US Long-Term Ecological Research Network

Landscape Position Project at North Temperate Lakes LTER: Vertical Lake Profiles 1998 - 1999

Abstract
Parameters characterizing the chemical limnology and spatial attributes of 45 lakes were surveyed as part of the Landscape Position Project. Parameters are measured at or close to the deepest part of the lake. A vertical profile of temperature, dissolved oxygen, and conductivity are collected at 1 meter increments Sampling Frequency: generally monthly for one summer; for some lakes, one or two samples in one summer Number of sites: 45
Dataset ID
95
Date Range
-
Maintenance
completed
Metadata Provider
Methods
We sample at the deepest part of the lake, taking a temperature and oxygen profile at meter intervals from the surface to within 1 meter of the bottom using a YSI Pro-ODO temp/DO meter.
Short Name
LPPPROF1
Version Number
8

North Temperate Lakes LTER: Northern Highlands Stream Chemistry Survey 2006

Abstract
We compared regional patterns in lake and stream biogeochemistry in the Northern Highlands Lake District (NHLD), Wisconsin, USA to ask how regional biogeochemistry differs as a function of the type of ecosystem considered (i.e., lakes versus streams); if lake-stream comparisons reveal regional patterns and processes that are not apparent from studies of a single ecosystem type; and if characteristics of streams and lakes scale similarly. Fifty-two streams were sampled using a stratified random design to determine regional distribution of 21 water chemistry variables during summer baseflow conditions.Sampling Frequency: once per site Number of sites: 52
Contact
Core Areas
Dataset ID
254
Date Range
-
Maintenance
completed
Metadata Provider
Methods
Site SelectionBecause lakes are a dominant feature of the region and stream characteristics could potentially differ based on their hydrologic connections to lakes, we classified streams into three categories as a function of their hydrologic connections to lakes. The first category was streams that had no lakes within the drainage network upstream of the sampling location. The second category was streams that originated from headwater lakes (i.e., no stream inlet but a stream outlet) and the headwater lake was the only lake in the drainage network above the sampling location. The final category had at least a single drainage lake (i.e., a lake with both stream inlet(s) and outlet) in the drainage network above the sampling location. We then used these categories to select sampling sites using a stratified random design for a variety of chemical and physical characteristics.All streams identified on 1:24,000 7.5 inch USGS topographical maps that crossed access points were selected as potential sampling locations and assigned to one of the three stream types. A stream could be classified by more than a single category depending on the sampling location within the drainage network. However, a single drainage network was never sampled more than once to ensure sample independence. Of the 500 possible sampling locations, 52 sites were selected and sampled.SamplingAll streams were sampled 7-10 channel widths upstream of an access point to minimize any influences caused by culverts and other features. Water samples were collected from the center of the channel using a peristaltic pump. Stream discharge was measured after Gore (2007) using cross sectional area and water velocity.Chemical AnalysesAll samples for both studies were collected and processed following the North Temperate Long Term Ecological Research (NTL-LTER) protocols (http://lter.limnology.wisc.edu). Filtering was done in the field using an in-line 0.45 μm membrane filter. All samples were stored on ice and returned to the laboratory where they were preserved according to NTL-LTER protocols. Acid neutralizing capacity (ANC) was determined by Gran titration (APHA 2005). DOC was measured on a Shimadzu TOC-V carbon analyzer. Total nitrogen and phosphorus (unfiltered, TN and TP; filtered, TDN and TDP), nitrate+nitrite (NO3-N), and ammonium (NH4-N) were quantified with an Astoria-Pacific segmented flow auto-analyzer. Soluble reactive phosphorus (SRP) in streams was measured colormetrically on a Beckman DU-800 spectrophotometer (APHA 2005). Anions (Cl- and SO4 2-) were measured using a Dionix DX-500 ion chromatograph and cations (Ca, Mg, Na, K, Fe, K, and Mn) on a Perkin Elmer ICP mass spectrometerDissolved inorganic carbon (DIC) and pH were quantified differently in the lakes and stream data sets. For the lakes data, DIC was determined with a Shimadzu TOC-V carbon analyzer, whereas DIC for the streams dataset was determined by headspace equilibration of acidified water samples in the field and direct measurement of carbon dioxide (CO2) gas on a Shimadzu gas chromatograph (Cole et al. 1994). pH measurements for the lakes dataset were quantified on non-air equilibrated samples in the lab with a Accumet 950 pH meter while direct measurements were taken in the field for the streams dataset using a hand-held Orion model 266 pH meter that was allowed to equilibrated about 20 min in the center for the stream channel.Several variables presented in this study were determined from calculations based on measured values. In streams, dissolved organic nitrogen and phosphorus (DON and DOP, respectively) were determined by the difference between inorganic nutrients and total dissolved nutrients (e.g., DOP = TDP-SRP). We were unable to determine DON in lakes due to the lack of inorganic nitrogen data. It was assumed that DOP approximately equals TDP in lakes because dissolved inorganic phosphorus concentrations in the region are typically below detection limits in the epilimnion during the summer months and consequently not quantified (NTL-LTER unpublished data).
Short Name
LOTTIG2
Version Number
19

