US Long-Term Ecological Research Network

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 Frequency: annually Number of sites: 11
Core Areas
Dataset ID
6
Date Range
-
LTER Keywords
Maintenance
ongoing.
Metadata Provider
Methods
SAMPLING SITES The same sampling sites are used each year. All sampling occurs between the 3rd week of July and Labor Day. Lakes are sampled in the following order: Trout, Allequash, Crystal, Big Muskellunge, Sparkling, Crystal Bog, Trout Bog, Wingra, Fish, Monona, Mendota. Sites for fyke nets, trammel nets and night seining sites were chosen by random process in 1981 for the Northern Highland State Forest lakes (Trout, Big Muskellunge, Allequash, Crystal, Sparkling). Sites for Lake Mendota were chosen in 1981, and for the other Madison lakes (Monona, Fish, and Wingra) in 1995. In 1998, all the Northern Highland lake sampling sites were recorded and archived as GPS coordinates. In 1999, all the Madison lake sites were recorded and archived as GPS sites. Prior to 1998 and 1999, fyke and trammel net sites were found each year by reference to lake maps, local landmarks, and stake locations. Gill nets are placed near the deep-hole, which is marked by a buoy and GPS coordinates, on each lake. In the bog lakes (Trout Bog and Crystal Bog), which are sampled with only fyke nets and minnow traps, there are no fixed sites; nets are placed equal distances apart around the entire circumference of the lake in approximately the same locations each year. NIGHT SEINING Night seining is conducted to achieve relative abundances of small fish species such as minnows, darters, sculpin, and young gamefish species on a yearly basis. Seining is most effective on small fish at night, due to reduced net avoidance, and is one of the most effective methods of catching small fish species. 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. The seine is pulled via two PVC or steel poles on either end of the seine. Prior to 1997, seine sites consisted of 100 meters of shoreline. This was subdivided into 3 seine hauls, each covering 33 meters. Stakes were placed to mark the beginning and end of each haul, with the first stake lettered A and the fourth (final) stake lettered D. In 1997, seine hauls were reduced to 2 hauls of 33m each. The final 34m of the 100m site (stakes C-D) is now used as an alternate seine site in the event of difficulty (snag, twisted net) in one of the first two hauls. Our convention is that the first haul (identified as "site number -1") is the one segment at the left end of the site, as one faces the site from the lake. The day crew working the lake will have marked the location of these stakes using green 12-hour chemical light sticks. There are 6 seine sites per lake for a total of 18 hauls per lake prior to 1997; starting in 1997, there are 12 hauls per lake. The seine crew approaches the site from the lake by boat in such a way as not to pass over the area to be seined. The seine is deployed using as little light as possible. An 8m length of rope is tied between the poles as a guide for the maximum spread of the seine. Two people, working 8 meters apart when possible, pull the seine on a course parallel to the shore line. The outside or deep person should be 8m from the shallow person (max rope length) or as deep as they can be without overtopping their waders (just below chest height). The inside or shallow person keeps as close to shore as possible without steeping onto dry land. When the shallow person is about 8 meters from the end of the haul heorshe moves very slowly, allowing the deep person to swing around toward the chemical light stick; both seiners should reach the light at the same time. The seine is quickly landed by crossing the poles and drawing the lead line together. The lead line is kept on the lake bottom while the wings are drawn in. When the bag reaches the poles it is picked up by the 4 corners. Fish are collected from the bag and processed before the crew goes on to the next haul. TRAMMEL NET The trammel net is used to sample fish species present near the bottom at the thermoclineorsubstrate interface. This area is utilized by a number of fish species, and is an important area of the lake due to the large change in temperature in a relatively short distance. As in the terrestrial environment, the thermocline acts as an ecotone and several fish species which require very different physical environments may exist in relatively close proximity. So achieving yearly fish abundances in this habitat is also important in determining long term trends in fish abundances. 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. The trammel net is set on the bottom, along a line perpendicular to the shoreline and crossing the thermocline. This can generally be accomplished by setting the shallow end in about 3 meters of water, and running the net out perpendicular to shore. Fish are picked out of the trammel net as it is brought back into the boat. The trammel net is set by the day crew at two sites in each lake, and fished for approximately 24 hours at each site. FYKE NETS Fyke netting is a very common method of sampling a wide size range of fishes which use littoral zone habitat. At different times of the day andoror season, many different fish species utilize the littoral zone area for feeding, digesting, and mating purposes. Sampling the abundances of fish species in this area, thus, is also very important in determining yearly changes in fish abundances. To monitor yearly changes in littoral fish abundances, fyke nets are deployed at six sampling sites in all 11 LTER study lakes. A separate set of three fyke nets of similar dimensions are used for the Northern Highland lakes and the Madison lakes. For the Northern Higland 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 s 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 has the dimensions 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. Each fyke