US Long-Term Ecological Research Network

Long-term fish size data for Wisconsin Lakes Department of Natural Resources and North Temperate Lakes LTER 1944 - 2012

Abstract
This dataset describes long-term (1944-2012) variations in individual fish total lengths from Wisconsin lakes. The dataset includes information on 1.9 million individual fish, representing 19 species. Data were collected by Wisconsin Department of Natural Resource fisheries biologists as part of routine lake fisheries assessments. Individual survey methodologies varied over space and time and are described in more detail by Rypel, A. et al., 2016. Seventy-Year Retrospective on Size-Structure Changes in the Recreational Fisheries of Wisconsin. Fisheries, 41, pp.230-243. Available at: http://afs.tandfonline.com/doi/abs/10.1080/03632415.2016.1160894
Contact
Core Areas
Creator
Dataset ID
357
Date Range
-
Maintenance
completed
Methods
Fisheries surveys of inland lakes and streams in Wisconsin have been conducted by the Wisconsin Department of Natural Resources (WDNR) professionals and its predecessor the Wisconsin Conservation Department for >70 y. Standard fyke net and boat electrofishing surveys tend to dominate the fisheries surveys and data collected. Most fyke net data on certain species (e.g., Walleye Sander vitreus and Muskellunge Esox masquinongy) originates from annual spring netting surveys following ice-out. These data are used for abundance estimates, mark and recapture surveys for estimating population sizes, and egg-take procedures for the hatcheries. Boat-mounted boom and mini-boom electrofishing surveys became increasingly common in the late 1950s and 1960s. Boat electrofishing surveys have typically been conducted during early summer months (May and June), but some electrofishing survey data are also collected in early spring as part of walleye and muskellunge mark-recapture surveys. Summer fyke netting surveys have been collected more sporadically over time, but were once more commonly used as a panfish survey methodology. Surveys were largely non-standardized. Thus, future users and statistical comparisons utilizing these data should acknowledge the non-standard nature of their collection. More in-depth description of these data can be found in Rypel, A. et al., 2016. Seventy-Year Retrospective on Size-Structure Changes in the Recreational Fisheries of Wisconsin. Fisheries, 41, pp.230-243. Available at: http://afs.tandfonline.com/doi/abs/10.1080/03632415.2016.1160894
Version Number
3

Biocomplexity Project: Sparkling Lake Smelt Removal

Setting Nets
  1. Set nets in areas of high catch first, moving clockwise around the lake.
  2. GPS location of net
  3. Record dates in that location
  4. Number nets consecutively from first net set. (Nets do not need to be pulled in order they were set.) If a net is moved, keep the same number and add an a, b, c, etc after.
  5. Sketch net location on a map with the net number (keep with In-Boat data sheets)
Pulling Nets
  1. Take

North Temperate Lakes LTER: Fish Lengths and Weights 1981 - current

Abstract
Data are collected annually to enable us to track the fish assemblages of eleven primary lakes (Allequash, Big Muskellunge, Crystal, Sparkling, Trout, bog lakes 27-02 [Crystal Bog] and 12-15 [Trout Bog], Mendota, Monona, Wingra and Fish). Sampling on Lakes Monona, Wingra, and Fish started in 1995; sampling on other lakes started in 1981. Sampling is done at six littoral zone sites per lake with seine, minnow or crayfish traps, and fyke nets; a boat-mounted electrofishing system samples four littoral transects. Vertically hung gill nets are used to obtain two pelagic samples per lake from the deepest point. A trammel net samples across the thermocline at two sites per lake. In the bog lakes only fyke nets and minnow traps are deployed. Parameters measured include species-level identification and lengths for all fish caught, and weight and scale samples from a subset. Dominant species vary from lake to lake. Perch, rockbass, and bluegill are common, with walleye, large and smallmouth bass, northern pike and muskellunge as major piscivores. Cisco have been present in the pelagic waters of four lakes, and an exotic species, rainbow smelt, is present in two. The bog lakes contain mudminnows.
The only sampling done in 2020 were a single gill-netting replicate in Sparkling, Crystal, and Trout lakes. Sampling in Fish Lake was suspended in 2021 due to significant lake level changes.
Sampling Frequency: annually Number of sites: 11.
Core Areas
Dataset ID
6
Date Range
-
LTER Keywords
Maintenance
ongoing.
Metadata Provider
Methods
The same sampling sites are used each year. All sampling occurs between the 3rd week of July and Labor Day. Sampling sites were chosen by random process in 1981 for the Northern lakes (Trout, Allequash, Sparkling, Crystal, and Big Muskellunge). Sites for Lake Mendota were chosen in 1981, and for the other Madison lakes (Monona, Fish, and Wingra) in 1995. All sites are identified with GPS coordinates, except on the bog lakes (Trout Bog and Crystal Bog) where nets are placed equal distances apart around the entire circumference of the lake in approximately the same locations each year.

