Colesante, R. T. 1996. Transportation and handling of walleye eggs, fry, fingerlings, and broodstock. 

Pages 79-83 in R. C. Summerfelt, editor. Walleye culture manual. NCRAC Culture Series 101, 

North Central Regional Aquaculture Center Publications Office, Iowa State University, Ames. 

Transportation and Handling 

of Walleye Eggs, Fry, 

Fingerlings, and Broodstock 

Richard T: Colesante, Oneida Fish Cultural Station, Constantia, New York 13044 

Introduction 

walleye have been propagated in North America since 

the late 1800s. Egg, fry and pond fingerling production 

programs arc widespread and well documented. Recent 

advances in culture techniques have enabled intensive 

production of large or advanced fingerlings. Culturists 

have shipped millions of walleye within and between 

many states in the continental United States. The New 

York State Department of Environmental Conservation 

(NYSDEC) Oneida Fish Cultural Station has shipped 

walleye eggs and fry to at least 17 states. This chapter 

describes practices used at the Oneida Fish Cultural 

Station in the handling and transportation of walleye 

broodstock, eggs, fry and fingerlings. 

Capture and transporting broodstock 

At the New York State Department of Environmental 

Conservation Oneida Fish Cultural Station, up to 

40,000 adult walleyes arc handled and transported 

during spring netting operations. Adults arc captured 

with trap nets on a daily basis. After capture, they are 

placedin tubs, 48 x 32 x 18 in (122 x 81 x 46 cm), with 

about 40 gal (150 L) of water. As many as 150 adult 

walleyes that average 1-3 lbs (0.4-1.4 kg) arc held in a 

tub. They are transported by boat up to 1 mile (1.6 km) 

to the hatchery, where the sexes arc hand-sorted into 

separate holdmg tanks. The elapsed time from removal 

of walleye from nets to placement into hatchery holding 

tanks is generally around 30 min. Once sorted, the fish 

are routinely crowded, 500 fisW150 ft' (4.2 m'), in tanks 

for up to 3 d or longer if water temperatures are low, 

-40°F (4.4"C). The seemingly "rough" handling for 

transportation and sorting is tolerated by adult fish with 

little mortality. The normal water temperature during 

the procedure is between 40 and 50°F (4.4 and 10.0"C). 

The stripping of adult walleye does not noticeably 

stress the fish. Walleyes arc handled using cotton 

gloves. The fish arc out of water less than one minute 

while being stripped before being returned to the 

stream. Normally, the post-release mortality associated 

with the entire netting and stripping operation is less 

than 20 fish. 

Egg fertilization and water hardening 

walleye eggs can be fertilized by either a wet or a dry 

method (Piper et al. 1982). Both produce acceptable 

results and preference of the culturist will probably 

determine the method used. Often, however, the dry 

method of fertilization is impractical in large field 

operations. 

Following fertilization, eggs must be continuously 

stirred because of egg adhesiveness. Stirring can be 

accomplished with paint brushes (sized according to the 

volume being stirred), turkey feathers or other similar 

implements. To prevent having to stir eggs to the end of 

water hardening, most culturists treat the eggs to 

remove or coat the adhesive substance on the egg shell. 

The two most common agents are tannic acid and 

fullers earth, although other agents are effective 

(Colesante and Youmans 1983; Baker 1985; Krise et al. 

1986). These agents arc generally applied to a mass of 

fertilized eggs at varying concentrations, stirred for a 

brief time, and then poured off. After rinsing, eggs are 

allowed to water harden with minimal care. If not 

treated, egg stirring must be done throughout the water 

hardening process, but this can contribute to egg 

mortality. 

NCRAC Culture Series 101 - Walleye Culture Manual 79 
Egg treatments with tannic acid can affect the color of 

eggs. Walleye eggs are yellowish in color and become 

darker as they age. When treated with tannic acid, the 

eggs turn from yellow to a dark brown or black (usually 

within three days). Although this color change may 

alarm many fish culturists, the treatment does not seem 

to reduce viability of the eggs. 

