by Craig Lemon
Hatchery Superintendent
June, 2014

In late winter and early spring each year staff from the Hackettstown State Fish Hatchery venture to various north Jersey lakes and reservoirs to obtain broodstock for the Division's warmwater and coolwater stocking programs. These adult fish are netted, brought to the hatchery for spawning, and then returned to their water of origin.

The 2014 spring trapnetting season seemed like it would never get here after the long, cold, icy, snowy winter. Looking back at the 18 year average, trapnets have been set for northern pike broodfish collection on or near March 10th. This year, hatchery staff would have had to cut through 12-15 inches of ice for that to happen! Mid-month came and went with little end in sight of getting nets in the water. Division Conservation Officer Shannon Martiak, whose patrol area covers the central part of the state, indicated anglers still ice fishing at Farrington Lake! With the days ticking away and anxiety/anticipation building, hatchery staff stayed in close contact with CO Martiak for the first signs of ice receding.

Northern pike are a species known to actually spawn under the ice and as the weeks went by concern about that happening was building. Finally, on March 24th, Farrington Lake was completely open; Hackettstown staff immediately set 3 South Dakota-style trapnets. At the same time, biologists from the Bureau of Freshwater Fisheries set additional nets in Farrington Lake to sample the pike population as part of a larger statewide study. Despite these efforts, only 7 northern pike were captured from March 24 to March 28. Of the seven pike, 4 were males and 3 were females. The biggest female was 37.3 inches long and weighing 12.28 pounds. She was ripe with eggs and spawned back at the hatchery producing 57,000 eggs. The 57,000 eggs were a long way from the over 250,000 needed to meet the state's 2014 stocking needs.

Staff checked the conditions at Budd Lake through the weekend of March 29-30; it remained completely frozen, but it was darkening up - a sure sign that it would break soon. A follow-up check Monday morning found the lake completely open; the ice had disappeared overnight.

First thing Tuesday morning, the crew set 2 Pennsylvania-style trapnets and one South Dakota hoping for some ripe female northern pike. Now, April 1st, it was the latest start in the 18 year history of trapnetting Budd Lake. Unfortunately, as feared, the 23 females captured over the next week were either immature or spent, meaning they had spawned while the lake was ice covered. In all, the 3 nets captured a total of 108 pike in 7 days compared to 164 in 5 days of fishing in 2013. This year's catch consisted of 64 males and the 23 females. The male pike averaged 3 pounds and 23.5 inches, ranging from .4-5.9 pounds and 12.8-29.2 inches long. The females averaged 2.62 pounds and 21.2 inches long, ranging from .66-7.8 pounds and 14.2-32.8 inches long. The nets also captured good numbers of white perch (5,734), black crappie (1,779), yellow perch (1,365), and sunfish (891). The 2014 northern pike program was saved by the hatchery's in-house broodfish. For the past 10-plus years the Hackettstown Hatchery has kept small numbers of male and female northern pike and muskellunge in two small hatchery ponds. They are used for viewing in the "Hog Trough" at the Division's Pequest Open House and the WILE Outdoor Expo in Colliers Mill in the fall, and are also utilized to cross with muskellunge to create tiger muskies. This year, four of the eight female pike were netted and ripened, producing 200,000 eggs.

It takes two to handle big muskies. Click to enlarge

In all 5 female northern pike produced 258,000 eggs in 2014 compared to 27 females that produced 880,000 eggs in 2013. Despite the low number of eggs taken, the hatchery had its highest percent hatch of all time at 71% and soon had 180,000 pike fry to start growing. Pike eggs hatch in 10 days, and the fry swimup looking to feed in another 5 days. Once hatched, northern pike grow fast! The pike are currently more than 5 inches in length and will be stocked in June when they reach their targeted size of 6-7 inches.

After a rough start with northern pike, things turned around 180 degrees with walleyes. While still fishing nets in Budd Lake for northern pike and a weekend approaching, staff saw ideal spawning conditions with a warm snap coming over the next few days and scrambled on a Friday afternoon to get a PA-style trapnet strategically placed, cutting off the mouth of Neldon Brook in Swartswood Lake.

After heavy spring runoff from ice and snow melting, and a recent heavy rainfall, the brook would be running full and attracting adult walleye in to spawn. What a great call that turned out to be. Early Saturday morning, April 5th, as the crew floated over the cage area of the trapnet and looked into the clear water all they could see were white tip tails and eyes. They struggled to lift the net onto the bow of the boat it was so full of walleye! Overnight, the net captured 244 walleyes, yielding over 800 pounds of fish!