Night seining is conducted on 6 seine sites per lake, each consisting of 100 meters of shoreline. Prior to 1997 this was subdivided into 3 seine hauls, each covering 33 meters. In 1997, seine hauls were reduced to 2 hauls of 33m each. The final section of the site is used as an alternate seine site in the event of difficulty in one of the first two hauls.
The seine used is 12.2 m long by 1.2 m deep, consisting of two 5.5 x 1.2 m wings surrounding a 1.2 x 1.2 x 1.2 m central bag. The wings are made of 6.4 mm stretch measure knitted delta-strength nylon mesh, and the bag is of 3.2 mm delta strength nylon mesh. The entire net is tarred. The two wings and the opening to the bag have weighted foot ropes and buoyed head ropes. An 8m length of rope is tied between the seine poles as a guide for the maximum spread of the seine.

A trammel net is set at two sites in each lake, and fished for approximately 24 hours at each site. The net is set on the bottom, along a line perpendicular to the shoreline and crossing the thermocline, with the shallow end at about 3m depth,. The trammel net used is 30.5 m long and 1.1 m deep. It consists of two outer nets of 170 mm square 32 kg test mesh multifilament nylon with an inner panel of 51 mm stretch mesh 9 kg test multifilament nylon. The three nets are connected at the leaded foot line and the buoyed head rope.

Fyke nets are deployed at six littoral sampling sites in each lake, and fished for approximately 24 hours. In Crystal Bog and Trout Bog lakes the fyke nets are suspended by placing floats on the hoops and frames to prevent the nets from sinking into the sediments. For the northern lakes, each fyke net is approximately 12 m long and consists of two rectangular steel frames 90 cm wide by 75 cm high and 4 steel hoops, all covered by 7 mm delta stretch mesh nylon netting. An 8 m long by 1.25 m deep leader net made of 7 mm delta stretch mesh nylon netting is attached to a center bar of the first rectangular frame (net mouth). The second rectangular frame has two 10 cm wide by 70 cm high openings, one on each side of the frame center bar. The four hoops follow the second frame. Throats 10 cm in diameter are located between the second and third hoops. The net ends in a bag with a 20.4 cm opening at the end, which is tied shut while the net is fishing. New nets of the same dimensions were purchased for the Northern Highland lakes in 2000. Fyke nets for the Madison lakes are 10 m long (including lead) with 1 rectangular aluminum frame followed by 2 aluminum hoops. The aluminum frame is 98 cm wide x 82 cm tall, and is constructed of 2.5 cm tubing, with an additional center vertical bar. The hoops are 60 cm in diameter and constructed of 5 mm diameter aluminum rod. The single net funnel is between the first and second hoops and is 20 cm in diameter. The lead is 8 m long and 1.25m deep, constructed from 7mm delta stretch mesh.

Crayfish traps are set on all lakes except the bog lakes (Crystal Bog and Trout Bog). Minnow traps are set only on the bog lakes. Prior to 1998, five traps were set at each fyke net site. Beginning 1998, three traps are set per site. Minnow traps and crayfish traps are set in shallow water (approx 1 m), 2 traps on one side, and 1 trap on the other side of the fyke net lead. Minnow traps are baited with 1 slice of bread, and crayfish traps with 120 g of beef liver. Traps are fished for approximately 24 hours. Crayfish are identified to species. Minnows caught in either crayfish or minnow traps are identified to species, and measured for total length. Minnow traps are galvanized steel two piece traps, 44.5 cm long by 30.5 cm maximum diameter with 2.5 cm diameter openings at the ends. The mesh size is 6.4 mm on a side. Crayfish traps are identical, but the opening hole of both sides of the trap has been forced to 5 to 7 cm. Crayfish sampling was terminated for the southern lakes circa 2004 after it was determined that the catch per unit effort was too low (2 crayfish caught in 500+ traps).

