MinnAqua


Hatchery Fact Sheet - New London

  • Seasonal, cool and warm water facility
  • Species produced: Walleye, Northern Pike and Muskellunge
  • Year Established: 1940

HISTORY

The New London Fish Hatchery (NLH) was established in 1940 in New London, MN and was built by the Works Progress Administration (WPA).  The NLH was originally owned and operated by the United States Fish and Wildlife Service (USFWS) until 1982. The hatchery consisted of three residences, 8 rearing ponds which were constructed in 1941 on land next to the Middle Fork Crow River, and a building in downtown New London. The downtown building housed a public aquarium, 8 concrete holding tanks and an egg hatching battery.  Seven additional ponds were constructed in the early 1950’s. A fish hatchery building was built in 1968 adjacent to the first two rearing ponds which contained 12 concrete raceways and 2 egg hatching batteries. In 1973, an outside earthen raceway was constructed between ponds 1 and 2 and a well was drilled.

In 1982, the USFWS closed the NLH due to budget constraints. One residence was sold and the other two were traded for public land (WPA) in the early 1980’s. The Minnesota Department of Natural Resources took over operations in 1983 by lease. Ownership of the NLH was transferred from the USFWS to the State of Minnesota in 1996 with all property transfers completed by 2003. The old USFWS fish hatchery building in downtown New London was demolished in 2006. Today, the NLH has 17 rearing ponds totaling 46 acres of water on 120 acres of land. Major improvements have occurred since the State of Minnesota took ownership.

Why was it established?

The USFWS hatched walleye eggs and raised walleye fry, fryling and fingerlings in the ponds. The ponds were also used to raise northern pike fingerlings, bluegill fingerlings, and largemouth bass fingerlings. A second well (10” artesian) was drilled in 1978 and put into use to raise trout and salmon.

Since the State of Minnesota took over operations in 1983, the NLH has been utilized to meet statewide stocking quotas for various fish species. The hatchery has hatched walleye eggs, northern pike eggs, muskellunge (muskie) eggs and white sucker eggs to feed the muskie fry. The rearing ponds have been used to raise walleye frylings and fingerlings, muskie fingerlings, smallmouth bass fingerlings and channel catfish fingerlings and yearlings.

What is the general technology used for the hatchery?

Surface water from the Middle Fork Crow River Reservoir (Millpond) is piped to the New London Hatchery and 17 rearing ponds (1.0 to 5.4 acres in size) by gravity. The water used by the hatchery is returned to the river after it passes through either the hatchery building or the rearing ponds. The water passes through a drum filter prior to reaching the hatchery and ponds.  The level of filtration depends on what size filter is used on the drum filter (500, 100, 30 micron). A booster pump (3hp 300 g.p.m) is needed to supply adequate water to the concrete tanks and hatching batteries inside the hatchery building.  Once the water is inside the hatchery building, it passes through an ultra violet sterilizer to kill pathogens. A heat exchanger is often used to cool the river water when water temperatures rise above desired temperatures during egg incubation in order to slow egg development and hatching. The river water is cooled in the heat exchanger by passing well water from an 8” well across the plates in the heat exchanger. An alarm system using the telephone is used inside the hatchery building. Floats are installed in all the concrete tanks and hatching batteries. The floats are designed to trigger an alarm for either high or low water levels. If an alarm is triggered, it calls workers and alerts them that there is a problem.

Pond 1 was divided into two ponds by the USFWS. Under the State of Minnesota ownership, Pond 2 (2.6 acres) was divided into two smaller rearing ponds (1.3 and 1.0 acres) with a smaller pond on the upper end for local seepage and runoff. There are inlets on both the upper and lower ends of each pond with the outlets draining into the Middle Fork Crow River. Several of the ponds have been re-shaped by the Minnesota Department of Natural Resources (MNDNR) construction crew since 1992. The MNDNR construction crew has also placed riprap along the bank of the Middle fork Crow River to prevent erosion and maintain the dike between the river and the NLH ponds.

Has the technology been modified since establishment?

