US Long-Term Ecological Research Network

Little Rock Lake - CWH Study at North Temperate Lakes LTER - Benthic Macroinvertebrates 2002 - 2004

Abstract
Benthic invertebrates were collected as part of CWH (coarse woody habitat) study on Little Rock Lake in Vilas county, WI. Pre-manipulation sampling of the macroinvertebrate communities was conducted in the summer of 2002 before the CWH reduction and six times after the reduction, in early, mid, and late summer (May-August) of 2003 and 2004. We divided the shoreline of Little Rock Lake into 50 m sections and randomly chose five sections from each basin for each separate sampling of macroinvertebrates. We collected two benthos and two CWH macroinvertebrate samples at each section. We constructed a benthos sampler by connecting a SCUBA tank to a 7.6 cm PVC pipe with a hose attached 10 cm from one end of the pipe (Wahle and Steneck 1991; Roth et al. 2007). A 500 m Nitex mesh bag was place at the top end of the pipe furthest from the attached hose. Once the tank was turned on, a vacuum formed that sucked the benthos sample into the bag. We used a 0.09 m2 hoop to delineate the benthos sampling area. We sampled CWH using a self-contained, battery-powered aquatic vacuum with a 500 m Nitex mesh bag (Vander Zanden et al. 2006). Sampling lasted for 30 seconds. All samples were stored in 95% ethanol until processed. Macroinvertebrates were identified to the lowest possible taxonomic level. Helmus M.R. and Sass G.G. (2008) The rapid effects of a whole-lake reduction of coarse woody debris on fish and benthic macroinvertebrates. Freshwater Biology, 53, 1423-1433 Number of sites: 44 Sampling Frequency: once pre-manipulation, 6 sampling regimes after reduction
Core Areas
Dataset ID
230
Date Range
-
LTER Keywords
Maintenance
completed
Metadata Provider
Methods
Benthic invertebrates were collected as part of CWH (coarse woody habitat) study on Little Rock Lake in Vilas county, WI. Pre-manipulation sampling of the macroinvertebrate communities was conducted in the summer of 2002 before the CWH reduction and six times after the reduction, in early, mid, and late summer (May-August) of 2003 and 2004. We divided the shoreline of Little Rock Lake into 50 m sections and randomly chose five sections from each basin for each separate sampling of macroinvertebrates. We collected two benthos and two CWH macroinvertebrate samples at each section. We constructed a benthos sampler by connecting a SCUBA tank to a 7.6 cm PVC pipe with a hose attached 10 cm from one end of the pipe (Wahle and Steneck 1991; Roth et al. 2007). A 500 m Nitex mesh bag was place at the top end of the pipe furthest from the attached hose. Once the tank was turned on, a vacuum formed that sucked the benthos sample into the bag. We used a 0.09 m2 hoop to delineate the benthos sampling area. We sampled CWH using a self-contained, battery-powered aquatic vacuum with a 500 m Nitex mesh bag (Vander Zanden et al. 2006). Sampling lasted for 30 seconds. All samples were stored in 95% ethanol until processed. Macroinvertebrates were identified to the lowest possible taxonomic level. Helmus M.R. and Sass G.G. (2008) The rapid effects of a whole-lake reduction of coarse woody debris on fish and benthic macroinvertebrates. Freshwater Biology, 53, 1423-1433 Number of sites: 44 Sampling Frequency: once pre-manipulation, 6 sampling regimes after reduction
Short Name
HELMUS1
Version Number
25

Lake Wingra Exclosure Experiment at North Temperate Lakes LTER: Sampledate Conditions 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. Auxiliary data collected while sampling for the exclosure experiment. Data include time of day, air temperature, cloud cover, wave height, bottom depth, wind speed and direction. 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
244
Date Range
-
Maintenance
completed
Metadata Provider
Methods
Measuring Air Temperature, Wind Speed, Wind Direction, percent Cloud Cover, and Wave Height1. Estimate air temperature and check forecast before and after going into the field.2. Estimate the wind speed. Record a range if the wind is variable (e.g. 10-15 mph).3. Face the direction that the wind is coming from. Use lake maps to determine which direction the wind is flowing.4. Estimate and record the percent cloud cover.5. Estimate and record the wave height in cm (record the vertical distance from wave crest to the wave trough).
Short Name
FOLWEXSMP
Version Number
18