Gill nets are set at the deepest point of all LTER lakes except Crystal Bog, Trout Bog, and Fish Lake. The nets are set for two consecutive 24 hour sets. The gill nets are a set of 7 nets, each in a different mesh size, hung vertically on foam rollers from the surface to the bottom of the lake, and chained together in a line. Each net is 4 m wide and 33 m long. From 1981 through 1990 the nets were multifilament mesh, in stretched mesh sizes of 19, 25, 32, 38, 51, 64, and 89 mm. In 1991, the multifilament nets were replaced with monofilament nets of the same sizes. Stretcher bars are installed at 10 meter intervals from the bottom to keep the net as rectangular as possible when deployed.

A boom style electrofishing system is used to sample the littoral zone fish community. Prior to 1997, four electrofishing transects were done on each lake. In 1997, the number of transects was reduced to 3. The same transects are used each year. Each transect consists of 30 minutes of current output, with the boat moving parallel to shore in 1-2 meters of water at a slow steady speed. We use the DC pulse system, with 240 volts at 3-5 amps. Transect lengths vary depending upon the size of the lake. If the end of a transect is reached before 30 minutes has elapsed, time is paused while the electrofisher loops back to the start of the transect. The transect is then repeated for the remaining time.

For all collecting methods, the fish are processed as follows. Each individual fish is identified to species. The total length of the fish is measured in mm, from nose to pinched tail. Prior to 1997, the weight of the first five fish of each species in each 10 mm size category was also measured, using Pesola spring balances. Starting in 1997, two fish are weighed for each species in each 5mm size category. A scale sample is collected from each yellow perch, rock bass, and cisco that is weighed. For gill net catches, the depth at which each individual is caught is also recorded.

Protocol Log. 1983: Discontinued fyke nets and trammel nets on Lake Mendota until 1995. 1984: Discontinued crayfish on Lake Mendota until 1995. Only gillnet and seines on Lake Mendota.1995: Resumed sampling Lake Mendota with the full suite of sampling gear. 1995: Began sampling Lakes Wingra, Monona, and Fish. 1997: Two fish are weighed for each fish species in each 5mm size category. Previously, five fish were weighed for each fish species in each 10mm size category. 1997: Data recording switched from manual field sheets to an electronic system. 1997: Changed from 4 to 3 electro-fishing runs per lake. 1997: Changed from 18 to 12 seine hauls per lake. 1998: Changed from 30 to 18 crayfish or minnow traps per lake. 2004: Discontinued crayfish or minnow traps on southern lakes. 2020: Fish sampling very limited due to pandemic. 2021: All night seining was discontinued.
Short Name
NTLFI01
Version Number
31

North Temperate Lakes LTER: Fish Length Frequency 1981 - current

Abstract
This data set is a derived data set based on fish catch and length data. Data are collected annually to enable us to track the fish assemblages of eleven primary lakes (Allequash, Big Muskellunge, Crystal, Sparkling, Trout, bog lakes 27-02 [Crystal Bog] and 12-15 [Trout Bog], Mendota, Monona, Wingra and Fish). Sampling on Lakes Monona, Wingra, and Fish started in 1995; sampling on other lakes started in 1981. Sampling is done at six littoral zone sites per lake with seine, minnow or crayfish traps, and fyke nets; a boat-mounted electrofishing system samples three littoral transects. Vertically hung gill nets are used to obtain two pelagic samples per lake from the deepest point. A trammel net samples across the thermocline at two sites per lake. In the bog lakes only fyke nets and minnow traps are deployed. Parameters measured include species-level identification and lengths for all fish caught, and scale samples and weight from a subset. Derived data sets include species richness, catch per unit effort, and size distribution by species, lake, and year. Dominant species vary from lake to lake. Perch, rockbass, and bluegill are common, with walleye, large and small mouth basses, northern pike and muskellunge as major piscivores. Cisco have been present in the pelagic waters of four lakes, and the exotic species, rainbow smelt, is present in two. The bog lakes contain mudminnows. Protocol used to generate data: The number of fish caught in each five mm length interval (0<length<5, 5<=length<10, etc.) have been summed over gear. In cases in which only a random subsample of fish were measured, the unmeasured fish have been assigned to the length categories based on the proportions in length categories for the measured fish of the subsample. Day seines were only used in 1981 and have been eliminated from this data set to make sampling effort across years comparable.
The only sampling done in 2020 were a single gill-netting replicate in Sparkling, Crystal, and Trout lakes. Sampling in Fish Lake was suspended in 2021 due to significant lake level changes.
Sampling Frequency: annually. Number of sites: 11
Core Areas
Dataset ID
8
Date Range
-
LTER Keywords
Maintenance
ongoing
Metadata Provider
Methods
The same sampling sites are used each year. All sampling occurs between the 3rd week of July and Labor Day. Sampling sites were chosen by random process in 1981 for the Northern lakes (Trout, Allequash, Sparkling, Crystal, and Big Muskellunge). Sites for Lake Mendota were chosen in 1981, and for the other Madison lakes (Monona, Fish, and Wingra) in 1995. All sites are identified with GPS coordinates, except on the bog lakes (Trout Bog and Crystal Bog) where nets are placed equal distances apart around the entire circumference of the lake in approximately the same locations each year.

