Karluk Lake Research Articles

A History of Sockeye Salmon Research, Karluk River System, Alaska, 1880–2010. By Richard Gard and Richard Lee Bottorff

Over 130 years of research on Sockeye Salmon Oncorhynchus nerka in the Karluk River and Lake system on Kodiak Island, Alaska, is presented by authors Richard Gard and Richard Bottorff in this schol...

Relocations of Earthquakes (1899–1917) in South-Central Alaska

I have relocated 18 earthquakes occurring in the south-central Alaska region between 1899 and 1917 using a bootstrap relocation technique. Locations of events within the Yakutat region suggest that the 1899 sequence began on 4 September with a MS = 7.9 event within the area of the Pamplona fault zone/western Transition fault zone, rupturing the western portion of the North American/Pacific plate interface. A MS = 7.4 event on 10 September appears to have ruptured the offshore portion of the plate interface to the east of the 4 September event. This was followed by a MS = 8.0 event that likely ruptured the onshore and down-dip portion of the plate interface. A MS = 7.0 event in 1908 may have ruptured a small portion of the plate interface between the 4 September and 10 September events. Events occurring between 1911 and 1916 in the Prince William Sound region appear to be slab events occurring in similar locations to more recent seismicity. Within the Kodiak region the 1900 earthquake of MS = 7.7 has a location consistent with the rupture of the Kodiak asperity which also ruptured during the 1964 great Alaska earthquake. Other large magnitude Kodiak events appear to be associated with regions of recent seismicity, including the Karluk Lake area of southwestern Kodiak Island and the Albatross Basin located offshore southeast of Kodiak Island. Space-time seismicity patterns since 1899 indicate that magnitude 6 to7 events have occurred with regularity in the Kodiak Island region; that there has been a lack of magnitude ≥ 6 events in the Prince William Sound region since 1964, and that the Yakutat region has remained notably quiescent at the magnitude ≥ 6 level.

Diatoms and sockeye salmon ( Oncorhynchus nerka ) population dynamics: Reconstructions of salmon-derived nutrients over the past 2,200 years in two lakes from Kodiak Island, Alaska

The return of hundreds to millions of adult sockeye salmon (Oncorhynchus nerka), which have returned from the ocean to their natal nursery lake environment to spawn, can result in significant nutrient loading. By analyzing sedimentary diatom assemblages from nursery lakes, we demonstrated that a salmon-derived nutrient signal could be traced over time and be used to infer past sockeye salmon population dynamics. We conducted a ∼2,200 year paleolimnological study of two Alaskan sockeye salmon nursery lakes, Karluk and Frazer lakes. The two lakes are very similar, except that sockeye salmon were only introduced into Frazer Lake in 1951 (first spawners returned in 1956). In both lakes we found a strong correspondence between diatom assemblages and the number of adult salmon spawners recorded in the historical data (∼40 and 70 years for Frazer and Karluk lakes, respectively). Given this robust relationship, we then used our analyses of diatoms from Karluk Lake over the past ∼2,200 years to gain insight into salmon-derived nutrient loading changes (which are directly related to the number of sockeye salmon spawners). The diatom record from Karluk Lake recorded dramatic species changes on both decadal and century timescales, and was strongly correlated with an independent indicator of sockeye salmon abundances, δ15N. Together, these data suggest pronounced variability in sockeye salmon abundances at Karluk Lake over the past ∼2,200 years. The direct impacts of regional environmental variability were not likely responsible for the patterns apparent in Karluk Lake, as the diatom and δ15N profiles from Frazer Lake were relatively stable prior to the introduction of sockeye salmon. Application of total phosphorus transfer functions to the Karluk and Frazer lakes' diatom records revealed that sockeye salmon carcasses substantially increased the trophic status in these lakes, which has important implications for the health of juvenile salmon that rear in nursery lakes. Overall, this paper illustrates the potential use of diatoms in reconstructing past sockeye salmon population dynamics, which in turn can lead to a greater understanding of the mechanisms influencing abundances of sockeye salmon.

