Methods and Technologies to Address the Frontier Questions
During the workshop, several cross-cutting issues emerged that highlight the research needs and requirements for advancing the understanding of polar ecosystems. Participants noted that a striking characteristic of the workshop was the ease with which these key issues emerged from the discussion. Many participants also emphasized enhancements and intensification of activities that have a presence now rather than new tools or techniques. These enhancements are intended to help scientists answer the frontier questions and address unknowns in the field. It is beyond the scope of this document to present all of these methods and technologies, however, many workshop participants highlighted the importance of a concerted effort to advance the establishment of long-term field and data observatories, synthesis and management centers, and education and outreach tools to improve the connection between polar research and societal needs.
Genomics is “the study of the structure, content, and evolution of genomes,” including the “analysis of the expression and function of both gene and proteins” (NRC, 2003). In this context, genomics encompasses functional genomics (gene and protein expression and function), structural genomics (analysis of the three-dimensional structures of proteins),
metabolomics (analysis of the metabolites produced and consumed by a population of cells), and many others (e.g., ecogenomics, metagenomics, pharmacogenomics, toxicogenomics). Genome sciences make use of, and are integrated by, the related disciplines of bioinformatics and computational biology. These genomic approaches offer global or near-global overviews of gene lists, and gene and protein expression. Genomic profiles also enable the exploration of the genetic content of organisms that cannot be studied by classical genetic methods.
Genomic studies have been used to show how Antarctic fish species have evolved to their current diversity levels during the evolution of the Antarctic continent and can be used to evaluate diversity changes as polar ocean temperatures warm and acidify (Ritchie et al., 1996; Bargelloni et al., 2000; Verde et al., 2006). Environmental genomics has proved to be particularly important in the study of marine and terrestrial microorganisms, most of which remain uncultured (Kimura, 2006). The application of genome science to study diversity-function relationships in polar systems has been highly productive and questions such as which organisms are present (analogous to the white pages in a phone book) and what metabolic functions are involved in biogeochemical transformations (analogous to the yellow pages in a phone book) can now be addressed at the molecular level. For example, a genomic approach has been used to study the biogeochemical transformations of gases in Antarctic lakes (Priscu et al., 2008), the phylogenetic and metabolic diversity of organisms immured in north and south polar ices (Christner et al., 2006; Miteva et al., 2008), the diets of krill (Martin et al., 2006), and the response of phytoplankton changes in the Arctic Ocean to freshwater input resulting from climate warming (Lovejoy et al., 2007).
New, and relatively inexpensive, pyrosequencing methods are replacing traditional Sanger sequencing, allowing for enormous amounts of information to be generated from the entire genome of environmental samples (metagenomics). New developments in pyrosequencing are expected to double the number of base pairs per read within the next year. The enormous amounts of data produced from these exhaustively sequenced samples will require novel bioinformatic tools to convert the data into a format that can be used by scientists to include in ecosystem models that address evolution, diversity, biogeography, biogeochemistry, and metabolic capacity in response to climate driven environmental change.
Workshop participants noted that the ability to understand polar ecosystems and their linkages to the regional and global climate system has been intimately linked to ongoing collections of satellite imagery
over the past few decades. For instance, observations of “greening” tundra, “browning” boreal forest, declining Arctic sea ice cover, shrinking ice sheets, and warming ocean waters have been enabled by long-term, large-scale, satellite-based datasets. Many workshop participants stressed that efforts to maintain and improve these long-term, consistent satellite observations are critical to continued understanding of the future fate of polar ecosystems. In some cases, these datasets already have a long-term expected observational record (e.g., with the 32-year ongoing Scanning Multichannel Microwave Radiometer (SMMR) and the Special Sensor Microwave/Imager (SSM/I) based sea ice products from 1978–present). However, other platforms highly utilized in the polar science community have had shorter lifetimes with no immediate plans for continuation (e.g., NASA’s QuikSCAT scatterometer for melt detection (among other parameters) operational from 1999–2009), which limits their use for longer-term observational studies. While new platforms take time to implement, additional technologies such as airborne lidar and spaceborne altimetry for various applications (including observations of terrestrial surface water storage changes, e.g., the NASA Surface Water and Ocean Topography (SWOT) mission scheduled for launch in 2020) should also come online in future decades.
Workshop participants also stated that new technological advances and release of previously classified high resolution imagery have the potential to transform the types of polar ecosystem related questions scientists can answer. For example, with Quickbird (61 cm) and WorldView (50 cm) data available to scientists, investigation of features previously unseen by lower spatial resolution satellites (e.g., sea ice melt ponds, glacial streams, individual trees and shrubs, and individual animals such as the Pacific walrus and Adelie penguin) has the potential to revolutionize the ability to detect and understand polar ecosystem change. Participants emphasized the importance of continuing to plan for satellite missions to avoid gaps and to deploy new technologies on these satellites to improve measurements of the polar cryosphere as the climate continues to change.
