Anchorage, AK, United States
Anchorage, AK, United States

Alaska Pacific University is a small liberal arts college located in Anchorage, Alaska, that emphasizes experiential and active learning. The university is a member of the Eco League, a group of five small universities and colleges with strong programs in Psychology and Environmental Studies as well as related topics. Wikipedia.

Time filter

Source Type

Saenger C.,Alaska Pacific University | Wang Z.,Yale University
Quaternary Science Reviews | Year: 2014

Geochemical variations in marine biogenic carbonates that are preserved in the geological record serve as proxies of past environmental change. However, interpreting most proxies is complicated by biologically-mediated vital effects, highlighting the need to develop new tools for reconstructing paleoenvironmental change. Recently, magnesium (Mg) isotope variability in carbonates has been explored extensively to determine its utility as a paleoenvironmental proxy. We review the results of these works, which have yielded valuable information on the factors affecting Mg isotope fractionation between carbonates and solution (δ26Mgcarb-sol) in biogenic and abiogenic carbonate minerals. Strong evidence exists for a mineralogical control on δ26Mgcarb-sol, with the negative offset from 0‰ following the sequence aragonite~3mol/mol) and saturation states (Ω >~3) that are similar to seawater suggest that δ26Mgcarb-sol has a temperature dependence of ~0.01‰ °C-1 and is insensitive to precipitation rate. In contrast, a significant precipitation rate dependence is observed in calcites precipitated from solutions with relatively low Mg/Ca ratios (<~3mol/mol) and saturation states (Ω <~3). This difference likely reflects varying mineral growth mechanisms and we discuss the degree to which δ26Mgcarb-sol may be affected by factors such as fluid inclusions, amorphous calcium carbonate precursors, ion attachment/detachment kinetics, surface entrapment and Mg speciation. High-Mg calcite organisms, which likely precipitate from relatively unmodified seawater, also exhibit a temperature dependence of ~0.01‰ °C-1, albeit sometimes with a systematic offset toward smaller fractionations. In contrast, strong vital effects in low-Mg calcite organisms, which exclude Mg from their calcifying fluids, lead to δ26Mgcarb-sol values that exhibit no clear temperature dependence and are offset from abiogenic experiments. The majority of biogenic aragonites have δ26Mgcarb-sol values that are slightly more positive than those in abiogenic experiments, but bivalves and one sclerosponge species can exhibit significantly larger fractionations. Although vital effects and analytical uncertainties will limit δ26Mgcarb-sol paleotemperature reconstructions to anomalies of at least ±10°C, Mg isotope variability in biogenic carbonates may be a useful proxy for the Mg isotope composition of seawater, which reflects continental weathering, dolomitization and hydrothermal activity. © 2014 Elsevier Ltd.

Carter B.T.G.,Alaska Pacific University | Nielsen E.A.,Northern Arizona University
Marine Policy | Year: 2011

The Cook Inlet beluga whale, one of five Alaskan stocks, is genetically distinct and geographically isolated from other populations. Historically, Cook Inlet whales were hunted commercially, for sport, and for subsistence uses. The Marine Mammal Protection Act (MMPA) of 1972 ended commercial and sport hunting; in 1999, subsistence hunting voluntarily ended. In 2008, Cook Inlet beluga whales were listed as endangered under the Endangered Species Act after annual aerial surveys indicated the population was not recovering as expected. A combination of natural and anthropogenic factors may be affecting this population's recovery. This study documented traditional and local ecological knowledge of Alaska Native subsistence hunters and fishers and commercial fishers through participatory research to explore ecological changes in Cook Inlet over time and to identify potential factors impacting this beluga whale population. Study results identified potential environmental and climate change factors including prey competition, health of beluga and their prey, and the presence of killer whales, the majority of which may indicate an ecosystem regime shift in the Cook Inlet region. Human-related factors included fisheries management and related prey reduction, water contamination, and anthropogenic-related noise. These results corroborate identified threats to beluga whales and also identify potential new areas of scientific investigation and management. As such this study demonstrates the value of incorporating traditional and local ecological knowledge into ongoing science and management. © 2010 Elsevier Ltd.