Since the State of Minnesota obtained ownership, several changes have been made. In the late 1990s, the smaller egg hatching battery was converted from using plastic jars (3qts eggs/jar) to 10-inch pvc “cannons” (20qts eggs/cannon) to increase the capacity to hatch walleye eggs. Adjacent to the hatchery building, a 3 compartment concrete raceway was constructed in 2000 to replace the old earthen raceway for holding fish.  A drum filter was installed in 2001 to filter the surface water supplying the NLH.  An ultraviolet sterilizer (UV) was installed in 1997 to kill pathogens (diseases, fungus and parasites) in the surface water.  A small Alfa Laval plate heat exchanger was installed in 2008, and used well water to cool the Mill Pond water flowing through the egg batteries (as much as 10oF below ambient water temperatures) when needed. Well water going through the heat exchanger does not come into direct contact with the Mill Pond water flowing through the egg hatching batteries, and the eggs are never exposed to the high iron levels found in the well water. Although the small heat exchanger had been highly successful in improving egg and fry survival at NLH, it was removed in June of 2012 and a larger Alfa Laval plate heat exchanger was installed in its place in the mechanical room of the hatchery building. The new heat exchanger has a larger cooling capacity, allowing for expansion of the egg hatching batteries at the NLH for additional Walleye eggs and for Northern Pike or potentially Muskellunge egg incubation. A UV filter (i.e. ultraviolet light sterilizer) is plumbed into the hatchery water supply line after the pumps and heat exchanger, and provides additional water treatment. The smaller heat exchanger was moved out to the large raceway building in March of 2013 for use in cooling Mill Pond water during the local walleye spawn take. Both heat exchangers were used in 2013 for walleye egg and fry production. Well water usage was approximately 7.1 million gallons in 2013.

Fish Management

Lake surveys and research provide the information used to select appropriate management tools.
In general, fish management tools fall into one of four categories:

  • protecting and restoring habitats and water quality
  • regulating the harvest
  • stocking
  • public education

Walleye Management

Minnesota has more walleye, walleye lakes, and walleye anglers than any other state. Each year, anglers harvest about 3.5 million walleye.

The best way to maintain walleye numbers is to protect critical habitats. Shore land zoning and related laws aid fish by controlling development and protecting spawning sites and aquatic plants that fish use for cover.

Stocking is another management tool used. Minnesota’s cool water hatcheries produce 2 - 5 million walleye fingerlings and millions of fry each year. Stocking can provide walleye fishing in lakes that lack spawning habitats but can otherwise support walleye. Stocking is also effective for lakes that have been “rehabilitated” or occasionally winterkill. Like any tool, stocking must be used appropriately. If misused, it will be ineffective or possibly harmful to existing fish populations. Stocked walleye may compete for food with other game fish, particularly largemouth or smallmouth bass.

Stocking a lot of small fish does not guarantee catching a lot of big fish. Fish managers estimate only 4 percent of the annual statewide walleye catch comes from stocked fish. The rest is the result of natural reproduction.

Loss of habitat, pollution, and increasing fishing pressure continue to be the biggest issues in walleye management. Everyone must work to improve water quality, control runoff and waterfront development, and maintain aquatic vegetation. Anglers, in addition, will need to comply with regulations and harvest only what they intend to use, for Minnesota to maintain a quality fishery.

Walleye Management

Minnesota has more walleye, walleye lakes, and walleye anglers than any other state. Each year, anglers harvest about 3.5 million walleye.

The best way to maintain walleye numbers is to protect critical habitats. Shore land zoning and related laws aid fish by controlling development and protecting spawning sites and aquatic plants that fish use for cover.

Stocking is another management tool used. Minnesota’s cool water hatcheries produce 2 - 5 million walleye fingerlings and millions of fry each year. Stocking can provide walleye fishing in lakes that lack spawning habitats but can otherwise support walleye. Stocking is also effective for lakes that have been “rehabilitated” or occasionally winterkill. Like any tool, stocking must be used appropriately. If misused, it will be ineffective or possibly harmful to existing fish populations. Stocked walleye may compete for food with other game fish, particularly largemouth or smallmouth bass.

Stocking a lot of small fish does not guarantee catching a lot of big fish. Fish managers estimate only 4 percent of the annual statewide walleye catch comes from stocked fish. The rest is the result of natural reproduction.

Loss of habitat, pollution, and increasing fishing pressure continue to be the biggest issues in walleye management. Everyone must work to improve water quality, control runoff and waterfront development, and maintain aquatic vegetation. Anglers, in addition, will need to comply with regulations and harvest only what they intend to use, for Minnesota to maintain a quality fishery.

Fish Production

Walleye Production

Walleye begin spawning in April as water temperatures approach 45 degrees. Workers collect, and then combine the eggs (also called roe) from female walleye and sperm (also called milt) from male walleye. Spawning usually lasts one to three weeks. The fertilized eggs are incubated at the NLH and fry hatch in approximately three weeks. The NLH annually hatches 15,000,000 to 20,000,000 walleye eggs from the Spicer area egg take; 12,000,000 to 18,000,000 walleye eggs from the private sector; and 35,000,000 to 65,000,000 Pike River strain walleye eggs from the Pike River which flows into Lake Vermillion at Tower, MN.

