Science of the Seasons: Little insects have huge role in Kenai River ecosystem

Over the past couple weeks, the Kenai River channel has been slowly opening.

Initially there was only a patch of thin ice at the outlet of Skilak Lake and then a few small areas of open water about a half-mile downstream. A number of overwintering swans and a few mergansers used these open-water areas to forage for food and find a little protection from predators.

Then the river channel opened up about a mile farther downstream. This slow downstream opening of the river will continue as the days lengthen and temperatures rise. Usually in April, the entire river will have an open channel with slabs of ice along each bank.

As the river opens and spring seems to be arriving, a number of aquatic insects will start to appear along the shore. Some of the very first insects will be a number of species of the dipteran family called chironomidae or “midges.”

These insects start emerging from the water when it reaches about 0.5 degrees Celsius. A large number of species of midges will emerge throughout the summer and fall until the water temperatures fall back down toward freezing again in late October or November.

We know at least 88 different species of midges live in the Kenai River. They are certainly the most abundant group of insects in this river, and probably the most abundant group in any freshwater river of the world. Not only are there more species of chironomidae than any other aquatic insect in the river, they are also going to be the group of insects with the largest number of individuals. It would surprise most people to know that there are probably around 100,000 midges that grow, develop and emerge from every square meter of river surface area. That equates to some staggeringly large numbers of insects emerging from the river each year.

Anyone who has traveled along the river in summertime has probably seen swarms of tiny bugs along the shoreline on a sunny day. These swarms of miniature, mosquitolike insects are mating swarms of midges. The males form the swarm and use a species-specific pitched sound to attract females. The females enter the swarm, mate and fly off to lay their eggs. Females can lay thousands of eggs in masses that stick to twigs, rocks or debris along the shore.

The eggs may hatch immediately into tiny larvae or may delay their development until many months later. These young larvae feed on algae, diatoms or fine detritus in the stream or river. Once they reach a certain size, they become pupae. After only a few days as pupae, they emerge and fly away as aerial insects. The adults usually do not feed, although a few are known to take in some sugar-rich fluids from flowers. The adults quickly mate and die within a week or two.

When the pupa becomes an adult, the pupal skin is left floating on the water surface. These pupal skins, called exuviae, remain on the water surface for a couple days and can be collected and identified to species. By collecting these exuviae, I was able to identify which midges were found in the Kenai River and when they emerged.

Even though these insects are only a couple millimeters long, they are a very important component of the aquatic community. They are a favorite food for virtually every species of fish. Young salmon fry feed heavily on midge larvae, pupae and adults. Many of the aquatic insect predators, like stoneflies, frequently feed on midges, too.

If you have ever seen swallows flying back and forth over the river or along most streams, you have seen another predator feeding heavily on midges. Because the adult midges are so small, we rarely recognize what the swallows are capturing. Dragonflies are well-known for feeding on mosquitoes, but they are also a major predator of adult midges.

While midges are certainly some of the smallest aquatic insects in the river, they play a disproportionately large role in the food web because of their high diversity and enormous numbers.

David Wartinbee, Ph.D, J.D., is a biology professor at Kenai Peninsula College’s Kenai River Campus. He is writing a series of columns on the ecology of the Kenai River watershed.

Science of the seasons: Stream debris can be good for fish, insects

The first raft or boat trip on the Kenai River each spring is a new adventure because the river will have changed significantly since the last trip in the fall. There will be new channels and unknown shallows that have to be noted in order to avoid costly repairs to the boat bottom or prop. Along with the substrate changes are the arrival or removal of large logs and, sometimes, entire trees. Sections of a river with significant numbers of logs and stumps are usually given a wide berth by boaters.

Logs and stumps are transients in the river until a large flood or ice jam washes them downstream. Eventually they will end up in the inlet and can create their own hazard out there. While in the river, however, the logs can have a significant impact on surrounding substrates and can become a temporary microcosm of riverine organisms, especially fish.

Most floating trees and logs are the result of normal bank erosion as the river meanders within its flood plain. “Sweepers” are frequently seen on the outside of river bends as the tree-supporting substrate is slowly washed away and trees bend over the river. As more and more of their support washes away, they dangerously skim the river surface until being completely uprooted. Once floating free, the strong current carries them downstream to the first shallow section. The limbs and branches are lighter and have more surface area than the stump and trunk end. Because of this, the heavier stump end tends to get dragged, begrudgingly, downstream.

Once a log or tree becomes “grounded” in the river, it starts changing the river substrates nearby. Water washing up against the unmoving trunk or stump will create a deeper hole below or to the side. Other areas along the log will slow the current so that sand, gravel and cobbles will be deposited there. By deflecting parts of the current, new channels will be created around the log. Some of the substrate and channel changes will in turn cause the log to be washed farther downstream. The process begins again as soon as the tree stops.

Once one log gets solidly lodged in the current, others seem to be attracted. In a fairly short period of time, with the arrival of new trees, large logjams can develop. As the numbers of logs build, so does the impact on the original water-flow pattern. Logjams can cause water to be diverted far from the original course and new side channels can be formed. These side channels create a variety of new pathways for the water to flow downstream.

Streams with numerous side channels are much more difficult to navigate with a motorboat than those with a clearly defined channel. However, rivers with more logjams, as well as an increased number of side channels, seem to have much fewer flash floods compared with rivers that have had logjams removed. By diverting water into numerous areas of the flood plain, the water moves downstream more slowly and is less able to erode away constraining lateral banks.

Various aquatic insects will use trees and stumps for an in-stream residence. Since many insects feed on fine, drifting organic particles found in the water , a spot on a tree limb with water drifting past is the best seat in the house. Some, like hydrospychid caddisfies, build filtering nets on these wooden substrates. Others, like black fly larvae, attach their abdomen to the limbs and filter out fine particles with special antennal fans. Because algae and diatoms will grow on the submerged wooden substrates, algal grazers will also be attracted to the logjam. In streams with soft, muddy bottoms, logjams and submerged trees can be some of the only available insect attachment sites.

For fish, and the astute fisherman, logs and stumps along a river are attractive areas. Because of the deeper channels around the logs, fish can find passageways if they are moving upstream. There are usually sections underneath the logjam where the current is slower than the surrounding stream and these areas are used as a fish refuge. Other fish will remain in the deeper sections underneath the log and wait for drifting or dislodged insects to wash right to them. Light shadows created by the tree or its limbs will also camouflage fish from potential predators. It’s kind of like an all-you-can-eat buffet for the fish in a sheltered restaurant.

Like virtually every other part of a stream or river, there are constant changes in the submerged trees and logs, as well as the rocky substrates around them. While these dynamic habitats can be dangerous for boaters, they can be a blessing for aquatic insects, fish and fishermen.

David Wartinbee, Ph.D, J.D., is a biology professor at Kenai Peninsula College’s Kenai River Campus. He is writing a series of columns on the ecology of the Kenai River watershed.

Muddying the waters — Hydrocarbon pollution reduced, turbidity churns up new river threat

By Jenny Neyman
Redoubt Reporter

Just as the Kenai River celebrates a victory over pollution, there’s evidence of another threat to ecology lurking below the surface.

Score one for the Kenai River, at least as far as hydrocarbons go. But that isn’t the only threat the Kenai is facing, Robert Ruffner, executive director of the Kenai Watershed Forum, told the Kenai Area Fisherman’s Coalition in a meeting Thursday. There’s another challenge lurking in — or murking up — the water: turbidity.