Lake Mendota Phosphorus Entrainment at North Temperate Lakes LTER 2005

Abstract
This dataset contains total (TP) and soluble reactive phosphorus (SRP) data collected in Lake Mendota during the summer of 2005 between 6/28/2005 and 10/14/2005 as well as high-resolution temperature data for that same time period . The phosphorus data were taken at five different locations where buoys were deployed. The buoys were deployed with HOBO temperature data loggers attached at 2 - 4 m intervals. Similarly the phosphorus samples were collected at 2 - 4 m intervals throughout the water column. The position of the five buoys changed a few times during the summer in an effort to monitor circulation patterns due to different wind directions and speeds. Manuscript using this dataset: Kamarainen, A.M., H. Yuan, C. Wu, S.R. Carpenter. 2009. One-dimensional and three-dimensional approaches converge on similar estimates of phosphorus entrainment in Lake Mendota. Limnology and Oceanography Methods 7:553-567 Sampling frequency: Water temperature: generally 1 min; some at 5 min. TP and SRP: approximately at 2 weeks intervals Number of sites: 12
Core Areas
Dataset ID
258
Date Range
-
Maintenance
completed
Metadata Provider
Methods
Kamarainen, A.M., H. Yuan, C. Wu, S.R. Carpenter. 2009. One-dimensional and three-dimensional approaches converge on similar estimates of phosphorus entrainment in Lake Mendota. Limnology and Oceanography Methods 7:553-567
Short Name
KAMWT05
Version Number
15

Allequash Creek sonde measurements summer 2006

Abstract
A sonde was used to measure conductivity, do, oxygen saturation, water temperature, pH, and oxidation-reduction potential. Sampling took place in Allequash creek above and below a bog and close to the lake. Sampling Frequency: 15 minutes Number of sites: 3
Core Areas
Dataset ID
253
Data Sources
Date Range
-
Maintenance
completed
Metadata Provider
Methods
see abstract for methods used.
Short Name
LOTTIG1
Version Number
28

Lake Wingra Exclosure Experiment at North Temperate Lakes LTER: Physical Limnology 2005 - 2008