Egg incubation 

Following water hardening (I -2 h depending on water 

temperature), eggs are generally placed in Downing 

style jars for incubation (Piper et al. 1982). Three qts 

(2.8 L) of water-hardened eggs are placed in each jar 

for optimum loading density. Water flow through the jar 

is initially set at 1.5 gpm (5.7 Lpm), but it is reduced 

after one day to 1.0 gpm (3.8 Lpm), and then increased 

again at hatching to 1.5 gpm (5.7 Lpm). 

In large-scale operations using surface water supplies, 

eggs must be treated to control fungus and prevent egg 

mortality. A common treatment is a 1,667 ppm formalin 

concentration in a 15-minute flow through treatment 

every other day. Because formalin is not approved by 

the Food & Drug Administration (FDA) for treatment of 

walleye eggs, an Investigative New Animal Drug permit 

(INAD) is required. In the spring of 1994, hydrogen 

peroxide was tested on walleye eggs at concentrations 

of 250, 350, and 500 ppm active ingredient for 15 min 

every other day. Egg survival was similar to that 

achieved with formalin, however, hydrogen peroxide 

&d not control egg clumping and clumps of dead eggs 

floated out of the jar and plugged the outlet during and 

shortly after treatment. Hydrogen peroxide is a chemical in the low regulatory priority class with the FDA, 

and an INAD is not required for its use. 

During egg incubation, dead eggs become less dense 

than live eggs and move to the top of the egg mass in 

the jar. Dead eggs are periodically removed from jars 

using a small siphon. This process invariably results in 

the collection of live eggs as well. At the Oneida Fish 

Culture Station, we place the eggs siphoned from the 

hatching jars into a “hospital” jar where a second effort 

is made to separate live from dead eggs. Any eggs 

siphoned from a hospital jar are discarded. By the time 

eggs are eyed, the jars contain mostly live eggs. 

Routine, regular cleaning (removal of dead eggs) of jars 

minimizes egg clumping and fungal problems and 

facilitates movement of hatched fry out of the jars. 

Shipping eggs 

Million of eggs have been successfully shipped from 

the Oneida Fish Cultural Station over the years. We 

have used the “dry method’ for the last 20 years to ship 

eggs. Eggs are transported in shipping boxes with 

perforated Styrofoam trays, cheese cloth and ice. Eggs 

can be successfully shipped any time after day 5, or 

about 90°F TU’s (5OOC TU’S) of incubation. It is not 

necessary to wait until the eyed egg stage to ship 

walleye eggs. Prior to shipment, dead eggs are removed, 

water is decanted from the jar, and the eggs are poured 

into a tub. Styrofoam trays are covered with cheese 

cloth and they are floated in a tank. We add three quarts 

(2.8 L) of eggs to each Styrofoam tray, then wrap the 

wetted loose ends of the cheese cloth over the eggs. The 

trays of eggs are then placed in the shipping box 

previously lined with a plastic garbage bag so moisture 

doesn’t damage the cardboard. Each box, 17 x 17 x 

21.5 in (length x width x height) (43.2 x 43.2 x 54.6 

cm), will receive 5 Styrofoam trays or a total of 15 qts 

(1 4 L) of walleye eggs. The top tray in the box has no 

eggs and is loaded with ice to help maintain temperatures. The bottom tray in the box is not perforated, 

receives no eggs and collects moisture from the trays 

above. The box is sealed with tape, and the eggs can be 

shipped. Shipment is normally by vehicle and/or air; 

eggs have survived 18 h trips with no apparent ill 

effects. 

Other methods of shpment are possible. These include 

placing eggs in plastic bags with water and oxygen and 

transporting them in a cooler. However, it is best not to 

ship eggs that might hatch during shipment, because 

eggs hatching in route could create water quality 

problems within the bag. 