Turbidity is muddy water — sediment suspended in the water column. It occurs naturally so it’s not pollution as it’s often thought of, like gasoline, oil or some other foreign substance dumped in the water. Turbidity can result from any number of natural circumstances, even a bear stirring up mud when it wades out to fish, or the fish flopping through shallow water if it happens to escape.

On the Kenai, there’s a certain amount of natural background turbidity, measured in NTUs (Nephelometric Turbidity Units). Five NTUs is about the level where turbidity becomes noticeable from clear water, Ruffner said. The Kenai’s normal background turbidity level can range from single digits up to the mid-20s, he said. The turbidity level can spike much higher — up to 50 or 60 NTUs — and still be a natural event, Ruffner said, when the Funny and Killey rivers pump runoff and meltwater into the Kenai.

But it can also occur from nonnatural events, as appears to be the case during July. The culprit, as it was with hydrocarbons, appears to be boats. As motorboat use increased during the summer, so did turbidity readings.

“Along the edge of the water where the boat wakes hit the bank there’s a pretty clearly defined zone of turbidity along the bank,” Ruffner said.

Mixing it up

The Kenai Watershed Forum studied turbidity this summer with instruments placed 15 to 30 feet from shore at Eagle Rock, river mile 11.5, and Swiftwater Park, river mile 23. The instruments took readings every 15 minutes from May 15 to Sept. 1 — except for a few hiccups.

“Somebody shot the buoy one day, which didn’t make us very happy. We lost a few day’s data,” Ruffner said. And at one point someone pulled the buoy at Swiftwater onshore. But, “we have a really good data set to take a look at this,” he said.

From mid-May to mid-June, turbidity levels were about the same at Swiftwater and Eagle Rock, ranging from single digits up to mid-20s NTUs. A little later in June, turbidity at both sites rose to a little above 50 NTUs for a few days, which is attributable to the Funny and Killey rivers discharging, Ruffner said.

In late June and July, things changed. The Swiftwater sensor, which is upriver from the busy motorboat section of the river, recorded turbidity levels similar to May and June, with a few increases in background turbidity from the Killey and Funny rivers. But Eagle Rock saw significant spikes in turbidity, up to just below 100 NTUs the first two weeks in July, and up to 140 and 150 NTUs the last two weeks of July. That’s 80 NTUs above even an elevated background level from the Funny and Killey rivers, and about 130 NTUs above a calm turbidity background.

The spikes at Eagle Rock occurred twice a day, once in early morning and once in the evening — which is typically when boats head out on the river and when they take out at the end of the day. The exception was Mondays, the drift boat-only day on the river, when there were no unnatural turbidity spikes.

“That’s a pretty repeatable pattern, and on Mondays we don’t see that,” Ruffner said. “There’s no other obvious explanation than boat traffic that causes those spikes.”

Even if the relationship between motorboat traffic and increased turbidity is clear, as Ruffner said, what isn’t clear is what might happen because of it.

One answer is nothing, at least for the time being. Ruffner said it takes two years of monitoring to establish baseline data, and the turbidity study will continue again this summer. And data can be interpreted in different ways. If DEC takes daily averages of turbidity levels, for example, that approach would obliterate the significance of the morning and evening spikes.

Coming up with clear turbidity data can be murky in and of itself, what with having to factor in the effects of tide changes, tributary stream drainage and river flow lag time between the two sensor locations.

“It’s a pretty monumental task, it’s not going to be simple,” Ruffner said. “If people want to question or consider how you get there, that’s one very obvious thing to criticize. I can see right away that I’m going to be faced with that challenge.”

Members of the Fishermen’s Coalition said they wanted to be proactive about the situation.

“Intuitively, it makes sense that there’s an impact there,” said Ken Tarbox. “… The burden of proof isn’t on biologists to show harm, the offending action has to show no harm, if you want to protect the resource.”

Jack Sinclair, area superintendent for the state Parks department, said that perhaps the Kenai River Special Management Area board will take up turbidity like it did hydrocarbon pollution and pursue regulatory changes to address the issue.

“We’ve gone through this once before and seen where it went, so maybe that will make a difference. I don’t know,” he said.

Dwight Kramer, chair of the coalition, said it may be up to concerned residents to drum up awareness of the topic if they want to see regulatory changes to address it, just as they did with hydrocarbons.

“I don’t think if we left it up to DEC we’d be where we are today,” Kramer said. “It might be incumbent on us, if we see this progressing in the next few years, to start pushing it from our level.”

So, what?

The Kenai’s turbidity can spike up to 50 or 60 NTUs naturally, and other rivers in the state, like the Yukon, can have higher turbidity levels than the Kenai and still support fish runs.

“When you look at the data you can tell that something different is going on. It’s pretty easy to see what is occurring naturally without going into any statistics or doing anything fancy from the data, and you can see these departures from what’s going on in the background,” Ruffner said. “The ultimate question is, so what? Is that a problem for the aquatic resources that are in the Kenai River and that make the Kenai River what it is? I don’t have a good answer for that.”

Turbidity can cause a variety of harms. For sight-feeding organisms, which can include juvenile fish, turbidity can mean they can’t see to find food. Certain sizes and shapes of particles can lodge in the gills of organisms that filter water. Turbidity can impact fish reproduction if sediment settles into the bottom of the river on spawning beds. And it’s a sign of bank erosion.

“That mud in the water is made up of the stuff that was on the bank,” Ruffner said.

Technically, the summer’s turbidity results put the Kenai out of compliance with water quality standards. For water bodies that don’t have a designated use — like recreation, transportation, etc. — by the state, the most stringent water quality standards under the Clean Water Act apply to it, Ruffner said. The state EPA hasn’t designated a use for the Kenai, or most water bodies in the state, so the standard for drinking water applies, which is no more than five NTUs above background levels. But Ruffner said he doubted this summer’s test results would land the river on the EPA’s impaired listing over turbidity anytime soon.

“The people who sit in the regulatory chair don’t really care what the people in the biology chair are saying. I doubt that we’re going to get an impaired status listing anytime soon,” he said.

There are a lot of questions still to sort out. Should turbidity be figured for the river as a whole, or in sections? Should turbidity results be looked at on an hourly, daily, weekly or some other basis? What effect do increases in turbidity have on the river?

People’s leaning on the politics of the river may affect their opinion of those questions.

“This is knowing full well that there will be people that will take this in and apply it to their interest, either for or against it, and that can’t be surprising to anybody. And it’s no different than what we saw with the hydrocarbon issue. People were able to spin that either way,” Ruffner said. “I don’t really know how people are going to take this and use it or not use it. From my perspective, if we’re documenting a problem with water quality, that ought to come first. We ought to protect water quality.”

Guest editorial: All power generation has an impact

The Kenai Peninsula hosts a couple hydroelectric generation facilities and a couple others were proposed in the past. With the ever-increasing costs of electricity, there are renewed activities looking into the feasibility of additional hydroelectric plants on the peninsula.

Unfortunately, there is a lot of rhetoric about these proposals that is misleading at best. A term being erroneously attached to the proposals and studies is “low impact.” However, hydroelectric power generation can hardly be called “low impact” when streams are completely dewatered or the entire biotic community is completely changed.

In order to generate electricity with water power, one needs a large volume of water that can be released on demand (whenever there is a demand for electricity). Also, in order to generate as much power as possible, the water needs a substantial “head.” That translates to mean the water source is dammed up as high as possible and allowed to generate power as the water is selectively released. The greater the height of the “head,” the greater the force the water exerts on the turbine impellers. That benefit of increased water height is why some of our well-known dams, like Hoover Dam or Grand Coolee, can generate so much electricity.

