Expedition Search

This project attempted to understand the role of carbon resources to the food webs of the Chukchi Sea, off the northwest coast of Alaska. The northern Chukchi Shelf receives large inputs of organic matter transported from the highly productive shelf regions of the North Pacific and from existing sources of primary production, including ice algae, sediment microalgae and phytoplankton. These contributions of highly changing organic carbon, together with potential benthic (from the bottom of the sea) sources of nutrients, likely contribute to the enormous secondary production (production of living material by organisms) of this region. In particular, the relatively shallow depths (40-55 m) and high bottom flow have created "hotspots" of biological productivity found in the vicinity of the Hanna Shoal region of the Chukchi Sea.

The research team included scientists from seven institutions and two federal agencies. The work took place over dozens of existing sampling stations and involved collaboration with other science studies in the region sponsored by federal, state, or industry interests. Due to the biological significance of this region and its importance for oil and gas exploration and development, the group examined the range of biological, chemical, and physical properties that define this ecosystem.

The group focused their efforts on the Hanna Shoal region, with the addition of a pelagic (from the open ocean) component to address standing stocks of phytoplankton and zooplankton, and a physical oceanographic study that addressed water mass movements through direct measurement of circulation, density, and ice conditions.

Applied Research in Environmental Sciences Nonprofit, Inc., ARIES, the Barrow Arctic Science Consortium, BASC, and the North Slope Borough of Risk Management are collaborating to plan, develop and implement a historical ecology model for the North Slope Coastal Region of Alaska.

Historical ecology is an applied research program that focuses on interactions of people and their environments. Research applications involve studying and understanding this relationship in both time and space to gain a full picture of all of its accumulated effects. The research program can be applied to understanding changes among community landscapes that can assist strategies for the future. For this proposal the emphases align with the ARIES mission that combines research, education, and community outreach.

The emphases are 1) a bibliographic database of relevant historical resources, 2) an examination of the shoreline to provide a time-series baseline 3) simulation models to demonstrate socio-natural cycles of change for the North Slope shoreline, 4) the historical ecology study of the shoreline, interactive mapping and database available as a web based resource to assist academia, industry, regional government and local communities for socio-cultural and management purposes, 5) an integrated team who can work with interested researchers, industry planners and Risk Management of the North Slope Borough to extract data and provide simulation models that apply to current studies of the region and 6) provide a variety of eco-heritage opportunities that include community participation in research, educational products, age level appropriate activities and outreaches for community service learning.

This includes natural and social science research and use of eco-heritage data for disaster preparedness among the "Next Generation", that is, middle and high school students. This aligns with the Cumulative Risk Integrated Operability Project (CRIOS) with DHS CREATE funds, since 2008, to reduce risks across emergency management jurisdictions of tribally inclusive geographic areas (TIGA). Here is the project website.

The expedition members visited several research sites in Greenland as part of an initiative to foster enhanced international scientific cooperation between the countries of United States, Denmark, and Greenland. The expedition members spent several days learning about the research conducted in Greenland, the logistics involved in supporting the research, and gain first-hand experience conducting experiments and developing inquiry-based educational activities.

In 2013, the work built on past expeditions and was supported by the National Science Foundation. The project was developed through cooperation with the U.S.-Denmark-Greenland Joint Committee, which was established in 2004 to broaden and deepen cooperation among the United States, the Kingdom of Denmark, and Greenland.

The program had two components

Kangerlussuaq Science Field School: 28 June - 10 July 2013

Science Education Week: 11- 18 July 2013

The Arctic is warming faster than any other biome on the planet, which makes it critically important to understand the influence of warming on ecosystem processes in this region. While arctic species are all well adapted to living in extreme environments, it is unclear how different species will respond to the environmental shifts that accompany climate change (e.g. longer growing seasons and warmer temperatures). Stronger responses by some species within a community could lead to changes in the structure of the food web and its role in arctic ecosystems. In the Alaskan Arctic, wolf spiders are the largest and most abundant invertebrate predators. A shift in their ecological role could therefore have an important impact on the entire food web.