Differential responses of zooplankton populations ( Bosmina longirostris ) to fish predation and nutrient-loading in an introduced and a natural sockeye salmon nursery lake on Kodiak Island, Alaska, USA

Stratigraphic changes in the remains of Bosmina longirostris from a lake with an introduced sockeye salmon population and a lake with a natural salmon run on Kodiak Island demonstrated markedly different responses to past fluctuations in salmon populations. In both lakes, there was a positive correlation between the density of Bosmina microfossils and the abundance of sockeye salmon. However, opposite size trends were observed in the two lakes. In Karluk Lake, which has a native sockeye salmon population, Bosmina mean carapace lengths were largest at high salmon densities, and mean mucro and antennule lengths were also large, suggesting strong predation pressure from cyclopoid copepods, and less intense pressure from juvenile sockeye salmon. As salmon-derived nutrients are important in driving primary productivity in this system, changes in zooplankton productivity track salmon escapement, but grazing pressure on Bosmina from juvenile salmon is less important than that from cyclopoid copepods. In Frazer Lake, a lake with an introduced salmon population, Bosmina morphologies were smallest during periods of high sockeye salmon in the lake, suggesting much stronger predation effects from sockeye salmon due to the suppression of Cyclops columbianus. Latent development of compensatory mechanisms and the delayed recovery of copepod populations to salmon introductions has resulted in zooplankton populations that are still recovering from shifts in fish populations that occurred decades earlier. The differential response of Bosmina populations between the natural and manipulated lakes suggests that care must be taken when attempting to extrapolate results from whole-lake manipulations and short-term experiments to natural systems.

Seismic Response of the Katmai Volcanoes to the 6 December 1999 Magnitude 7.0 Karluk Lake Earthquake, Alaska

A sudden increase in earthquake activity was observed beneath volcanoes in the Katmai area on the Alaska Peninsula immediately following the 6 December 1999 magnitude ( M W) 7.0 Karluk Lake earthquake beneath southern Kodiak Island, Alaska. The observed increase in earthquake activity consisted of small ( M L < 1.3), shallow ( Z < 5.0 km) events. These earthquakes were located beneath Mount Martin, Mount Mageik, Trident Volcano, and the Katmai caldera and began within the coda of the Karluk Lake mainshock. All of these earthquakes occurred in areas and magnitude ranges that are typical for the background seismicity observed in the Katmai area. Seismicity rates returned to background levels 8 to 13 hours after the Karluk Lake mainshock. The close temporal relationship with the Karluk Lake mainshock, the onset of activity within the mainshock coda, and the simultaneous increase beneath four separate volcanic centers all suggest these earthquakes were remotely triggered. Modeling of the Coulomb stress changes from the mainshock for optimally oriented faults suggests negligible change in static stress beneath the Katmai volcanoes. This result favors models that involve dynamic stresses as the mechanism for triggered seismicity at Katmai.

Genetic contribution of three introduced life history forms of sockeye salmon to colonization of Frazer Lake, Alaska

Colonization of Frazer Lake (Kodiak Island, Alaska) by sockeye salmon (Oncorhynchus nerka) represents a rare, successful introduction of this species into a new environment. Eggs, fry, and adults were introduced repeatedly into Frazer Lake from 1951 to 1971. Donors originated from three source populations, each with different life histories: late-run lake shoreline spawners (Karluk Lake), early-run inlet tributary spawners (Red Lake), and late-run lake outlet spawners (Ruth Lake). We used six nuclear DNA (nDNA) microsatellite loci and mitochondrial DNA (mtDNA) to determine which donor population(s) had colonized the principal spawning habitats of Frazer Lake: three shoreline areas and four inlet tributaries. Based on nDNA comparisons, two shoreline-spawning populations were most similar to the shoreline donor, and the four tributary-spawning populations were most similar to the tributary donor. However, five of the seven Frazer Lake populations appeared to be influenced genetically by more than one donor. Genetic distances based on mtDNA were independent of life histories with high (relative to nDNA) interpopulation variation, suggesting significant female founder effects and poststocking drift. Our data suggest that life history adaptations of donor populations were critically important for successful colonization of Frazer Lake, thus underscoring the need to consider life history traits in other introduction and recovery programs.

