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Genetic diversity in coastal cutthroat trout and Dolly Varden in Prince William Sound, AlaskaGriswold, Kitty E. 13 June 2002 (has links)
Genetic diversity of two salmonid species, Dolly Varden (Salvelinus
malma) and coastal cutthroat trout (Oncorhynchus clarki clarki) in Prince William
Sound, Alaska were examined at multiple spatial scales with three molecular
markers. Pleistocene glaciers covered what is now Prince William Sound 8,000-
12,000 years ago and both species colonized the region subsequently. Because
these species have different migratory behavior and historic ranges I expected to
see different patterns of genetic diversity within Prince William Sound. Haplotype
frequency and nucleotide diversity in sixteen mitochondrial DNA (mtDNA)
restriction fragment enzymes combinations in Prince William Sound were higher in
Dolly Varden than in coastal cutthroat trout, which were close to fixation. Low
estimates of these measures in coastal cutthroat trout may reflect a founder effect
resulting from colonization of this region from a single glacial refuge (Cascadia)
and low dispersal capacity. To examine if genetic diversity in coastal cutthroat
trout was higher in areas of glacial refuge, three additional locations from
throughout their distributional range were examined with the same restriction
enzymes. Haplotype frequency and nucleotide diversity were lower in areas that
were glaciated than estimates of the same measures in a glacial refuge. Again,
founder effects during colonization of the three glaciated sites may account for
these results. Genetic variation of Dolly Varden and coastal cutthroat trout was
also examined within and among populations in Prince William Sound with
microsatellites and allozymes. The pattern of genetic variation in coastal cutthroat
trout was complex. There was lower genetic diversity within populations that were
recently colonized following recent de-glaciation (150-350 ybp). Genetic diversity
among some coastal cutthroat trout populations was high, which possibly reflects
restricted migration. In other trout populations there was low diversity among
populations, possible reflecting historic gene flow. In Dolly Varden, genetic
variation among anadromous populations in Prince William Sound was low. There
were large differences among resident and anadromous populations. These data
provide information for the management for both species, which may reduce the
risk of the loss of genetic diversity within local populations. / Graduation date: 2003
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Foraging behavior and productivity of a non-colonial seabird, the marbled murrelet (Brachyramphus marmoratus), relative to prey and habitatKuletz, Katherine J. 10 April 2008 (has links)
No description available.
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Breeding habitat of harlequin ducks in Prince William Sound, AlaskaCrowley, David W. 09 December 1993 (has links)
Breeding habitat of Harlequin ducks (Histrionicus
histrionicus) was studied in eastern Prince William Sound,
Alaska, during 1991 - 1993. Streams in Prince William
Sound were surveyed for Harlequin ducks and monitored with
mist nets. Physical characteristics of 24 Harlequin
breeding streams were compared to those of 24 streams not
used for breeding using 2 sample, principal components and
logistic regression analyses. Nests were located using
radio-telemetry of marked females.
Harlequin ducks resident in eastern Prince William
Sound selected the largest anadromous salmon streams
available for nesting. Volume discharge of breeding
streams averaged 3.2 m��/s and was the most important factor
in habitat variation between streams used and not used by
breeding Harlequins. Expansive estuaries and intertidal
deltas present at the outflow of large streams were
important foraging and loafing areas of Harlequin ducks.
Although nesting females generally avoided smaller salmon
streams their intertidal estuaries were often used for
foraging by females and molting males. The largest streams
in Prince William Sound, glacially fed rivers, were not
used by breeding Harlequins.