In situ Instrumentation
Workshop participants pointed out that the development of robust in situ environmental sensor instrumentation for evaluating key processes in polar ecosystems is essential to investigate the causes and consequences of environmental change. Time series observations at critical spatial and temporal scales of the various systems of interest (atmosphere, cryosphere, marine, and terrestrial) are essential to differentiate natural fluctuations from anthropogenic change. Technological advances in biological sensors are needed to approach the current sensor capability for
high-resolution physical measurements on land and sea. More sophisticated biological and chemical sensor techniques are needed to track species composition of plankton, pCO2 and pH, nutrients like silica and ammonium, and acoustic and video capabilities on fixed and floating mooring arrays for observations for marine mammals and benthic species, respectively. Workshop participants discussed the development of smaller sensor packages that can be deployed over larger spatial scales, such as sensors currently attached to fish, seabirds, and seals. Development of systems that can survive in winter, particularly in ice-covered seas, is crucial, given the continuing logistical difficulty of making human-attended observations.
SUSTAINED LONG-TERM OBSERVATIONS
In situ Observations
Because of their remote location and harsh environment, the polar regions lack sufficient observational assets to meet existing needs for research support, forecasting, and modeling, especially in winter. Thus, several participants noted the need for a vastly enhanced, expanded, and better-integrated system of sustained observations to support frontier scientific research in the polar regions. A network of in situ instrumentation and communications is one critical element of the wider system. Currently, sustained observations are mostly limited to atmospheric sampling and relatively few manned and automated, but often widely-spaced weather stations, especially in Antarctica. One example of such a network that is now being implemented is the Arctic Observing Network (AON) under SEARCH (Study of Environmental Arctic Change), consisting of a suite of atmospheric, land, and ocean sensors, ranging from ocean buoys to satellites. Besides weather, observing systems are needed to document and quantify sea ice, glacier, and ice sheet dynamics, fluxes of greenhouse gases, and the distributions and activities of organisms and biogeochemical cycles.
The Southern Ocean Observing System (SOOS; e.g., Schofield et al., 2010) will address several of these needs, but emphasis still centers on geophysical processes (ice dynamics, circulation, and climate) and is limited to the ocean. Better observations of the continental interior remain a barrier to a comprehensive, continental-scale observing and forecasting capability. In situ sensor systems are a challenge in polar regions where extreme weather and ice are constant threats to performance, communication, and survival of assets. Few of the current instrument platforms such as moorings, AUVs, and Gliders cope adequately with such conditions. Thus, an integrated observing network for land, oceans, and atmosphere
is not only a prerequisite for frontier research, but also a frontier area in its own right.
Monitoring Impacts on People
Workshop participants noted the importance of monitoring for change that affects humans in polar regions as climate change impacts threaten the health, safety, and cultural preservation of indigenous populations. For much of the year, research in Arctic regions is limited by sea ice and harsh weather that restrict access using traditional methods. This has limited data acquisition in the past and obscured understanding of events, processes, and variability of the environment over much of the region during parts of the year. The majority of workshop discussions on this topic centered on subsistence community impacts in the Arctic. Long-term data on properties and phenomena such as storm surges, sea ice thickness, permafrost melt, and tundra lake extents are critical to understanding the processes themselves, assessing impacts, devising mitigation plans, and modeling future change.
Suggested means of monitoring includes typical weather stations, the establishment of a long-term ecological research (LTER) station in the off-shore waters (Chukchi and Beaufort Seas) similar to those already in place in the Antarctic, and other permanent data collection sites, such as the proposed cabled seafloor observatory at Barrow, Alaska (Barrow Cable Observatory). Greater coordination between industry, local, and federal research programs was also discussed. Frequent sampling intervals that support monitoring of this nature are needed. Several workshop participants stressed the need to fund long-term integrative data collection sites to support this objective.
An important theme from workshop discussions was the central role of a long-term, large-scale circum-Arctic and Antarctic observation network in detecting change. Some of the goals of long-term ecological monitoring include detection, attribution, and prediction of regional and large-scale climate changes. These changes are more readily identifiable with the inclusion of biological sentinels. For some time now marine mammals have been considered excellent sentinels of ocean conditions (Laidre et al., 2008; Moore and Huntington, 2008) because of their sensitivity to anthropogenic and natural environmental impacts and because they are typically long-lived, with a large insulating layer of blubber that has a tremendous capacity to retain lipophilic (attracted to and easily dissolved in fats) pollutants. Because of difficulties with time, access, and
cost, scientists cannot study all species all the time. Workshop participants stressed the importance of identifying the key species that would be proxies to help understand climate impacts. For example, whales could be appropriate sentinels by providing outreach and education opportunities, because these “charismatic megafauna” easily capture the public interest further demonstrating relevance to this research.
Biotic Community Composition
Changing climates are likely to cause major biotic shifts in Arctic and Antarctic biological communities that will ultimately result in altered community compositions. While a great deal of research tends toward understanding ecosystem impacts, there is insufficient information available on community composition to provide adequate understanding of the severity of those potential changes. Because of this data void, workshop participants discussed the importance of understanding and defining the current system in order to better understand how change will affect that system. Additionally, there was discussion about the major difference in adaptability by the Arctic and Antarctic systems. Some scientists suggest that it is likely that the Arctic is much more resilient because of the existence of highly variable conditions that probably developed alternative trajectories for responses by the community’s organisms compared to a much less variable Antarctic system.