Genetic contribution of three introduced life history forms of sockeye salmon to colonization of Frazer Lake, Alaska

Colonization of Frazer Lake (Kodiak Island, Alaska) by sockeye salmon (Oncorhynchus nerka) represents a rare, successful introduction of this species into a new environment. Eggs, fry, and adults were introduced repeatedly into Frazer Lake from 1951 to 1971. Donors originated from three source populations, each with different life histories: late-run lake shoreline spawners (Karluk Lake), early-run inlet tributary spawners (Red Lake), and late-run lake outlet spawners (Ruth Lake). We used six nuclear DNA (nDNA) microsatellite loci and mitochondrial DNA (mtDNA) to determine which donor population(s) had colonized the principal spawning habitats of Frazer Lake: three shoreline areas and four inlet tributaries. Based on nDNA comparisons, two shoreline-spawning populations were most similar to the shoreline donor, and the four tributary-spawning populations were most similar to the tributary donor. However, five of the seven Frazer Lake populations appeared to be influenced genetically by more than one donor....

Influence of Carcass-Derived Nutrients on Sockeye Salmon Productivity of Karluk Lake, Alaska: Importance in the Assessment of an Escapement Goal

Abstract The fishery for Karluk Lake (Kodiak Island, Alaska) sockeye salmon Oncorhynchus nerka has undergone a period of high production (1920s to mid-1940s), decline (mid-1940s to late 1970s), and recovery (late 1970s to present). We evaluated historical spawner–recruit data and recent (1980–1994) limnological data to develop an escapement goal (EG) to provide maximum sustainable yield for sockeye salmon. Ricker analysis of the spawner–recruit data explained only a small proportion of the total variation (r 2 = 0.17) in log e recruit/spawner (R/S) and exhibited a significant first-order autocorrelation (r 1 = 0.68; P < 0.0001). Ricker time–polynomial regression exhibited no significant residual autocorrelation, explained 71% of the variation in log e R/S, and indicated that intrinsic productivity (α parameter) has remained fairly constant, whereas system capacity (β parameter) has been temporally unstable. Markov transition probabilities indicated that escapements between 0.8 and 1.0 million fish maximiz...

A quantitative investigation of shape variation in Didymosphenia (Lyngbye) M. Schmidt (Bacillariophyta)

Abstract We investigated populations of the diatom genus Didymosphenia from Lake Baikal, two localities in China, in Lake Karluk, Alaska, and in Lake Superior using quantitative shape analysis. Four different taxa were distinguished in the Lake Baikal material, two belonging to recognized species, and two of uncertain affinities. All populations from Lake Baikal were characterized by a common developmental trajectory, different from populations from other localities. All populations except those from Karluk Lake and Lake Superior could be distinguished from one another with a high degree of confidence on the basis of shape alone.

Comparative catches and food habits of dolly varden and arctic charrs, Salvelinus malma and S. alpinus, at Karluk, Alaska, in 1939?1941

For many years the seriousness of the predations of dolly varden (Salvelinus malma) upon the eggs, alevins and juveniles of Pacific salmons (Oncorhynchus) has been a controversial subject. Over $ 300,000 was spent in Western Alaska from 1920 to 1941 for bounties on dolly varden in the belief that they were serious salmon predators. The writter undertook this study because of an intense desire to evaluate the need and justification for such a bounty system. The incidental examination of stomach contents of charrs which were captured for tagging or for tag recovery purposes from Karluk Lake and Karluk River on Kodiak Island, Alaska, and from Shelikof Strait and Uyak Bay during the summer months of 1939, 1940 and 1941 presented an excellent opportunity to pursue such a project. Stomachs were collected and contents analyzed from 1,992 arctic charr (Salvelinus alpinus) and 2,565 dolly varden charr (Salvelinus malma), taken by beach seine, gill net, fyke net, hook and line and by weir trap from Karluk Lake; from 956 dolly varden taken by seine and weir trap from the Karluk River; and from 462 dolly varden taken by beach seine and commercial salmon traps in Uyak Bay. Among the more than 5,000 charr stomachs examined, only 42 were found to contain salmon smolts, parr or alevin. Examination of 500 stomachs taken from dolly varden charr captured in the lower Karluk River at the height of the red salmon (Oncorhynchus nerka) smolt migration in May of 1939 revealed very little evidence of predation on the smolts in fresh water. There was some evidence that this relationship may have changed after the migrating charr had become adjusted to salt water, although the examination of 460 stomachs of dolly varden captured in salt water revealed nothing particularly incriminating in its role as a salmon predator. The fact that the downstream migration of the dolly varden reached its peak before that of the red salmon smolts was considered significant. Examination of the 4,500 charr stomachs at Karluk Lake in the months from April through September led to the discovery that two distinct species of charrs were present, one, the dolly varden, primarily stream-inhabiting and anadromous, and the other, the arctic charr, primarily lake-inhabiting and nonanadromous. Although red salmon eggs constituted 32% of the total volume of food ingested by both species of charr at Karluk Lake, there was considerable evidence that they were consumed in salvage or scavenger feeding, and there was practically no evidence that they were consumed as a result of predatory feeding. Only five, or one-tenth of one percent, of the thousands of charr stomachs examined at Karluk Lake contained red salmon parr or alevin.