Scheel D.,Alaska Pacific University | Bisson L.,Alaska Pacific University
Journal of Experimental Marine Biology and Ecology | Year: 2012

We attached sonic transmitters to, and tracked, 40 giant Pacific octopuses (Enteroctopus dofleini) ranging from <1 to 21kg in size in south-central Alaska using near-continuous tracking by fixed-array receivers and intermittent tracking with a mobile receiver. We documented area use, daily activity patterns, spatial scale of movements and whether these differed by octopus size, and whether octopuses actively selected habitats. Near-continuous fixed tracking provided positions about every 4 min over a limited area, while intermittent mobile tracking provided positions every 1-6h but over open and larger areas. Mantle-mounted transmitters on modified Peterson disks had >83% retention to the end of a tracking period (range <1day [before animal left the study area] to at least 88days post-release), an improvement over published studies. Octopuses were found to be stationary or hiding 94% of the time. Otherwise, octopuses were active throughout the day but more so from midnight to 0500. During low tides, movements were restricted for animals in intertidal habitats but not for those deeper. Maximum movement distance from release was 4.8km (by a 16.5kg female). Minimum convex polygon area use averaged 4,300m 2 for the smallest animals to an average over 50,000m 2 for the largest during 2 to 20days of tracking, substantially larger than previously reported. Larger octopuses moved further and used greater area than smaller animals, but differences between sexes were not significant.Stationary behavior and periods without detection (rest) by fixed near-continuous tracking were bi-modally distributed, with peaks < 3. h duration and > 18-48. h. Direct movements (indicating relocation or den switching) were common at night, central-tendency movements (indicating localized area use and return to den) were common at dawn, and stationary behavior was common in daylight, although each pattern occurred at all periods. Central-tendency movements recorded by intermittent tracking were oriented parallel to contours, while movements without central-tendency crossed contours, suggesting that animals navigate by contour following to return to a known den. During a relocation experiment, octopuses released at shallow depths moved deeper and those released deeper moved shallower, both into habitats with greater kelp cover. Although > 90% of their time was spent stationary and hiding, Enteroctopus dofleini utilizes information about its environment (contour following), selects habitats (preference for more kelp cover), and occupies large use areas (minimum convex polygons) by making substantial direct movements from previous use areas. © 2012 Elsevier B.V.

Agency: NSF | Branch: Continuing grant | Program: | Phase: ITEST | Award Amount: 1.36M | Year: 2014

This project expands, implements and conducts research on a previously developed framework for providing indigenous students with the workforce skills and knowledge needed for future Earth system science careers. The framework proven effective for Inupiat students during the NSF/ITEST-funded Arctic Climate Modeling Program (ESI-0525277) will be scaled up to develop culturally responsive STEM instruction for 1500 Yupik and Native Hawaiian middle school students and their 60 teachers. The multifaceted scale-up project includes: a broader research setting, more school districts, diverse indigenous cultures, additional STEM workforce practices, and a broader expert pool. The goal of the scale-up is to answer the research question, Under what circumstances are the PREPARES framework for offering culturally responsive STEM instruction effective in increasing indigenous student disposition toward participating in future Earth system science careers? Student objectives include assessing three indicators of student disposition toward STEM careers: (a) STEM academic achievement, (b) interest in STEM careers, and (c) STEM workforce skill readiness. Teacher objectives related to program sustainability include increasing educator STEM content knowledge and pedagogical strategies aligned with STEM workforce practices. Research by randomized controlled trial will determine framework transferability and identify circumstances and steps needed to expand its adoption to a broader array of U.S. schools.

This project is a professional development program for non-Native teachers of indigenous students. The project offers training that helps teachers provide culturally responsive science, technology, engineering and math (STEM) instruction in areas, such as Alaska and Hawaii, that support strong indigenous populations, but where the vast majority of teachers are non-Native. The research component will gather data and information that will advance the understanding of a framework for broadening indigenous participation in STEM study and careers. The activity targets middle school students because research indicates that middle school is a time when engagement in STEM studies begins to decline. Encouraging indigenous students to view completing high school as a step toward STEM careers is important because Native students compose a high percentage of the dropout population in Alaska and Hawaii. Culturally responsive STEM training is needed because many STEM teachers enter their preparation programs with little or no inter-cultural experience and with beliefs and assumptions that undermine the goal of providing an equal education for all students.