net is set in shallow water perpendicular to shore such that the net mouth is covered by about 1 meter of water when possible. When the net is properly set, the lead is perpendicular to shore, vertical and not twisted, the mouth of the net is upright and facing shore, and all the hoops are upright. When the net is pulled in, the hoops and frames are gathered together and lifted into the boat. The net is positioned over a live well with the net mouth upward. One frame at a time is lifted and any fish present are shaken down into the next chamber, until all the fish are in the bag, which is emptied into the live well. Three fyke net sites are set per day (for two days), each with a single net in the middle of a 100m site, for a total of 6 fyke net sites per lake. Due to the soft bottom, and small size of the bog lakes, minnow traps and fyke nets are the only gear used to sample the fish community of these systems. The fyke nets are suspended by placing floats at the apex of each hoop, and on the top of the opening frames. This is done to prevent the nets from sinking into the soft sediments at the bottom of the bogs. CRAYFISH AND MINNOW TRAPS There have been introductions of exotic crayfish species in recent years into many north temperate lakes. Monitoring yearly abundances of crayfish species is important in determining the status and extent of the invasions. 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. Starting in 1998, three traps are set per site. Thus, prior to 1998, thirty traps were set on each lake (covering 6 sites.) As of 1998, 18 traps are set on each lake. 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 per trap to attract minnows inhabiting the bogs. Crayfish traps are baited with 120 g of liver. Traps are fished for approximately 24 hours . Crayfish are identified to species and returned to the lake. Minnows caught in either the crayfish or minnow traps are identified to species, measured for total length. Minnow traps used 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. GILL NETS In most lakes, there are species of fish which inhabit the pelagic (open water) zone. These fish species can have a large impact on lake ecosystem dynamics when they occur in abundance. To monitor yearly changes in the abundance of pelagic fish species, we sample the deep basin of eight of the LTER lakes with vertical gill nets. Our gill nets are a set of 7 nets, each in a different mesh size, hung vertically from foam rollers, 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. One side of the net is marked in meters from top to bottom. Stretcher bars have been installed at 5 meter intervals from the bottom to keep the net as rectangular as possible when deployed. The bottom end is weighted with a lead pipe to quicken the placement of the net and to maintain the position of the net on the bottom. 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 nets are set in a straight line, each connected to the next, and anchored at each end of the line. Once the nets are in position, they are unrolled until the bottom end reaches the bottom, and then tied off to prevent further unrolling. The nets are pulled by placing each net onto a pair of brackets attached to the side of the boat and rolling the net back onto its float; the fish are picked out as the net is brought up, placed in tubs according to depth. The fish are processed when the net is completely rolled up and before it is redeployed. ELECTROFISHING We use a boom style electrofishing system 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. Two crew members in the bow of the boat dip up all stunned fish, placing them in the live well for processing at the end of each transect. Transect lengths vary depending upon the size of the lake. If the end of a transect is reached before 30 minutes has elpased, time is paused while the electrofisher loops back to the start of the transect. The transect is then repeated for the remaining time. In 1999, dip nets were standardized to 10 foot poles attached to 18in. x 20in. tear drop shaped hoops. The nets are made of 7 mm stretch mesh. PROCESSING THE CATCH For all collecting methods, the fish are processed as follows. Each individual fish is identified to species. If it cannot be positively identified, after it is processed, it is preserved in 10percent buffered formalin or 95percent ethanol for later identification. The total length of the fish (measured from nose to end of caudal fins pinched together) is measured in mm. Prior to 1997, the weight (g) of the first 5 fish of each species in each 10 mm size category was also measured, using the appropriate Pesola spring balance (fish weight registering in the middle range of scale). A tally sheet was used to record how many fish in each size category had been measured. Starting in 1997, 2 fish are weighed for each fish species in each 5mm size category. Also in 1997, data recording switched to an electronic system which tallied measured fish. For yellow perch, rock bass, and cisco, a scale sample is collected from each weighed fish. This is removed from the left side of the fish, above the lateral line and below the origin of the dorsal fin. Scale samples are stored in scale envelopes and labeled with a unique ID number, the date the scale was taken, a lake ID number, the species code, land length and weight. For gill net catches, the depth at which each individual is caught is also recorded. Fish from all gear (except gillnets) are held in live wells during processing. Fish are sorted by species into buckets, processed as quickly as possible, and returned to the lake. Fish from the gillnets are very rarely alive. If alive, they are usually badly damaged when the nets are raised. PROTOCOL CHANGES 1983 Discontinued fykenets 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 full suite of sampling gearr 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</p>
Short Name
NTLFI01
Version Number
29

