• Activity patterns of moose on the Kenai Peninsula, Alaska, as influenced by season and food availability

      Bevins, John S. (1989-09)
      Research was conducted at the Moose Research Center, Kenai Peninsula, Alaska, to determine activity patterns and budgets of moose. Mercury tip-switch transmitters mounted on the lower foreleg of moose and a computerized data acquisition system were tested for remote monitoring of moose activity. The activities of 2 adult female moose within each of 4 2.6 km² enclosures were monitored from mid-December 1985 through early April 1986. Comparisons were made between activities of moose in enclosures with differing levels of deciduous browse. No significant difference could be demonstrated in activity level among animals in different enclosures. Although the amount of forage varied, all enclosures appeared to provide poor winter habitat for moose. Seven moose monitored in the enclosures from June through August 1986 were significantly more active than during winter, due to shorter mean resting bouts during summer. There was no difference in mean active bout length between seasons.
    • An age structured model for assessment and management of Copper River chinook salmon

      Savereide, James W. (2001-08)
      Chinook salmon in Alaska support human uses through a variety of fisheries. Age-structured assessment models are rarely used for estimating the abundance of exploited stocks. This thesis develops a model for the Copper River chinook salmon population to show its advantages over typical assessment models. Information consists of catch-age data from three fisheries (commercial, recreational, subsistence), and two sources of auxiliary data (escapement index, spawner-recruit relationship). Four approaches utilizing different information sources are explored. Results suggest that an approach utilizing pooled catch-age data with time-varying brood-year proportions produces the best estimates, although retrospective and sensitivity analyses suggest that all four approaches explored are robust. The model should assist managers when making management decisions, because it integrates all sources of information, accounts for uncertainty, and provides estimates of optimal escapement. The model shows promise as a method for assessing and forecasting chinook salmon populations.
    • Application of decision analysis in the evaluation of recreational fishery management problems

      Merritt, Margaret Faye; Reynolds, James B.; Criddle, Keith R. (1995)
      Fisheries management is a decision-making process, yet typically formal decision analysis techniques are not used in structuring problems, quantifying interactions, or arriving at a prioritized solution. Decision analysis tools are applied in the decision-making process for Alaska's recreational fisheries management as a means to reduce risk in management at the policy (Chapter 2) and field (Chapter 3) levels. In Chapter 2 the analytic hierarchy process is applied to the recreational fishery for chinook salmon (Oncorhynchus tshawytscha) in the Kenai River. Model structure is developed through an iterative interview process involving individuals asked to represent the perspectives of 15 different stakeholders. Individual stakeholder judgments are combined using a geometric mean, and maximax and maximin criteria. The sensitivity of the results to under-representation is explored through various models. Despise the contentious differences of perspective represented among stakeholders, the analytic hierarchy process identifies management options that enjoy broad support and limited opposition. In Chapter 3 decision analysis is applied to the recreational spear fishery for humpback whitefish (Coregonus pidschian) in the Chatanika River. A modified form of catch-age analysis is used to combine information derived from creel surveys and run age composition with auxiliary information in the form of mark-recapture estimates of abundance. Four systems are used in weighting annual observations: prior beliefs regarding their reliability, by the inverses of their variances, through a combination of these two weighting schemes, and equal (no) weights. The perception-weighted model generates the most reasonable estimates of abundance, which are relatively precise and associated with small bias. Forecasts of mature exploitable abundance are calculated based on various recruitment scenarios, maturity schedules, and exploitation rates. From these outcomes, the odds of stock abundance occurring below a threshold level are presented. By applying decision analysis methodologies which incorporate judgments and perceptions into decision-making affecting fisheries, sensitivity to uncertain information is made explicit, components of the problem are structured, interactions among components of the problem are quantified, and options are prioritized, thus increasing the chances of finding an optimal solution.
    • Application of molecular markers to mixed-stock analysis of Yukon River fall chum salmon

      Flannery, Blair G. (2004-05)
      Country of origin provides the basis for allocating harvests of Yukon River chum salmon. The genetic divergence among Yukon River chum salmon populations adjacent to the international border as revealed by allozyme and micro satellite variation is insufficient to determine the country of origin of returning fish using mixed-stock analysis (MSA). Consequently, we investigated the resolution provided by alternative genetic markers in an attempt to detect levels of divergence that would be sufficient for MSA. We analyzed 10 Yukon River chum salmon populations for variation at 30 variable amplified fragment length polymorphism (AFLP) loci and for mitochondrial DNA (mtDNA) restriction site variation. We assessed these markers for their utility in MSA and, for mtDNA, phylogeographic analysis. The AFLP results show that MSA was most successful when mixtures were allocated to regions. The AFLP data were able to provide improved country of origin MSA estimates for the border populations with a 6.5% improvement for the Canadian populations over micro satellite analysis. No divergence in mtDNA haplotype frequency distributions was detected (P>0.05) within the Yukon River. Lack of mtDNA divergence likely resulted from a Pleistocene bottleneck that led to panmixia of the mtDNA genome.
    • Aquatic community responses to stream restoration: effects of wood and salmon analog additions