Agency: NSF | Branch: Standard Grant | Program: | Phase: ARCTIC SYSTEM SCIENCE PROGRAM | Award Amount: 159.81K | Year: 2015


Accurate records of natural variability that cover broad temporal and spatial scales, and that capture intervals of non-linear change are needed to fully comprehend the arctic system. This project aims to develop the first system model to simulate the full chain of processes that control how weather and climate affect the processes that lead to deposition of a sediment record in lakes in glaciated watersheds. This model provides an alternative approach to previous statistically-based models traditionally used by paleo-climatologists to infer past climate variability from lake sediment records. The new process-based quantitative understanding will lay the groundwork for future studies that will be aimed at recovering records of environmental and climate change that extend back thousands of years.

This project will contribute to ongoing efforts through collaborations with: utility managers of the Municipality of Anchorage who are planning for diminished glacier meltwater input to Eklutna Lake, a major source of their electricity and freshwater and with resource managers at US Fish and Wildlife Service who are developing a monitoring network for the Arctic Refuge and who are striving to foresee future changes in habitat quality associated with glacier retreat. This project will benefit climate science researchers by leading to more accurate climate reconstructions, which will be used as benchmarks for validating global climate model output. Finally, it will support four early-career scientists and will train graduate and undergraduate students in system-science research.


The primary goal of this project is to develop a system model that encodes the major processes that govern the amount and grain size of sediment that accumulates in arctic lakes in glaciated catchments, and to acquire the field-based data for model input and testing. Sediments that accumulate at the bottom of arctic lakes contain a wealth of information about how major features of the surrounding watershed have varied on seasonal to millennial time scales, as well as how they have responded to natural and anthropogenic forcings. Lakes in glaciated watersheds record changes in the melt rate of upstream glaciers, which are among the most dynamic components of the evolving arctic system. The sediment stored in glacier-fed lakes often comprise distinct rhythmic layers that represent annual cycles. These varved sediments are among the most valuable of all natural archives on Earth because they can be placed on a precise time line, and because they accumulate at a rate that is sufficiently high to track environmental variability on annual, and often seasonal, scales. They have been used extensively to reconstruct past climate changes in the Arctic, most often relying on statistical correlations between records from long-term weather stations and varve thickness. These statistical correlations disregard the complex and time-evolving interactions within the glacier-hydrology-lake-sedimentation system that link climate to changing properties of sediment deposited at the lake bottom. A more process-based understanding of the interactions that control sedimentation within lakes of glaciated catchments is needed to provide the next generation of paleoclimate reconstructions. By incorporating a system-modeling approach, a process-based system model will be developed to capture dynamic nonlinearities in the glacier-hydrology-lake-sedimentation system. The system model will couple three existing model components: a physically based, spatially explicit hydrological model, which includes a glacier sub-model; an empirically based sediment-flux model; and a process-response, basin-filling sedimentation model. The system model will be applied to three glaciated watersheds that fall along an environmental gradient spanning from the sub-Arctic to the High Arctic, including Lake Linne (Svalbard), Lake Peters (near McCall Glacier, Arctic National Wildlife Refuge), and Eklutna Lake (near Anchorage, Alaska). This study builds on extensive previous and on-going process studies at or near each of the study sites. Existing data and proposed glacier, hydrology, limnology, and sediment process studies will provide the input data to run the system model and to validate its output.