Walleye fry T 

In most applications, walleye fry hatch and are carried 

(swim) out of an incubation jar into a holding tank. The 

fry are about 0.3 in (7.9 mm). They do not have an 

inflated swim bladder. Significant morphological and 

physiological changes occur as walleye are nourished 

through the yolk sac. The initiation of exogenous 

feeding occurs between 180 and 21 6°F TU’s (1 00 and 

120°C TU’S) (Krise and Meade 1986). Fry in holding 

tanks are normally held at high densities. Because 

cannibalism can occur in first-feeding fry, one objective 

of fry stoclung programs should be to stock fry prior to 

first feedmg. The time window for transfer at the 

80 NCRAC Culture Series 101- Walleye Culture Manual 
Oneida Fish Cultural Station is normally 3-5 d after 

hatch. When stoclung, fry should be harvested from 

holding tanks and stocked daily whenever possible. 

Enumerating fry 

The most common method of enumerating walleye fry 

involves volumetric displacement (Piper et al. 1982). 

Fry capture from the holdmg tank is facilitated by first 

concentrating fry to specific areas of the holding tank. 

Because newly hatched fry are positively phototactic, 

they will concentrate where the light intensity is the 

greatest. As walleye age during yolk sac absorption, 

their dnplacement value changes (Colesante 1989). 

Accurate enumeration requires frequent sampling. 

Other methods of enumerating fry exist. For instance, 

an electronic counter is commonly used in research type 

applications (Kindschi and Barrows 1991) where 

accuracy is critical. 

Transporting fry 

Transportation of fry is accomplished by placing fry 

directly in a transportation tank or by placing fry in 

plastic shipping bags with water and pure oxygen. 

Transportation tanks are usually insulated fiberglass or 

wood tanks with covers, and aerators, agitators and/or 

bottled oxygen. The size of tanks vary, but generally are 

around 300 gal (1 150 L); a single transport truck might 

carry 6 or more tanks (Carmichael and Tomasso 1988). 

Transportation of walleye fry requires that pure bottled 

oxygen be delivered to the water in the transportation 

tank. Agitators and aerators create excessive turbulence 

in the tank and can injure the delicate fry. Pure oxygen 

is usually delivered by air diffusers or rubber hose with 

fine holes in it. In New York, fry are loaded into tanks at 

a rate of one million fry per 50 gal (189 L) of water 

(5,291L). Six hours of transportation time under these 

conditions has no adverse effect on fry. Fry are removed 

by draining or siphoning them from the tank to minimize handling. If fry are stocked from a boat, siphoning, draining or bailing out of the boat tank is desirable 

and minimizes the use of nets. 

When stocking small numbers of fry, such as those 

destined for earthen culture ponds, plastic bags can be 

used. The use of plastic bag in shipping large numbers 

of fry at high density has been linked to mortality. 

(Colesante and Schiavone, 1980). Fry tend to settle in 

comers and in the bottom of the bag. Mortality can 

result even with adequate dissolved oxygen in the 

water. 

NYSDEC guidelines for transporting and stocking 

fry: 

Large stockings of more than 1 million fry: 

Fry should be placed directly in truck compartments at 

a rate of 1 million per 50 gal (1 89 L) of water. Oxygen 

should be bubbled into the Compartment. The loadmg 

rate can be prorated for different capacity transportation 

tanks. 

A. Fry should be siphoned into a live car on a boat, 

tempered as needed, and boat stocked in open 

water areas. Fry should be drained or siphoned 

from the live car into the lake. 

B. If it is not possible to do (A), fry should be 

tempered on the transportation truck by adding 

water and siphoned directly into the lake. 

Consideration should be given to stocking in 

stream currents (inlets) in hopes of carrying fry to 

pelagic areas. 

Stocking for less than 1 million fry within 3 h of the 

Oneida Fish Cultural Station. 

A. Transportation should be as in 1A or lB, if 

B. 

practical. 

