzooplankton-ciliate-grazing-rates In conjunction with the Long Term Ecological Research (LTER) project in the McMurdo Dry Valleys of Antarctica, lakes were monitored for microzooplankton by a team based out of the University of Nottingham (led by Johanna Laybourn-Parry). This dataset shows grazing rates of ciliates feeding on cryptophytes between November 1997 and January 1998. The sample for this micro dataset was gathered at the Lake Fryxell. 1997-11-01 1998-01-01 ground condition  Data for this file was submitted by Johanna Laybourn-Parry to the data manager at INSTAAR on October 21, 1998. Files were sent via e-mail as well as a hard copy. The original version of the file is stored on the Unix system in "/data1/data/lakes/plankton/laybourn-parry/DV". Upon arrival at INSTAAR, the data manager reformatted the file to present it in a relational mode. This was done using Microsoft Access. It was then exported in comma delimited ascii and MS-DOS text format to present on the web. Links to these files are provided above. On 2006, metadata was standardized to the EML format.  in 2014, metadata was enhanceded with the Drupal Ecological information management system (Inigo San Gil).  Completed in 2016 As needed The Lake Fryxell basin is formed by a moraine depression in a wider portion of the Taylor Valley. It has a number of moraine islands and shallower areas, as well as several relatively well developed deltas. The lake is fed by at least 10 meltwater streams with a total drainage catchment of 230 km2. The lake is dammed to the southwest by the Canada Glacier and is topographically closed. It is perennially ice covered; during summer months, an ice-free moat generally forms around much of the lake margin. Lake levels have risen ~2 m between 1971 and 1996. There are no surface outflows; the only known water loss is through ice ablation (evaporation, sublimation and physical scouring). Valley: Taylor Distance to Sea : 9 Maximum Length (km): 5.8 Maximum Width (km): 2.1 Maximum Depth (m): 20 Surface Area (km^2): 7.08 Ice Thickness Average Surface (m): 3.3 - 4.5 Volume (m^3 * 10^6): 25.2 163.259582519531 163.048782348633 -77.597076416016 -77.622711181641 18m 18m meter LTER Core Areas population dynamics None <cntorg>McMurdo Dry Valleys LTER</cntorg> <onlink>http://mcmlter.org/</onlink> <span property="dc:title" content="McMurdo Dry Valleys LTER" class="rdf-meta element-hidden"></span> Name: Inigo San Gil Role: data manager Not Applicable Not Applicable Field and/or Lab Methods Ciliate samples were collected from Lake Fryxell by drilling a hole through the thick ice cover (approximately 4m thick) above the deepest point of the lake. A 2.21 Niskin bottle was used to retrieve duplicate 500 ml water samples from a 9m depth. The water samples were fixed in Lugol's iodine and concentrated by settling, prior to counting in a Sedgewick-Rafter counting chamber under phase microscopy at x160. Cryptophyte biomass was calculated by measuring 50 cells on each preparation. Biovolume was derived by applying an ellipsoid geometric shape and converted to carbon using a conversion figure of 220fg C/microm3. Ciliate ingestion rates were determined using live cryptophytes. Ciliates were incubated in the dark at 2 degrees C until no autofluorescence from ingested cryptophytes was visible within the cells. Freshly collected cryptophytes were concentrated by gravity filtration. The ciliates were then incubated with two concentrations of cryptophytes, 8500/ml and 15000/ml. The former concentration is typical of the deep maximum of cryptophytes in Lake Fryxell, the latter is close to the highest level ever recorded in Lake Fryxell. Ingestion rates were measured at 6 intervals over an 8 hour period. Samples were fixed with ice-cold 2% glutaraldehyde (final concentration), filtered onto 10 microm polycarbonate filters and viewed under epifluorescence microscopy. Ingested cryptophytes were visible within the ciliates by their orange autofluorescence. Fifty ciliates were examined on each preparation. Ciliate samples were collected from Lake Fryxell by drilling a hole through the thick ice cover (approximately 4m thick) above the deepest point of the lake. A 2.21 Niskin bottle was used to retrieve duplicate 500 ml water samples from a 9m depth. The water samples were fixed in Lugol's iodine and concentrated by settling, prior to counting in a Sedgewick-Rafter counting chamber under phase microscopy at x160. Cryptophyte biomass was calculated by measuring 50 cells on each preparation. Biovolume was derived by applying an ellipsoid geometric shape and converted to carbon using a conversion figure of 220fg C/microm3. Ciliate ingestion rates were determined using live cryptophytes. Ciliates were incubated in the dark at 2 degrees C until no autofluorescence from ingested cryptophytes was visible within the cells. Freshly collected cryptophytes were concentrated by gravity filtration. The ciliates were then incubated with two concentrations of cryptophytes, 8500/ml and 15000/ml. The former concentration is typical of the deep maximum of cryptophytes in Lake Fryxell, the latter is close to the highest level ever recorded in Lake Fryxell. Ingestion rates were measured at 6 intervals over an 8 hour period. Samples were fixed with ice-cold 2% glutaraldehyde (final concentration), filtered onto 10 microm polycarbonate filters and viewed under epifluorescence microscopy. Ingested cryptophytes were visible within the ciliates by their orange autofluorescence. Fifty ciliates were examined on each preparation. unknown cliatgrz Location Name Name of lake where measurement was made (lake fryxell) The data provider Name of lake where measurement was made (lake fryxell) Beginning Date Earliest date on which samples were taken The data provider calendar date/time mm/dd/yyyy gregorian calendar Ending Date Latest date on which samples were taken The data provider calendar date/time mm/dd/yyyy gregorian calendar Depth (m) Depth at which sample was drawn from lake The data provider 0 20 meter 1 Type of Organism Category describing species The data provider Category describing species Min ingestion rate (cryptophytes/ciliate/h) Lowest rate at which cryptophytes were consumed The data provider 0 #ofcryptophytes/ciliate/hour 0.01 Max ingestion rate (cryptophytes/ciliate/h) Highest rate at which cryptophytes were consumed The data provider 0 #ofcryptophytes/ciliate/hour 0.01 Min cryptophyte biomass removed daily (microg C / l) Lowest amount of cryptophyte biomass consumed in 24 hours The data provider 0 microgofcarbon/liter 1 Max cryptophyte biomass removed daily (microg C / l) Highest amount of cryptophyte biomass consumed in 24 hours The data provider 0 microgofcarbon/liter 1 McMurdo Dry Valleys LTER The data distributor shall not be liable for innacuracies in the content http 1 0 \n 1 column , https://mcm.lternet.edu/sites/default/files/cliatgrz.csv None 2014-11-04 2014-11-04 McMurdo Dry Valleys LTER http://mcmlter.org/ Biological Data Profile of the Content Standards for Digital Geospatial Metadata devised by the Federal Geographic Data Committee. Drupal Ecological information Management Systems, version D7, Biological Data Profile module