2008 Graduate Student Research Award - Top Five Master’s applicants
Applicant: Mayumi Arimitsu, University of Alaska Fairbanks
Project Title: Environmental gradients and prey availability within Kittlitz’s Murrelet foraging
habitat in Kenai Fjords, Alaska
Abstract: Environmental gradients and prey availability likely influence the distribution of
Kittlitz’s Murrelets, a seabird species that typically feeds on small-schooling fishes near tidewater
glaciers in coastal Alaska. Kittlitz’s Murrelet populations have declined dramatically in recent
decades, coincident with the rapid retreat of glaciers. Relatively little is known about the feeding
ecology of this species, however, causes for the decline may include changes in marine habitat
and prey availability. The overall goal of this study is to characterize prey availability and
foraging habitat of the Kittlitz’s Murrelet over the course of the breeding season in Kenai Fjords,
Alaska. Specifically, the objectives are to characterize environmental gradients relative to glacial
features, and to document changes in prey availability relative to observed environmental
gradients. Spatial and temporal variability of the marine ecosystem within three fjords will be
assessed during the early, middle and late 2008 breeding season. Sampling efforts will include
measures of nutrients, oceanography, primary productivity, and zooplankton. Fish abundance will
be quantified with hydroacoustics while conducting surveys for Kittlitz’s Murrelets and other
marine predators. Hydroacoustic backscatter will be ground-truthed for species composition using
a trawl and an underwater video system. Multivariate analysis of species composition, abundance,
and habitat will include principal components analysis, hierarchical clustering, and non-metric
dimensional scaling of similarity indices. This research will improve our understanding of glacial
fjord ecosystem dynamics, and improve the ability to manage and protect fish and wildlife
populations.
Applicant: Elizabeth Atwood, University of Washington
Project title: Influence of coastal-origin mesoscale eddies on ichthyoplankton assemblages in the
Gulf of Alaska
Abstract: Ocean conditions can potentially impact fish species with drifting early life history
stages. Mesoscale eddies formed along the continental shelf of the Gulf of Alaska (GOA) during
winter and spring are large and ubiquitous, facilitating cross-shelf water exchange. These
mesoscale eddies may facilitate transport of early larval stages of fish from shelf to slope. I
propose to examine the relationship between ichthyoplankton (eggs, larvae, juveniles) and
mesoscale eddies propagating along the GOA shelf break. In a multi-faceted approach, I will first
examine ichthyoplankton assemblages from three well characterized eddies (Haida, Sitka, and
Yakutat) that were sampled in 2005. I will compare ichthyoplankton indices from within eddy to
shelf regions using data from spring 2003. These samples will be analyzed for relative indices of
diversity and abundance of eggs, larvae, and juveniles of species within each eddy. Using
historical altimetry data (1993 – present), I proposed to reconstruct a time series of eddy presence
in the western GOA (particularly in the Kodiak Island – Shelikof Strait region) to characterize
annual eddy seasonality, strength, frequency, and persistence in the western GOA. I will then
look at correlations between eddy properties (timing, magnitude, frequency, propagation
direction) and annual abundance estimates of ichthyoplankton collected over the continental shelf
in the same region. Resulting patterns will be modeled to describe the relationship between life
history of shelf-spawning species and mesoscale eddy dynamics. Results will help determine
whether eddies are a source of larval exchange between the continental shelf and slope, and
elucidate mechanisms that could be applicable to other, less well characterized areas such as the
Bering Sea.
2008 Graduate Student Research Award - Top Five Master’s applicants
Applicant: Ella Bowles, University of British Columbia
Project Title: Application of DNA techniques: Analyzing Steller sea lion and walrus diets using
PCR based methods
Abstract: Diets of pinnipeds are typically described from hard part remains recovered in
fecal samples; however, some prey are not represented by hard parts and there are other
limitations to accurate species resolution and quantification (biomass estimation), and
some predators pass few hard parts (e.g., walrus). DNA analysis of fecal samples has
shown promise in addressing some of these biases. In addition to identifying presence or
absence of prey in scat, a new DNA technique (real-time PCR) has the potential to
estimate the biomass (quantity) of prey consumed. One preliminary study suggested that
this technique can be applied to fecal analysis in Steller sea lions. We will apply real-time
PCR to scat samples from Steller sea lions fed known diets to more thoroughly validate
and assess the limitations of this technique to determine the quantities (biomass) of prey
consumed. We will also undertake a pilot study using Pacific walrus scats collected in
March 2008 in the Bering Sea to determine whether DNA analyses can determine their
diets (the only current way to determine walrus diet is from the stomachs of animals shot
close to shore, which may not be representative of walrus wintering on the Bering Sea).