If not practical, fry can be transported by placing 

lots of 100,000 fry in a standard hatchery bag, 

18 x 36 in (46 x 91 cm), with 2.6 gal (1OL) of 

water and 1.3 gal (5 L) of oxygen. Bags should 

float freely in a hatchery tank compartment with 

at least 6 in (15.2 cm) of water. The truck should 

not stop for periods of longer than 15 min. Water 

in bags should be tempered by floating them in 

the receiving water only if absolutely necessary. It 

is preferable to release fry immediately into 

receiving water. Fry are released from the bag by 

opening it or cutting it with a knife and dumping 

the fry and water. 

Stocking less than 1 million fry in excess of 3 h from 

the Oneida Fish Cultural Station. 

A. Transport as in 1A or 1B if possible. 

B. Otherwise, transport as in ZB, except 50,000 fry 

will be placed in each bag. 

It is possible to transport fry freely in a truck compartment (as in 1) and float bags in the same compartment 

(as in 2B or 3B). 

NCRAC Culture Series 101 - Walleye Culture Manual 81 
Small fingerlings 

Handling and Transportation 

Intensive culture of small (>lin, 22.5cm) fingerlings is 

relatively new. At the Oneida Fish Cultural Station, 

brine shrimp-fed walleye with newly inflated swim 

bladders [day 8 of life) have been harvested from 

rectangular units, transported by truck and stocked. Fish 

were harvested by siphoning them into tubs; tubs with 

water and fish were poured into transport tanks with an 

oxygen life support system. Transportation was for 2 h, 

and fish were not stressed at the time of stocking. 

Thirty day-old brine shrimp-fed walleyes (about 1 in, 

2.5 cm, long), when raised at the Oneida Fish Cultural 

Station, are exceptionally sensitive to handling. When 

30-day-old walleye come in contact with a net, many 

immediately go into shock and die. Generally by day 

40, this sensitive period is over and normal handling of 

walleyes is possible. 

Handling and transporting 1.2-2.0 in (3.2-5.1 cm) 

walleyes harvested from earthen ponds create a different set of problems. Many variables in a pond program 

can affect handling and transportation success, and 

fingerling survival. Among the variables are: inability to 

control water temperatures; the need to seine the 

fingerlings in many cases; contact of fingerlings with 

macrophytes, algae, crayfish, and aquatic insects in a 

concentrated situation as the pond drains; variation in 

conhtion factor of fingerlings due to problems associated with maintenance of food supply; deterioration of 

water quality as the pond drains. Culturists should 

concentrate on minimizing the effects of these variables 

on harvested walleyes. For example, ponds should be 

harvested on cool days and in the morning when 

possible. Algae and macrophytes, especially in the area 

of the kettle or catch basin, should be removed. Ponds 

should be harvested prior, during or immedately after 

zooplankton disappears to minimize deterioration of 

condition factor. Fish captured in the bag of a seine or 

corralled in a net should be removed in water with a 

bucket or with a hand net to minimize the contact of 

fish with the seine. 

New York State Department of Environmental Conservation (Bureau of Fisheries) employs the following 

standard procedure for pond harvesting: remove fish 

from pond to truck with the least contact with nets as 

possible; drain fingerlings from truck to holding tank 

and hold overnight; gradually cool water to 65°F 

(18°C); remove tadpoles, crayfish and other undesirable 

organisms; next morning, remove dead fish and sample 

fish in holding tank; load transportation truck by 

displacement or weight and use aerators or oxygen for 

life support (depending upon fish size); temper water in 

tank at the stoclung site if the difference is 10°F (5.6"C) 

or more; drain or siphon fingerlings (if possible) to 

minimize netting at the stoclung site. 

Effects of water temperature on transportation and 

handling 

Some researchers have recommended 7 1.6"F (22°C) for 

the intensive culture of walleye fingerlings (Huh et al. 

1976). However, fish culturists generally attempt to 

maintain rearing water temperatures at 68°F (20°C) or 

less, In doing this, culturists accept slightly slower fish 

growth to obtain greater survival, in part because 

bacterial levels (and potential Qseases) increase as 

water temperatures exceed 68°F (20°C) (Austin and 

Austin 1987). 

