STRAWBERRY RESERVOIR — It is a fact, biologists tell us, that a fish can swallow another fish half its size. Meaning a 20-inch fish can swallow a 10-inch fish, with some difficulty.
But they don't. What fish choose to do is take smaller bites, a fact that brought about changes in the management plan at Utah's most popular fishing water.
In truth, said Alan Ward, project leader at Strawberry Reservoir for the Utah Division of Wildlife Resources, "We looked at more than a thousand prey fish pulled from the stomachs of other fish and found 98 percent were 7 inches or smaller. Only 2 percent were fish 8 inches or larger ... which is why we've started to plant fish that are 8 inches, and we're now seeing the results in our gill nets."
Earlier this month the wildlife agency completed its annual spring gill net sampling.
"The results are very encouraging," Ward said. "Our survival rate among cutthroats and rainbows is much higher."
Each spring and fall the DWR conducts netting surveys. Special nets are strung out in the late afternoon at established locations around the reservoir and are then pulled early the next morning.
Fish caught in the nets are identified, weighed and measured, and their stomachs are checked to help determine menu items.
In the past, fish planted in Strawberry were 7 inches or smaller and, biologists believe, were quickly eaten by larger fish and birds. As a result, gill net sampling showed very low survival rates.
After studying the dining habits of fish two years ago, the DWR decided to bump up the stocking size to 8 inches.
"What we found this spring was cutthroat numbers look good, if not better than last year. We also found good number of smaller cutthroat, which is the big story here," Ward said.
"We also found that rainbow numbers are getting better each year. Here, too, we're seeing much higher survival. Some of those rainbow we planted two years ago are already up to 17 and 18 inches."
After a treatment to remove all fish in 1990 because of high Utah chub numbers, it was decided that only fertile Bear Lake cutthroat, a formidable predator, kokanee salmon and sterile rainbow would be planted.
It was also decided that fishing regulations would protect the cutthroat but allow the catching of rainbow.
Today, fishing regulations at Strawberry allow anglers to catch and keep four trout and/or kokanee salmon. In that limit only two cutts can be under 15 inches and only one over 22 inches, and cutthroat between 15 and 22 inches must be released.
According to Ward, the responses to the new regulations and planting programs were immediate. Netting results in 2009 showed marked improvement in fish survival compared to 2006, 2007 and 2008, when sampling showed little, if any, survival.
In the first net pulled this spring, there were at least a half dozen rainbow in the 3- to 4-pound range and several cutthroat of similar size. In the second net, a deep-set net, there was a 5-pound cutthroat and at least a dozen rainbows and cutts in the 3- to 4-pound range.
All total, in the second of four nets, there were at least 75 fish, both large and small, and nearly as many crayfish. It took both Jeremy Christensen and Taylor Kimball of the DWR to lift the large tub holding the fish and net onto the roof of the boat and then to the back of the craft.
The first net, said Justin Robinson, project biologist, was set in the back of the Meadows area.
"We selected this location because of how shallow the bay is and how warm the water gets. Chubs like this area. Also, after the treatment in 1990, if chubs were to show up, this is where we would have found them. We continued to use this location not only to see what the chubs are doing, but also the cutthroat," Robinson said.
Those fish caught in the nets, he noted, were big and fat and had great color.
One fish, a 14-inch rainbow, had been planted last year and had nearly doubled in size and, by the end of summer, should be between 16 and 17 inches.
The second net, the deep-set net, was in an area called Meadows East, which is just east of the Narrows. This net held the largest and the most fish, and the most crayfish.
The third net was set in the Meadows Southeast area and the fourth at Haws Point, a popular fishing spot for shore anglers because of the steep drop-off.
Once the four nets were pulled, the group headed back to shore and to the DWR raceways behind the Strawberry visitors center.
Once there, volunteers and DWR staff removed the fish from the nets and set about doing the lab work.
The first things recorded were the length and weight. The fish were then placed under the black light to determine their age.
Prior to being planted, fish are blasted with a fine inert plastic in one of three colors — orange, red or green. The color identifies the year. When placed under a black light, the color identifies the age class.
"Once we have the age class, we can look at things like survival, growth rate and return to creel. There's all kinds of information we can get under the light," said Ward. "We can also identify hatchery fish and those from natural production. Over the past 18 years, we've had about 35 percent of our cutthroat come through natural reproduction. The only way we can get this information is by marking the fish. It's one of the best tools we have for managing and following the populations."
The slot limit was originally 15 to 20 inches. A few years ago it was widened in order to leave more of the larger cutthroat in the reservoir in the hope they would eat more of the chubs.
And it appears the management plan is working.
"Chub numbers are down considerably," said Ward. "Last year during spring netting we caught 611 chubs. This year we caught only 245. The one caveat is the water temperatures were cooler this year, and chubs are more active in warmer water."
There was also an increase in the number of suckers caught in the nets, and Ward said this is something that "we'll have to watch."
Because the sampling of kokanee is so small, he said he would have to wait on anglers' reports over the next few weeks before estimating population trends.
The one mystery this year was the appearance of a single whitefish in a net.
"As far as I can tell, there has never been a whitefish in Strawberry. How it got here or where it came from is a mystery. It's unlikely it was illegally planted, because the whitefish is not a sport fish. Also, whitefish are typically found only in rivers and streams," he said.