Five million walleye eggs in incubators Click to enlarge

The next two mornings proved to be just as good, capturing an additional 151 and 186 walleye respectively. In just three days, a total of 581 walleyes were captured, eclipsing the old record of 352 in 2007 caught over a 9-day period. The net captured eight other species, but in very low numbers. This could be attributed to the fact that the walleyes are migrating from different sections of the lake towards Neldon Brook to run up and spawn, while the cool water temps were keeping many of the other species movements down. (For more on this spectacular run see Swartswood Lake Walleye Run Best Ever!) The male walleyes averaged 2.74 pounds and 19.2 inches, ranging from 1.14-5.22 pounds and 14.9-23.8 inches. The females averaged 4.45 pounds and 21.1 inches, ranging from .88-10.56 pounds and 13.4-28 inches. It was the peak of the spawning season as 104 of the 120 (87%) females captured were ripe. The 104 females gave 8.2 million eggs, averaging about 78,846 eggs per fish. The eggs hatching success was 55%. Hatchery staff set up 500,000 two-day old fry into one large hatchery pond for growout and another 2.5 million fry were stocked in the Delaware River from Milford, PA to Belvidere, NJ. The expected hatchery pond production of walleye fingerlings is about 100,000 two-inchers and 35,000 four-inchers. (View walleye collection data, 2000-2014 [pdf, 32kb])

Having captured record numbers of walleyes from Swartswood Lake and water temps rising toward the 50-degree mark, staff quickly switched gears once again and headed further north to Greenwood Lake knowing that muskies would be migrating into the shallow southern end of the lake to spawn. On April 10th, two Pennsylvania trapnets and a South Dakota trapnet were set near the mouth of Belcher's Creek. The nets were fished for 6 days and captured 35 muskies, the third highest number behind the 46 in 2009 and the 37 in 1999. The 20-year average muskie catch is 22 fish.

The strategically placed nets captured 12 muskies on the first day, one third of the 7-day total. Unlike 2013, when the male to female catch ratio was 9 males to 20 females, the 2014 number was nearly split down the middle with 17 males and 16 females, with two fish being immature. The males averaged 11.1 pounds and 35.3 inches, ranging from 6.98 - 15 pounds and 31.5 - 38.7 inches. The females averaged 17.8 pounds and 41.9 inches and ranged from 12.64 - 22.7 pounds and 37.5 - 45.5 inches. Of the 16 females captured, 6 of them were spawned with male muskies yielding 388,640 purebred eggs, an average of 64,773 per female. Four of the other females were crossed with northern pike males, which yielded 261,815 tiger muskellunge eggs.

The nets also captured 111 walleyes with a handful weighing over 10 pounds and many of the females in the 6-8 pound range. During the week they also captured 13 other species of fish including, but not limited to, 324 white and 3022 yellow perch, largemouth and smallmouth bass, chain pickerel and two large tiger muskellunge. The tigers were the largest the hatchery ever collected measuring 44.6 and 43.3 inches. Water temperatures ranged from 46 to 54 degrees. For 17 of the past 18 years, with the exception of 2012 when low water levels kept us out of Greenwood Lake, the crew has followed muskie trapnetting efforts at Greenwood with Echo Lake Reservoir. This year, staff decided to skip trapnetting Echo Lake for several reasons: Greenwood netting activities produced over 500,000 muskie eggs; 500 holdover muskie fingerlings measuring 9.7 inches were stocked in Echo Lake earlier this spring; and the hatchery maintains about 25 male and female Leech Lake strain muskies (same strain as in Echo Lake Reservoir) on-site. In 2014, these on-site broodfish were spawned to produce 141,000 eggs. The Leech Lake strain is a spotted muskie first purchased and stocked by Muskies Inc. Chapter 22 in Echo Lake Reservoir, and since then the reservoir has only received stockings of this spotted muskellunge. Leech Lake is a famous muskie fishing lake in northern Minnesota.

Seasonal Fisheries Worker Lauren Senn with a monster tiger muskie, the largest ever trapped in NJ. Click to enlarge

Overall, hatchery staff took 530,163 muskie eggs from 8 females, compared with 2,046,473 in 2013 from 24 females. This year's eggs hatched at 60%, one of the highest ever (compared to just 30% in 2013). Once hatched, the 315,000 fry fed off their yolk sacs for the first seven days. After their yolk sacs were absorbed, they began to free swim (swimup fry). This phase begins the toughest month at the hatchery as we work to convert a high percentage of these fry onto dry pelleted diets. This conversion period begins with rearing and feeding the 7-day old muskie fry brine shrimp every few hours, including the middle of the night, as the muskies respond more quickly to a moving feed source as opposed to the dry feed that drops straight down through the water column.

The tiny fry are fed brine shrimp for 14 day, with more dry feed mixed in every day, weaning the fry off of the shrimp by the end of the two week period. As the fry are growing the feed particle size is increased every couple of days, as the fish seem to target the larger feed pellets as soon as they are introduced. This helps greatly in reducing cannibalism. By this time a good percentage (>80%) will have taken to the dry food diet. The muskie fry are raised both intensively indoors in hatchery tanks and more extensively outdoors in earthen ponds. The target is 12,000 ten-inch fingerlings. They should reach this size by October 15th in time to be float stocked into lakes, rivers and reservoirs.