The primary bacterium of concern in walleye culture is 

Flexibacter columnaris (Nickum 1978), a ubiquitous 

pathogen that can cause mass mortality of walleye in 

hatchery environments. The transmission of coEurnnaris 

has been linked to routine mechanical injury (as from 

handling) in fingerling walleye (Hussain and 

Summerfelt 1991). This bacterium flourishes at water 

temperatures above 68°F (20°C) (Bullock 1986). 

Therefore, handling and transportation of walleye 

should occur below this temperature. When walleye 

must be handled at higher temperatures, such as during 

the harvest of pond fingerlings, extreme care must be 

exercised. 

Advanced fingerlings 

walleye raised intensively and fed formulated diets 

become tolerant to handling and transportation stress. 

Other than common sense, such as not handling sick 

fish and not handling them when water temperatures are 

excessive, these fish can be sampled weekly, inventoried, netted, and transported using the same methods 

used to handle salmonids. 

Loading rates in transport tanks for pond-raised or 

intensively-raised walleye fingerlings are similar to 

trout (Piper et al. 1982). Three-quarters of a pound (340 

g) of 5 in (12.7 cm) walleye fingerlingdgal (3.785 L) of 

transport water are commonly used in New York. 

82 NCRAC Culture Series 101- Walleye Culture Manual 
Usually, with larger fingerlings, mechanical aerators or 

agitators are used to generate acceptable life support 

conditions in insulated transport tanks. There should be 

no starvation period prior to shipping as this could 

promote nipping and cannibalism. 

The use of chemicals in transport water has been 

examined (Piper et al. 1982; Leitritz and Lewis 1980; 

McCraren and Millard 1978). Salt is commonly used to 

alleviate stress during transport. With walleyes, 

however, care should be exercised. Significant losses of 

pond-raised fingerlings have occurred when they were 

shipped in moderately hard water with salt to a 

soft-water hatchery. Immediately upon siphoning from 

truck to hatchery water, the fish went into shock and 

died. Other shipments from that hatchery without salt in 

the transport water produced no mortality. 

This chapter has highlighted methods associated with 

handling and transporting walleye. Even though 

walleye can be very sensitive to this type of stress, they 

can be successfully handled and transported in culture 

operations. 

Ref ere n ces 

Austin, B., and D.A. Austin. 1987. Bacterial fish pathogens: disease in farmed and wild fish. Ellis Horwood 

Ltd., Chincester, West Sussex, England. 

Baker, J.P. 1985. An examination of methods to eliminate adhesiveness and increase survival of walleye 

eggs for hatchery production. Technical Report No. 

85-6, Michigan Department of Natural Resources, 

Fisheries Division, Lansing, Michigan. 

Bullock, G.L., T.C. Hsu and E.B. Shotts, Jr. 1986. 

Columnaris disease of fishes. Fish Disease Leaflet 

No. 72. United States Department of Interior, Fish 

and Wildlife Service, Washington, D.C. 

Carmichael, G.J., and J.R. Tomasso. 1988. Survey of 

fish transportation equipment and techniques. 

Progressive Fish-Culturist 50(3): 155-1 59. 

Colesante, R.T. 1989. Intensive culture of walleye - 

1989. New York State Department of Environmental 

Conservation Fisheries Report, Albany, New York. 

Colesante, R.T., and A. Schiavone, Jr. 1980. Walleye fry: 

shipping and stocking mortality. Progressive FishCulturist 42: 238-239. 

Colesante, R.T., and N.B. Youmans. 1983. Waterhardening walleye eggs with tannic acid in a production hatchery. Progressive Fish-Culturist 45: 126-1 27. 

Huh, H.T., H.E. Calbert, and D.A. Stuiber. 1976. Effects 

of temperature and light on growth of yellow perch 

and walleye using formulated feed. Transactions of 

the American Fisheries Society 105: 254-258. 