News Article | January 28, 2016

An octopus displays dark color and spread web and arms. Credit: David Scheel Octopuses have generally been viewed as solitary creatures—and their color-changing abilities primarily as a means to hide from hungry predators. But, after binge watching more than 52 hours of octopus TV, researchers reporting in the Cell Press journal Current Biology on January 28 have found that octopuses actually do have a social life. And it's not without drama. "We found that octopuses are using body patterns and postures to signal to each other during disputes," says David Scheel of Alaska Pacific University. "The postures and patterns can be quite flashy, such as standing very tall, raising the body mantle high above the eyes, and turning very dark." The octopuses in question belonged to a species known as Octopus tetricus living in the shallows of Jervis Bay, Australia. Scheel and his colleagues were tipped off that something interesting might be going on in that bay by a diver who alerted an online community of people interested in cephalopods that he'd seen something interesting. The researchers followed up from there, ultimately witnessing 186 octopus interactions and more than 500 actions. In all that video, the octopuses spent more than 7 hours interacting. Scheel along with colleagues at the University of Sydney noticed some intriguing patterns: when an octopus with a dark body color approached another dark octopus, the interaction was more likely to escalate to grappling. When a dark octopus approached a paler one, the pastier octopus more often retreated. When the opposite happened and a light octopus approached a darker one, the latter more often stood its ground. "Dark color appears to be associated with aggression, while paler colors accompany retreat," Scheel says. Octopuses also displayed on high ground, standing with their web spread and their mantle elevated. Octopuses in that "stand tall" posture frequently also sought higher ground. The researchers suspect the octopuses' behaviors are meant to make themselves appear larger and more conspicuous. The findings expand scientists' understanding of how octopuses interact and communicate with each other. The researchers now suspect that social interactions among octopuses are likely to occur wherever food is plentiful and hiding places are scarce. They'll continue to study these octopuses and to explore how their social lives might influence the size of the population. More information: Current Biology, Scheel et al.: "Signal Use by Octopuses in Agonistic Interactions"

News Article | February 3, 2016

Octopuses use body colour and posture to communicate to others during aggressive encounters, suggesting that they are more social than previously thought. Octopuses are considered to be more solitary animals than many squid or cuttlefish. David Scheel of Alaska Pacific University in Anchorage and his colleagues reviewed filmed interactions between pairs of Octopus tetricus off the coast of New South Wales, Australia. Octopuses were darker when they were about to fight an approaching animal and paler when they were set to flee. When dark in colour, the animals also changed their posture — by standing tall on higher ground and spreading the webs between their arms. The octopuses could be using these signals to communicate their size, strength and willingness to fight to a rival, the authors say.

News Article | January 28, 2016

Scientists have known for a while that octopuses and other cephalopods (like squid) are capable of changing color and shape on a magnificent level. This ability was generally thought to be a camouflage tactic, but now researchers are observing octopuses using appearance-altering skills as a way to either incite or back down from confrontation. A team from Alaska Pacific University, led by David Sheel, found that octopuses adopting similar hues and postures are more likely to fight. An angry octopus will flush darker, but a retreating octopus will turn a paler color to de-escalate the confrontation. Octopuses can also adopt intimidating or submissive postures to go with the color change. In video shot by the researchers, some southern Australian octopuses are shown engaging in two different conflict scenarios. In the first, one octopus adopts a darker color to signal aggression, and its opponent maintains its previous coloring. By not submissively changing color or posture, the second octopus is saying “let’s do this.” In the second scenario, one dark-colored octopus stretches itself out to look as tall and imposing as possible, and its competitor turns a paler shade, presumably to communicate that it plans to back down and scurry away. However, Sheel noted in his team’s research that confrontations were rare, and thinks the body language patterns are designed to reduce conflict as much as possible. Since octopuses are very solitary animals who mate infrequently, this would serve a worthwhile evolutionary purpose—fewer octopuses killed in combat. Sheel told New Scientist “what’s interesting is the tolerance they have for one another. There must be some incentive to get along.” If only humans could learn from our eight-tentacled friends.

