Current Projects ~ Arctic Alaska Coastal Ecosystems

Collaborative Research: Terrestrial Linkages to Microbial and Metazoan Communities in Coastal Ecosystems of the Beaufort Sea
(NSF-ARC 1023465)

 

P.I.s: Kenneth H. Dunton, James W. McClelland, Byron C. Crump

Post-docs: Colleen T. E. Kellogg, Tara Connelly

Students: Matt Khosh, Carrie Harris

 

Publications

 

Harris, C. M., J. W. McClelland, T. L. Connelly, B. C. Crump, and K. H. Dunton. 2016. Salinity and Temperature Regimes in Eastern Alaskan Beaufort Sea Lagoons in Relation to Source Water Contributions. Estuaries and Coasts:1-13.

 

Presentations

 

Crump, B.C., Kellogg, C. T. E., Doherty, M., Fortunato, C. S., McClelland, J., Connelly, T., and K. Dunton. 2013. Seasonal and spatial drivers of estuarine bacterial community composition: a comparison of three estuaries. Invited talk at the 22nd Biennial Conference of the 
Coastal and Estuarine Research Federation, San Diego, CA, November 3-7, 2013

 

Dunton, K. H., McClelland, J. W., Connelly, T. L., Crump, B. C., Kellogg, C., Liu, Z., and N. D. McTigue. 2013. Food webs of arctic lagoons: comparative studies from open-water and ice-covered periods. 22nd Biennial Conference of the 
Coastal and Estuarine Research Federation, San Diego, CA, November 3-7, 2013

 

McClelland, J. W., Connelly, T. L., Khosh, M. S., Crump, B. C., Kellogg, C., and K. H. Dunton. 2013. Nutrient and Organic Matter Dynamics in Seasonally Open and Closed Lagoon Ecosystems along the Eastern Alaska Beaufort Sea Coast. 22nd Biennial Conference of the 
Coastal and Estuarine Research Federation, San Diego, CA, November 3-7, 2013

 

Kellogg, C. T. E., Crump, B. C., Connelly, T. L., McClelland, J. W., and K. H. Dunton. 2013. Seasonality in coastal Beaufort Sea microbial community. 5th International Conference on Polar & Alpine Microbiology, Big Sky, MT, September 8-12, 2013

 

Kellogg, C.T.E., B. C. Crump, T.L. Connelly, J. W. McClelland, and K. H. Dunton. 2013. Seasonality in coastal Beaufort Sea microbial community. 5th International Polar and Alpine Microbiology Conference, Big Sky, Montana.

 

Connelly, T., J.W. McClelland, S. Linn, M.S. Khosh, and K.H. Dunton. 2013. Seasonal variations in particulate organic matter sources and composition in arctic lagoons related to changes in the physio-chemical environment, ASLO Aquatic Sciences Meeting, New Orleans.

 

Connelly, T., J.W. McClelland, K.H. Dunton, and M.S. Khosh. 2013. Distinct seasonal variations in quantitative and qualitative inputs of particulate organic matter into arctic lagoons as revealed by fatty acid profiles. Gordon Research Conference on Polar Marine Science, Ventura.

 

Dunton, K.H., J.W. McClelland, B.C. Crump, T.L. Connelly, C. Kellogg, S.E. Linn, and M.S. Khosh. 2013. The role of terrestrial inputs of organic matter in arctic lagoons: Comparative studies from open-water and ice-covered periods, ASLO Aquatic Sciences Meeting, New Orleans.

 

McClelland, J.W., T.L. Connelly, M.S. Khosh, B.C. Crump, C. Kellogg, and K.H. Dunton. 2013. Seasonality of organic matter in lagoon ecosystems along the eastern Alaska Beaufort Sea coast. Gordon Research Conference on Polar Marine Science, Ventura.

 

Dunton, K.H., J.W. McClelland, T. Connelly, S. Linn, and M. Khosh. 2012. The role of terrestrial inputs of organic matter in arctic lagoons: Comparative studies from open-water and ice-covered periods. AGU Fall Meeting, San Francisco.


Project Description:


Coastal ecosystems of the Arctic receive extraordinarily large quantities of terrestrial organic matter through river discharge and shoreline erosion.  The fate of this organic matter is of local interest as it relates to biological production in the coastal ocean. It is also of broader interest with respect to global biogeochemical cycling.  The prevailing paradigm is that terrestrial organic matter inputs to the Arctic Ocean are highly recalcitrant.  However, most studies supporting this paradigm were conducted during mid to late summer.  We propose that terrestrial organic matter, both in dissolved and particulate form, provides an important carbon and energy subsidy that supports and maintains heterotrophic activity and food webs in coastal waters during much of the year.  We expect that the proposed study will transform our fundamental understanding of terrestrial organic matter processing and the significance of coastal ecosystems in the Arctic.

 

Beginning in summer, 2011, our work will focus on a set of 12 field sites along the Alaskan Beaufort Sea coast, in the vicinity of Barter Island and the Inupiaq village of Kaktovik (Fig. 1).  We will examine linkages between biological communities and organic matter inputs from land by comparing sites ranging from lagoons to open coastal systems that receive differing amounts of freshwater runoff and also differ markedly in their exchange characteristics with shelf waters.  Our overarching question is “How do seasonally distinct terrestrial inputs of water and organic matter influence microbial and metazoan communities in coastal waters of the Alaskan Beaufort Sea?”  We will address this question with a seasonally-explicit sampling program that includes field trips during the 9-month ice covered period as well as summer.  Measurements of water and sediment chemistry, natural abundance isotopic tracers, and benthic and water column community characteristics including diversity using tag pyrosequencing will be used to evaluate the importance and impact of terrestrial inputs under different hydrologic/hydrographic conditions.

 

Understanding the fate of terrestrial carbon in arctic coastal waters is especially important now, as the arctic system enters a period of rapid climatic change.  Changes in terrestrial organic matter export could influence total production as well as the balance between autotrophy and heterotrophy in arctic coastal waters. Such shifts have consequences for local human populations that use coastal food webs for subsistence and for the broad scientific community interested in land-sea coupling. Our proposed work focuses on fundamental questions about the fate of terrestrial organic matter in arctic coastal waters that must be answered before we can effectively consider future changes in land-sea coupling in the Arctic.

Text Box:  Fig. 1. Map of the Alaskan Beaufort Sea coast (top) and close-up of the area east of Barter Island (bottom). The proposed field program will be conducted within a 30 nautical mile radius of Barter Island, with an emphasis on sites between Kaktovik Lagoon and Nuvagapak Lagoon.  The village of Kaktovik is located on Barter Island.

 

 

 

Hypotheses:

 

1. Variations in terrestrial organic matter among sites (i.e., concentrations in the water column and surface sediments) will correlate strongly with salinity and, in turn, the proportion of terrestrial organic matter in biota (as defined by isotope data) will be strongest at lagoon sites where runoff is relatively high and tidal exchange is relatively low.  These variations in organic matter sources control community structure and phylogenetic composition among sites.

 

2. The relative importance of terrestrial versus marine organic matter as a food source will decrease from a maximum in winter to a minimum in late summer.  Signals of this seasonal change will manifest as changes in community characteristics and as shifts in the isotopic composition of community members.