Ten nest sites of Harlequin ducks in eastern Prince
William Sound were located on southwest facing, steeply
sloping banks of small, first order tributaries near
timberline elevation. Nests were associated with woody
debris and shrubs, in shallow depressions or cavities, and
were beneath the canopy of old growth forest. Microhabitat
produced by a southwest aspect, snow shadow provided by the
forest canopy, and sloping stream bank may provide nesting
sites earlier in the spring compared to surrounding areas. / Graduation date: 1994
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Behavioral constraints on harlequin duck population recovery from the Exxon Valdez oil spill in Prince William Sound, AlaskaRizzolo, Daniel J. 05 February 2004 (has links)
I investigated the relationship between harlequin duck (Histrionicus
histrionicus) behavior and lack of recovery from the Exxon Valdez oil spill in
Prince William Sound, Alaska. First, I evaluated the hypothesis that harlequin
ducks in winter have little flexibility to increase foraging time in response to
disturbance because they are constrained to forage during daylight. Eight radio-tagged
harlequin ducks wintering in Resurrection Bay, Alaska were monitored for
evidence of dive-feeding at night. Each radio-tagged individual was detected
during an average of 19.5 of 22 nocturnal monitoring sessions and signal loss
indicative of diving behavior was not detected during a total of 780 minutes of
signal monitoring. In contrast, the same 8 radio-tagged birds were detected during
an average of 9.1 of 12 daytime signal monitoring sessions and signal loss
indicated diving behavior during an average of 62 �� 7% of 5-minute daytime
monitoring periods (total of 364 minutes of signal monitoring). Thus the harlequin
ducks monitored in this study rarely, if ever, fed by diving at night, possibly due to
reduced foraging efficiency and (or) increased predation risk at night. This result
suggests that harlequin ducks in mid-winter may be severely time-limited in their
foraging, especially in northern parts of their winter range. Therefore, subtle
changes in energy requirements and (or) time-activity budgets as a result of
continued exposure to residual oil from the Exxon Valdez oil spill may affect the
ability of harlequin ducks to meet their daily energy requirements.
Second, I tested the hypothesis that exposure to crude oil affects time-activity
budgets of harlequin ducks. Controlled oil-dosing and plumage-oiling
experiments were conducted using adult female harlequin ducks in captivity. I
found no evidence that ingestion of weathered Prudhoe Bay crude oil affected the
occurrence of feeding activity during 30-minute observation periods, nor was there
evidence of effects on time spent feeding. Effects of crude oil ingestion on
maintenance activity were detected, but were neither consistent between the 2 years
of the study, nor dose-dependent for the 2 doses administered (2 and 20 mL kg�����
wk�����), and therefore did not strongly support an oil-dosing effect on maintenance
activity. Consequently, these results provided little support for the hypothesis that
oil ingestion affects time-activity budgets of captive harlequin ducks, at least for
the doses and conditions of captivity used in this study. Plumage-oiling reduced
feeding activity in captive harlequin ducks. The estimated probability of feeding
during 30-minute observation periods for birds in the high-exposure oiling group (5
mL of crude oil) was 53% less than that of non-oiled controls. Oiled birds
exhibited a trend of reduced time feeding with increasing level of external-oiling;
this effect was greatest among birds in the high-exposure oiling group, which spent
43% less time feeding than non-oiled birds. Reduced feeding was associated with
less time in the water dive-feeding and presumably lower heat loss. Trends in the
occurrence of maintenance activity and time spent in maintenance activity for birds
in the high-exposure treatment suggested plumage-oiling increased maintenance
activity, but results were not conclusive. The behavioral changes associated with
plumage-oiling in captivity would likely reduce fitness in the wild, where a high
proportion of time must be spent in the water feeding. If residual Exxon Valdez oil
sequestered in beach sediments enters the water column where it may be
encountered by harlequin ducks, external exposure may lead to reduced feeding
activity. This, in turn, may compromise survival, particularly during mid-winter
when the time available for diurnal foraging is low and maintenance energy
requirements are high. / Graduation date: 2004
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Characterizing the winter movements and diving behavior of subadult Steller sea lions (eumetopias jubatus) in the north-central Gulf of AlaskaBriggs, Holly Beth 25 April 2007 (has links)
Recent studies indicate a 70% decrease in the Alaskan Steller sea lion (SSL) population
(ca. 5% per year) since the early 1980's. In accordance with a 1997 status classification of the
Western Steller sea lion (WSSL) stock as endangered, the "critical habitat" for the species was to
be defined. This habitat has now been designated to include 10-20 nautical mile buffer zones
around most rookeries and haulouts in the Gulf of Alaska (GOA) and Aleutian Islands. However,
these zones were based on limited, summer, foraging data.
The primary objective of this study was to characterize juvenile SSL diving behavior
and habitat use along the Kenai Peninsula and Prince William Sound (PWS) from winter to
spring. Fifteen free ranging, subadult SSL of both sexes were captured and equipped with
satellite telemeters at five haulout sites in PWS and Resurrection Bay, Alaska. Telemeters
transmitted for an average of 122 days (range 38-181 days). A total of 11,692 locations were
received and 217,419 dives recorded.
All sea lions exhibited localized movements parallel or close to shore (3-15 km
offshore). Young of the year (YOY) exhibited high site fidelity. Older juvenile sea lion lions
were less restricted in their movements and traveled greater distances (200-400km) visiting a
variety of islands, buoys, and other locations in PWS.