Abstract
Starting in late summer 2005, Wisconsin Dept of Natural Resources (WDNR), Dane County, Friends of Lake Wingra (FOLW), and NTL-LTER initiated a 3-year experiment in Lake Wingra to test the response of the native macrophyte community to clearer water produced from a major carp reduction program. This demonstration-scale experiment includes the construction of a 1.0-hectare rectangular carp exclosure with its solid vinyl walls extending from the lake shoreline to a water depth of 2.9 meters. NTL-LTER conducts the routine limnological monitoring of the lake and exclosure and is leading the science evaluation of potential lake restoration activities. The exclosure experiment was terminated in the fall of 2008. The exclosure was removed from Lake Wingra at that time. Sampling is done both within the exclosure and at a control site located nearby in the littoral zone. The sample location within the exclosure is equidistant from the side walls and approximately 75 meters from the shore in a water depth of approximately 2.5 meters. The control site sample location is approximately 75 meters west of the exclosure sample site at the same approximate distance from shore and water depth. Samples are taken at the same time and on the same schedule as the NTL-LTER limnological sampling on Lake Wingra, e.g., biweekly spring through summer, every 4 weeks in the fall, and once during the winter depending on ice conditions. Parameters measured within the exclosure and at the control site include water temperature, dissolved oxygen, secchi depth and chlorophyll-a. Additional parameters measured only within the exclosure include total Kjeldahl nitrogen, nitrate + nitrite nitrogen, ammonia nitrogen, total phosphorus, dissolved reactive phosphorus and dissolved reactive silica. Parameters characterizing the physical limnology are measured within the exclosure and at a nearby control site in the littoral zone at 1-m depth intervals. Measured parameters in the data set include water temperature, dissolved oxygen, as well as the derived parameter percent oxygen saturation. Secchi disk depth is also measured. Auxiliary data include time of day, air temperature, cloud cover, wind speed and direction, and wave height. Sampling Frequency: generally bi-weekly during ice-free season from late March or early April through early September, then every 4 weeks through late November. Number of sites: 2
Dataset ID
192
Date Range
-
Maintenance
completed
Metadata Provider
Methods
Reading Temperature and Dissolved Oxygen1. Before leaving to sample a lake, check to make sure that there are no air bubbles under the probe membrane of the YSI TemperatureorDissolved Oxygen meter. If there are air bubbles or if it has been several months since changing the membrane (or if the instrument does not calibrate well or the oxygen readings wander), change the membrane as explained in the manual. Note: We have always used the Standard membranes. If adding water to new membrane fluid bottle (KCl), make sure to add Milli-Q water and not the CFL distilled water.2. Be sure to always store the probe in 100percent humidity surrounded by a wet sponge or paper towel.3. Turn on the temperatureordissolved oxygen meter at least 30 minutes before using it. It is best to turn it on before leaving to sample a lake as it uses up batteries slowly.4. Calibrate the meter using the chart on the back of the instrument (adjusted to the Madison altitude - 97percent oxygen saturation). Leave the plastic cap on the probe (at 100percent humidity). The temperature should not be changing during the calibration. Zero the instrument. When the temperature equilibrates, adjust the oxygen to correspond to the chart. After calibrating the instrument, switch the knob to percent oxygen saturation to make sure it is close to 97percent.5. Take readings at 1 meter intervals making sure to gently jiggle the cord when taking the oxygen readings (to avoid oxygen depletion). Jiggling the cord is not necessary if using a cable with a stirrer. Take half meter readings in the metalimnion (when temperature andoror oxygen readings exhibit a greater change with depth). A change of temperature greater than 1degreeC warrants half-meter intervals.6. Record the bottom depth using the markings on the temp.oroxygen meter cord and take a temperature and dissolved oxygen reading with the probe lying on the lake bottom. Dont forget to jiggle the probe to remove any sediment.7. If any readings seem suspicious, check them again when bringing the probe back up to the surface. You can also double check the calibration after bringing the probe out of the water (and putting the cap back on).
Short Name
FOLWEXPH
Version Number
18

North Temperate Lakes LTER: High Frequency Meteorological and Dissolved Oxygen Data - Crystal Bog Buoy 2005 - 2014

Abstract
The instrumented buoy on Crystal Bog is equipped with a dissolved oxygen sensor, a thermistor chain, and meteorological sensors that provide fundamental information on lake thermal structure, weather conditions, and lake metabolism. Data are usually collected every 10 minutes with occasional periods of 2 minute data for short periods to answer specific questions. The D-Opto dissolved oxygen sensor is 0.5m from the lake surface, thermistors are placed every 0.25m throughout the water column, and meteorological sensors measure wind speed, relative humidity, and air temperature. After correcting for flux to or from the atmosphere and vertical mixing within the water column, high frequency measurements of dissolved gases such as carbon dioxide and oxygen can be used to estimate gross primary productivity, respiration, and net ecosystem productivity, the basic components of whole lake metabolism. Sampling Frequency: varies for instantaneous sample. averaged to hourly and daily values from one minute samples Number of sites: 1
Core Areas
Dataset ID
118
Date Range
-
Maintenance
ongoing
Metadata Provider
Methods
see abstract for methods description
Short Name
CBBUOY1
Version Number
11

North Temperate Lakes LTER: High Frequency Water Temperature Data - Crystal Bog Buoy 2005 - 2014