Lake Wingra Exclosure Experiment at North Temperate Lakes LTER: Secchi Disk Depth 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. Secchi disk depth is measured within the exclosure and at a nearby control site in the littoral zone . The disk is circular, 20 cm in diameter, and has alternating black and white quadrants. It is lowered using a calibrated Kevlar rope to minimize stretching. Readings are made on the shaded side of the boat without the aid of a plexiglass viewer. The points at which the disk disappears while being lowered and reappears while being raised are averaged to determine Secchi depth. Other parameters measured at depth include water temperature and dissolved oxygen. 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
Core Areas
Dataset ID
189
Date Range
-
LTER Keywords
Maintenance
completed
Metadata Provider
Methods
Secchi disk depth is measured within the exclosure and at a nearby control site in the littoral zone . The disk is circular, 20 cm in diameter, and has alternating black and white quadrants. It is lowered using a calibrated Kevlar rope to minimize stretching. Readings are made on the shaded side of the boat without the aid of a plexiglass viewer. The points at which the disk disappears while being lowered and reappears while being raised are averaged to determine Secchi depth.
Short Name
FOLWEXSE
Version Number
9

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).
Publication Date
Short Name
FOLWEXPH
Version Number
7

Lake Wingra Exclosure Experiment at North Temperate Lakes LTER: Nutrients 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 nutrient chemistry are measured at the surface within the exclosure in Lake Wingra. These parameters include total Kjeldahl nitrogen, nitrate + nitrite nitrogen, ammonia nitrogen, total phosphorus, dissolved reactive phosphorus and dissolved reactive silica. Total nitrogen is calculated by adding Kjeldahl nitrogen and nitrate/nitrite. Ammonia nitrogen is already included in the Kjeldahl nitrogen value. 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: 1
Core Areas
Dataset ID
191
Date Range
-
Maintenance
completed
Metadata Provider
Methods
Samples for nitrateornitrite and ammonium are collected together with a peristaltic pump and tubing and in-line filtered (through a 40 micron polycarbonate filter) into new, 20 ml HDPE plastic containers with conical caps. The samples are stored frozen until analysis, which should occur within 6 months. The samples are analyzed for nitrateornitrite (and ammonium) simultaneously by automated colorimetric spectrophotometry, using a segmented flow autoanalyzer. Nitrateornitrite is determined by utilizing the automated cadmium reduction method, as described in Standard Methods, where the absorption is monitored at 520 nm.The detection limit for nitrateornitrite is approximately 2 ppb and the analytical range for the method extends to 4000 ppb.Ammonium is determined by utilizing the Berthelot Reaction, producing a blue colored indophenol compound, where the absorption is monitored at 660 nm.The detection limit for ammonium is approximately 3 ppb and the analytical range for the method extends to 4000 ppb.Method Log: Prior to January 2006 samples, nitrateornitrite was determined on a Technicon segmented flow autoanalyzer. From 2006 to present, nitrateornitrite is determined by an Astoria-Pacific Astoria II segmented flow autoanalyzer.Samples for total and dissolved phosphorus and nitrogen analysis are collected together with a peristaltic pump and tubing and in-line filtered, when necessary, (through a 40 micron polycarbonate filter) into 120 ml LDPE bottles and acidified to a 1percent HCl matrix by adding 1 mL of ultra pure concentrated HCl to 100 mls of sample. For every sample acidification event, three acid blanks are created by adding the same acid used on the samples to 100 mls of ultra pure water supplied from the lab. Once acidified, the samples are stable at room temperature until analysis, which should occur within one year. Until acidification, the samples should be refrigerated at 4 degrees Celsius.The samples must first be prepared for analysis by adding an NaOH–Persulfate digestion reagent and heated for an hour at 120 degrees C and 18-20 psi in an autoclave.The samples are analyzed for total nitrogen and total phosphorus simultaneously by automated colorimetric spectrophotometry, using a segmented flow autoanalyzer. Total phosphorus is determined by forming a phosphoantimonylmolybdenum complex and the absorption is monitored at 880 nm.The detection limit for total phosphorus is approximately 3 ppb and the analytical range for the method extends to 800 ppb.Method Log: Prior to January 2006 samples, total phosphorus was determined on a Technicon segmented flow autoanalyzer. From 2006 to present, total phosphorus is determined by an Astoria-Pacific Astoria II segmented flow autoanalyzer.
Short Name
FOLWEXNU
Version Number
7