The future of trophy-sized fish begins at Hackettstown Click to enlarge

In addition to meeting New Jersey's fish culture needs the Hackettstown Hatchery also assists coolwater program needs of other states. For the 7th straight season the hatchery has provided the New York Department of Environmental Conservation's South Otselic Fish Hatchery with 120,000 tiger muskellunge fry. In early April, NY hatchery personnel picked up the 120,000 female muskellunge x male northern pike cross tigers. Over the winter we also received requests from the Connecticut DEEP Bureau of Natural Resources for 50,000 northern pike fry and from the Massachusetts Division of Fisheries and Wildlife for any surplus northern pike fingerlings we might have. On April 25th, Ed Mihofsky, a Connecticut fisheries biologist, made the trip to Hackettstown and left with 50,000 northern pike fry to be stocked in a production marsh to see how they would grow. On May 5th, two Massachusetts fisheries biologists made the trip down and picked up 23,494 two-and-a-half-inch fingerling northern pike to be stocked in a large inland lake. The Hackettstown Hatchery also supplied the Pennsylvania Fish and Boat Commission with 57,000 swimup tiger muskellunge fry and 150,000 muskie fry.

All of these fish are provided at no charge to our neighbors and are part of an ongoing multi-state fish trade that has gone on for many years. Most of New Jersey's cool and warm water stocking programs started with eggs and fry supplied from Pennsylvania and New York hatcheries. New Jersey has been receiving 2,000 fingerling landlocked Atlantic salmon from the State of Massachusetts since 2006. State pathologists sample all of these fish before transport to insure they are free of disease.

All adult muskies handled at the hatchery over the past seven years have been tagged with orange streamer tags inserted near the base of the dorsal fin. The tags bear the message "CALL HACKETTSTOWN HATCHERY (908) 852-4950" along with a tag number. Anglers who call in to report catching a tagged fish will be told when the fish was tagged, and its length and weight at the time of tagging. Reports of tagged fish provide the hatchery and state fisheries biologists with important growth information on the state's muskellunge, so please report your catch.

In coordination with fisheries biologists from the Bureau of Freshwater Fisheries, the Hackettstown Hatchery is raising the following numbers of northern pike, muskellunge, tiger muskies, and walleyes to meet the state's needs for 2014:

24,520 northern pike fingerlings for stocking in:
Cranberry Lake (Sussex County); Pompton Lake and Pompton River (Passaic County); Spruce Run Reservoir (Hunterdon County); Budd Lake (Morris County); Farrington Lake (Middlesex County); Deal Lake (Monmouth County); Millstone River and the Passaic River.

11,111 muskellunge for stocking in:
Greenwood Lake, Monksville Reservoir and Echo Lake Reservoir (Passaic County); Lake Hopatcong (Morris and Sussex Counties), D&R Canal 10-mile stretch (Somerset and Mercer Counties); Manasquan Reservoir (Monmouth County); Carnegie Lake and Mercer Lake (Mercer County); Mountain Lake and Furnace Lake (Warren County); Shenandoah Lake (Ocean County); Little Swartswood Lake (Sussex County); and DOD Lake (Salem County).

207,950 walleyes for stocking in:
Lake Hopatcong (Morris County), Swartswood Lake (Sussex County), Greenwood Lake (Passaic County), Canistear Reservoir (Sussex County), Monksville Reservoir (Passaic County) and the Delaware River (Mercer, Sussex and Warren counties).

The Hackettstown State Fish Hatchery also raises 13 other species of fish for waters throughout the state - see the hatchery's production and stocking summaries for details. All fish raised at the Hackettstown Hatchery are stocked in public waters throughout the state to provide recreational fishing for licensed anglers and their families.

The hatchery also raises several species of fish to assist the state's mosquito control efforts. The hatchery stocks 2-3 million fish annually. The Hackettstown Hatchery is supported entirely through the sale of fishing licenses and federal Sport Fish Restoration Program grant monies generated from the sale of fishing equipment.

Below are summary tables of fish collected in spring, 2014.

NORTHERN PIKE

WATERBODY	# DAYS NETS WERE SET	# FISH CAUGHT	AVERAGE LENGTH (INCHES)	LARGEST FISH (INCHES)	AVERAGE WEIGHT (POUNDS)	LARGEST FISH (POUNDS)
BUDD LAKE	7	108	22.9	32.8	3.00	7.8
FARRINGTON LAKE	4	7	31.9	37.3	7.5	12.28

MUSKELLUNGE

WATERBODY	# DAYS NETS WERE SET	# FISH CAUGHT	AVERAGE LENGTH (INCHES)	LARGEST FISH (INCHES)	AVERAGE WEIGHT (POUNDS)	LARGEST FISH (POUNDS)
GREENWOOD LAKE	6	35	38.6	45.5	14.5	22.66

WALLEYE

WATERBODY	# DAYS NETS WERE SET	# FISH CAUGHT	AVERAGE LENGTH (INCHES)	LARGEST FISH (INCHES)	AVERAGE WEIGHT (POUNDS)	LARGEST FISH (POUNDS)
SWARTSWOOD LAKE	3	581	19.8	28.0	3.26	10.56

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