Abstract
The instrumented buoy on Crystal Bog is equipped with a thermistor chain that measures water temperature from depths ranging from the surface to 2.25m placed every 0.25m throughout the water column. The surface temperature sensors are attached to floats so that they are as close to the surface as feasible. The Crsytal Bog buoy is also equipped with a dissolved oxygen sensor and meteorological sensors that provide fundamental information on lake thermal structure, weather conditions, and lake metabolism. Data are usually collected every 10 minutes with occasional periods of 2 minute data for short periods to answer specific questions. After correcting for flux to or from the atmosphere and vertical mixing within the water column, high frequency measurements of dissolved gases such as carbon dioxide and oxygen can be used to estimate gross primary productivity, respiration, and net ecosystem productivity, the basic components of whole lake metabolism. Sampling Frequency: varies for instantaneous sample. averaged to hourly and daily values from one minute samples Number of sites: 1
Core Areas
Dataset ID
119
Date Range
-
Maintenance
completed
Metadata Provider
Methods
The instrumented buoy on Crystal Bog is equipped with a thermistor chain that measures water temperature from depths ranging from the surface to 2.25m placed every 0.25m throughout the water column. The Crsytal Bog buoy is also equipped with a dissolved oxygen sensor and meteorological sensors that provide fundamental information on lake thermal structure, weather conditions, and lake metabolism. Data are usually collected every 10 minutes with occasional periods of 2 minute data for short periods to answer specific questions. After correcting for flux to or from the atmosphere and vertical mixing within the water column, high frequency measurements of dissolved gases such as carbon dioxide and oxygen can be used to estimate gross primary productivity, respiration, and net ecosystem productivity, the basic components of whole lake metabolism. Sampling Frequency: varies for instantaneous sample. averaged to hourly and daily values from one minute samples
Short Name
CBBUOY2
Version Number
26

Biocomplexity at North Temperate Lakes LTER; Coordinated Field Studies: Coarse Woody Habitat Data 2001 - 2009

Abstract
These data were collected to test for changes in the population dynamics and the food webs of the fish populations of Little Rock and Camp lakes, Vilas County, WI, USA. Little Rock Lake was the site of a whole-lake removal of coarse woody habitat in 2002 and Camp Lake was the site of a whole-lake coarse woody habitat addition in 2004. Sampling began in May of 2001 and ended in August of 2006. Some sampling was repeated from 2007 to 2009. Number of sites: 4. Two lakes with reference and treatment basin in each lake.
Core Areas
Dataset ID
215
Date Range
-
Maintenance
completed
Metadata Provider
Methods
Fish were collected by beach seining, hook and line angling, and minnow traps. Commonly captured species were largemouth bass, bluegill, yellow perch, rock bass, and black crappie. Population Estimates: Chapman-modified continuous Schnabel mark-recapture population estimates were conducted on each basin of Little Rock and Camp lakes annually. Adult population estimates for largemouth bass, yellow perch, rock bass, and black crappie were calculated for Little Rock Lake during 2001-2006. All fish were captured by hook and line angling, minnow traps, and beach seining. Adult population estimates for largemouth bass and bluegill were calculated for Camp Lake during 2002-2006. All fish were captured by hook and line angling and beach seining. Fish Length/Weight Tag data: Length, weight, and mark data was recorded for all fish used to collect diet information. Diet information was collected from up to 15 individuals of each species biweekly May-September using gastric lavage. Diet information was collected from largemouth bass, yellow perch, rock bass, and black crappie in Little Rock Lake from 2001-2005 and 2007 - 2009. Diet information was collected from largemouth bass and yellow perch in Camp Lake from 2002-2005. Fish Length Tag data: Length and mark data was recorded for all fish used to calculate the mark-recapture population estimates. Length and the mark were recorded from all fish captured in Little Rock and Camp lakes from 2001-2006. Length and mark data exists for all fishes collected in Little Rock Lake from 2001-2006 and 2007 - 2009. Fish species from Little Rock include largemouth bass, yellow perch, rock bass, and black crappie. Length and mark data exists for all fishes collected in Camp Lake from 2002-2006. Fish species from Camp Lake include largemouth bass, yellow perch, and bluegill. All fish were captured by beach seining, hook and line angling, and minnow traps. Minnow trap CPUE: Minnow traps were the most effective gear for capturing yellow perch on Little Rock Lake. Standardized minnow trapping was conducted on both basins of Little Rock Lake in 2003-2005. In 2003, 10 minnow traps in each basin were deployed biweekly and picked twice per week. In 2004-2005, 20 minnow traps in each basin were deployed biweekly and picked twice per week. Catch per unit effort was calculated as catch of yellow perch per trap. Age Growth Rates: Growth rates were calculated for a subset of fish collected from Little Rock Lake (2001-2004) and Camp Lake (2002-2005). Back-calculated growth rates from five fish from every 10 mm size increment were examined. In the process, age was determined from scale samples and length at each annulus was back-calculated. Size-specific growth rates were calculated based on the relationship between fish length at age and ln transformed growth rate at age. Back-calculated growth information was assessed from largemouth bass, yellow perch, rock bass, and black crappie in Little Rock Lake. Back-calculated growth information was assessed from largemouth bass and bluegill in Camp Lake.
Short Name
BIOSASS1
Version Number
9