Lake Wingra Exclosure Experiment at North Temperate Lakes LTER: Chlorophyll 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. Chlorophyll is measured within the exclosure and at a nearby control site in the littoral zone. Spectrophotometric analysis and fluorometric analysis are done on integrated samples from surface to 1 meter. The first data table below, Chlorophyll - Tri Chlor Spec, contains only the Tri_chlor_spec values for the exclosure and control samples. This measurement is the sum of chlorophyll a concentration and phaeophyton concentration using a spectrophotometer. The second data table, Chlorophyll - Full Series, contains all the results of the spectrophotometric analysis and fluorometric analysis. 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
Core Areas
Dataset ID
190
Date Range
-
LTER Keywords
Maintenance
completed
Metadata Provider
Methods
Chlorophyll is measured within the exclosure and at a nearby control site in the littoral zone. Spectrophotometric analysis and fluorometric analysis are done on integrated samples from surface to 1 meter.
Short Name
FOLWEXCH
Version Number
7

Biocomplexity at North Temperate Lakes LTER; Coordinated Field Studies: Zooplankton Presence/Absence 2001 - 2004

Abstract
Zooplankton samples were taken at approximately the deepest part of 58 lakes included in the "cross-lake comparison" segment of the Biocomplexity Project. The samples were from years 2001 through 2004. The study lakes are located in Vilas County, Wisconsin and were chosen to represent a range of positions on gradients of both human development and landscape position. Zooplankton samples were analyzed for planktonic crustacean and insect species. Number of sites: 58 Sampling Frequency: each site sampled once
Core Areas
Dataset ID
208
Date Range
-
Maintenance
completed
Metadata Provider
Methods
Wisconsin Net samplesLower the Wisconsin net to the bottom sample depth ( top of the net should be one meter above the bottom). Pull it up slowly at a rate of about 3 seconds per meter. A slow haul prevents the net from pushing water and plankton away from the mouth of the net. To drain the cup swirl it until the water level is below the lower mesh window, then pour contents into the sample jar. Avoid inverting the cup while swirling, as you will lose the sample into the net. Rinse the inside of the cup with 95percent ETOH several times adding the rinse to the sample jar. Wait until the chemistry crew member is finished taking Temp or D.O. profile before taking the Wisconsin net sample, so as not to stir up the sediments. Take replicate sample.
Short Name
BIOZOOP1
Version Number
7

Biocomplexity at North Temperate Lakes LTER; Whole Lake Manipulations: Aquatic Macrophytes 2001 - 2010

Abstract
Macrophyte surveys were conducted on Sparkling Lake, Vilas County, Wisconsin in mid-July of the years 2001 to 2004 and 2007 to 2009. Eight sites were chosen that corresponded to trap survey sites for rusty crayfish and represented the range of macrophyte communities in the lake. At each site, we swam a transect perpendicular to shore from 0 to 4 m depths. A tape measure extended from shore to the 4 m depth contour, and buoys were placed at the 1, 2, 3, and 4 m depth contours. Quadrats were placed along each transect at 1 m intervals. We visually estimated the percent cover of each macrophyte species within a 0.24 meter squared quadrat. Transect: corresponds to trap survey site number. Quadrat: occur at 1 m intervals starting from shore (0) and going until you reach the 4 m depth contour (highest number). Substrate: substrate within the quadrat categorized as muck, sand, gravel, cobble, logs, leaves, or any combination of these. Abundance: percent cover of each species within the quadrat determined by visual estimation. The percent covers of all species within a quadrat do NOT necessarily add to 100. Depth Interval: depth interval that each quadrat was in. Quadrats between 0 and 1 m deep are in depth interval 1, those between 1 and 2 m deep are in depth interval 2, etc. Number of sites: 8 Sampling Frequency: annually during summer
Core Areas
Dataset ID
216
Date Range
-
Maintenance
completed
Metadata Provider
Methods
Macrophyte surveys were conducted on Sparkling Lake, Vilas County, Wisconsin in mid-July of the years 2001 to 2009. Eight sites were chosen that corresponded to trap survey sites for rusty crayfish and represented the range of macrophyte communities in the lake. These sites corresponded to trap survey sites 1, 4, 10, 16, 20, 23, 27, and 35. At each site, we swam a transect perpendicular to shore from 0 to 4 m depths. A tape measure extended from shore to the 4 m depth contour, and buoys were placed at the 1, 2, 3, and 4 m depth contours. We visually estimated the percent cover of each macrophyte species within a 0.24 meter squared quadrat. Quadrats were placed along each transect at 1 m intervals. Thus, we used fewer quadrats on transects with a steeper slope. At site 23, we only found a macrophyte on one event: Vallisneria sp. in 2004.Transect: corresponds to trap survey site number.Quadrat: occur at 1 m intervals starting from shore (0) and going until you reach the 4 m depth contour (highest number).Substrate: substrate within the quadrat categorized as muck, sand, gravel, cobble, logs, leaves, or any combination of these.Abundance: percent cover of each species within the quadrat determined by visual estimation. The percent covers of all species within a quadrat do NOT necessarily add to 100.Depth Interval: depth interval that each quadrat was in. Quadrats between 0 and 1 m deep are in depth interval 1, those between 1 and 2 m deep are in depth interval 2, etc.
Short Name
BIOSPMAC1
Version Number
8