Most dives were short (mean duration = 1.1 min) and shallow (mean depth = 10.8 m),
with animals diving to an average maximum depth of 193 m. During winter (January and February), many dives (>40%) occurred during the daytime (0900-1500 LT). However, by April
and May this pattern shifted and the animals made most of their dives (>40%) during the night
(2100-0300 LT). This relationship was more pronounced for dives deeper than 20 m and
coincided with the seasonal increase in photoperiod.
Subadult SSL, especially YOY, remained within the 20 nautical mile coastal zone during
winter and spring. Shallow, nearshore waters provide important habitat during this critical
period of transition to nutritional independence. However, more conclusive data on SSL
foraging ecology is necessary to better understand locations and depths preferred by the species.
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Boating in Alaska's Prince William Sound : modeling and assessment of recreational use /Wolfe, Phillip E. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 140-144). Also available on the World Wide Web.
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Crisis communications : an examination of spokespersons use of response strategies in newspapers during the Sea Empress and Exxon Valdez groundingsLarsson, Steinar January 1997 (has links)
This study was a replication of Fitzpatrick and Rubin's study of response strategies used in crisis communication. It differed though, in the type of crisis analyzed. While Fitzpatrick and Rubin studied cases of sexual harassment, this study examined oil spills of two supertanker groundings. Both the Exxon Valdez and the Sea Empress groundings, and especially Acomarit and Exxon, the companies responsible were examined by using content analysis. Units of analysis were statements by each company's spokesperson covered in either four American or four Norwegian newspapers. These statements were then categorized as one of four response strategies defined by Fitzpatrick and Rubin which were as follows: (1) The traditional public relations strategy, (2) The traditional legal strategy, (3) Mixed strategy, and, (4) Diversionary strategy.On behalf of these response strategies the study stated two hypotheses:H1: The spokespersons of Acomarit used the traditional public relations strategy significantly more than the traditional legal strategy, as defined by Fitzpatrick and Rubin, in Norwegian newspapers.The hypothesis was accepted.H2: The spokespersons of Exxon used the traditional legal strategy significantly more than the traditional public relations strategy, as defined by Fitzpatrick and Rubin, in American newspapers.The hypothesis was partially accepted.The study used an American and a Norwegian coder to secure reliability. Holsti's coder reliability test yielded eighty percent for the American statements, and seventy percent for the Norwegian statements.The study also indicated that the traditional public relations strategy was the most used response strategy. This was different to what Fitzpatrick and Rubin found in their study. They found the traditional legal strategy was used the most in cases of sexual harassment.However, both Exxon and Acomarit used the traditional public relations strategy more than the traditional legal strategy, but differed significantly in their use of mixed strategy and diversionary strategy. Exxon was found to have used the diversionary strategy significantly more than Acomarit. The researcher indicated that this may have been one of the contributing factors which lead to Exxon's public relations nightmare. In addition, Exxon was found to have used more spokespeople than Acomarit, which in turn may have made it difficult to centralize the information flow. / Department of Journalism
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Range-use estimation and encounter probability for juvenile Steller sea lions (Eumetopias jubatus) in the Prince William Sound-Kenai Fjords region of AlaskaMeck, Stephen R. 21 March 2013 (has links)
Range, areas of concentrated activity, and dispersal characteristics for juvenile Steller sea lions Eumetopias jubatus in the endangered western population (west of 144° W in the Gulf of Alaska) are poorly understood. This study quantified space use by analyzing post-release telemetric tracking data from satellite transmitters externally attached to n = 65 juvenile (12-25 months; 72.5 to 197.6 kg) Steller sea lions (SSLs) captured in Prince William Sound (60°38'N -147°8'W) or Resurrection Bay (60°2'N -149°22'W), Alaska, from 2003-2011. The analysis divided the sample population into 3 separate groups to quantify differences in distribution and movement. These groups included sex, the season when collected, and the release type (free ranging animals which were released immediately at the site of capture, and transient juveniles which were kept in captivity for up to 12 weeks as part of a larger ongoing research program). Range-use was first estimated by using the minimum convex polygon (MCP) approach, and then followed with a probabilistic kernel density estimation (KDE) to evaluate both individual and group utilization distributions (UDs). The LCV method was chosen as the smoothing algorithm for the KDE analysis as it provided biologically meaningful results pertaining to areas of concentrated activity (generally, haulout locations). The average distance traveled by study juveniles was 2,131 ± 424 km. The animals mass at release (F[subscript 1, 63] = 1.17, p = 0.28) and age (F[subscript 1, 63] = 0.033, p = 0.86) were not significant predictors of travel distance. Initial MCP results indicated the total area encompassed by all study SSLs was 92,017 km², excluding land mass. This area was heavily influenced by the only individual that crossed over the 144°W Meridian, the dividing line between the two distinct population segments. Without this individual, the remainder of the population (n = 64) fell into an area of 58,898 km². The MCP area was highly variable, with a geometric average of 1,623.6 km². Only the groups differentiated by season displayed any significant difference in area size, with the Spring/Summer (SS) groups MCP area (Mdn = 869.7 km²) being significantly less than that of the Fall/Winter (FW) group (Mdn = 3,202.2 km²), U = 330, p = 0.012, r = -0.31. This result was not related to the length of time the tag transmitted (H(2) = 49.65, p = 0.527), nor to the number of location fixes (H(2) = 62.77, p = 0.449). The KDE UD was less variable, with 50% of the population within a range of 324-1,387 km2 (mean=690.6 km²). There were no significant differences in area use associated with sex or release type (seasonally adjusted U = 124, p = 0.205, r = -0.16 and U = 87, p = 0.285, r = -0.13, respectively). However, there were significant differences in seasonal area use: U = 328, p = 0.011, r = -0.31. There was no relationship between the UD area and the amount of time the tag remained deployed (H(2) = 45.30, p = 0.698). The kernel home range (defined as 95% of space use) represented about 52.1% of the MCP range use, with areas designated as "core" (areas where the sea lions spent fully 50% of their time) making up only about 6.27% of the entire MCP range and about 11.8% of the entire kernel home range. Area use was relatively limited – at the population level, there were a total of 6 core areas which comprised 479 km². Core areas spanned a distance of less than 200 km from the most western point at the Chiswell Islands (59°35'N -149°36'W) to the most eastern point at Glacier Island (60°54'N -147°6'W). The observed differences in area use between seasons suggest a disparity in how juvenile SSLs utilize space and distribute themselves over the course of the year. Due to their age, this variation is less likely due to reproductive considerations and may reflect localized depletion of prey near preferred haul-out sites and/or changes in predation risk.
Currently, management of the endangered western and threatened eastern population segments of the Steller sea lion are largely based on population trends derived from aerial survey counts and terrestrial-based count data. The likelihood of individuals to be detected during aerial surveys, and resulting correction factors to calculate overall population size from counts of hauled-out animals remain unknown. A kernel density estimation (KDE) analysis was performed to delineate boundaries around surveyed haulout locations within Prince William Sound-Kenai Fjords (PWS-KF). To closely approximate the time in which population abundance counts are conducted, only sea lions tracked during the spring/summer (SS) months (May 10-August 10) were chosen (n = 35). A multiple state model was constructed treating the satellite location data, if it fell within a specified spatiotemporal context, as a re-encounter within a mark-recapture framework. Information to determine a dry state was obtained from the tags time-at-depth (TAD) histograms. To generate an overall terrestrial detection probability 1) The animal must have been within a KDE derived core-area that coincided with a surveyed haulout site 2) it must have been dry and 3) it must have provided at least one position during the summer months, from roughly 11:00 AM-5:00 PM AKDT. A total of 10 transition states were selected from the data. Nine states corresponded to specific surveyed land locations, with the 10th, an "at-sea" location (> 3 km from land) included as a proxy for foraging behavior. A MLogit constraint was used to aid interpretation of the multi-modal likelihood surface, and a systematic model selection process employed as outlined by Lebreton & Pradel (2002). At the individual level, the juveniles released in the spring/summer months (n = 35) had 85.3% of the surveyed haulouts within PWS-KF encompass KDE-derived core areas (defined as 50% of space use). There was no difference in the number of surveyed haulouts encompassed by core areas between sexes (F[subscript 1, 33] << 0.001, p = 0.98). For animals held captive for up to 12 weeks, 33.3% returned to the original capture site. The majority of encounter probabilities (p) fell between 0.42 and 0.78 for the selected haulouts within PWS, with the exceptions being Grotto Island and Aialik Cape, which were lower (between 0.00-0.17). The at-sea (foraging) encounter probability was 0.66 (± 1 S.E. range 0.55-0.77). Most dry state probabilities fell between 0.08-0.38, with Glacier Island higher at 0.52, ± 1 S.E. range 0.49-0.55. The combined detection probability for hauled-out animals (the product of at haul-out and dry state probabilities), fell mostly between 0.08-0.28, with a distinct group (which included Grotto Island, Aialik Cape, and Procession Rocks) having values that averaged 0.01, with a cumulative range of ≈ 0.00-0.02 (± 1 S.E.). Due to gaps present within the mark-recapture data, it was not possible to run a goodness-of-fit test to validate model fit. Therefore, actual errors probably slightly exceed the reported standard errors and provide an approximation of uncertainties. Overall, the combined detection probabilities represent an effort to combine satellite location and wet-dry state telemetry and a kernel density analysis to quantify the terrestrial detection probability of a marine mammal within a multistate modeling framework, with the ultimate goal of developing a correction factor to account for haulout behavior at each of the surveyed locations included in the study. / Graduation date: 2013