Besides aesthetic considerations, there are a number of very well-known impacts that dams always exert on a stream. Perhaps the first thing to understand is that any dam instantaneously changes the stream from a moving body of water into a lakelike reservoir. Virtually all stream species of algae, diatoms, insects, crustaceans, fish and associated animal life will be displaced by lake-associated species. All areas that were once valuable spawning sites for resident and anadromous fish will be filled with silt and sediments when the flow ceases. No further spawning will occur there. This stream disruption will continue as far upstream as the water is allowed to back up.

As a point of reference, the Kenai River gets backed up for almost 15 miles by the twice-daily tidal changes of 20 to 30 feet. Thus a lot of river or stream can be impacted by a relatively “low impact” dam.

Downstream of the impoundment there are other issues. Hydroelectric dams release water for power generation on a schedule that fits human power needs, not the stream needs. Most power is actually needed during daylight or normal working hours so more water is released during the day. Depending upon the size of the receiving stream, daily variations in water releases can raise or lower stream levels by a foot or more. Small streams can go from bank full conditions to drought levels on a daily basis. This unnatural fluctuation eliminates a great many stream organisms. While some stream invertebrates will remain in the now altered stream, the species assemblage will be unlike the original inhabitants and total biomass within the stream will be heavily reduced downstream of the dam. The invertebrate losses will then cause a heavy reduction in the fish populations that relied on them for food.

Since the stream below an impoundment has its flow closely regulated, there are no more floods. At first blush that may seem to be a good thing. However, streams benefit from periodic flooding and high waters. These events clear out fine particles deposited in the stream and re-sort the gravels into like-sized sections. Salmon look for these uniform-sized gravel beds to use for spawning.

Another seemingly subtle change caused by dams and impoundments is the temperature of the waters being released. Water coming from the bottom of a reservoir will be colder than the normal stream temperature and water released from the surface of the reservoir tends to be much warmer than normal stream water. Generally, the winter water outflow is warmer than normal and the summer water outflow is cooler than normal. Some large dams can produce detectable thermal changes in the outflow streams for dozens and dozens of miles downstream. The concern here is that we know many aquatic organisms depend upon temperature changes to signal times for migration, emergence, reproduction, etc. Thus, subtle changes in water temperatures on a seasonal and daily basis can disrupt the life cycles of the remaining organisms.

These are just a few of the changes a dam can exert upon a stream. If we are going to consider hydroelectric power generation on the Kenai Peninsula we will have to consider the tradeoffs and decide what we value most highly. These will be some difficult decisions. Remember, there is no “free lunch,” and there is no “low-impact” way to generate power.

David Wartinbee, Ph.D, J.D., is a biology professor at Kenai Peninsula College’s Kenai River Campus.

Editorial: As the river churns ...

Just when it seems the Kenai River is on the road to recovery following news that hydrocarbon pollution has been cleaned up in July, results of a new study are stirring up renewed concern over the health of the river.

Robert Ruffner, executive director of the Kenai Watershed Forum, had a good news, bad news presentation for the Kenai Area Fishermen’s Coalition on Thursday.

The good: Test results from this summer show a dramatic reduction in hydrocarbon pollution in the lower reaches of the Kenai River, attributed to a regulation banning two-stroke outboard motors in favor of cleaner-burning, four-stroke models and direct fuel-injection two-strokes.

When the lower Kenai River was placed on the Environmental Protection Agency’s impaired listing due to pollution, tests found hydrocarbon levels at 20 to 25 parts per billion during peak fishing season in July, well over the limit of 10 ppb. In July 2008, those numbers were down to two to five ppb, Ruffner said.

There’s some discrepancy in the numbers, and water-quality testing will continue this summer to nail down the most accurate results possible. Ruffner said water levels and tides were high this summer, which may have aided in the dilution and flushing out of pollutants. And there’s some question over how the lab treated one of the four hydrocarbon compounds it tested for, which may have skewed results slightly higher than they should be.

Then there was the bad news: Turbidity testing from the summer shows significant spikes during late June and especially July, which Ruffner relates to peak boat use on the river.
Turbidity — muddy water — occurs naturally to some extent, but it appears that human activity is causing a literal stir on its own. Sediment in water can impact a fish’s ability to feed and spawn, and certain sizes of particles can lodge in gills and harm organisms. It’s also a sign of bank erosion.

The tricky part comes in determining how much impact is too much, and what should be done about it. The Kenai’s turbidity level can spike up to 40 or 50 NTUs (the measurement for turbidity) due to natural conditions. Human activity seems to be pushing it up significantly higher, to 150 NTUs.

But where’s the line when unnatural becomes unhealthy?

Common sense says there’s an impact from that much sediment being washed into the river, but science has yet to specifically identify the impact and quantify how serious it is.
Then comes the regulatory process to decide whether rules will change to address the issue.

After having just emerged from this process with hydrocarbons, it’d be nice to sit back and relax on the river for a while. But having a resource like the Kenai running through our backyards means we also have the ongoing duty of caring for it.

That duty may be laborious sometimes, but the Kenai River is worth it.

Cool effects — River ice forms wherever it can amid flowing water

Even when smaller streams have a covering of ice, larger rivers have open sections throughout the coldest months of winter.

Stream and river water slowly lose enough heat to the colder air so ice forms in various ways. In small, slow-moving streams, ice often forms a layer on top of the stream just like it forms on top of lakes. The ice covering the stream tends to be thinner than ice found on lakes because of the moving water underneath. And during winter months, stream levels usually drop and the ice may end up covering an air space with the flowing stream below. Because of the air space between ice and flowing water, the ice doesn’t get any thicker.

In larger, faster streams, the first ice to form is along the slow-moving edges. When the river water gets more uniformly colder, frazil ice forms, and it looks like slush in the water. Winter steelhead fishermen sometimes see what looks like blobs of snow floating downstream. This is frazil ice being formed in the moving, super cooled water, probably right before their eyes. This slushlike ice gets thicker and packs together until it collects on the sides, bottom and top surface of the channel. If you are seeing frazil ice forming in your favorite trout stream, it’s time to put the fly rod away for the season.

Newly formed stream ice tends to block off parts of the channel, but water remains free-flowing in some sections all winter long. Since many streams receive their water from lake outflow, like the Kenai River below Kenai Lake or Skilak Lake, much of the water is too warm to immediately form ice. This is why we frequently see open water under the bridge between Kenai Lake and the start of the Kenai River.

Another major source of water for winter streams is groundwater. Groundwater, by definition, has not been exposed to colder air and is considerably warmer than the rest of the water in the stream. So, we often end up with warmer water flowing between and underneath layers of ice. These flowing channel areas and deeper areas of liquid water are the critical wintertime refuge for resident populations of grayling, trout and whitefish.

When exposed sections of stream water gets very close to freezing, such as later in the winter months, another kind of ice may form. Usually at night or early morning when air temperatures are at their coldest, anchor ice can form. This type of ice looks like a clear layer of ice covering the bottom of the stream. The anchor ice layer may temporarily restrict or block off some of the under-the-ice channels that were flowing previously.

The flowing water can’t descend through the sediment and can’t move laterally so it breaks through the ice somewhere and flows on top of the ice cover. This is called river overflow.