This project explored the role of wolf spiders within arctic communities and specifically, whether climate change is stimulating changes in these predators that could influence the structure and function of food webs. In particular, arctic warming could increase decomposition of the large amounts of carbon stored in permafrost soils. Increased decomposition would result in higher levels of atmospheric carbon dioxide and methane, which are heat-trapping greenhouse gases. Potential shifts in spider feeding ecology as a result of climate change could therefore have important and far-reaching consequences for arctic plant community dynamics and ecosystem processes. This research examined the extent to which arctic wolf spiders influence the structure and function of food webs and measured whether their impact on the community is changing with warming.

Tremendous stores of organic carbon frozen in permafrost soils have the potential to greatly increase the amount of carbon in the atmosphere. Permafrost soils may thaw sporadically, and melting ground ice can cause land-surface subsidence called "thermokarst failures". These failures change the rate and amount of carbon released with the unanticipated outcome being that soil carbon can be mixed-up from a depth and exposed to sunlight as the land surface fails. Sunlight can photo-degrade organic carbon and alter the carbon's ability to support bacterial respiration to produce carbon dioxide. Whether UV exposure will enhance or retard the conversion of newly exposed carbon to carbon dioxide is currently unknown—in this study team is providing the first evidence that this alteration will be amplified by photochemical processes and their effects on microbes.

The research team is trying to understanding exactly how sunlight and bacteria degrade dissolved organic matter by determining how fast these processes convert newly released dissolved organic matter to carbon dioxide, compared to dissolved organic matter already in surface waters. The team will accomplish their research objectives with a series of laboratory experiments to determine rates of photodegradation and microbial processing of dissolved organic matter from different sources, and a series of landscape comparisons and sampling transects to characterize dissolved organic matter degradation in small basins and large rivers extending from the headwaters to the Arctic Ocean. Ultimately, this research will attempt to answer questions such as whether carbon export from tundra to oceans will rise or fall and how reactive the exported carbon will be. The team hopes to be able to measure the ultimate impact of impending disturbances, including climate change, on the net carbon balance of the Arctic and its interaction with the global carbon cycle.

In the Arctic, bright summers and dark winters are a fact of life and can lead humans to rely on clocks and routines to tell them when to eat or sleep, but how do animals function under these conditions? Circadian rhythms refer to the "internal body clock" that regulates the approximately 24-hour cycle of biological processes in animals and plants. Rhythms in body temperature, brain wave activity, hormone production, and other biological activities are linked to this 24-hour cycle. The Earth's light-dark cycle provides the strongest influence on circadian rhythms and is thought to be the primary driver for the emergence and evolution of internal clocks. In the Polar Regions, however, photoperiod exhibits extreme annual variation because of near 24 hour sunlight in the summer and 24 hour darkness in the winter. In the absence of a well-defined light-dark cycle, some arctic residents lose their daily organization of behavior and physiology, and it is thought that the molecular clockwork that drives circadian rhythms may be weak or absent in arctic vertebrates.

The research team has recently found that the arctic ground squirrel displays daily rhythms of body temperature throughout the arctic summer, in the absence of a light-dark cycle. The current study continues investigate the circadian rhythms in arctic ground squirrels during the continuous daylight present during the active summer season and continuous dark of the 6-8 months of hibernation spent sequestered in a burrow. The team wants to understand why arctic ground squirrels, unlike other arctic vertebrates, appear to maintain 24-hour rhythms during the active season. They hypothesize that the persistence of circadian rhythmicity allows ground squirrels to reduce energy expenditure by anticipating predictable changes in its immediate surroundings. They continue to test their hypothesis by experimentally phase-shifting free-living ground squirrels to be active at 'night' and estimating their subsequent rates of energy expenditure.

Antarctic notothenioid fishes are uniquely adapted to life in the extreme conditions of the Southern Ocean. Waters surrounding Antarctica are unlike any other. The Southern Ocean is isolated from other oceans by the Antarctic Circumpolar Current, it is very cold with temperatures at or near -1.8 degrees Celsius, and the water is rich in oxygen. Notothenioids have evolved many physiological traits that enable them to survive in this remarkable environment. They lack a swim bladder and have antifreeze proteins that prevent their bodies from freezing. Members of one family of notothenioids, the Channichthyidae (icefishes), are unique among all vertebrates because they lack the circulating oxygen-binding protein, hemoglobin.