Brown Bear Movements and Habitat Use at Karluk Lake, Kodiak Island

Brown Bear Movements and Habitat Use at Karluk Lake, Kodiak Island

Travel Time and Influencing Factors for Migrating Adult Sockeye Salmon in Karluk River, Alaska

Travel time of adult sockeye salmon (Oncorhynchus nerka) through the Karluk River, Alaska, was determined from fish tagged with Petersen disks about 2 miles (3 km) inside the river mouth and timed as they reached a weir at Karluk Lake, 21 miles (34 km) upstream. Migration time to the weir averaged 7 days for spring run and l0 days for fall run fish. The influence of three factors on travel time was determined by multiple regression analysis. Most important was time of season, followed by number of fish and rainfall.

Brown Bear Predation on Sockeye Salmon at Karluk Lake, Alaska

Effects of predation by brown bears ( Ursus arctos ) on sockeye salmon ( Oncorhynchus nerka ) were studied at Grassy Point Creek, a tributary o£ Karluk Lake on Kodiak Island, Alaska, during the summers of 1964 and 1965. In 1964 bears were allowed free access to the stream, but iIl 1965 an attempt was made to exclude them with an electric fence. Bears were efficient predators in the stream, killing up to 79 percent of the salmon in 1964; hoSwever, only 9.6 percent of the dead females sampled were unspawned bear-killed fish. The maximum estimate of eggs lost to bear predatioln in 1964 was about 1 million, compared with a total lo,ss, from all causes, of 8 million potential eggs. As a result of certain behavioral patterns of sockeye salmon, bears usually take spawned-out rather than unspawned females. The ratio of males to females in each year's escapement approached 1:1; the ratio among bear kills was about 3:2. Males acted as a buffer against predatiojn on females. The fence reduced bear predation by two-thirds. It is concluded that bear predation has little adverse effect o!n the production of sockeye salmon. salmon began in 1882; the fishery developed rapidly until about 1907, after which it began a long irregular decline ( Fig. 2 ) . From 1888 to 1907, the annual run averaged about 3.4 million fish; but after 1P7 the runs generally decreased, and from 1946 to 196S, averaged only 0.7 million fish annually. Since l924, when the White Act was prassed ( legislation providing for an escapement of at least SO percent of each year's run to salmon streams in Alaska ), most of the escapements to the Karluk system were of this magnitude, but the numbers of salmon in the runs continued to

Structure and Distribution of a Kodiak Bear Population

Population characteristics of the Kodiak bear (Ursus middendorffi) were investigated in the Karluk Lake drainage, a 96-square-mile area within the Kodiak National Wildlife Refuge. The drainage contained 160 bears, for a density of 1 bear per 0.6 square mile, although some areas attained concentrations of 10 bears per square mile. The mean litter size for cubs was 2.36 and 2.17 for yearlings. Age-class percentages were: cubs, 26; yearlings, 22; 2 years, 17; 3 years, 10; and bears 4 years old and over, 25 percent. The sex ratio was relatively even in the younger age-groups, but in adults, females constituted 78 percent. This was attributed to selective hunting for larger males. This study was conducted to obtain information about various population characteristics of the Kodiak bear. It was one phase of a long-term investigation presently underway in the Kodiak National Wildlife Refuge in Alaska. The data, needed as a basis for managing bears hunted for trophy purposes, were obtained during the period 1954-62. DESCRIPTION OF THE STUDY AREA The study area, encompassing 96 square miles, included all of the Karluk Lake drainage except the Karluk River, which drains the system and flows 20 miles before entering Shelikof Strait. Karluk Lake, 12 miles long and 1-2 miles wide, is fed by two smaller lakes and numerous streams (Fig. 1). Red salmon (Oncorhynchus nerka) spawn in the water system during summer and fall months. The study area, with the exception of the northern and southern extremities, is surrounded by mountains 1,0003,500 feet in elevation. Mild temperatures and a mean annual precipitation of 60 inches promote vigorous plant growth. A large portion of the drainage is covered by dense thickets of alder (Alnus crispa), willow (Salix spp.), and elderberry (Sambucus racemosa pubens). These thickets are interspersed with meadows containing grasses, sedges, and fireweed (Epilobium angustifolium). Intermittent groves of black cottonwood (Populus trichocarpa) are found along streams and lakeshores, and plants associated with the alpine zone occur on mountaintops.