Because the water has considerable inertia and gravity moving it along, huge amounts of water can suddenly begin flowing on top of the ice. River overflow can sometimes be measured in depths of feet and can be quite problematic for travelers. One might expect the overflow to immediately freeze, since it is in contact with cold air. However, if there is snow cover on the ice, overflow water can remain liquid for many days, even when the air temperatures are extremely cold.

Some of the most spooky, and also some of the funniest, stories I have ever heard were told by a well-known Iditarod musher when talking about his experiences with river overflow. In some situations he had his entire sled floating and his dogs swimming in overflow when the air temperatures were minus 10.

In many areas of Alaska, wintertime travel routes are on top of frozen rivers. Most of the time the river ice cover is more than thick enough to support the person, dog sled, snowmachine or even a pickup truck. However, because of constantly changing under-ice channels and the dangers of river overflow, traveling on frozen rivers can be very dangerous, too.

David Wartinbee, Ph.D, J.D., is a biology professor at Kenai Peninsula College’s Kenai River Campus. He is writing a series of columns on the ecology of the Kenai River watershed.

Kenai River be dammed — Government planned to plug Kenai Lake for hydro power

Editor’s note: This is the third in a series of stories examining possible Homer Electric Association hydroelectric projects near Moose Pass. Next week’s story will focus on controversy surrounding the existing hydroelectric project at Cooper Lake.

By Jenny Neyman
Redoubt Reporter

If federal government had gotten its way in 1952, the Kenai River would have been dammed at the outlet of Kenai Lake.

Instead of the gently sloping gravel bars where anglers fish year-round, bears and eagles find plentiful meals amid the blue-green water and drift boats and river rafts begin their journeys, the headwaters of the river in Cooper Landing would be spanned by an earth-filled dam 100 feet high and 1,800 feet long.

That’s 556 feet longer than the Hoover Dam.

The mammoth project would have dramatically and purposefully transformed a large swath of the central Kenai Peninsula, from the headwaters of the Kenai east to Resurrection Bay.

Plans called for using the dam to cause the level of Kenai Lake to rise and back up into the Snow River delta, which would be dredged to bring the water level even closer to the divide where it drains south into Resurrection Bay. A tunnel nearly four miles long would pierce the bedrock of the natural divide from Kenai Lake to Bear Lake. Another half-mile tunnel would be bored from Bear Lake to Lost Creek to the east in order to lower the elevation of Bear Lake from 200 feet to at least 50. The whole project would mean the waters of Kenai Lake could be forced to drain south into Resurrection Bay, rather than west as it naturally does into the Kenai River and eventually Cook Inlet.

The purpose of all this?

Power. Lots of it.

The project would have included a power plant at the north end of Bear Lake expected to produce more than 140 million kilowatt-hours of electricity a year by utilizing the 1 million acre-feet of water storage that would be created with the dam in Kenai Lake.

Homer Electric Association’s plans to investigate installing four low-impact hydroelectric projects in the Moose Pass area brings renewed interest to using water for power in the Cooper Landing area. HEA’s plans have some new twists — especially the low-impact approach — but the co-op is hardly the first to ponder the feasibility of hydroelectricity in the Kenai Mountains.

Crescent Lake has nearly been the host of a hydro project before. In 1955, the Seward Petticoat Gazette newspaper had a story about a hydroelectric project at Crescent Lake, “which will eventually make low cost electric energy available to the residents of the Seward and surrounding territory,” the story states. It goes on to talk about attempts to obtain necessary permits from the Bureau of Public Roads and the Forest Service. A contractor for the state of Alaska also studied the area for hydro in the 1980s.

The Kenai River dam idea was outlined in a January 1952 report called “Our rivers: Total use for greater wealth — Reconnaissance Report on the Potential Development of Water Resources in the Territory of Alaska,” which was presented to the 82nd Congress, first session, as House document 197. The U.S. Department of the Interior, Bureau of Reclamation, compiled it.
The stated purpose of the report was to investigate, “What of the water resources of Alaska? Have they any value? Should they be developed? These and a host of other questions have long needed answering.”

All regions of Alaska were reviewed in the report, and some were found to be more promising for hydroelectric projects than other. Southcentral, in particular, was deemed to be promising because it was thought that more power would result in more development.

“Cook Inlet area is the hub of Alaska, geographically, industrially, as a transportation center, and for accelerated development in agriculture and miscellaneous enterprises,” the report states. “The growth of this area is a healthy one, for it is not dependent on a single industry, nor on unstable resource development. Yet many of the resources are virtually untouched, a major one being the water resources. Agriculture, coal and metal mining, lumbering, fishing, and transportation have combined to serve as a nucleus for a stable economy. Lack of power and other water resource development has thus far prevented an even more impressive ‘chain reaction’ that would not only expand the existing developments, but would attract new manufacturing industries to the area.”

The Kenai River basin was seen as a likely candidate for hydroelectric projects because of ample lakes and glacial drainage streams, plus the Alaska Railroad and beginnings of the Seward and Sterling highways provided access to the area. But only one project — the biggie — was suggested as actually taking place.

“The basin offers numerous possibilities for small-power installations at relatively low construction cost. The only development considered is one using Kenai Lake for storage,” the report states.

A few other hydro sites on the peninsula were considered in the report. A proposed dam across Resurrection River about nine miles from the river’s mouth in Resurrection Bay at Seward would be 235 feet high and 2,000 feel long. That would create a reservoir with a 320,000 acre-feet capacity. A tunnel would carry water five miles downstream to a power plant that could generate more than 60 million kWh per year. The report questioned the feasibility of this project, however, due to geologic conditions.

Tustumena Lake is mentioned, but no projects were proposed, since it wasn’t seen as an area primed for development.

“The importance of the basin lies chiefly in its agricultural possibilities and the fact that much of it is underlain by coal-bearing sediments,” the report states.

Other than that, Cook Inlet itself got a nod of interest, but no specific recommendations:

“Cook Inlet has one of the highest tidal ranges in the world. Among the combination of factors that cause such large differences between high and low tides, at times exceeding 50 feet, are the configuration of the inlet and its bottom topography. This potentiality is worthy of future study.”

The report doesn’t include any study of what the ramifications of such large-scale hydro projects would be on fish, wildlife or any other aspect of ecology. But the report’s introduction does include a statement that seems to be at odds, to put it mildly, with the idea of plugging the Kenai.

“The fishing industry ranks first in importance in Alaska’s economy. This position can only be maintained if man-made destructive elements are minimized. The fish and wildlife service should be consulted to make certain that proposed structures for water resource development do not hinder the ‘run,’ of salmon.”

But the introduction also states that, “the construction of many of these dams is highly probable in view of future demands for power and water.”

Had it been built, the Kenai River as we know it today would cease to exist.

“It would have dewatered most of the upper river and we wouldn’t have any inputs until you got to Skilak Lake, really, except the Russian River input. Yeah, it’d be a pretty small stream,” said Robert Begich, a biologist with the Alaska Department of Fish and Game. “It would have cut, boy, a lot of production. All species of salmon go across Kenai Lake and spawn in the tributaries … and in the lake itself.”

Rainbow and Dolly Varden trout also spawn up past the outlet of Kenai Lake. Salmon and trout spawning occurs elsewhere along the river, but cutting off Kenai Lake would have had a drastic impact.

“They would have survived, but the whole system wouldn’t have been as productive. It would be too big of a landscape change. There’d be fish, but not very many,” he said.

