At New Jersey's
Only State Trout Hatchery, Nature Gets a Helping Hand
by Jeff Matthews
Hatchery Superintendent
Every year, on
opening day of trout season, New Jersey's lakes and streams teem with
trout, thanks to the work of staff at the Pequest Trout Hatchery.
Last spring alone, the hatchery topped its stocking average of 600,000
trout by releasing an additional 30,000 fish.
Pequest Hatchery raceways
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After hatching and a 17-month growing period
through spring 1984, Pequest staff released the new facility's first
trout in New Jersey's lakes and streams. Today, descendants from that
first hatch provide all of Pequest's trout eggs and milt, the fluid
that contains sperm, to fertilize the eggs.
| Each year, the
production cycle begins in early fall when the staff collects and
fertilizes trout eggs in a process known as stripping. Stripping
is done by manually applying pressure to the trout's abdomen,
forcing females to expel their eggs and males to expel milt. Eggs
and milt are mixed in plastic basins to achieve fertilization.
To meet the hatchery's production goals,
Pequest staff takes about 650,000 each of brook trout and rainbow
trout eggs and about 400,000 brown trout eggs. The overall hatch
rate of all three species averages approximately 65 percent.
The fertilized eggs are placed in incubators
where running water supplies oxygen until hatching, which
generally takes 30 to 35 days. The hatchery's water supply comes
from six artesian production wells in the Pequest Valley that
provide up to 7,000 gallons per minute. Remaining at 52 degrees
Fahrenheit year round, the continuous flow of water is critical to
maintaining a trout production cycle.
Upon hatching, the young trout
are called "sac-fry" because the yolk sac remains attached to the
trout's abdomen. The sac-fry are taken from the incubators and
placed in fiberglass tanks in the main portion of Pequest's
nursery building. The yolk sac nourishes the young fish for about
two weeks. |
Stripping eggs from broodstock
Placing eggs in incubator tray
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Sac fry |
Once the yolk sac is
absorbed, the fry are able to swim and will be fed a
high-protein diet eight times a day by automatic feeders
suspended over the nursery tanks.
After the winter and
early-spring growing cycles, the trout's survival rate is
between 85 to 95 percent, and the fish, now called fingerlings,
average three to four inches.
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| Fish are sorted by
size, and the fish densities in the tanks are reduced. Surplus
fingerlings are stocked or are used for interstate trading
programs. Remaining fingerlings are placed in outdoor pools,
called raceways, at a rate of 13,500 fish per pool. Throughout the
summer, Pequest staff maintains 19 pools of brook trout, 19 pools
of rainbow trout and 10 pools of brown trout.
After the summer growing
period, the fish are again sorted for size. Numbers are reduced,
and the raceways are reset at a rate of 12,500 fish per pool. This
sorting generally yields about 48,000 surplus fish, averaging 5.8
inches. They are used for stocking during the third week of the
fall trout stocking program. |
Fish pump used for sorting
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Feeding raceway trout
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Meanwhile, fish that will be
stocked in the spring are fed four times per day. Inventories are
taken, and feed totals are calculated monthly to adjust growth
rates of the trout. Pequest's goal is to produce fish that average
10.5 inches by spring, when up to 580,000 trout will be available
for stocking. Pre-season spring
stocking begins in mid-March; three weeks before opening day of
the trout fishing season, trout are released throughout New
Jersey. Excess and older broodstock are also liberated during this
time.
When stocking ends, there's no break in the
action at Pequest. The cycle of raising fish from eggs is
continuous, and before long, fish for next year's spring stocking
will be in the outdoor raceways. |
| Other interesting programs are
under way at the hatchery. For example, several pools unused in
late summer and early fall are put into production to accommodate
Pequest’s fall, winter, and
sea-run
trout stocking programs. The fall program yields about 45,000
yearling rainbow trout. Increasing water flows and feeding rates
accelerated the growth of these yearling fish to an average of ten
inches by the fall. |
Brown trout
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Pequest’s
winter program produces 12,000 rainbow trout that average
about 11 inches, and are stocked in December and January every
year. The sea-run program produces 30,000 surplus brown trout from
the spring yearling sort. These brown trout are reared to eight
inches and released in the estuary of the lower Manasquan River.
The Pequest Trout Hatchery and Natural Resource
Education Center offers self-guided tours of its trout production
operations. The center is open daily from 10 a.m. to 4 p.m.,
excluding holidays. For information, call 908-637-4125.
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