Biocomplexity at North Temperate Lakes LTER; Coordinated Field Studies: Chemical Limnology 2001 - 2004

Abstract
Chemical Limnology data collected for Biocomplexity Project; Landscape Context - Coordinated Field Studies Replicate chemical samples were pumped from the surface water (0.5m depth) and secchi depth was recorded at each lake. Temperature/dissolved oxygen profiles were taken throughout the water column at one meter intervals on all lakes. For more detail see the Water Sampling Protocol. Sampling Frequency: During 2001, temperature/dissolved oxygen profiles and secchi depths were taken twice during the stratified summer period. Chemistry samples were only taken once during the 2001 stratified period. From 2002 through 2004, all chemical and physical water samples were taken once during June (or resampled during the stratified period if June samples were bad). All lakes in which color, DIC/DOC, and chlorophyll samples were taken in 2001 were resampled in 2002 due to error in collection and/or analysis. Number of sites: 62 Vilas County lakes were sampled from 2001-2004 (approximately 15 different lakes each year).
Dataset ID
41
Date Range
-
Maintenance
completed
Metadata Provider
Methods
Environmental Sampling and Analysis: Physical, chemical and biological samples were taken above the deepest point in each lake during the summer stratification period (June, July, or August). Water samples were collected from one half meter depth using a peristaltic pump, and were analyzed for pH, alkalinity, specific conductance, water color, chlorophyll-a, dissolved organic and inorganic carbon, total phosphorus, and total nitrogen (Appendix Table 1). Secchi depth, temperature and dissolved oxygen profiles, and vertical plankton tows were also taken at the deepest point. Temperature and dissolved oxygen concentrations (DO) were measured through the water column at 1 meter increments.. Conductivity, TP-TN, alkalinity and pH water samples were collected unfiltered while water for DIC-DOC and color water samples was filtered through nucleopore polycarbonate filters. Alkalinity, pH, and DIC-DOC samples were filled to the top and sealed quickly to prevent CO2 loss or invasion. Samples containing air bubbles were recollected. Chlorophyll samples were collected on glass fiber filters in the field. Water chemistry and chlorophyll a analyses were done at the Trout Lake Biological Station, Boulder Junction, WI except for TP, TN, DIC and DOC samples, which were analyzed at the Center for Limnology-Lake Mendota Laboratory, Madison, WI.
NTL Keyword
Short Name
BIOCHEM1
Version Number
7

North Temperate Lakes LTER: High Frequency Water Temperature Data - Trout Lake Buoy 2004 - current

Abstract
The instrumented buoy on Trout Lake is equipped with a thermistor chain that measures water temperature from thermistors placed throughout the water column. From 2004 to mid-summer 2006, thermistors were placed every 0.5-1m from the surface through 14m, and every 2 to 4m from 14m to the bottom of the water column at 31m. The surface temperature sensors are attached to floats so that they are as close to the surface as feasible. In July 2006, a new thermistor chain was deployed with sensors placed every meter from the surface through a depth of 19 meters. This configuration lasted through 2008 and was used again 2012-2014. In the period 2009-2011, thermisters were place every meter down to 20m and then every two meters to a final depth of 32m. From 2015 to present, thermistors are spaced 0.25 meters from the surface to 1m, 0.5 meters down to 4 meters depth, and 1m spacing to 14 meters. Four more thermisters are at depths of 16, 20, 25 and 30 meters. Sampling frequency was 10 minutes in 2004-2005 and again 2007-2010. It was 2 minutes in 2006. Since 2011, sampling frequency has been every minute.The Trout Lake buoy is also equipped with a dissolved oxygen sensor and meteorological sensors that provide fundamental information on lake thermal structure, weather conditions, and lake metabolism. After correcting for flux to or from the atmosphere and vertical mixing within the water column, high frequency measurements of dissolved gases such as carbon dioxide and oxygen can be used to estimate gross primary productivity, respiration, and net ecosystem productivity, the basic components of whole lake metabolism. Number of sites: 1. Hourly and daily averages are computed from the high resolution data.
Core Areas
Dataset ID
116
Date Range
-
Maintenance
ongoing
Metadata Provider
Short Name
TRBUOY2
Version Number
28
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