“Yeah, it would have been a big landscape change. A doozy, that’s for sure,” Begich said. “We’d all have less to do.”

The Kenai River dam never came to be, but it wasn’t for lack of consideration. Documents show the federal government was considering installing hydro on the Kenai decades before the 1952 Interior report. In an Alaska Archaeological Survey supplemental report, “Sterling Highway Archaeology” from 1985-1986, put out by the state of Alaska Department of Natural Resources, Division of Geological and Geophysical Surveys, there’s mention of Frank Towle, the first resident in Cooper Landing to get a title to his homestead from the federal government, in 1932.

Prior to Towle, Cooper Landing homesteaders weren’t granted titles to the land because of a 1921 Federal Power Authority restriction limiting entry to federal lands within a quarter mile of the Kenai River and Kenai Lake, the report states. The power authority had a dam in mind that was expected to raise the lake level 6 feet. During the ’20s, no action was taken on a hydro project, so the Forest Service requested that the Federal Power Authority loosen restrictions on land in the area that wouldn’t be affected by the planned dam, which it did on May 10, 1934, according to the report.

The authority then began lifting restrictions on a case-by-case basis, “if individual homestead or homesite permit holders could demonstrate that their improvements to the land would not be adversely impacted by a 6-foot rise in the water level on Kenai Lake or the Kenai River,” the report states.

Had a dam been built and the lake level increased 6 feet, “We would have a better lake view,” joked Mona Painter, Cooper Landing historian and longtime resident.

Levity aside, the magnitude of what might have occurred is staggering to consider.

“It’s been interesting what they’ve planned over the years,” Painter said. “It’s a complete plan about how they were going to have the water go toward Seward and have hydroelectric power that way. Can you imagine? It would have just been huge. Where the bridge is now there would have been a big dam. It would have been huge.”

Editorial: Arguments over life jackets are all wet

The Division of Parks and Outdoor Recreation has a simple request: That commercial sport fishing guides on the Kenai River require their clients to wear class III personal flotation devices. Parks wants to make the requirement one of the stipulations guides must agree to in order to get a Kenai River Commercial Guide Permit.

The Kenai River Professional Guide Association has some convoluted reasoning as to why that shouldn’t happen: It’s too expensive, not necessary and unfair.

In a meeting of the Kenai River Special Management Area Advisory Board last week, Dave Goggia, vice president of the guide association, said it would “cost an awful lot” to put life jackets on boats for all clients — kids to 350-pound adults.

This from an organization that supported regulations requiring a switch from two-stroke to four-stroke motors on the river, despite the multiple thousands of dollars it costs to upgrade to a four-stroke. The guide association also didn’t complain about the costs involved in switching motors from 35 horsepower to 50 hp when that regulation went into effect. Yet the one-time expense of buying type III PFDs, which will last for years to come, is an onerous economic burden?

The Coast Guard already requires guides — and everyone else on the river — to carry type I PFDs, so some guides may already have the more substantial type III PFDs onboard. If they don’t, Trustworthy Hardware sells type III life jackets for about $50 a pop. If individual guides don’t want to buy enough PFDs on their own to supply whatever size clients they may get, then pool resources. Guides could maintain a stockpile of multiple sizes of PFDs to use to outfit clients, like the rafting companies on the upper Kenai do. When clients book trips — which is typically well in advance, so short notice is no excuse — have them specify what size PFD they’ll need.

Guides may be nervous about how the Lower 48’s economic crisis will affect business this summer, and rightfully so. If buying life jackets really does put that much crimp in a guide’s economic outlook, then do like most businesses and pass the cost on to clients. Adding just $2 onto the cost of a charter would recoup the cost of a $50 life jacket in 25 trips. Since most guides make two trips a day with multiple clients onboard, it would balance out in no time. And if an extra $2 is the breaking point between whether a client books a trip or not, guides have much bigger problems than PFDs to worry about this summer.

Goggia also argued that requiring clients to wear type III PFDs isn’t necessary. “We try to ensure safety on the river and we’re all about trying to be safe, but we don’t want to overdo it,” he was quoted as saying in the Peninsula Clarion.

Overdo it? How is wearing a suitable PFD overdoing it? Especially when there are kids and elderly passengers in the boats. It’s a good idea, even if the stipulation gets watered down to just requiring clients to wear type I life jackets. For healthy, fit adults wearing a proper PFD, a dunk in the glacial-fed, fast-moving waters of the Kenai is life threatening. Without one, it can easily be disastrous.

But the guides are being singled out, Goggia said. That much is true, but it’s not unreasonable for Parks to do so. As Jack Sinclair, area Parks superintendent, points out, Kenai River guides are the leaders in the industry. They set standards for everyone else. With guides leading the way in ensuring a higher level of safety on the river, it will pave the way for others to follow their example.

That should be a role guides aspire to, not bail on.

Science of the seasons: Many factors affect lake ice formation, thickness

As air temperatures descended this fall, most lakes became covered with a layer of ice.

Shallow lakes, with lots of surface area compared to the volume, froze first, and some very shallow lakes or ponds freeze all the way to the bottom. At the other end of the size spectrum, those lakes with large volumes and great depths, like Kenai, Skilak, Hidden and Tustumena lakes, are the last to freeze.

The reason for slower ice formation is due to the huge amount of heat loss that must occur before ice is formed. A basic property of water is that it takes a lot of heat loss — one calorie per gram of water — to cause a reduction of 1 degree Celsius. Then it takes even more heat loss — 80 calories per gram of water — to get ice to form after the water has already reached zero degrees Celsius.

In order for a lake to freeze, the entire water body, top to bottom, needs to drop down to 40 C. Another pivotal property of water that comes into play here is that water is most dense at 40 C, and thus it sinks to the bottom when it reaches that temperature. Water that is colder (or warmer) will be less dense and will remain above the deeper, 40 C water. Eventually, the entire lake will be at 40 C.

As the cold winter air on the surface causes the top layer of lake water to get colder yet, it becomes less dense and stays on top. Once it has gotten cold enough to freeze, it is 10 percent less dense than liquid water and, as we all know, ice floats. At that point, all the water underneath the ice is going to be 4 C or colder.

Initially, the formation of ice insulates the underlying lake water from further heat loss. However, heat is continually being lost from the ice. As ice loses heat, the underlying water freezes and ice forms on the bottom of the ice layer. It is not uncommon for ice to grow to 30 inches or more in lakes on the peninsula.

Lakes that have continued inflow of water after an ice cover has formed may have thinner ice cover in areas where groundwater seeps in or where stream water enters. Inflowing water will probably not be as cold as the lake water, so it will rise and possibly melt some of the overlaying ice. Even if the incoming water is colder than 40 C, it will stay on the top of the lake and may still cause some thinning of the overlaying ice. As careful ice skaters have known for a very long time, it is good to avoid those areas where water is still entering a lake.

As water enters and leaves a lake through normal input or drainage patterns, it can have an impact on the ice surface. Imagine a situation where water continues to enter the lake but the shallow outflow is blocked off with ice. The water level will rise imperceptibly and will push up on the ice. Since all lake ice covers have cracks, the rising pressure of extra water underneath can push liquid water through the cracks.

Water leaking through the fissures in the ice is referred to as overflow. When overflow occurs, unfrozen water sits on top of the ice. At times, overflow can be many inches deep. If there is no snow cover, the air will rapidly cool and freeze the newly exposed water. However, a thick snow cover acts as an efficient insulator and keeps the water from contact with the much colder air. Because of this insulating ability of snow cover, lake overflow may remain liquid for weeks at a time.