As for current fishing conditions, recent fishing reports lean toward fair to slow fishing success. Ward said this is usually the case in the spring. The water is still cold, the fish not as active, and the hatching of spring bugs help keep the fish full and less interested in lures and baits.
As the water begins to warm and fish become more active, fishing will improve. As summer progresses, waters become even warmer and the fish begin to move to deeper, cooler waters.
If spring gill net sampling is any indication of what's to come, anglers can expect to catch more and larger fish.
State fishing report
Deer Creek — Anglers report good success for trout, whether fishing from a boat or the shoreline. The water level is high.
Jordanelle — Good fishing from boats, tubes and the shoreline.
Provo River — Catching fish with small (size 20 or smaller) midge imitations above I-15 and up to Deer Creek Dam. Sow bugs are a good pattern as well. The river is running a little high. Also catching many white bass on the lower stretches of the river near Utah Lake.
Strawberry — Recent fishing has been hit-or-miss, but it should improve as the weather and water warm up over the next few weeks. A recent hatch on the reservoir is keeping the fish full.
Yuba — Catching walleye at Yuba using bottom bouncers on the north side of the narrows. Also catching perch and pike.
Bear Lake — Rainbow trout are being stocked in the lake, which will provide anglers with a new summertime opportunity.
Lost Creek — Found large numbers of chubs and some large cutthroats, rainbows and tiger trout in last week's survey.
Mantua — Boat and shore fishing is good for bluegill up to 9 inches. Having some success for trout and bass. Shore anglers had success for rainbows with flies and for bass with tube bait.
Pineview — Boat anglers had fair success for bass. Try areas with gravel and structure in the water. Fishing should pick up as the water temperature rises.
Weber River — Fair to good fishing between Wanship and Coalville. The water level is high, and water quality is fair. Caddis have hatched during the last three weeks. Spinners and lures are working well.
Flaming Gorge — Lake trout fishing has been good to excellent. Fishing just below the surface down to 90 feet. Some success jigging while others prefer trolling. Burbot fishing has been good through the ice, but now it's time to catch them from the shore or from boats. Try targeting rocky points and cliffs near the main channel at depths from 10 to 50 feet. Use just about anything that glows. Kokanee fishing is picking up as the water gets warmer. Anglers who target rainbows report good to excellent fishing from the shoreline and from boats. Fish are shallow and cruising the shoreline. The bass are just starting to appear.
Huntington North — Gill net sampling found a wide range of bass sizes and age classes with fish ranging from 10 inches to 4.5 pounds. One 9.5-pound channel cat was caught in a net. A few large trout turned up in the nets, including two that weighed 3 pounds. Despite the fact that numerous bass may be seen cruising along the face of the dam, catching them has been difficult.
Scofield — A huge insect hatch made conditions difficult for anglers over the weekend.
Enterprise — Fair to good fishing for rainbows with popular techniques. A recent survey found that the rainbows that were stocked in 2009 have survived well and are growing fast.
Fish Lake — Jigging for splake is producing the most consistent success. Anchor just outside the weed line in 20 to 40 feet of water. Fish light-colored jigs or flashy lures like Kastmasters a couple feet of the bottom. Make sure to tip jig or lure with fish meat — chub, perch or sucker — or half of a minnow. Fish shallower for perch. Trolling for rainbows is fair to good. Fishing is spotty for lake trout.
Gunlock — Largemouth bass were restocked in 2009 and had a very successful spawn. There will be a lot of small fish, up to 10 inches, available this year.
Mill Meadow — Fishing for brown trout is fair to good with minnow-imitating lures and streamers. Best success during the morning and evening and on cloudy days. The perch limit has been increased to 50, so harvest as many perch as possible to help the population stay in balance with available food.
Minersville — Improved fishing, especially for anglers trolling from a boat. Mostly catching fish in the 10- to 14-inch range. A few anglers have caught trout fishing from the dam. The lake is rising because of runoff. The upper end of the reservoir is muddy. Smallmouth bass fishing is improving as the water temperature rises and should continue to improve. Recent surveys found that trout are making a comeback. There are a good number of 12- to 14-inch rainbows and a fair number of fish up to 21 inches.
Panguitch — Anglers report slow to fair fishing. Try fishing with jigs, Kastmasters and Rapalas close to the shore or trolling. Although fishing is spotty, the fish that are being caught are big and in great condition. All of the fish are healthy and strong, and there is a good mix of rainbow and cutthroat trout, with a scattering of tiger trout. Cutthroat and tiger trout 15 to 22 inches must be released.
Ramp and temperature reports
According to the latest ramp report from the Utah Division of Parks and Recreation, the only ramp closed is at Wide Hollow at Escalante State Park, which is currently under construction.
Water temperatures are rising, but only a few are at the comfortable level. Temperatures at Gunlock State Park, Sand Hollow State Park and Quail Creek State Park in the southern tip of the state are in the lower 70s.
Huntington State Park, Hyrum Lake State Park, Otter Creek State Park, Red Fleet State Park and Starvation State Park are holding around 60 degrees.
The coldest waters are at Jordanelle State Park (52 degrees), Palisade State Park (49 degrees) and Scofield State Park (52 degrees).
Water temperatures at Flaming Gorge are 54 degrees and at Strawberry 50 degrees.