Night seining is conducted on 6 seine sites per lake, each consisting of 100 meters of shoreline. Prior to 1997 this was subdivided into 3 seine hauls, each covering 33 meters. In 1997, seine hauls were reduced to 2 hauls of 33m each. The final section of the site is used as an alternate seine site in the event of difficulty in one of the first two hauls.
The seine used is 12.2 m long by 1.2 m deep, consisting of two 5.5 x 1.2 m wings surrounding a 1.2 x 1.2 x 1.2 m central bag. The wings are made of 6.4 mm stretch measure knitted delta-strength nylon mesh, and the bag is of 3.2 mm delta strength nylon mesh. The entire net is tarred. The two wings and the opening to the bag have weighted foot ropes and buoyed head ropes. An 8m length of rope is tied between the seine poles as a guide for the maximum spread of the seine.

A trammel net is set at two sites in each lake, and fished for approximately 24 hours at each site. The net is set on the bottom, along a line perpendicular to the shoreline and crossing the thermocline, with the shallow end at about 3m depth,. The trammel net used is 30.5 m long and 1.1 m deep. It consists of two outer nets of 170 mm square 32 kg test mesh multifilament nylon with an inner panel of 51 mm stretch mesh 9 kg test multifilament nylon. The three nets are connected at the leaded foot line and the buoyed head rope.

Fyke nets are deployed at six littoral sampling sites in each lake, and fished for approximately 24 hours. In Crystal Bog and Trout Bog lakes the fyke nets are suspended by placing floats on the hoops and frames to prevent the nets from sinking into the sediments. For the northern lakes, each fyke net is approximately 12 m long and consists of two rectangular steel frames 90 cm wide by 75 cm high and 4 steel hoops, all covered by 7 mm delta stretch mesh nylon netting. An 8 m long by 1.25 m deep leader net made of 7 mm delta stretch mesh nylon netting is attached to a center bar of the first rectangular frame (net mouth). The second rectangular frame has two 10 cm wide by 70 cm high openings, one on each side of the frame center bar. The four hoops follow the second frame. Throats 10 cm in diameter are located between the second and third hoops. The net ends in a bag with a 20.4 cm opening at the end, which is tied shut while the net is fishing. New nets of the same dimensions were purchased for the Northern Highland lakes in 2000. Fyke nets for the Madison lakes are 10 m long (including lead) with 1 rectangular aluminum frame followed by 2 aluminum hoops. The aluminum frame is 98 cm wide x 82 cm tall, and is constructed of 2.5 cm tubing, with an additional center vertical bar. The hoops are 60 cm in diameter and constructed of 5 mm diameter aluminum rod. The single net funnel is between the first and second hoops and is 20 cm in diameter. The lead is 8 m long and 1.25m deep, constructed from 7mm delta stretch mesh.