Hussain, M., and R.C. Summerfelt. 1991. The role of 

mechanical injury in an experimental transmission of 

f lexibacter columnark to f i ng e r I i n g walleye. Jou r n al 

Iowa Academy of Science 98: 93-98. 

Kindschi, G.A., and F.T. Barrows. 1991. Evaluation of an 

electronic counter for walleye fry. Progressive FishCulturist 53: 180-1 83. 

Krise, W.F., L. Bulkowski-Cummings, A.D. Shellman, 

K.A. Kraus, and R.W. Gould. 1986. Increased walleye 

egg hatch and larval survival after protease treatment 

of eggs. Progressive Fish-Culturist 48: 95-1 00. 

Krise, W.F., and J.W. Meade. 1986. Review of the 

intensive culture of walleye fry. Progressive FishCulturist 48: 81 -89. 

Leitritz, E., and R.C. Lewis. 1980. Trout and salmon 

culture. Publication No. 41 00. Agriculture Sciences 

P u bl icat i o ns, U n ive rsi ty of Cal i fo r n ia, Berkeley, 

California. 

McCraren, J.P., and J.L. Millard. 1978. Transportation of 

warmwater fishes. Pages 43-88 in Manual of Fish 

Culture, Section G. United States Department of 

Interior, Fish and Wildlife Service, Washington, D.C. 

Nickum, J.G. 1978. Intensive culture of walleyes: the 

state of the art. American Fisheries Society Special 

Publication 1 1 : 187-1 94. 

Piper, R.G., I.B. McElwain, L.E. Orme, J.P. McCraren, 

L.G. Fowler, and J.R. Leonard. 1982. Fish hatchery 

management. United States Fish and Wildlife 

Service, Washington, D.C. 

NCRAC Culture Series 101 - Walleye Culture Manual 83 
84 NCRAC Culture Series 101- Walleye Culture Manual 
Lilienthal, J. D. 1996. Distribution of walleye fry and fingerlings. Pages 85-87 in R. C. Summerfelt, 

editor. Walleye culture manual. NCRAC Culture Series 101. North Central Regional Aquaculture 

Center Publications Office, Iowa State University, Ames. 

Distribution of Walleye Fry and Fingerlings 

James D. Lilienthal, Minnesota Department of Natural Resources-Fisheries Section, Route 4 Box 19A, Little 

Falls, MN 56345 

Introduction 

Walleye fingerlings have been stocked by the Minnesota Department of Natural Resources (DNR) Fisheries 

Section since the 1930s. Prior to that, walleye stocking 

was accomplished exclusively with fry. 

million fryhank). Most fry are 12-48 h old when 

packaged for distribution. The 5-gal (18.9 L) plastic 

jugs have been used for at least 15 years and are the 

most popular container. The jugs are filled with 2.5-3 

gal (9.5-11.4 L) of water and up to 100,000 fry (1 lb, 

0.45 kg). The cap of each jug is fitted with an air valve 

so they can be filled with oxygen. Fry have been 

Fry stocking 

where suitable, fry stockmg is the most cost effective 

stocking method for maintaining lake populations. Each 

year, the DNR stocks about 250 lakes totaling over 

300,000 acres (1 21,500 ha) with up to 250 million fry. 

Statewide, distribution costs (transportation and labor 

for stocking) average about $0.10/1,000 fry, for an 

annual cost of about $40,000. 

transported for up to 8 h using these containers. The 

jugs have rigid corners so fry are not crushed, and the 

jugs are much easier to load and handle than plastic 

bags. 