      Martin, Aaron Eugene (2007-08)
      Many aquatic ecosystems in the Pacific Northwest have been impacted by land use activities. Often these impacts have resulted in deleterious effects that directly or indirectly limited the capacity of habitat to produce fish. Habitat restoration potentially increases the quantity and quality of resources available to the aquatic communities within these impaired systems, thus increasing biotic integrity and fish production. In this study, responses of aquatic communities exposed to woody debris bundle and salmon analog additions were measured in the year following creation of off-channel, fish habitat in southcentral Alaska. Biofilm, invertebrates and juvenile coho salmon, Oncorhynchus kisutch, were sampled in four treatment types (control, wood, analog, and analog+wood). Biofilm significantly increased in analog enriched treatments. No treatment effects were detected in benthic invertebrate responses, however, treatment differences were detected in coho diets. Coho density and standing stock were significantly higher in the wood treatment, and coho in the control treatment showed signs of density-dependent limitations. Condition for fish was highest in the analog enriched treatments after treatment additions. These results suggest salmon analog and woody debris bundle additions may be viable short-term restoration tools, providing a boost in food and shelter for aquatic communities in habitats undergoing restoration.
    • Aspects of red squirrel (Tamiasciurus Hudsonicus) population ecology in interior Alaska

      Krasnowski, Paul Vincent (1969-05)
      Red squirrel (Tamiasciurus hudsonicus preblei) population ecology was investigated in a field study conducted between 21 September 1967 and 30 October 1968 near College, Alaska. Population density on the 21 ha study area was one squirrel per 1.1 ha during the spring 1968 and one per 1.2 ha during the fall 1968. Territoriality appears to be somewhat relaxed during the spring, and there are non-territorial squirrels present at that time. Young of the year squirrels can be distinguished from adults, at least through October, according to the degree of closure of the epiphyses of the radius and ulna. Immature males can be distinguished from adults on the basis of testis weight during the fall. Immature squirrels constituted 57.1% of the population sample during the fall 1967 and 51.3% during the fall 1968. Males formed 66.7% of the sample of adults and 64.0% of the sample of immature squirrels. Males were not significantly heavier or larger than females. Mean tail length of immature squirrels exceeded that of adults. Fall molt commences for all red squirrels during late August and September. The spring molt commences for females during March, whereas males do not molt until May. Testes measurements and female reproductive condition indicate that there is a single annual reproductive season, from late February through April. Squirrels breed during their first spring at about 10 to 11 months of age. Estimated mean litter size was 4.20 based on embryo counts and 3.92 based on placental scars. The most frequent litter size was four.
    • Assessment and prediction of electroshocked-induced injury in North American fishes

      Holliman, Farland Michael (2003-05)
      Electrofishing has served as an efficient method for scientific sampling of freshwater fishes since the mid-1900s, but it has become apparent since the 1990's that electroshock can cause fish injury. Electroshock-induced fish injury (damage to hard or soft tissues), which is primarily manifested as vertebral fracture or hemorrhage (broken blood vessels) along the backbone, can be a critical determinant of fish survival. The ability to predict factors influencing fish injury rate (the proportion of. injured fish in a sample) would be very useful to biologists. To test the null hypothesis of no effect of electrical waveform (W), voltage gradient (E), and fish size (S) on injury rate, I conducted controlled electroshock experiments on chinook salmon Oncorhynchus tshawytscha, rainbow trout O. mykiss, channel catfish Ictalurus punctatus, largemouth bass Micropterus salmoides, bluegill Lepomis macrochirus, and hybrid striped bass Morone saxatalis x M. chrysops. Data collected included electrical stimulus, fish behavioral response (R), length (L) and weight (W), and injury status (present/absent). Vertebral injury was determined using radiography, and hemorrhage by bilateral filleting. My model selection criteria, which was based on Akaike's Information Criterion (AIC), indicated that risks for both types of injury in chinook salmon and channel catfish were best represented by the (W, E, S) model, the (W, S) model for both types of injury in rainbow trout, the (W, E) model for hemorrhage and the (W, E, S) model for vertebral injury in largemouth bass, the (W) model for both injury types in hybrid striped bass, and, that risk for injury in bluegill injury was best described by the null model (no effect of W, E, S). A mechanistic model relating electrical stimulus, the force of contraction, and the resistance to contraction to electroshock-induced injury, using (R) as a surrogate for electrical stimulus, (L) as a surrogate for force of contraction, and vertebral count (V) as a surrogate of resistance to injury, was explored. Application of the mechanistic model (R, L, V) to the pooled data set demonstrated a strong predictive relationship. This model offers guidance for the reduction and prevention of electroshock-induced injury for all species in all situations.
    • An assessment of trap efficiency to estimate coho salmon smolt abundance in a small Alaskan stream