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; Whole Lake Manipulations: Exotic Crayfish Removal 2001 - 2019

Abstract
As part of a whole-lake experiment to overexploit a rusty crayfish (O. rusticus) population in Sparkling Lake, Vilas County, Wisconsin, crayfish were intensively trapped and removed from the lake from early to mid June through late August starting from 2001through 2008. From 2001 to 2004, removal traps were concentrated on the southern and western shorelines of the lake, where cobble is prevalent and catch rates were highest. Starting in 2005, additional traps were used and trapping effort was spread around the entire perimeter of the lake. Additional traps (perimeter) were set on standard arrays at 43 sites around the lake at 1 m deep from 2001 through 2006. In 2001 and 2003, traps (depth transect) were also set on standard arrays that ranged from 0.5 to 12 m deep. From 2001-2004, trap_site corresponds to one of the 43 standard sites where the trap was set. For perimeter and depth transect trapping, one trap is set at a trap site. During the removal trapping, 10 traps are set at each of the standard trapping sites. The trap_id identifier contains more information about the spatial location of a removal trap. From 2005-2008, traps were numbered sequentially moving clockwise around the lake starting at site 1, with no reference to standard trapping sites from previous years. In 2009, traps were set at the 43 standard sites. Capture data were recorded starting in 2009 but crayfish were not removed. Daily catch statistics: The data table Crayfish Daily Capture Summary provides the number of each species captured each day in the perimeter and removal traps. Also included are data on the number of traps pulled on that day and the number of trap_days these traps represent. These data can be used to calculate capture rates. The data table Crayfish Daily Capture by Station has daily catch statistics at the capture site level. Crayfish length measurements: Prior to 2005, a crayfish that was measured could be associated with the specific trap in which it was captured. These length data are included in the Crayfish Individual data table. Starting in 2005, carapace measurements were only taken on 50 randomly selected O. rusticus individuals each day. The data table Crayfish Carapace Length contains these data which are not associated with specific traps. Trap site locations: The data table Sparkling Lake Crayfish Trap Sites contains the location of the 43 standard crayfish trap sites. See Crayfish Removal Protocol for further explanation of TECHNIQUE and TRAP_ID fields. Number of sites: 43 trap sites Sampling Frequency: annually during summer
Dataset ID
217
Date Range
-
LTER Keywords
Maintenance
completed
Metadata Provider
Methods
Two approaches for trapping were used in the initial phase of this study: removal trapping and "standardized surveys". Traps set for removal of rusty crayfish were concentrated in areas of the lake to maximize catch rates. In 2001, removals began on 14 August 2001 and traps were emptied daily during the last 2 weeks of August. From 2002 on, crayfish are trapped and removed from mid to late June through late August. Traps are wire mesh minnow traps with openings widened to 3.5-cm diameter. (In 2001, other traps and trapping methods were also evaluated.) Traps are baited with 4- 5 dead smelt.Removal traps were set in arrays of 10 at 10-m intervals along the 1-m depth contour, and were emptied daily during during 2001 - 2003 and every 1 to 4 days starting in 2004. Removal traps were concentrated on the southern and western shorelines of the lake where catch rates are highest from 2001-2004. From 2005-2008, traps were set around the entire perimeter of the lake. From 2001 to 2004 the sex of each crayfish in a trap was recorded, and a randomly selected subsample of the daily crayfish catch was used to estimate mean size. From 2005-2008, the number of crayfish in each trap was recorded, and a randomly selected subsample of 50 individuals was measured and their sex was determined.To assess the environmental predictors of rusty crayfish catch rates, "standardized surveys" were conducted prior to harvest in 2001 through 2006. Standardized