Ice cover on a lake can decrease the exchange of oxygen from the air into the water. Snow cover can reduce the amount of light reaching the lake bottom to virtually nothing, and very little oxygen-producing photosynthesis can occur.

Bacterial breakdown of dead plant materials on the lake bottom uses up much of the limited oxygen. By the end of winter, there can be very little oxygen left in the water. In some cases, there is so much oxygen depletion that the fish die. Shallower lakes are most often the ones with winter fish kills. Generally, lakes that are more than 15 feet deep can retain enough oxygen in the water to prevent overwinter fish kills.

Because there are so many variables — such as lake size, snow cover, incoming waters and variable air temperatures — that impact how fast ice forms, always check ice thickness before venturing onto the surface. This fall when prospecting for a lake to do some early ice fishing, I found one lake with a mere 4 inches of ice, and a lake less than half a mile away had more than 9 inches.

Have fun on the ice, but be careful the ice is thick enough for your intended use.

David Wartinbee, Ph.D, J.D., is a biology professor at Kenai Peninsula College’s Kenai River Campus. He is writing a series of columns on the ecology of the Kenai River watershed.

Blind sided — Flats duck hunters tangle with Parks over regulations

By Jenny Neyman
Redoubt Reporter

Steve Meyer has been fall duck hunting on the Kenai River Flats since he was a kid over 30 years ago, practicing his shots at communal duck blinds set up even before he ever set foot on the flats, and teaching his kids to do the same. Some seasons Meyer spends as many as 90 days hunting between September and December.

“I’m pretty avid, and frankly I don’t shoot that many ducks. I just love doing it,” Meyer said.

Meyer’s habits haven’t changed much over the years, but somewhere along the line the legality of them did. He and his fellow flats duck hunters have been informed that the blinds they’ve used for decades and much of the territory they shoot from is off limits, and has been for quite some time.

“It’s traditional. We’ve been doing this for as long as any of us can remember, hunting these areas, and there was never any problem. Now all of a sudden Parks decided they’re going to start enforcing something we weren’t even aware of,” Meyer said.

The Kenai River Flats are under the jurisdiction of the Alaska Division of Parks and Outdoor Recreation, managed locally by the Kenai River Special Management Area. Parks regulations stipulate no hunting within a half-mile of any developed structures on the flats — including homes, roads, parking lots and the Warren Ames Memorial Bridge — and no permanent structures.

That means the two blinds hunters have been using for decades had to go.

“Those blinds had been left alone all these years, they’d almost become community blinds. People took their kids out there, and they were fairly close and easy access, and all of a sudden this year they disappeared,” Meyer said.

The fact that the blinds had been there for so long without being torn down and replaced every time a hunter used them made them permanent structures, which aren’t allowed in state parks, said Jack Sinclair, area Parks superintendent. Perhaps the department could have done better in warning hunters the blinds were going to be removed, but the result would have been the same, he said.

“In the end we would have to have those out of there anyway. There wasn’t any way to compromise on that particular issue,” Sinclair said.

The issue of shooting boundaries may be negotiable, at least hunters hope it is.

The common practice on the flats is to keep a quarter-mile distance from structures when shooting.

“All the duck hunters that have been down there this year are kind of stunned that we’re not allowed to hunt down there anymore,” said Scott Miller, of Soldotna.

“Last year Parks started constricting where we could hunt. They were being very cordial about it, trying to inform us these areas we traditionally hunted out there were being closed down, not because they’d been open, but they’re starting to enforce the original KRSMA half-mile rule,” he said.

KRSMA took over management of the flats in 1985. The purpose of the half-mile restriction is to protect people and property along the flats. Hunters say that’s more space than necessary, and Meyer and others took a proposal to the KRSMA board Oct. 9 to request a change to a quarter-mile shooting restriction.

The 15 or so hunters making the request have a report on the lethality of shotguns used in waterfowl hunting showing they are safe beyond a quarter mile. They also found examples from around the Kenai Peninsula, state and country where a quarter-mile restriction is the norm for shotgun hunting, including Watson Lake on the Sterling flats, the Anchorage coastal area and Mendenhall Lake in Juneau.

Hunters asked Parks representatives if people living along the flats had complained about duck hunters over the years while they were operating on a quarter-mile boundary. They had not.

“We’re a pretty responsible group of people. They never had complaints, it just didn’t happen. We weren’t shooting up people’s houses or anything like that,” Meyer said.
So why is it a problem? And why now?

It’s a problem because the regulations stipulate a half-mile, Sinclair said.

“Now after all these years they have more money because of the oil (increased state revenue from high oil prices), they’re getting more enforcement officers down there,” Miller said.

The half-mile restriction cuts off prime hunting areas, including the major ponds many hunters like to frequent, Miller said. You either have to get a boat and float the river, or do like Meyer does and walk out beyond the KRSMA border about a mile and a quarter below the bridge.

“There’s essentially almost nowhere you can hunt from Eagle Rock down until you get way down on the flats,” Miller said.

The flats have been a favorite hunting spot for Miller’s family for decades. He’s hunted there with his dad, and his brother, Brian, has recently gotten into it. They’ve taught their kids to hunt, as well.

“It’s a fun, family thing, just kind of a nice area close to home. You can get out there on a weekend or evening or something and do a little duck hunting and fishing,” Miller said.

“We have all been kind of closed in down there because of development and we know we can’t hunt how we used to 20 years ago, but we still want to have an area to go,” he said. “We realize we’ve been restricted because of the housing, and that’s fine, but I’d like to see the areas that can be open, opened, because that’s not really a reason to shut down a traditional-use thing.”

Meyer said the flats are the best hunting spot close to town. Beyond that is the outlet of Skilak Lake, but that’s not ideal because fall rainbow trout fishermen can make it dangerous to hunt there.

“We’re just running out of places to go. It seems like it’s another stab at hunters, and Alaska’s supposed to be kind of about hunting. It’s just as traditional as any subsistence here, or any of the fishing that we have here,” Meyer said. “We’re kind of a minority, but people who want to hunt, that’s part of why we’re here. It may not seem like a big thing, but it’s just another one of those small segments that gets pulled away from people, and then it’s on to the next thing. It just gets a little concerning.”

Sinclair said there’s nothing he can do about the regulation — it has to go through the board process to be changed — but he hopes to see that happen by next hunting season.

“I think Parks realizes, at least I do, that there’s a need to have those kind of uses maintained on the river. I don’t think we’re trying to block that from happening,” Sinclair said.

Meyer said he’s going to stay involved in the process, in the hope that hunters’ traditional use of the flats becomes legal use once again.

“We’re certainly going to give it our best shot,” he said.

Cold feet don’t foul up ducks — Waterfowl have several strategies for keeping tootsies toasty during icy months

Throughout winter, many Alaskans participate in various outdoor activities like skiing, skating, snowshoeing, ice fishing and snowmachining. A common problem for all participants is keeping their feet warm. There are a variety of possible solutions for cold feet: waterproof and breathable boots, extra socks, highly insulated boots and even heat-generating chemical or electric warmers.

But what about the waterfowl that remain along the rivers and streams all winter? Do they make Bunny Boots for ducks?

There are several species of ducks, mergansers and even swans that frequent the Kenai River watershed all winter long. They can usually be found in or near open water sections because that is where they can feed and it provides them protection from terrestrial predators like fox, coyotes, wolves and lynx. Nonswimming ducks can be found standing or lying on ice for long periods of time and they do not freeze. What’s their secret?