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Effects of diet and crude oil ingestion on growth and biochemistry of captive-reared pigeon guillemots (Cepphus columba)Hovey, Andrew K. 01 October 2002 (has links)
The pigeon guillemot (Cepphus columba) population in Prince William
Sound has failed to recover from declines that occurred both before and after the
Exxon Valdez Oil Spill (EVOS). Post-spill studies of pigeon guillemot breeding
biology have identified three potential factors limiting recovery: (1) predation on
eggs and nestlings; (2) declines in the proportion of high-lipid, schooling forage
fish (sand lance [Ammodytes hexapterus], herring [Clupea pallasi], and capelin
[Mallotus villosus]) in the diet; and (3) continued exposure to residual oil from the
spill. This laboratory study with captive-reared pigeon guillemots at the Alaska
SeaLife Center investigated two aspects of the species' biology that are relevant to
restoration in the aftermath of EVOS. First, we investigated the role of dietary
factors (prey type, quantity of food consumed, dietary fat content, and energy
intake rate) in limiting the growth, development, survival, and fledging condition of
nestling pigeon guillemots. The objective was to understand how changes in prey
availability and prey quality might affect pigeon guillemot productivity. Second,
we fed nestlings sublethal doses of weathered Prudhoe Bay crude oil (PBCO) and
then measured several potential biomarkers of effects from this pollutant. These
dose-response experiments were designed to (1) better understand the impact on
nestling guillemots of petroleum hydrocarbons in food, (2) calibrate existing and
potential biomarkers of exposure to PBCO in pigeon guillemots in a controlled,
laboratory setting, and (3) develop better nondestructive biomarkers of exposure to
PBCO in pigeon guillemots in particular, and seabirds in general.
Results of feeding experiments indicated that most variation in nestling
growth rates could be explained by variation in daily energy intake. The type of
forage fish consumed, the lipid or protein content of the forage fish, and even the
quantity of food consumed daily did not have as strong an effect on nestling
guillemot growth as did daily energy intake. The metabolic efficiency and growth
performance of nestling guillemots was not enhanced on high-lipid diets, contrary
to results with nestlings of some other seabird species. Instead, structural growth
(wing length) in nestling guillemots was somewhat stunted on high-lipid diets.
These attributes of guillemot nutritional requirements are associated with the
guillemots' nearshore foraging niche and high food provisioning rates to nestlings.
The average lipid content of sand lance, juvenile herring, and capelin may represent
the optimal dietary lipid content for nestling pigeon guillemots. This study supports
the hypothesis that guillemot productivity is limited by the availability of these forage fishes through effects on energy provisioning rates to nestling guillemots.
Consequently, recovery of pigeon guillemot populations injured by EVOS is likely
linked to recovery of these key forage fish stocks.
Results of the oil-dosing experiments indicated that nestling guillemots are
resistant to small doses of weathered PBCO in their food. No nestlings died or
suffered noticeable health effects following dosing. The high dose in this study (0.5
ml kg����� day�����) was sufficient to induce hepatic cytochrome P450A1 (a liver enzyme
indicative of contaminant exposure), but growth rate, fledging mass, and blood
chemistry were largely unaffected. None of the 12 plasma or hematological
markers examined responded in a dose-dependent manner to ingestion of weathered
PBCO, except lactate dehydrogenase (LDH). Although baseline stress hormone
(corticosterone) levels were not different between oil-dosed and control nestlings, a
standardized acute stress protocol revealed that corticosterone was more elevated
during stress for oiled nestlings compared to controls. Although we were not
successful in identifying a noninvasive biomarker (e.g., growth) or a blood
biomarker (e.g., haptoglobin) of crude oil exposure in nestlings, we were able to
confirm that levels of hepatic cytochrome P4SO1AI and corticosterone during
stress were elevated by the sublethal doses administered during our experiments.
Based on this and other studies, it is unlikely that the failure of pigeon guillemots to
recover from EVOS is due to effects on nestling health of residual oil in food. / Graduation date: 2003
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