Lakes are generally stocked with 500-1,000 fry/littoral 

acre (1,236-2,472/ha), but experimental rates of up to 

3,000 fry/acre (7,413/ha) may be used. Littoral acres 

are defined as all water less than 15 ft (4.6 m) deep. In 

lakes where fewer than 2 million fry are needed, the 

preferred stocking method involves hauling the fry in 

jugs and stocking them from a boat, well off shore, on 

the calm side of the lake. Larger lakes receiving several 

Fry are distributed to stocking sites in 5-gal (18.9 L) 

plastic jugs (Figure 1) with oxygen (100,000 fry/jug); 

large plastic bags with oxygen (1 00,000 fry/bag); or 

140-gal (530 L) fish distribution tanks with oxygen (>I 

Figure 1. Plastic jugs @gal, 18.9-L) used by the Minnesota DNR for 

walleye fry distribution. The jugs are filled with 2.5-3 gal (9.5-11.4 L) of 

water and up to 100,000 fry (1 Ib, 0.45 kg). 

million fry are most often stocked 

from trucks; fry are hauled at low 

densities (-10,000 fry/gal, 

2,642L). Fry are released into the lake 

by draining the hauling tanks through a 

tube along the calm shore of the lake. 

Fingerling stocking 

Some waters, however, are not well 

suited to fry stocking, as survival is 

low and inconsistent. Walleye populations in these lakes are maintained by 

stochng fingerlings. In an average 

year, 300 lakes are stocked with 

fingerlings. In Minnesota, raising 

walleyes to fingerling size began in the 

late 1930s. Initially this was done in 

small (c20 acres, 7.3 ha) drainable or 

natural ponds. The ponds were 

harvested either by seining or by 

NCRAC Culture Series 101 - Walleye Culture Manual 85 
Chapter 4 -Transportation and Handling 

3 Xs 150 - hg 

Fx 100 - tor 

.- =fi 

a - 

m 

C 50 7 

ii 

0 

trapping at the outlet. By the late 1960s, natural pond 

use became more common; and by 1985, only 12 

drainable ponds were in use statewide, comprising only 

2% of the total production acreage. Through the 1980s, 

the size and number of natural ponds increased, use 

peaked in 1986 at 374 ponds with an average size of 

58.6 acres (21.4 ha), for a total of 21,907 acres (7,992 

ha). That year, a record of 5,647,430 walleye fingerlings 

weighing 197,450 lb (89,750 kg) were distributed to 

lakes throughout the state. The distribution cost of these 

fingerlings ranged from $0.20-$0.50/lb ($0.44 to $1 .lo/ 

kg), depending on the productivity of the pond. 

equipped with oxygen systems that include a regulator, 

flow meters, and 12 in (30.5 cm) micro-bubbler 

airstones. Some of the new tanks on larger trucks have 

built-in thermometers and oxygen probes. A trailer with 

a twin 200-gal (757 L) tank is often used in conjunction 

with this truck (Figure 4). The tanks are equipped with 

6-in (1 5 cm) camlock drains, and camlock-equipped 

""~""~""~""~" drain hoses are a part of each unit. Addtional equipThe impacts of fingerling stochng on fish community 

structure continue to be evaluated by fishery research 

and management personnel. All stocking proposals 

must be described in a lake management plan before 

being approved at the regional and at the state levels. As 

a result of these guidelines, the number of fingerlings 

Pond production of fingerlings 

Production ponds are generally stocked with 5,000 fry/ 

acre (12,355/ha) from a boat. An average fall survival 

from all 250 ponds (averaging 50 acres, 20.25 ha) of 

5% will provide an adequate supply of 4-6-in (100- 

150-mm) fingerlings (averaging 25 fish/lb, 55/kg,) to 

meet the statewide stocking quotas. MNDNR walleye 

fingerling production has averaged 3.1 million fingerlings per year since 1980. A host of climatic conditions 

are the most important determining factors in having a 

good production year in our natural ponds. 

Harvest methods 

The ideal water temperature for harvesting fingerlings 

is 50-60°F (10.0-15.6"C). Most of the fingerlings are 

captured from the production ponds with trap nets with 

3/8 in (1 cm) mesh. Heavy duty welded aluminumjon 

boats (the welded aluminum floors in these boats are 

easy to keep clean), equipped with at least 25 hp 

motors, are used to transport fish from the traps to the 

distribution trucks, Each boat is equipped with a 30-gal 

(1 13.6 L) fish holding tank. Aeration equipment is not 

used in the harvest boat, however, salt (1 cup) is added 

to the holding tank water to alleviate handling stress. 