Waterfowl actually allow their feet to get very cold, keeping them just above freezing temperatures. Since their feet contain mostly bones and tendons surrounded by thick skin, there isn’t a critical need for the feet to stay any warmer. All of the muscles moving the feet are in the upper legs, and they are maintained at normal body core temperatures of 102 to 106 degrees Fahrenheit.

If we immersed our feet in icy water for any length of time, our body core temperatures would drop drastically. Waterfowl do it all day long and are easily able to keep their core temperatures fairly steady. How?

Physiologically, waterfowl have a special blood vessel system at the start of their legs called a “counter current exchanger” that warms the blood returning from the feet. Cold venous blood coming from the feet runs very close to warm arterial vessels carrying blood toward the feet. The blood leaving the body is cooled and the returning blood is warmed. This way, very little heat is actually lost to the outside world from the feet.

While it might appear that their feet could actually freeze, the supplying arterial blood vessels can be dilated or constricted to allow just enough extra warm blood into the feet to keep them from actually freezing.

There are also several behaviors that these birds can use to help keep their feet warmer or to reduce body heat loss. One method is to stand on only one foot. When on one foot, the other can be tucked up close to the body and kept warm within the insulating feathers. If you observe this one-foot stance behavior, watch to see that they will periodically switch feet.

Another common behavior is for the waterfowl to rest completely on the ice with both feet tucked up into the breast feathers. Their breast plumage provides amazing insulation, and they are able to maintain their body temperatures while sleeping on the ice. Their heads and beaks can also be tucked under a wing or buried in the feathers to preheat the air they take in and to retain some of the heat they lose during respiration.

This superb insulating quality of waterfowl breast feathers is well known and used in popular winter clothing filled with duck or goose down. Perhaps the very first down jackets were made by a number of Alaska Native populations. Dozens of waterfowl breast skins were sewn together to make very warm winter coats. Examples of these bird-skin coats can be seen in a number of Alaska museums.

In the case of waterfowl, they really do have “cold feet and a warm heart.”

David Wartinbee, Ph.D, J.D., is a biology professor at Kenai Peninsula College’s Kenai River Campus. He is writing a series of columns on the biology of the Kenai River watershed.

Water works: Insects master submerged breathing

I remember as an elementary school student watching a classmate attempt to drown a grasshopper by holding its head under water. The grasshopper endured the insult long enough for the childish attention span to turn to some other endeavor, and the insect was released to swim another day.

While the grasshopper was in danger of being squeezed too hard and perhaps getting a bath it neither needed nor wanted, it was in absolutely no danger of drowning with its head under the water.

Insects take in their air by way of a special set of spiracles on the thorax and the abdominal segments. The many spiracular openings lead to a series of very fine, hollow tracheal tubules that repeatedly branch until they are about one micron in diameter (one micron equals 1/1,000,000 of a meter).

These very fine tubules are surrounded by insect hemolymph (insect blood) that can absorb oxygen from the tubules and give back carbon dioxide. In order to refresh the air in these tubules, insects simply stretch or move the abdominal segments. If you watch an insect for a while, it will periodically stretch the abdomen, much like you and I do when we elevate the chest and draw in a fresh breath of air.

So how do the many aquatic insects live completely under water if they use air-filled tracheal tubes for oxygen exchange? There are several interesting solutions to this problem. Many aquatic insects are so small that they are able to simply exchange gases from the water right through their thin exoskeleton.

Another approach can be found in several groups like the mayflies and caddisflies that have special gills as larvae. Some of these gills look like a miniature brush of fine tubes, while others resemble flattened footballs attached to each abdominal segment. These gills exchange gases that are then channeled into the tracheal tubes.

Mosquito larvae and some other dipteran (flies) larvae have a tiny tube that they extend above the water surface so they can take air directly into their tracheal tubes. This is like breathing through a straw while still completely submerged.

(While we now appreciate the damage that was done to our wetlands, this is why years ago oil was spread over swamps in attempts to control mosquitoes. The surface oil would plug up the mosquito respiratory structures and the larvae would die.)

The colder the water is, the more oxygen it can hold. Warm water, on the other hand, can hold much smaller amounts of oxygen. Most streams in Alaska are so cold that it is no hardship for insects to get all the oxygen they need. During the winter months, when the water is at its coldest, the insects are able to get all the oxygen they can use so they are very active feeding and growing.

In warmer waters the oxygen is limited so insects must resort to additional measures. Some insects use hemoglobin in their hemolymph that is the same bright red color as our blood. The insect hemoglobin, just like ours, helps hold onto oxygen and spread it throughout the insect body. In an effort to extract the limited oxygen from warm water, some insects flap their gills in the current to bring them in contact with more water. Yet others can undulate their bodies to create a current or even build little tubes that funnel water past their gills.

When these immature aquatic insects leave the water to become aerial adults, part of the emergence process involves shedding their gills. They then use the normal spiracular openings and tracheal systems for their breathing as adults. When we consider that many insects can fly nonstop for hours, the insect’s simple breathing system apparently works quite efficiently.

David Wartinbee, Ph.D, J.D., is a biology professor at Kenai Peninsula College’s Kenai River Campus. He is writing a series of columns on the biology of the Kenai River watershed.

Mosquitoes not gone for long

While we may have complained about an early cold snap this year, we certainly did not complain when the mosquitoes disappeared. But where are they now? Did the frost kill them all? And how do they reappear with the first couple warm days in the spring?

There are several dozen species of mosquitoes found in Alaska, and each of them has its own particular life cycle, although all of them are aquatic. Some prefer lakes, others ponds or various marshy habitats. Eggs are laid in the water and hatch out to become “wrigglers,” or larvae. Most of the larvae feed on algae or dead plant materials. They then form a pupa and shortly afterward emerge and become the aerial mosquitoes we love to hate.

The females usually mate and then look for a blood meal — and your arm looks like a great source of that blood. Note that only the females need a blood meal, so those buzzing around your head are all female mosquitoes.

When you and I swat at the mosquito that’s buzzing about, we probably don’t take the time to differentiate the particular species. But each species has its own approach to surviving the Alaska winters.

Many species overwinter as an egg that is laid in water during late summer or early fall. The egg remains underwater in a diapause state of inactivity until spring thaws. In the spring when water temperatures rise, the eggs hatch and the larvae feed voraciously. Within a week or so, they pupate and quickly become the aerial insects we know so well.

Another overwintering approach is for adults to find a safe hiding spot and wait out the cold of winter. Often these hiding spots are within leaf piles on the forest floor, in tree holes or under tree stumps. These areas, especially with a snow cover, provide insulation from the very coldest temperatures of winter.

An important goal for overwintering adults is to prevent ice crystal formation within their hemolymph (insect blood). First they reduce the amount of water in their hemolymph, kind of like concentrating their blood. Then they produce glycerol within the hemolymph, which acts as antifreeze. Now the adult is protected down to some pretty impressive temperatures. This activity is just like what we do to our automobile radiators each winter. However, if the temperatures around the adult fall below their protected temperature range, the adult will die. Very cold temperatures during a winter with minimal snow cover can reduce the spring population of early mosquitoes.

For overwintering adults, when the ambient temperatures rise in the spring, they are quickly able to leave the hiding place and seek out a blood meal. One particularly large Alaska mosquito uses this overwintering technique so well that it is called the “snow mosquito.” These are usually the first large mosquitoes we see flying around when there is still snow on the ground in early April.

