Much of Michigan's chinook salmon program is dependent upon state fish hatcheries. Although Department of Natural Resources fisheries officials have documented significant natural reproduction of the Great Lakes' largest salmon in a number of rivers, not all streams produce. In order to spread the fish around the lakes and create runs in specific locations, the DNR maintains a significant stocking effort.

Producing salmon for stocking begins with an egg-take operation. This year, Scott Heintzelman, the fisheries technician supervisor at the Harrietta Field Station, headed up a crew of about a dozen fisheries personnel from the division's hatcheries and research and management sections for a week's worth of collecting chinook salmon eggs and milt at the Little Manistee Weir at Stronach.

The weir prevents salmon from migrating any further upstream. The DNR pumps water through a channel alongside the weir that stimulates the salmon to swim in that direction and up a fish ladder into a series of concrete ponds. The fish are held in these ponds until the females' eggs are mature enough to collect.

"Males are never a problem for ripeness," Heintzelman said. "It's almost 100 percent, all of the time."

When 70 percent of the females are ripe, fish handling begins. A contractor, who markets the fish and excess eggs from the operation, pushes the salmon from the ponds into a raceway, where they are lifted into a slotted bucket. The bucket is submerged in a bath of water that has carbon dioxide added to sedate the fish. The contractor raises the bucket and dumps the fish on a sorting table -- though you'd hardly notice they have been sedated.

Fisheries Division personnel separate the ripe chinook salmon, unripe females and excess males (there are almost always more males) for spawning. Excess and unripe fish are counted and dumped into a bin for the contractor. This year, personnel also separated jacks (sexually precocious and early maturing males) that had adipose fin clips. Those fish had tetracycline added to their food in the hatchery that makes a chemical mark on their otoliths (inner ear bones). Other fish, including brown trout, steelhead and most coho salmon, are released back into the river upstream from the weir.

Ripe adults are transferred to a large tub. Staffers hang up females; they are injected with compressed air to flush their thousands of eggs into a bucket. Other staffers milk the males by massaging their bellies until they release their milt into paper cups.

After fish have had their reproductive products removed, they are taken to a table where staff members perform a quick physical exam, opening their bellies and examining their hearts, kidneys, liver and spleen and checking for excess fluid in the body cavity. Any abnormality -- oversized organs, spots on organs, deformities or tumors -- results in the eggs or milt being rejected.

In years past, the staffers performed a quick chemical test for bacterial kidney disease (BKD) before accepting the reproductive products from a fish. But research has shown the test produced too many false positives and there are now effective methods for disinfecting the eggs for BKD as well as viral hemorrhagic septicemia virus (VHSv). Full fish health inspections are conducted on all broodstock lots of fish and 60 chinook salmon were sampled just prior to the egg-take. These fish currently are being examined at the Aquatic Animal Health Laboratory at Michigan State University.

Once the milt and egg donors pass physical inspection, the milt is dumped into the bucket of eggs -- fish are spawned one to one -- along with a saline solution to facilitate fertilization. The fertilized eggs are water-hardened with an added antibiotic to kill any BKD bacteria that maybe inside the eggs, then transferred to five-gallon buckets. Each bucket can handle the spawn from nine to 11 females.

The egg-laden buckets receive a long bath with oxygenated well water. Eventually, they are bathed in an antiseptic solution -- the last disinfectant at the weir -- for about 30 minutes to kill any viruses and bacteria on the outside of the eggs and then are returned to the cold-water bath until the buckets can be capped and loaded for transport to the hatcheries.

This year, the Little Manistee Weir was called upon to provide four million eggs for the Platte River Hatchery and 3.2 million for Wolf Lake Hatchery (which includes 600,000 that will be shipped to Indiana after eye-up). Once those are quotas are met, personnel from the Illinois DNR arrive to take another million eggs for their hatchery operation.

"The understanding is the Michigan quota comes first," Heintzelman said. "Then we work on out-of-state needs."

During egg-take, the weir is a popular stop for school groups, who get a tour of the facility provided by interpreters from state fish hatcheries.

"We have almost 600 kids coming through here in four days," Heintzelman said.

About two-thirds of the school groups visiting the Little Manistee Weir are part of the DNR's Salmon in the Classroom program and the students often will pick up the eggs for their program right at the weir. Getting the fertilized eggs directly from the weir allows students to see the eggs develop through eye-up. Classes that get their eggs from the hatcheries receive eggs that are post eye-up.

The egg-take crew arrives at the weir around 8 a.m. and begins setting up for the day. By 9 a.m., they're handling fish. Staffers generally take eggs until about 1:30 p.m., when the crew begins preparing the eggs for transfer to the hatcheries and cleaning up. It's non-stop work.

"Everything has to go to the hatcheries as soon as they're ready," Heintzelman said.

The crew handles about 1,000 to 1,500 fish a day.

"If the (gender) ratio is right, 1,000 fish is great," Heintzelman said. ""If they're running heavy to males (as they sometimes do in the early days of egg-take) it'll take a few hundred more."

Egg-take lasts about 10 days total; the crew does not work weekends to avoid overtime costs.

The contractor sells any fish that are suitable for human consumption to retailers, but most of the chinooks are past their prime by the time they're handled, so they won't make good meals. Most of the salmon carcasses end up going to the pet-food industry. Most of the eggs are sold for bait.

Using an outside contractor to handle the carcasses allows the DNR to dispose of salmon without having to handle and landfill the fish themselves, saving a huge amount of DNR personnel time and money, and landfill space by ensuring the fish are fully used.

The Little Manistee Weir has been in operation since 1968 and is the main source of chinook salmon and steelhead trout eggs for the hatchery program. Since the weir was built, fisheries personnel have handled more than 750,000 chinooks there, keeping much of Michigan's Great Lakes salmon program alive and swimming.