Salt (0.5%) is added to hauling tanks to reduce stress, 

especially when bullheads are mixed in with the 

walleyes. Typically, water in the holding tank is 

changed each time fish are loaded from the harvest boat 

onto the dstribution trucks. 

requested by management personnel has decreased 

(Figure 2). It is estimated that only 250 production 

ponds (as opposed to 374 ponds in 1986) will be needed 

each year to fill all fingerling requests. From information gained through these studies, new stochng 

strategies are being developed that should eliminate 

stoclungs that are unproductive or harmful. New fish 

stocking guidelines require that the number of fingerlings and the frequency at which they are stocked must 

be compatible with the fish community structure and 

must meet the realistic goals of the management plan 

for each lake. 

250 1 

1 

*0° 1 U n 

Transportation procedures 

A typical DNR fish hauling truck is a 1 ton expanded 

cab, 4-wheel drive pickup with a large horsepower V-8 

engine and a twin 140-gal (530 L) compartment 

distribution tank (Figure 3). The hstribution tanks are 

86 NCRAC Culture Series 101- Walleye Culture Manual 
Transportation and Handling - Chapter 4 

Figure 3. Typical DNR fish hauling truck with twin compartments (140- 

gal, 430-L). 

a lot of sorting (e.g., crayfish, bullheads, 

salamanders, etc.) must be done. 

Typically, dip nets containing 20-30 lb 

(9.1-13.6 kg) of fingerlings are emptied 

into the distribution tanks. At water 

temperatures of 55" F (12.8"C) or less, 

loads of up to 1.5 lbs/gal (180 gal) are 

used. If the water temperature is greater 

than 55" F (12.8" C), or the fish are 

small (> 30/lb, 66kg) and the transportation time is greater than 2 h, then l lb/gal 

(120 g/L) is recommended. 

With approximately 3 million fingerlings 

going to about 300 lakes, logistics and 

communication are critical. This huge 

statewide program is coordinated by the 

regional managers and the fish production coordinator in St. Paul. Weekly, and 

often daily, status reports are generated 

each fall so that fingerling distribution is 

aerators in our distribution tanks was discontinued three 

years ago, and no problems have been experienced. 

During the early part of the harvest season, the dstribution trucks are filled with a mixture of well and lake 

water, but later in the season, only well water is used. 

About 125 gal (473 L) of water and 5 lb (2.3 kg) of salt 

(0.5%) are added to each tank. An anti-foam agent is 

recommended for long hauls. 

equitable across the state. In Little Falls (central 

Minnesota), we generally grow fingerlings in six ponds 

with an average size of 200 acres (73 ha), however, 

waters from 20 (7.3 ha) to 600 acres (219 ha) have been 

used. Knowledge of the walleye's role in dfferent types 

of water and different fish communities is critical to 

successful management. 

In the past, fingerlings were enumerated while being transferred from the 

boats to the trucks by first filling 5- 

gal (18.9 L) buckets with water until 

they weighed 20 lb (9.1 kg), adding 

the fish, and then re-weighng the 

bucket before dumping the fish into 

the hauling tanks. This year, weighing type dip nets were used to move 

the fingerlings from the boat directly 

to the scale then onto the truck. This 

method was faster, caused less 

congestion in the loadmg area, 

eliminated the unnecessary addition 

of water to the hauling tanks, and did 

not seem to cause more stress than 

the bucket method. The bucket 

method may still be necessary when Figure 4. Trailer with twin (200-gal,757-L) tanks that is used for 

distribution of fingerling walleye. 

NCRAC Culture Series 101 - Walleye Culture Manual 87 
Chapter 4 -Transportation and Handling 

88 NCRAC Culture Series 101- Walleye Culture Manual