While people are enjoying wintertime activities like skiing, snowmachining or ice fishing, beneath the snow and ice are mosquito adults or eggs, waiting for the return of warmer temperatures.


David Wartinbee, Ph.D, J.D., is a biology professor at Kenai Peninsula College’s Kenai River Campus. He is writing a series of columns on the biology of the Kenai River watershed.

Guest editorial — Mowing down reed canary grass

Why attack?

Reed canary grass is a non-native species that was intentionally planted on the Kenai Peninsula to control erosion. Unfortunately, the grass grows so well, even in the middle of rivers and streams, that it can cause the channel to narrow or dam up completely.

When this happens in salmon streams, loss of fish habitat can occur, along with the creation of barriers to spawning and migration.

Plan of attack

Since the reed canary grass that Kenai Watershed Forum is going after is located near salmon streams, spraying herbicide is not our first choice for getting rid of the grass.

Instead, black tarps will cover the grass to block out sunlight for several summers. In cases where the grass is growing in the channel of the river, the plant will be repeatedly mowed down below the water level in an effort to drown it.

Did we win?

While the grass is not yet waving a white flag, KWF made significant progress this summer at Jim’s Landing, Beaver Creek and Bing’s Landing. Still, there are over 250 known infestations of reed canary grass on the Kenai Peninsula, but most of them are less than an acre, making this an ideal time for control measures. If all goes well, next year’s battlegrounds will include Boat Launch Road and Slikok Creek.

Josselyn O’Connor is the membership coordinator and office manager with the Kenai Watershed Forum.

River watch: Leaves play vital role in health of salmon streams

Riparian vegetation includes the trees, shrubs and herbaceous plants that surround any stream. This vegetation is critically important for the Kenai River, Anchor River, Quartz Creek and most streams on the Kenai Peninsula. These plants provide dropped leaves, bud scales, twigs and even pollen grains that end up in the streams. This vegetable matter provides the energy that supports a majority of the aquatic insects and invertebrates that in turn are food for the fish populations of the receiving streams.

Leaves descend in a short but major pulse in the fall. If an average tree has close to 200,000 leaves, leaf fall can mean a huge organic material influx for the stream. These leaves are at first unusable by the insects until they are attacked by aquatic bacteria and fungi. A few days after inoculation by these bacteria and fungi, the protein content of the leaves actually rises and they become a favorite for a special group of insects. The nymphs and larvae of a couple species of stoneflies and craneflies will skeletonize the leaves and create large amounts of very fine particles that drift downstream. (We’ve all seen the nonbiting cranefly adults when we see a critter buzzing around that looks like a mosquito on steroids.)

These finely chopped-up leaves then become the food of choice for a great many aquatic insects found in these streams. The most common caddisfly in the Kenai River, Brachycentrus, sits on rocks in the stream and catches these fine particles with leg hairs. Some other caddisflies, like Arctopsyche, use specially spun underwater nets to trap the fine particles for their dinner. Many of the mayfly larvae, as well as a great many of the midges, use these leaf fragments as a major food item, too. Black fly larvae — we call the pesky adults “whitesocks” — have specially evolved antennal fans that are used to trap these chopped-up leaves as a major portion of their diet while in the larval stage. Additionally, there is a whole host of nearly microscopic invertebrates (many are related to shrimp) that also use these particles in our streams and rivers.

As every fly fisherman knows, these insects and invertebrates are a major source of food for the resident fish. So, we tempt rainbows, grayling and even lake trout with our fur and feather mimics of these insect larvae and adults. Less widely known is the reliance of our young salmon fry on the smallest of the invertebrates and insects. The more insects our salmon fry can eat, the bigger they will be and the greater their survival will be when they head out to the ocean.

It has been shown that streams with hefty riparian input will support large insect populations and in turn a large population of salmon and trout. The Kuparuk River on the North Slope has almost no riparian input and has very few insects that support only a very small population of grayling. Riparian input each year plays a major role in the overall food chain for our resident fish and the temporary salmon found in our peninsula streams.

There are federal- and state-mandated building and logging setbacks from streams and rivers for very good reasons. Obviously, we don’t want our structures to suffer flood damage and we don’t want our close proximity to the stream to be a source of stream pollution, either. However, the stream’s need for the leaf input each fall is often overlooked, even though these leaves are an important energy engine that fuels the stream and the fish populations. The take-home message is to preserve the riparian vegetation along all of our streams.


David Wartinbee, Ph.D, J.D., is a biology professor at Kenai Peninsula College’s Kenai River Campus. He is writing a series of columns on the biology of the Kenai River.

Die and let live — Cycle of salmon spawning serves valuable purpose on Kenai River

One of the mysteries that has vexed stream ecologists for years involves large Pacific salmon that return from the oceans to spawn in headwater streams and promptly die. Very few fish grow this large and only reproduce once during their lifetime. As an example, halibut can reproduce for decades in the ocean, and many freshwater trout species will reproduce each year for dozens of years.

Evolutionary theories predict that for such an unusual behavior to exist, there must be a benefit to the species when the adults die. Wouldn’t it be better for the adults to survive and reproduce multiple times? The mystery is becoming clearer these days, thanks to stream and fisheries researchers from all over the country and throughout the world.

First, it must be understood that most streams along the Pacific Coast are nutrient-poor. This means that there are not high concentrations of minerals and essential elements in the waters that would support plant and algal growth. In turn, there is only marginal plant growth along and within the stream. The in-stream and riparian (located along the stream banks) plant growth can normally support only small populations of invertebrates that then become food for stream fish. Because of this nutrient-poor stream water situation, salmon have evolved an anadromous life cycle.

Anadromous fish lay their eggs in a stream that cannot actually provide adequate sustenance for their offspring, so the young soon migrate into the oceans to complete their growth. The surrounding oceans are nutrient-rich and provide great opportunities for young fish to find food. As an example, many Alaska silver salmon stay in headwater streams for three years and grow to only 6 inches in length.

They then head to the ocean and return to spawn one year later weighing 10 to 16 pounds. They obviously found a lot of food out in the ocean that they could not have found in the stream where they were hatched.

Since the streams are so nutrient-poor, it now appears that the dying adult salmon carcasses release substantial amounts of elements into the stream. Those nutrients, like the fertilizer we use on our gardens, enable in-stream vegetation and riparian plants to thrive. Those plants then deposit their leaves, twigs, bud scales, pollen, etc., back into the stream. In turn the leaves are used as food sources by various aquatic invertebrates — mostly aquatic insects. The insect populations are then able to grow large enough to support the resident fish and the newly hatched salmon fry.

There has been considerable research on these nutrients using what are called stable isotopes. We know the oceans provide higher concentrations of Nitrogen-15 while atmospheric-captured nitrogen is mostly Nitrogen-14. By looking at the nitrogen isotopes found in riparian vegetation and plants near Alaska salmon streams, we now know that a considerable amount of nutrients in these plants came from the ocean and arrived there as part of salmon tissues.

So, the dead salmon along a stream are providing nutrients for plants that will in turn provide nutrition for the food of the young salmon — a complicated but effective circle of nutrients from adult salmon back to juvenile salmon.

The next time you see a grotesque fish carcass along a stream, remember that it is providing food for its young just as any good parent would do.

David Wartinbee, Ph.D, J.D., is a biology professor at Kenai Peninsula College’s Kenai River Campus. E-mail your science questions to redoubtreporter @alaska.net.