Fry are stocked into area lakes and natural rearing ponds depending upon management plan needs. Fry in rearing ponds at the NLH are raised to the fryling stage in 30 to 40 days. The fry in the natural rearing ponds are raised to fingerlings by fall, both of which are raised to meet statewide stocking quotas. Currently, The NLH produces walleye fry for Spicer area lakes and rearing ponds, Windom and Hutchinson area lakes and sales to the private hatcheries when requested. The NLH also uses rearing ponds to produce Pike River Strain walleye frylings for statewide distribution within the Pike River strain lakes.

Northern Pike Production

Northern pike egg take and incubation at the NLH started in 2011. Northern pike begin spawning in late March when streams start flowing from snow melt and spring rains.  Northern pike prefer flooded grasslands and marshes for spawning. In nature, the adults swim into flooded lowland areas, lay their eggs and return to the lake.  To aid in numbers of northern pike in certain lakes, workers collect, then combine the eggs and milt from the adults. Fertilized eggs are transported to the NLH and hatch in approximately 2 weeks.

Northern pike fry are stocked into northern pike spawning areas (NPSAs) which are shallow drainable nursery ponds adjacent to fishing lakes. After the fry grow to fingerling size, the pond is drained into the adjacent lake. These ponds are used when the northern pike population in a lake needs supplementing based on recent survey results according to the lake management plan goals.

In 2011 and 2012, the NLH hatched 385,000 and 942,000 eggs respectively. The NLH hopes to increase the number of northern pike eggs in the future by refining methods that will increase egg fertilization rates.

Muskellunge Production

The New London hatchery receives Leech Lake Brood Muskellunge transplants (small fingerlings) from the Waterville and St. Paul hatcheries. A total of 20,873 muskie fingerlings were stocked at densities ranging from 800 to 2,017 fish per acre in 2014. A total of 9 drainable hatchery ponds (14.92 acres) were used for muskie production. The amount of muskie fingerlings and ponds used varies each year as the state’s needs change each year.

The New London hatchery has averaged a 27% survival rate over the last 5 years for muskie fingerling production. Many factors play into the survival of muskie fingerlings. Inadequate forage, unseasonably cool/warm summers, bird predation, stocking densities etc.

Muskellunge fingerlings produced at the New London hatchery are distributed to other fisheries areas in Minnesota. In 2013 Bemidji, Brainerd, Detroit Lakes, Fergus Falls, Glenwood and Montrose all received muskie fingerlings.

Science Informing Management

What types of research help with management decisions for this hatchery?

  • The success of stocking walleye frylings raised in hatcheries such as the NLH, is currently being evaluated in certain lake classes.
  • Frylings raised in the NLH ponds can supplement natural walleye rearing ponds when a pond’s evaluation shows a fry stocking failure.
  • Walleye fry produced at the NLH are often marked with a product called OTC, which can enable fishery managers to determine the contribution of stocked fish compared to naturally reproduced fish.
  • The success of northern pike fry stocked into NPSAs is being evaluated as a method to replace stocking pre-spawn adult fish. These adult fish must pass disease certification first, which requires sacrificing a subsample of fish.
  • If management for muskie is expanded, the NLH may be called upon to produce more fish.

What other factors are involved with management decisions involving this hatchery?

  • The success and social acceptance of certain species of fish i.e. channel catfish, muskie, are big factors in the decision to raise a certain species at a hatchery such as the NLH.
  • Over the years, the NLH has been involved in hatching and rearing several different species of fish to meet statewide stocking quotas. The NLH has hatched walleye, northern pike, muskie, and white sucker eggs. The hatchery has also pond raised walleye frylings and fingerlings, muskie fingerlings, smallmouth bass fingerlings, and channel catfish fingerlings and yearlings.

What types of research or other science activities occur along with the activities in the hatchery?

  • Walleye fry or fryling have been marked prior to being stocked into lakes. Natural reproduction of walleye is evaluated by collecting a sample of walleye fingerlings by fall electrofishing and comparing the number of marked fish versus unmarked fish.
  • Some of the ponds at the NLH have been used for efficacy studies of OTC marked walleye fry to test how well the marking method works.
  • Northern pike eggs have a low fertility and hatching rate. Workers at the hatchery are researching/developing methods to improve this issue.

How does the data collected and/or research conducted at this hatchery inform/affect fisheries managers and fisheries habitats?

The fish produced at the New London Fish Hatchery may be the sole source of a fish species in a lake; may supply fish as a supplemental stocking; or as a reintroduction stocking and are evaluated by fisheries managers. Marked fish help managers determine effectiveness of stocking and the amount of natural reproduction in a lake. The marked fish in an efficacy pond determines how good the mark is in fish that were stocked into a study lake.

TOURS & VISITS

With advanced scheduling, we give tours to schools, scouts, clubs etc. This allows us to reach a large number of visitors with our limited staff. Our tours are educational and informational in nature and may be customized for the group. Tours are given Monday - Friday between 8:00 a.m. and 3:30 p.m.    Phone: (320) 796-2161.