surveys were comprised of perimeter trapping and depth trapping. Although perimeter trapping occurred every year, depth trapping only took place in 2001 and 2003. For perimeter trapping, 43 traps were baited with 120 g of beef liver and set for 24 hours at 1-m depths at 100-m intervals along the shoreline. Perimeter traps were set on 6 dates in June through August. Three days after the June and July perimeter trapping events, 14 depth transects were set around the perimeter of the lake. Depth transects were spaced 300-m apart and along the transect, traps were set at 0.5, 3, 5, 8 and 12-m depths. Perimeter trapping at the 43 sites, but not the associated depth transect trapping, was done on four dates in 2002 and continued to be done for three to five dates annually through 2006.Trap_id: During removal trapping, from 2001-2004 10 traps were set at each of the standard trapping sites. For years 2001- 2004, the trap_id of removal traps includes additional information about the spatial location of the trap. The first number of the trap_id indicates the trap site (1 to 43) and the number after the dash identifies which trap of 10 was pulled from the site as you move clockwise around the lake. For example, trap 12-1 is at the flagpost of site 12, trap 12-5 is approximately halfway between sites 12 and 13, and trap 12-10 is just before you arrive at site 13.Starting in 2005, the removal traps are distributed equally around the lake starting at trap site 1 and proceeding in a clockwise direction. These traps are given trap_ids of sequential numbers as they are lifted. These trap_ids do not relate directly to the trap site. However, you can calculate the approximate trap site for each trap by knowing the total number of traps set over the 43 standard trap sites. In 2005, a total of 277 traps were initially set. In 2006, 220 traps were set over the 43 sites. During the initial retrieval in 2006, data were grouped for each of the 22 sets of 10 traps. To make these data comparable to the rest of the removal trap data, the crayfish represented in the grouped data were assigned randomly to individual traps within the 10 trap set. In 2007, the maximim trap_id was 269. In 2008, the maximum trap_id was 289.Removal: Traps set annually at 43 sites around the lake and fished through the trapping season. In 2002, additional single traps were set near logs and other likely places which were not in close proximity to other traps. These traps have -MIN appended to the trap number in TRAP field.Perimeter: Traps set annually (through 2006) on standard arrays at 43 sites around the lake at 1 m deep for a limited number of days. The last year perimeter traps were used was 2006.Depth Transect: Traps set on standard arrays that ranged from 0.5 to 12 m deep. Depth transects were set in 2001 and 2003 only.Lead: Traps were set at the ends of a “lead” made of aluminum flashing and staked to the bottom of the lake in 2001 only. Experiment was to see if the flashing would be a barrier to the crayfish, and would lead crayfish into small minnow traps. Traps were set at different depths. Leads were set at survey sites: 7, 15, and 26. (Site is indicated in the TRAP field for these traps). Traps were set at each end of the lead and along the middle, as indicated by the depth they were set.Minnow: Minnow traps set in 2001.Commercial: Experimental large box traps used only in 2001.Wik: Traps designed by Don Wik and used in 2002 only. These were square traps with trapezoid-shaped ends, and an entrance on the top of the trap.References:Hein, Catherine L., Brian M. Roth, Anthony R. Ives, and M. Jake Vander Zanden. 2006. Fish predation and trapping for rusty crayfish (Orconectes rusticus) control: a whole lake experiment. Canadian Journal of Fisheries and Aquatic Sciences: 63 383-393Hein, Catherine L., M. J. Vander Zanden, John J. Magnuson. 2007. Invasive trapping and increased fish predation cause massive population decline of an invasive crayfish. Freshwater Biology:
Update 2021
Table biocom_crayfish_daily_station was extened by summarising 2001-2006 data from biocom_crayfish_individual. New data are added for 2011-2019
Short Name
BIOSPCR1
Version Number
10
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