Landscape Position Project at North Temperate Lakes LTER: Fish 1998 - 1999

Abstract
As part of the Landscape Position Project, we conducted fish sampling on each of 26 lakes using a variety of gear types. Sampling was conducted beginning in the 3rd week in June and running through the endof July in 1998. In 1999, sampling was conducted from early July through August. We used vertical gillnets of various mesh sizes (19, 32, 51, 64, 89-mm stretch mesh) to sample pelagic fishes. The nets were fished in the deep basin of each lake for one diel cycle. We used fyke nets to sample fishes in the shallow near shore areas. Three nets were set, one each at differing locations defined by substrate type (muck, sand and cobble) for one diel cycle. Three crayfish traps were set along side each of the fyke nets. We performed electrofishing over two, 30 minute transects along the near shore area between 0.3 and 1.5-m in depth. Our goal was to capture, identify and measure as many game and non-game fish species as possible Sampling Frequency: one survey on each lake in late June through August of 1998 or 1999 Number of sites: 26
Core Areas
Dataset ID
100
Date Range
-
LTER Keywords
Maintenance
completed
Metadata Provider
Methods
Fish SamplingFish sampling was conducted on each lake at least one month after thermal stratification had taken place, beginning on the 3rd week in June and running through the 3rd week in July. This was done to minimize the effects of winter stress and spawning on fish weight given their length. Several gears were employed to estimate fish diversity in each lake, each being effective at catching a different set of fishes.Vertical gillnets were employed to sample pelagic fishes. A spectrum of mesh sizes (19, 32, 51, 64, 89-mm stretch mesh) were used, with each mesh size effectively catching a different size range of fish. The nets were fished in the deep basin of each lake for one diel cycle.Fyke nets were employed to sample fishes in the shallow near shore areas. Mini fyke nets with a mouth opening 0.75-m high by 1.25-m wide constructed with 4-mm delta mesh, with a 1-m by 5-m single lead were set so as the lead ran perpendicular from shore and that the mouth sat in approximately 1-m of water. There were 3 nets set at differing locations defined by substrate type (muck, sand and cobble) for one diel cycle. Three crayfish traps were set along side each of the fyke nets so as to sample the same habitat type sampled by each fyke net.Electrofishing occurred in the near shore area between 0.3 and 1.5-m in depth. Two 30 minute transects were performed such that a variety of substrate types were sampled. The dipnets used to net fish during electrofishing consisted of 4-mm delta mesh and were capable of retaining small fishes (down to 20-mm). Our goal was to capture and identify as many game and non-game fish species as possible.Fish ProcessingFish caught in each gear type were processed by measuring mass and total length of all fish of each species; however, a subset of each species was measured when the catch rate was high. Two fish in each 5-mm size class for each species were weighed and length measurements were taken so as to collect weight measurements for a wide size range of each species. If the catch of a given species in a given size class (small, medium or large) within a particular set or electro-shocking run exceeded 30 fish, 30 were measured for each species. Those not measured for length in each size class were counted and recorded so as to associate them with those that were measured to allow length frequency distributions to be generated while expediting our processing and avoiding redundant weight and length measuring. Each fish was identified to genus and species using the taxonomic key in Becker (1983). Any game fish killed were turned over to the appropriate Department of Natural Resource Game Warden.
Short Name
LPPFISH1
Version Number
9

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: Rainbow Smelt Removal 2001 - 2009

