by Kim Cameron
The Kokanee salmon spawning at Wolford Reservoir reached record breaking numbers in its eighth year. The eggs collected at Wolford help restock the other Kokanee populations across the state. In 2009, many populations became infected with gill lice effectively stopping spawning operations at Lake Granby, Williams Fork and Green Mountain Reservoir.
Kokanee salmon are landlocked Pacific sockeye salmon, and spend their entire lives in fresh water. Kokanee are not able to successfully spawn naturally, so they get some assistance from the Colorado Parks and Wildlife. CPW aquatic biologist Jon Ewert has spent the last 13 years perfecting the art of salmon spawning.
Over a period of 22 days, nearly 5 million eggs were harvested from 7,809 ripe females. Ewert noted this collection at Wolford was the biggest kokanee spawn operation he has been involved with.
Kokanee salmon were introduced into Lake Granby in the 1950s and spawning operations have been on-going throughout Grand County for decades.However, Kokanee salmon were introduced into Wolford in 1996 and spawning operations began in 2012.
“We built this up from nothing a decade ago. We truly started from scratch with Wolford,” he said while recalling its humble beginnings with himself and the late Clark Barker, their spawn bowls sitting
on a makeshift card table set up in the mud next to the boat ramp.
“This year was by far the most satisfying and for me personally. I consider it the biggest accomplishment of my career to date,” said Ewert somewhat emotionally. “This year’s success is the culmination of a decade’s worth of efforts and decisions large and small, that positioned us to be able to produce this kind of number.” Wolford now produces 32 times more than is needed to restock itself.
Originally, everything was based around the boat ramps. Later though, it was found the salmon naturally gravitated to the natural coves off of the reservoir. The coves provide a stream-like feel and also provide the gravelly shelves that are formed from the rising and falling of the reservoir water levels. This simulates the natural environment if the kokanee could reproduce on its own. One of these coves proved to be a perfect place to establish the spawning traps.
In the depth of 10 feet a maze of curtains is set-up to help funnel the salmon into the salmon traps holding them there for collection. This year over 2,000 salmon were collected the first day in subzero temperatures. And even though on most days there is a waiting list of eager individuals for the harvested salmon to be dispersed, the coldest day brought out only six people. “We were filling coolers,” said Ewert expanding that the left-over fish were taken to the Denver Aquarium to feed the sharks and other attractions. CPW also shares eggs to hatch with the Aquarium so one of the exhibits featuring salmon actually have their origins from Wolford.
After the salmon enter the holding pens, they are then taken into the barge where work crews of seasonal help and volunteers are stationed to hand collect eggs and fertilize them. Within seconds after fertilization, the eggs are being washed and stored for transportation to the Glenwood Springs State Fish Hatchery, a cold water hatchery, run by former Kremmling resident, Josh Pulliam.
The Wolford kokanee salmon mostly spawn at age 3 or 4. This year they ranged in size from 11-17 inches, with the females averaging 13 inches and the males averaging 14 inches The state record for a kokanee salmon is a 27-inch, 7-pound, 5-ounce kokanee from Blue Mesa Reservoir.
Even though immature kokanee are silver colored, salmon ready to spawn change to red hues with the males almost turning a shade of burgundy. Ripe females are heavily laden with eggs and males grow a hooked jaw and humped back.
The eggs are collected into a bowl from ripe females by stroking her abdomen from front to back. Ewert cautions if not done properly eggs can be damaged towards the rear. The males are then used to fertilize the eggs in a very similar motion used on the females. In each bowl, a ratio of three females to two males is used.
It is common for there to be more females, and the males have to be used conservatively, Ewert explains. As the eggs are fertilized they visibly become more opaque and less translucent.
The bowl is then sent to the washing crew who use 44 degree water from the reservoir to sift through the eggs and remove any fecal matter and damaged eggs. The eggs are then placed in a beverage cooler that you might find at a potluck dinner. The beverage cooler is modified with screens to hold the eggs and a siphoning system to circulate water and holds about 96,000 eggs.
The eggs in the cooler are initially placed in an iodine solution to help sanitize them and rid them of any bacteria or fungus. This helps prevent disease from being introduced into the hatchery. After an hour, the iodine solution is siphoned off and replaced with filtered reservoir water. The container of eggs is then ready to be shipped to the hatchery.
Among those collecting eggs, was Justin Perkins from the Glenwood Springs State Fish Hatchery who noted the eggs would be counted and sorted again upon arrival to the hatchery.
The eggs will hatch in approximately 110 days and the growth of the newly hatched salmon would be tailored with colder and warmer temperature of water to grow them to 1-2 inches in time for a spring release.
In May, 120,000 one-inch fingerlings will be transported back to Wolford to be released and begin again.
The spawning process at Wolford has become more refined throughout the years, and Ewert thanked the numerous volunteers and staff for all their suggestions and for those who devised creative mechanical solutions to enhance operations.
“Without Wolford’s contribution this year, we would not have been able to meet our statewide need for eggs,” Ewert said. “Instead, we have a small surplus and will be able to ship half a million to New Mexico that they requested. It’s hard to overstate how important Wolford has become in our statewide Kokanee program.”