Knowing what and how much marine mammals eat is central to implementing recovery
plans and for resolving conflicts between marine mammals and commercial fisheries.
Applicant: Olivia Lee, Texas A&M University
Project Title: Movements and foraging behavior of northern fur seal (Callorhinus ursinus) pups
from the Commander Islands during their first winter at sea
Abstract: High mortality rates of pups during their first winter at sea may be contributing to the
decline of northern fur seals on the Pribilof Islands, but due to their highly dispersed migratory
nature, little is known about individuals during this life stage. In contrast, the northern fur seal
population on the Commander Islands has been stable over the last decade. Dive behavior and
movements are hypothesized to be similar for pups from both populations, but differences could
explain whether Commander Island pups increase their survival rates by using different foraging
tactics or exhibiting different habitat preferences. The objectives of this study were to determine
whether differences in movements, habitat associations, and diving and foraging behavior existed
between the two populations. A total of 17 males and 18 females from Bering Island, Russia were
instrumented with Mk10-AL satellite tags and stomach temperature pills in late October 2007.
Habitat associations will be determined using GIS data of bathymetry, geostrophic currents, sea
surface temperature and sea surface height anomalies, and chlorophyll a concentrations.
Preliminary analyses indicate similar nocturnal diving behavior, and overall wide ranging
movements across the north Pacific and Bering Sea when compared to the behavior of pups from
the Pribilof Islands. Most ingestion events also occurred during the dark hours, which is
consistent with the deeper and longer dives recorded from both populations during this time
period. However, a large proportion of pups from the Commander Islands appear to reach preyrich areas after shorter time periods and distances traveled than pups from the Pribilof Islands. A
detailed analysis of movement patterns could reveal whether Commander Island pups have
survival advantages during their first winter at sea, that could partially explain the divergent
population trends. The foraging data may also provide important information on the preferred
foraging habitat of northern fur seal pups, and be useful in mitigating human impacts on critical
fur seal habitat.
2008 Graduate Student Research Award - Top Five Master’s applicants
Applicant: Shannon O’Brien, University of Washington
Project Title: Impacts of climate change on Pacific sleeper sharks (Sominous pacificus) and cooccurring benthic shark species, spiny dogfish (Squalus acanthias) and bluntnose sixgill sharks
(Hexanchus griseus), as revealed by DNA sequences
Abstract: Management and conservation efforts focus on the use of genetic techniques to
determine population structure of species, largely overlooking potential applications of analyses
to explain past demographic events. However, demographic events during the last glacial period
may provide insight into the current genetic diversity of species, as well as potential responses to
current climate change. Phylogeography, a field of molecular ecology research, has been used to
describe geographic distribution of phylogenetic lineages and genetic diversity, providing access
to past demographic events such as population divergence, bottlenecks, and expansion. Such
information can often be gleaned from relatively small samples and are especially powerful when
used in comparison among or within species. Here, I propose to apply molecular techniques to
similar shark species found in the Bering Sea, Gulf of Alaska and North Pacific, the Pacific
sleeper shark (Sominous pacificus), the spiny dogfish (Squalus acanthias), and the bluntnose
sixgill shark (Hexanchus griseus). I propose that understanding phylogeography and resulting
demographic histories of these sharks will provide insight to (1) how these species were affected
by climate changes during the last glacial cycle which will allow predictions about population
responses to current and future climate change; (2) historic population sizes and expansion time,
which will add to current understanding of populations; and (3) how the demographic history of
sleeper sharks compares to that of the spiny dogfish and sixgill sharks, two species with similar
life histories and ecologies. This comparison will help to better understand the effects of climate
change.