The loss of hemoglobin is considered a neutral mutation; one that neither enhances nor reduces fitness. However, the team hypothesizes that the loss of hemoglobin may be an advantage because hemoglobin promotes the formation of reactive oxygen species that damage macromolecules. Overall, the team's research was aimed at understanding the unique physiological and biochemical traits that have arisen in fishes during their evolution in the chronically cold waters of the Southern Ocean.

This project examined the poorly-understood interaction of climate change and microbial methane production in wetland soils in the Lapland region of Finland. The research team conducted field and lab experiments to determine the role of arctic wetlands in global carbon cycling. Similar experiments have also been completed by the research group in the Alaskan arctic, making this project part of an investigation into the potential global-scale response of arctic wetlands to impending climate changes.

The Arctic is experiencing the most dramatic warming due to climate change of all global systems. As arctic soils warm, the resulting rise in microbial activity increases emissions of carbon dioxide and methane, further accelerating global climate change. Because the vast majority of global carbon is stored in soils, and soil carbon is in flux with atmospheric carbon, soil microbes can either alter or exacerbate climate changes.

Methane is a powerful, carbon-based greenhouse gas, and wetlands are the largest natural source of methane to the atmosphere, but factors that influence net methane emissions from arctic wetland soils are not well understood. The Lapland region of northern Finland offered an ideal research environment because it has carbon-rich arctic wetlands different from those that exist in North America, offering the opportunity to comparatively study the controls on methane flux from arctic wetland ecosystems. More generally, carbon cycling research is critical for building accurate global climate models, which inform social and international climate change mitigation policies.

The goal of the team's research was to develop a past climate and precipitation record of Central Alaska over the past 1000 years. In order to accomplish this task, the team extracted and analyzed a series of three ice cores from an ice divide between the North and South Peaks of Mount Hunter within Denali National Park and Preserve. They also continued ice depth and surface velocity surveying of major glaciers within Denali National Park and have plans for using this information to develop improved ice volume estimates and historical glaciological reconstructions of Central Alaska.

Research at this site is important as it completes the development of a spatial ice core array (a range of data) in the North Pacific that has been underway since the early 2000s, including climate records from the St. Elias Mountains, Coast Range, Brooks Range, and Wrangell Mountains. Mt. Hunter in central Alaska lies in a different precipitation and climate regime from these regions, and thus represents the missing piece in this array needed to evaluate spatial precipitation and atmospheric circulation changes on various timescales in this region of the Arctic. Considering the apparent teleconnections (climate phenomena related to each other and occurring large distances from one another) between the Arctic and Antarctic climate and meteorology, completing this array of ice cores may also provide information that is particularly useful for world glaciological and climate modeling purposes. More information about the project can be found at the University of Maine website.

The carbon cycle is the means by which carbon is moved between the world's soils, oceans, atmosphere, and living organisms. Northern tundra ecosystems play a key role in the carbon cycle because the cold, moist, and frozen soils trap organic material and slow their decomposition. This very slowly decaying organic material has caused carbon to build up in the Arctic during the past thousands of years. Historically, the tundra has stored large amounts of carbon. Now warming in the Arctic is slowly causing the permafrost to thaw and the tundra to become warmer and dryer. As the earth warms and permafrost thaws, this previously frozen carbon is released as carbon dioxide and goes into the atmosphere, turning the tundra into a source of carbon, rather than a sink. Because carbon dioxide is a greenhouse gas, this additional carbon dioxide creates a positive feedback that leads to even further warming.

Little is known about respiration in the arctic winter. The team used five different methods in hopes of finding the best way to measure how much carbon is being released from northern ecosystems in the winter. Measuring winter respiration directly from experimentally warmed plots and understanding the drivers of wintertime tundra respiration will have the added benefit of being able to improve global arctic carbon models. More information about the project can be found here.