Abstract
Rainbow smelt (Osmerus mordax) are a harmful invasive species in lakes of northern Wisconsin. Smelt were first detected in Sparkling Lake, Vilas county, WI in 1980 and their population has since increased dramatically. We attempt to remove rainbow smelt from Sparkling Lake through a combined strategy of harvest and predation. If successful, such a strategy might be employed to restore other Wisconsin lakes invaded by smelt to a more natural species assemblage without resorting to piscicides. The data sets presented here report the harvest component of smelt removal. An assessment of the rainbow smelt population, supplementing annual LTER data, was performed during the late summer of 2001. The spring removal effort began in 2002 at ice out using multiple gear types. In 2002, the removal effort also continued from mid to late summer using horizontal gill nets. However, from 2003-2009 we took advantage of smelt spawning behavior and our efforts were condensed to a spring removal at ice-off and we utilized only fyke nets. The total weight of each catch was recorded and length-weights as well as sex ratios were documented for a subset of the catch from each removal event. The removal effort resulted in the removal of the majority of the adult population multiple times. However, smelt are a robust species and the population continuously rebounded from large removal years. As a result, catches have fluctuated from 16kg to nearly two tons. We have observed an overall reduction in fish size and an increase in the proportion of males to females. Sampling Frequency: annually
Dataset ID
218
Date Range
-
LTER Keywords
Maintenance
completed
Metadata Provider
Methods
Setting NetsSet nets in areas of high catch first, moving clockwise around the lake.GPS location of netRecord dates in that locationNumber 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.Sketch net location on a map with the net number (keep with In-Boat data sheets)Pulling NetsTake lake map with net numbers and In-Boat data sheetRecord date, time, collectors namesAt each net, record net number, number of bags and any comments (note anything unusual)For a zero catch&hellip; note if the net was fishing (tipped over, twisted, etc). If there were no problems write NORMAL SET.Try to set the net in exactly the same location. (Over burlap if applicable)Data CollectionIf there is not enough time, please follow this order for priority of data collection.Daily CatchUse Daily Catch sheetRecord date, net number, bag number, number of bags from that netWeigh bags in kilograms. Record.Note if fish were kept for sex determination, length &ndash; weight or scales and the number kept.Sex ratioUse Sex sheetRandomly select 2 nets. Sample 50 fish from each net.Record date and net numberWeigh two empty buckets and record weight.Separate fish by sex. Try not to squeeze out eggs/sperm.Count number of males and females. Record.Weigh buckets with males or females in them. Record.Length WeightUse Length Weight sheetSelect a random net and sample 30 fish from itRecord date, net number, if fish were frozenRecord length, weight and sex.Compare to scale sheet. Collect scale sample if category is not filled. Pull scales from behind the dorsal fin. Note on data sheet that scales were taken. Scale envelopes should have date, length, weight, net number and sex of fish on them.
Short Name
BIOSMLT1
Version Number
36

Biocomplexity at North Temperate Lakes LTER; Coordinated Field Studies: Predation Study Data 2000 - 2004

Abstract
These data were collected to track changes in dietary composition, changes in age and growth structure, and changes in species and size of prey of fish predators in Sparkling Lake, Vilas County, WI, USA. Sampling began in May of 2000 and ended in September of 2004. Fish were collected with a boat-mounted electrofishing system, usually by conducting a complete lap around Sparkling Lake shortly after dark. Commonly captured species were rock bass, smallmouth bass, and walleye. Less common species were pumpkinseed sunfish and yellow perch. Dietary Composition: Fish stomach contents were collected by gastric lavage, and fish were released after capture. Stomach contents were sorted and counted by major taxonomic groups, dried in polystyrene weighboats at 57 deg C for 48hrs, and then weighed to 0.001g. The count under a taxonomic group heading indicates how many individuals of that group were found in that diet sample. The mass of that group is given in the adjacent &#39;&#39;net wt&#39;&#39; column. Diets varied across sampling dates and years, with a trend towards decreased abundance of the exotics rusty crayfish and rainbow smelt and increased reliance on native minnows. Prey Data: Fish stomach contents were collected by gastric lavage, and fish were released after capture. Once collected, crayfish and fish prey were measured unless advanced digestion had occurred. If possible, the carapace, right chela and left chela of crayfish prey were measured . Due to digestion, it was usually not possible to get all three measurements. The total length of prey fish was recorded. Young-of-year smelt and crayfish were often too small or digested to measure; these were often just counted. Gut labels on each sampling date correspond with the same gut labels in other datasets. Prey fish and crayfish size and composition varied across sampling dates and years, with a trend towards decreased abundance of rusty crayfish and rainbow smelt and increased reliance on native minnows. Age Growth Data: Scale samples were taken from captured predator fish in the summers of 2000, 2001, 2002, and 2004. Number of sites: 1 - Sparkling Lake Sampling Frequency: 2000: twice; 2001-2004 weekly or biweekly
Core Areas
Dataset ID
128
Date Range
-
LTER Keywords
Maintenance
completed
Metadata Provider
Methods
please see abstract for methods description
Short Name
BIOROTH1
Version Number
7

Biocomplexity at North Temperate Lakes LTER; Coordinated Field Studies: Fish Individual 2001 - 2004