An area of concern that arose during workshop discussions was that the potential impacts on community composition in the Arctic due to an ice-free or ice-reduced regime, including reductions in permafrost and the arctic ice cap, will allow for profound terrestrial, under-sea, and surface changes that may permanently alter taxonomic composition, as is already being experienced with northerly migrating tree and other plant species, range expansion by species into previously marginal habitat areas, and southerly migration of ice-dependent species in search of food. Another potential negative consequence of climate change is the loss of synchrony between plant and animal species where, for example, a long-distance migratory bird species arrives when adequate food resources are unavailable. Many workshop participants stressed that each of these concerns point ultimately to an important research need to continue to study the diversity of a population, not just the morphological diversity, but at a genetic level.
Marine LTER in the Arctic
Marine ecosystems are complex systems that can potentially adapt to perturbations in ways that purely physical systems cannot. Long-term
biological process-level studies are necessary in order to evaluate ecosystem response to both natural and anthropogenic influenced climate forcing. The high value of LTER sites for process-oriented biological studies to understand ecosystem-level complexity was highlighted during the workshop, with participants noting that there are ongoing terrestrial and marine U.S. LTER sites in the Antarctic, but only terrestrial U.S. LTER sites in the Arctic. Thus, workshop participants highlighted the need for a marine LTER site in the U.S. Arctic to evaluate status and trends in ecosystem dynamics in regions of the western Amerasian Arctic off Alaska where sea ice is retreating rapidly and where the productive marine ecosystem is already undergoing change, such as a northward migration of both lower and high trophic organisms. This site would also support critical winter studies for understanding temporal impacts on key species and biogeochemical processes and their role in human sustenance. Whether it be one focused regional site or a latitudinal-based “Distributed Biological Observatory” concept of transect lines in the marine system for key biological and environmental studies (Grebmeier et al., 2010), it is clear a marine LTER would provide critically needed data for understanding status and trends for input not only into marine processes, but also into regional terrestrial system models that evaluate ecosystem responses to climate forcing. Such a site would also play a significant role in understanding how indigenous societies cope with a changing marine environment.
DATA SYNTHESIS AND MANAGEMENT
International Coordinated Efforts
Many workshop participants stated that international coordinated research efforts at both poles are essential to track land and marine ecosystem change on the appropriate time and space scales. Ongoing and developing projects, such as those supported through the International Arctic Science Committee (IASC) and the Scientific Committee on Antarctic Research (SCAR) planning efforts, are facilitating polar and global ecosystem measurements to track the impacts of climate warming. Workshop participants emphasized the valuable discussions encouraged by interactions between scientists from both polar regions. In this vein, the recently supported continuation of the IASC/SCAR sponsored Bipolar Action Group (see http://www.scar.org/about/partnerships/iasc/bipag.html) should help facilitate cross-fertilization of ideas and development of research programs investigating scientific questions pertinent to both poles.
Polar Systems Institute
Several workshop participants recognized the need for Arctic and Antarctic scientists (and both marine and terrestrial) to meet together to explore, and in many cases, identify new research challenges with important societal implications. Along with the PRB itself, the LTER Network has pioneered this area of scientific interaction and synthesis, with two Arctic (terrestrial only) and two Antarctic (one marine, one terrestrial) LTER sites, although in general the usual mode is for the two groups to meet separately, for example, in SCAR and IASC. The need for institutional mechanisms to facilitate better interdisciplinary, cross-polar dialog and more formalized synthesis activities was a major theme of workshop discussions. It was further noted that among the several U.S. polar research institutes, either cross-polar or disciplinary breadth is usually weak. Therefore workshop participants suggested that a Polar Synthesis Institute, possibly similar in scope and operation, could help the National Center for Ecological Analysis and Synthesis (NCEAS) to advance toward new frontiers in polar climate change and other areas of cryosphere research.
SCIENCE-TO-SOCIETY INTERFACE: DATA DISSEMINATION AND OUTREACH
Discussions on improved strategies of information dissemination resulted in a recognized need for increased communication of results in political arenas, in order to engage local and federal policymakers. For example, communications between scientists and agency representatives in lay language exchanges could help overcome the fact that scientists are generally not well-versed in “political-speak.”
During the workshop, it was noted that outreach requirements are becoming important and essential components in current requests for proposals, a notion widely supported by the group. It is clear that the future of science resides in a holistic approach that integrates science and society. Outreach that is accessible to non-scientists and that is also culturally sensitive is central to publicizing the causes and impacts of global climate change. In the future, the return of results to affected communities is likely to become a requirement, which will enable polar researchers to reach out and connect with societies and residents of these regions. Engaging indigenous residents in all steps of the research process, including identification of research needs, data collection, analysis, and dissemination of findings, provides unique opportunities for scientists to learn from those who live in the polar environment and know it extremely well.