Complex Ecosystem Interactions Over Multiple Spatial and Temporal Scales: The Biocomplexity of Sanak Island

The greater North Pacific region is one of the worlds most important fisheries. Recent dramatic decreases in the numbers of many species in this region have perplexed biologists, caused sweeping and underinformed management decisions, and provoked cultural disintegration of many Alaska Native villages.

Data gathered during the 20th century show that there have been other periods of low productivity for species, often followed by periods of abundance. These patterns also are evident in paleoecological and archaeological data from the last 5,000 years, thereby emphasizing the critical character of a central question: Given varying population cycles of humans, salmon, groundfish, sea mammals, birds, and many other species in the North Pacific region as well as varying harvests by the higher trophic levels, how do people sustain populations, ecosystems, and the peoples and cultures who depend on them for social, political, economic, and cultural identity?

To investigate the complex interactions among natural and human systems on and around Sanak Island in the Aleutian chain of Alaska, an interdisciplinary research team will study humans as part of the northern ecosystem. The investigators will examine interrelationships among the modern and prehistoric, terrestrial and marine, and local and regional systems, including both empirical and theoretical explorations.

In previous projects, the investigators have observed that the indigenous Aleut were not just simple and passive harvesters but were active participants in a regional ecosystem that includes them as significant forces. The implications of this approach require the integration of anthropology, archaeology, geology, ecology, mathematics, climatology, and history, the perspective of many spatial and temporal scales, and the seamless merging of theoretical approaches from many fields. Because the Aleut have been harvesting resources on the north Pacific for thousands of years, they have been included in models and reconstructions of the islands ecosystem as ecosystem engineers, as more ordinary components of food webs and landscapes, and as passive responders to a world that is primarily driven by largely external forces like climate and geomorphic evolution.

This project will result in development and application of modern analytical techniques drawn from the study of complex systems in order to better understand the roles of peoples in the history and functioning of the Earth. The investigators are constructing and analyzing the first extensive food webs that extend over millennial time scales. The project is distinctive because of its extensive explicit inclusion of people as components of food webs. The investigators are pioneering the development of techniques for extracting information from data in which error is necessarily confounded with time period, and the project will yield data that can be compared across times. The investigators are extensively developing and testing methods for interfacing data from diverse sources that inherently differ in resolution and data structure (e.g., ancient middens, climate reconstruction by proxy and modeling, various direct censuses), and they are expanding the application of stable isotopes to study ecological and paleoecological phenomena that emphasize large-scale ecosystem structure and function.

The investigators also will bring new perspectives to the relationships of diversity and productivity of ecosystems, comparing systems across very long time scales , and they will advance understanding of sustainable patterns of food web and ecosystem structures and dynamics. The project will incorporate indigenous knowledge, local history, and direct community participation in data collection, and it will give residents a voice in the process of scientific advisement through both collaboration and through the analysis of marine policy that directly affects their daily lives. The project will provide critical scientific data to inform policy regarding long-term data on the role of humans in the dynamics of North Pacific ecosystems, and it will illuminate the state of historical shifting baselines in the ecosystem over deep time. The investigators are exploring a new way of doing scientific research in this kind of setting by incorporating local people as part of a complex ecosystem rather than an external impact to be externally regulated. This project is supported by an award resulting from the FY 2005 special competition in Biocomplexity in the Environment focusing on the Dynamics of Coupled Natural and Human Systems.

Lead Investigator: 
millenial food webs, stable isotopes
Sanak Island in the Aleutian chain of Alaska
Temporal Scope: 
pre-historic - contemporary
Spatial Scope: 
Natural System: 
subarctic island, terrestrial, marine
Human System: 
indigenous livelihoods, modern regulation