Tributary Homing of Sockeye Salmon at Brooks and Karluk Lakes, Alaska

The degree of preference of sockeye salmon (Oncorhynchus nerka) for spawning in specific tributaries to Brooks and Karluk Lakes, Alaska, was studied in 1960 and 1961. Adult sockeye salmon begin to congregate around stream mouths soon after entering these lakes. At Brooks Lake, groups of fish were seined from various stream mouths and marked with distinctive tag color combinations. One group of tagged fish from each seine haul was released back into the original donor congregation as a control, and one or more groups were transported and released into congregations around other tributary mouths. Strength of tributary preference was determined by comparing the number of fish from each group distributed on the various spawning grounds. Eighty-three per cent of the 958 fish tagged were recovered at weirs and on stream and lake surveys. Distribution to spawning areas of sockeye salmon in control and transported groups was virtually identical. The study at Brooks Lake was followed by a study at Karluk Lake to explore further the strength of tributary preference. Very few sockeye salmon experimentally prevented from entering their preferred tributary chose an alternative spawning area. Most continued to attempt to enter their blocked tributary until death. A final study at Karluk Lake confirmed the fact that sockeye salmon entering the lake were predisposed to spawn in a particular tributary and could not be conditioned to enter an alternative tributary. We conclude that sockeye salmon are indeed homing to particular tributaries in these small lakes. The biological and management implications of these findings are discussed.

Live-Trapping and Handling of Brown Bears

A paucity of life history information on bears has encouraged biologists to test live-trapping techniques. Erickson (1957) and Black (1958) have reported on methods used on black bears (Ursus americanus) in Michigan and New York. In Yellowstone National Park, Craighead, et al. (1960) have developed methods for handling grizzly bears (Ursus horribilis). This paper deals with the methods employed to live-trap brown bears (Ursus middendorffii) on the Kodiak National Wildlife Refuge in Alaska. This study was conducted in the Karluk Lake drainage. Red salmon (Oncorhynchus nerka) spawn in the lakes and tributaries in summer and fall months. Since salmon are an important food item for brown bears, they concentrate along streams and lake shores during this period and may be successfully trapped. Travel within the study area was by foot and boat as no roads exist on the refuge. Investigations were conducted in the summers of 1957 through 1961.

Notes on the Phytoplankton of Karluk Lake, Kodiak Island, Alaska

Notes on the Phytoplankton of Karluk Lake, Kodiak Island, Alaska

Adult Brown Bears Climb Trees

On July 26, 1956, while counting spawning salmon on Salmon Creek, a tributary of Karluk Lake, Kodiak Island, the writer and two other Fish and Wildlife Service employees were startled to find an adult female brown bear (Ursus middendorffi) watching us from a large cottonwood tree. The bear was 10 feet up on the first limb, leaning against the trunk. Twenty feet above her was a young cub of about 80 pounds. The author stopped to photograph the bear and it then came down the trunk headfirst in a threatening rush and into the brush on our side of the stream. When we attempted to cross the stream the bear again charged, this time directly downstream with threatening growls and coughing noises. As we retreated, the bear stopped and returned to the base of the tree, where we lost sight of her. On a subsequent visit to the...

Mammals Collected in the Karluk Lake Region, Kodiak Island, Alaska

Mammals Collected in the Karluk Lake Region, Kodiak Island, Alaska

Freshwater Algae of Alaska 2. Some New Forms from the Plankton of Karluk Lake

Freshwater Algae of Alaska 2. Some New Forms from the Plankton of Karluk Lake