      Eskelin, Anthony Alexander (2004-08)
      Smolt abundance is commonly estimated using trap efficiency-based methods; however, few studies have investigated the accuracy of trap efficiency estimates. The objectives of this study were to: (1) test the hypotheses that (i) trap efficiency is not affected by release timing nor release distance, (ii) trap efficiency-based estimates of smolt abundance are concordant with smolt-adult mark-recapture estimates, and (2) evaluate if water level and turbidity influence trap efficiency. In Deep Creek, Alaska, during 2001 and 2002, coho salmon Oncorhynchus kisutch smolt abundance was estimated using trap efficiency-based methods and compared to independent smolt-adult mark-recapture estimates. Marked smolts were released at two times of day (1200 hours and 0000 hours) and two release distances upstream of the trap (400 m and 1500 m) every 2 to 4 d throughout each year. Trap efficiency estimates were highly variable (range 0%-55%) and trap efficiency-based estimates of abundance were not concordant with smolt-adult mark-recapture estimates. Release timing and turbidity significantly influenced trap efficiency, whereas release distance did not. Several assumptions of the trap efficiency approach were not met, which produced biased estimates and conflicting results among years when comparing estimation techniques. These results suggest that assumptions of the trap efficiency-based methods be fully assessed to accurately estimate smolt abundance.
    • Bald eagle (Haliaeetus leucocephalus alaskanus) nesting related to forestry in southeastern Alaska

      Corr, Patrick O. (1974-05)
      There were 136 nests located by aerial survey along 225 miles of beach in six logged plots and six virgin plots. Nest densities during the three years were 0.20, 0.23, and 0.20 active nests per beach mile. Islets present within 2 miles of a logged main shore provided nesting territories for eagles not able to find suitable nest sites along the logged shore. Spatial distribution of active nests indicated a 1.25 mile territory radius per nesting pair. Statistical comparison (Mann and Whitney U test) of mean territory size found in logged versus virgin plots showed no significant difference in territory size between the two plot types. Nests located in beach fringe timber remaining after harvesting were utilized frequently because of the lack of alternate nest sites in the immediate vicinity; these nest sites were highly susceptible to wind throw. Storm damage resulted in the loss of 20 per cent of the known nests during winter 1968-1969. It is recommended that buffer zones (10 chain radius - 660 feet) around eagle nests be maintained during harvesting, and that logging activity in the vicinity of nesting eagles be curtailed during April and May. Also, smaller, scattered timber sales should be promoted to ensure that extensive beach strip logging does not remove potential nest sites along miles of shoreline.
    • Beaver population ecology in interior Alaska

      Boyce, Mark S. (1974-05)
      The ecology of beaver (Castor canadensis Kuhl) populations along two streams in interior Alaska was studied in 1972 and 1973. The two study areas were similar in most respects, except for the history of human trapping intensity. The heavily trapped population exhibited the following contrasts to the essentially unexploited population: (1) higher mortality among adult age classes, (2) higher survivorship of the prereproductives, (3) a sex ratio with a preponderance of females, (4) decreased age at first breeding and consequently, (5) a smaller average size at maturity. Males appear to expend lower effort for parental activities than do females, and consequently exhibit higher survivorship than their mates. Population regulating mechanisms, management implications, and the evolution of an optimal life history strategy are discussed. The distribution and abundance of beaver colonies were related to habitat types and characteristics of the physical environment by multiple linear regression analysis.
    • Bird use of arctic tundra habitats at Canning River Delta, Alaska

      Martin, Philip D. (1983-12)
      Seasonal patterns of abundance of shorebirds and Lapland Longspur were studied at the Canning River delta. Study plots with differing habitat characteristics were examined: upland, mesic, and lowland tundra, and coastal saline flats. Nesting density was greatest in the mesic plot, but the lowland received intense use by late summer transients; use of the saline habitat was consistently high. Cold weather in July, 1980 probably reduced prey availability. Aquatic habitats, especially polygon troughs, produced a high proportion of the adult insect biomass. Comparison of energetic requirements of birds with the energetic value of their prey supply suggests that food could have limited reproductive success. Availability of both aquatic and terrestrial insects may contribute to high breeding bird density in structurally diverse habitats. Heavy use of wet/flooded tundra by late summer migrants probably reflects abundance of midge (Diptera: chironomidae) larvae in pond sediments.