Crayfish traps are set on all lakes except the bog lakes (Crystal Bog and Trout Bog). Minnow traps are set only on the bog lakes. Prior to 1998, five traps were set at each fyke net site. Beginning 1998, three traps are set per site. Minnow traps and crayfish traps are set in shallow water (approx 1 m), 2 traps on one side, and 1 trap on the other side of the fyke net lead. Minnow traps are baited with 1 slice of bread, and crayfish traps with 120 g of beef liver. Traps are fished for approximately 24 hours. Crayfish are identified to species. Minnows caught in either crayfish or minnow traps are identified to species, and measured for total length. Minnow traps are galvanized steel two piece traps, 44.5 cm long by 30.5 cm maximum diameter with 2.5 cm diameter openings at the ends. The mesh size is 6.4 mm on a side. Crayfish traps are identical, but the opening hole of both sides of the trap has been forced to 5 to 7 cm. Crayfish sampling was terminated for the southern lakes in 2004 after it was determined that the catch per unit effort was too low (2 crayfish caught in 500+ traps)

Gill nets are set at the deepest point of all LTER lakes except Crystal Bog, Trout Bog, and Fish Lake. The nets are set for two consecutive 24 hour sets. The gill nets are a set of 7 nets, each in a different mesh size, hung vertically on foam rollers from the surface to the bottom of the lake, and chained together in a line. Each net is 4 m wide and 33 m long. From 1981 through 1990 the nets were multifilament mesh, in stretched mesh sizes of 19, 25, 32, 38, 51, 64, and 89 mm. In 1991, the multifilament nets were replaced with monofilament nets of the same sizes. Stretcher bars are installed at 10 meter intervals from the bottom to keep the net as rectangular as possible when deployed.

A boom style electrofishing system is used to sample the littoral zone fish community. Prior to 1997, four electrofishing transects were done on each lake. In 1997, the number of transects was reduced to 3. The same transects are used each year. Each transect consists of 30 minutes of current output, with the boat moving parallel to shore in 1-2 meters of water at a slow steady speed. We use the DC pulse system, with 240 volts at 3-5 amps. Transect lengths vary depending upon the size of the lake. If the end of a transect is reached before 30 minutes has elapsed, time is paused while the electrofisher loops back to the start of the transect. The transect is then repeated for the remaining time.

For all collecting methods, the fish are processed as follows. Each individual fish is identified to species. The total length of the fish is measured in mm, from nose to pinched tail. Prior to 1997, the weight of the first five fish of each species in each 10 mm size category was also measured, using Pesola spring balances. Starting in 1997, two fish are weighed for each species in each 5mm size category. A scale sample is collected from each yellow perch, rock bass, and cisco that is weighed. For gill net catches, the depth at which each individual is caught is also recorded.

Protocol Log. 1983: Discontinued fyke nets and trammel nets on Lake Mendota until 1995. 1984: Discontinued crayfish on Lake Mendota until 1995. Only gillnet and seines on Lake Mendota.1995: Resumed sampling Lake Mendota with the full suite of sampling gear. 1995: Began sampling Lakes Wingra, Monona, and Fish. 1997: Two fish are weighed for each fish species in each 5mm size category. Previously, five fish were weighed for each fish species in each 10mm size category. 1997: Data recording switched from manual field sheets to an electronic system. 1997: Changed from 4 to 3 electrofishing runs per lake. 1997: Changed from 18 to 12 seine hauls per lake. 1998: Changed from 30 to 18 crayfish or minnow traps per lake. 2004: Discontinued crayfish or minnow traps on southern lakes. 2020: Fish sampling very limited due to pandemic. 2021: discontinued all night seining.
Publication Date
Short Name
NTLFI03
Version Number
33

Lake Wingra: Fish Lengths and Weights

Abstract
Data are collected annually to enable us to track the fish assemblages of Lake Wingra. Sampling is done at six littoral zone sites per lake with a beach seine, minnow or crayfish traps, and fyke nets, while a boat-mounted electrofishing system samples four littoral transects. Vertically hung gill nets are used to obtain two pelagic samples per lake from the deepest point. A trammel net samples across the thermocline at two nearshore sites per lake. Fish are identified to species. Lengths are measured for all fish caught, while weight and scale are collected from a subset. Derived data includes catch per unit effort and size distribution by species, lake, and year. Sampling Frequency: annually. Number of sites: 1. Note that 2020 data does not exist due to insufficient sampling.
Core Areas
Dataset ID
181
Date Range
-
LTER Keywords
Maintenance
ongoing
Metadata Provider
Methods
see abstract.
Short Name
FOLWFI01
Version Number
20

Cross Lake Comparison at North Temperate Lakes LTER - Zooplankton Biomass Study 2006