Abstract
Fish Data collected for Biocomplexity Project; Landscape Context - Coordinated Field Studies. The eight sportfishes of concern in this dataset; Bluegill, Pumpkinseed, Bluegill-Pumpkinseed hybrid, Largemouthbass, Smallmouthbass, Rockbass, Walleye, and Yellowperch, are the only species for which standard metrics (length (mm) and weight (g)) were taken. All other fish were identified to species and counted. Sampling Frequency: annually Number of sites: 58
Core Areas
Dataset ID
43
Date Range
-
LTER Keywords
Maintenance
completed
Metadata Provider
Methods
(revised 6or28or02)NOTE: This protocol is for each sample site. Eight sites are sampled on each lake.Day CrewEquipment checklist:25 (50 halves) Minnow Traps and Floats Measuring board25 (50 halves) Crayfish Traps and Floats GPS25 slices Beef Liver (6.5 packages) Balances (5, 10, 30g)25 slices of white bread (2 bags) Computer16 Reflectors 12 volt batteriesForceps Data sheetsScale Envelopes and paper (write in rain) Full fuel tankID keys PFDsForceps OarsSmall Tubs AeratorsMinnow nets Measuring tapePlace 1 slice of white bread in each minnow trap and 1 slice of beef liver in each crayfish traps. Minnow traps have 2.5cm diameter openings and crayfish traps have 7.6cm openings.Locate the beginning of each site using the GPS.Set three minnow traps and three crayfish traps in shallow water (approx. 1 m), spaced approximately 15m apart along the 50m riparian transect corresponding with plots A, C, and E. Set the crayfish and minnow traps within two meters of each other.Traps are fished for approximately 24 hours. Crayfish are identified to species, counted per trap, and returned to the lake. Fish caught in either the crayfish or minnow traps are identified to species. Bluegill, pumpkinseed, rock bass, largemouth bass, smallmouth bass, yellow perch, and walleye are measured for total length, weighed and scales taken if necessary (see processing fish below). Any other species caught are identified to species, counted for each trap, and returned to the lake.After pulling the traps at each site, set out the reflectors for electrofishing. The reflectors should be placed 25m before the start of the adjacent riparian transect and 25m after the end of the transect.Night CrewEquipment Checklist:Fishboards (large and small) ElectrofishBoxBalances (5, 10, 30, 60, 100, 500, 1000 grams) ForcepsComputer HeadlampsScale envelopes Cliplights (2)Batteries (2-12 volts) Running lightsFull fuel tanks (generator and boat) AeratorsPFDs GPSOars Dip nets (2)Big Tubs (3) Small tubsRubber boots and gloves (2 pairs) Spotlight (2)Locate each site by finding the reflectors with the spotlight.Electrofish eight 100m transects on each lake after sunset.Follow a 1.5m depth contour along the shoreline, but make sure to electrofish near littoral structure (docks, cwd, etc).Two dipnetters will net all fish regardless of size and place them in the livewell.The driver should record the average DC electrical output in amps and the time taken to complete each transect on the driver datasheet.times Note &ndash; Communication between the driver and the netters is essential. It is the netters responsibility to let the driver know about obstructions (logs, rocks, etc) in the water and to let them know if they have to back up for missed fish. Dont be shy, the driver has to hear you over the generator.PROCESSING FISHSort fish into small tubs by species if necessary.Measure the total length (from nose to end of caudal fins pinched together) in mm and weight in grams for these seven species:Bluegill PumpkinseedLargemouth Bass Smallmouth BassRock Bass Yellow PerchWalleyeTake several scales from 5 fish of each of these species (bluegill, largemouth bass, smallmouth bass, yellow perch, and walleye) from each 10mm size class. Keep track of the number of samples taken from each of these species using the scale tally sheet.For yoy fish (for yoy lengths see Table 1), take lengths and weights of 30 fish of each of the above seven species per lake. If possible take several of the 30 required fish from different locations, not all from the same site.Weights should be taken with the appropriate sized spring balance &ndash; the fish should be in the mid-range of the scale.Record the date, lake code, site number, fish ID number, species, length, and weight on the scale envelope.Take the scales from behind the left pectoral fin if looking at the fish from the dorsal side. Place at least 5 scales in the scale envelope.Take the third dorsal spine from 5 yellow perch and bluegill for each age class (Table 1). Place it in the scale envelope.Identify all other fish and keep a count for each species for each trap or electrofish run.If a fish cannot be positively identified, preserve it for later identification.Revive fish that have not recovered by holding them by their dorsal surface in the water and gently rocking them to the left and right to move water across the gills.times Note - Remember to hang pesola spring balances to dry after each sampling. If the springs rust they are not reliable. Spring balances are to be calibrated weekly.
Short Name
BIOFISH1
Version Number
6
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