News Article | January 29, 2016

Octopuses are well-known masters of camouflage and skillful escape artists, but they aren't exactly famous for their social skills. Scientists have long thought that this many-armed denizen of the deep was strictly solitary and didn't interact much with its fellows, reserving its color-shifting ability for intimidating predators — or hiding from them. But a new study reveals that both male and female octopuses frequently communicate with each other in challenging displays that include posturing and changing color. And certain behavior patterns emerged that accompanied different color-shifting displays. If two octopuses approached each other and displayed dark colors, the encounter was likely to escalate aggressively and lead to physical confrontation. But an octopus displaying paler colors usually indicated that it was preparing to retreat, the researchers found. A diver in Jervis Bay, Australia, initially spotted the unusual octopus behavior, writing about it in an online post that attracted the scientists' attention. To decode the octopuses' social "language," the scientists captured and screened 52 hours of footage of the Octopus tetricus species, a mottled, grayish-brown cephalopod known as the common Sydney octopus and also — somewhat more amusingly — the gloomy octopus. Despite its mopey-sounding name, what the scientists observed wasn't a community of isolated sulkers, but a highly engaged and interactive bunch. [Video: Watch Octopuses Argue Through Body Patterns And Postures] "Because octopuses were known to kill each other at times and be cannibalistic, the general sense is that they wouldn't interact a lot and wouldn't use signals," David Scheel, the study's first author, told Live Science. But Scheel, who is a professor of marine biology at Alaska Pacific University, had already found a scattering of reports from prior studies that suggested "there was another story going on," he said. "Some octopuses have been seen in displays that may have occurred to woo potential mates, and some have [been] found in aggregations. So, there have been hints in the literature that suggest this may have been possible, but no focused reports that looked just at signaling among octopuses." What Scheel and his colleagues observed was novel — a site where the gloomy octopuses would visit and confront each other, over and over again. "One of the early bits of video that I saw showed one octopus approaching another in a fairly dramatic way — dark and standing very tall, and the other one crouched down, turned pale and then fled," Scheel told Live Science. "It just looked to me like they were signaling, so we just followed from there to try and explore that idea." Anywhere from three to 10 octopuses appeared at the site on a given day, the researchers noted. In the 52 hours of recorded footage, over 7 hours showed octopus interactions, with 345 instances of changing colors and 512 examples of physical movements, such as grappling or reaching toward each other. Reaching was the most common interaction the scientists saw, making up 72 percent of all the physical interplay; the octopuses touched each other very infrequently, the scientists recorded. They observed one posture repeatedly — when the octopus would "stand tall," extending its arms outward and drawing itself upward. An octopus that was standing tall would usually also display a dark color and raise its mantle, all of which, the researchers said, appeared to signify aggression toward another octopus. Other cephalopods, like cuttlefish, are known to assume a darker color during disputes, with males displaying a "dark face." If two male cuttlefish show each other dark faces, the confrontation usually turns physical, while if only one of the males puts on his dark face, the paler-faced cuttlefish typically backs down, a behavior pattern strikingly similar to the one the researchers observed in the octopuses' color displays. "Signaling is well-documented in cuttlefish and squids," Scheel said, "so in that way it isn't really surprising to suggest that octopuses do the same thing." [Cuttlefish Cuties: Photos of Color-Changing Cephalopods]

Octopuses were believed to be solitary sea creatures since sightings of them on separate occasions rarely show them with other cephalopods. However, an interesting discovery in Australia's Jervis Bay shows that these eight-limbed creatures can also be quite sociable. A group of scientists from Sydney, New York and Alaska used a GoPro to record 52 hours of footage of octopuses interacting in a rare social setting. Study co-author Matthew Lawrence first observed the unusual gathering during one of his dives. He then decided to post his discovery on a cephalophod enthusiast website, which is how Professor David Scheel from the Alaska Pacific University and Peter Godfrey-Smith from the University of Sydney and University of New York found out about it. Binge watching more than 50 octopuses is not exactly easy even with the help of students, especially since these cephalopods have mimicking abilities. "It's harder than it sounds. Trying to keep track of who's who is very difficult. They can change color or shape in a second, and when one moves into view it is hard to tell whether they are a new animal – or one that you've been watching for ages," Godfrey-Smith said. Of course, most have seen how an octopus behave in science channels on television, but to actually observe those behaviors in action and in response to another of its kind is very interesting. Scientists already observed how octopuses tend to change its color depending on how threatened or relaxed it feels and how it fights off predators, but to witness two octopuses "bickering" or being aggressive towards another – trying to make themselves look bigger and darker – is new. Take a look at a video of Octopus fights below. Scientists are not exactly sure whether it is a natural, but rarely seen living situation for octopuses. Perhaps those that have gathered in the middle of Jervis Bay are just tolerating each other since there are a lot of scallops to go around. "There's a lot of pushing other animals around, kicking them out of the site, and sometimes vigorous fights," he added. It seems watching an octopus society is a lot like watching an MTV reality show. The study titled "Signal Use by Octopuses in Agonistic Interactions" was published in Current Biology on Thusday.

Loading Alaska Pacific University collaborators
Loading Alaska Pacific University collaborators