Abstract
This project investigates why zooplankton size, but not biomass, has been found to influence the phosphorus (TP) - chlorophyll a (chl a) relationship (Pace 1984, Carpenter et al. 1991, Carpenter et al. 2001).
Dataset ID
220
Date Range
-
LTER Keywords
Maintenance
completed
Metadata Provider
Methods
Total phosphorus, chlorophyll a, and zooplankton samples were collected from 19 lakes in northeastern Wisconsin and Upper Michigan. Thirteen lakes are in Vilas County, WI (Star Lake, Anvil Lake, Stormy Lake, Camp Lake, Crab Lake, Little Crawling Stone Lake, Sparkling Lake, Lake Laura, Big Portage Lake, Crystal Lake, Tuesday Lake, Trout Lake, Lac du Lune, and Lynx Lake), one lake is in Oneida County, WI (Indian Lake) and 5 lakes lie within the University of Notre Dame Environmental Research Center (Peter Lake, Paul Lake, Tuesday Lake, Crampton Lake and Long Lake). The lakes were sampled in late May and June 2006. All sampled lakes lie within the coordinates 45 36 to 46 18 N and 89 00 to 89 54 W. Samples were collected from the deepest part of each lake. Lake information: Data collected on the sampledate include air temperature, an estimate of cloud cover, an estimate of wave height, maximum depth, secchi depth, and the depths of the epilimnion, metalimnion, and hypolimnion. Lakes identified as being located in UNDERC lie within the University of Notre Dame Environmental Research Center near Land O Lakes, Wisconsin, USA (89 32 W, 46 13 N). The location of the remaining lakes is identified by county - either Vilas or Oneida. Zooplankton Biomass: Five replicate zooplankton samples were collected from the deepest spot of each lake using vertical tows with a Wisconsin net (80 um mesh, 0.11 m radius). The tow was from 2 meters above the bottom of the lake to the surface. Zooplankton samples were preserved in 70percent ethanol. Each sample was drained through an 80 um mesh and sub-sampled three times using a 1 mL Hensen Stempel Pipette, and all zooplankton present in each subsample were identified down to genus or species. Thirty zooplankton of each genus or species in each 1 mL rep were measured using an ocular micrometer and a Leica MZ-8 dissecting microscope. To calculate biomass, the average weight for each species or genus per sample was applied to published dry weight- length regressions. Length-weight regressions (see methods) used to calculate biomass Zooplankton Lengths: Thirty zooplankton of each genus or species were measured using an ocular micrometer in a Leica MZ-8 dissecting microscope. All measurements are in mm. Note: Length measurements for Holopedium gibberum are of the post abdominal claw (between the setae natatores and the terminal claw). Total body length can be determined from the equation: Post abdominal claw length (um) equals 191.64 times Total Length (mm) plus 37.0 (Yan and Mackie 1986) Water Temperature/Dissolved Oxygen Profiles: A temperature and dissolved oxygen profile was taken on each lake on the sampling date Total Phosphorus and Total Nitrogen: Six samples were collected to determine the total phosphorus of each sampled lake. Triplicate 100-mL integrated samples were collected with a plastic tube (1.9 cm diameter) from the epilimnion. Discrete total phosphorus samples were collected with plastic tubing (0.6 cm) and a peristaltic pump from the middle of the metalimnion, the top of the hypolimnion and 1 meter above the bottom of the hypolimnion. Samples were preserved with 1 mL of Optima HCl and analyzed spectophotometrically for total phosphorus and total nitrogen. Some of the lakes were not completely stratified at the sampledate slightly altering the sampling method. In Crab Lake, Stormy Lake and Trout Lake the thermal profile made it difficult to determine the division between meta- and hypolimnion, so two additional samples were collected - from the metalimnion and from the top of the hypolimnion. In Anvil Lake, Big Portage Lake, Camp Lake, and Indian Lake, only one hypolimnion sample was collected because the lakes are shallow and were not completely stratified. Chlorophyll-a: Six integrated chlorophyll a samples (three epi- and three metalimnion) were collected from each lake using a plastic tube (1.9 cm diameter) and analyzed flourometrically. Sampling Frequency: Each of 19 lakes sampled once Number of sites: 19
Short Name
ZPBMASS
Version Number
22
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