Historical accounts of Colonial Maine indicate that rivers, estuaries, and nearshore marine ecosystems once sustained abundant wildlife. Yet, by the mid-20th century, overharvesting and industrialization resulted in the ecological collapse of river systems and a concomitant decline of related coastal fisheries. River, estuarine, and marine ecosystems are linked ecologically by anadromous fish. Alewives, blueback herring, and shad, among other species, once migrated to their natal spawning grounds in rivers and lakes by the millions. After spawning, they and billions of juvenile fish emanated from the rivers and estuaries into the nearshore marine environment. This annual influx of fish constituted an important supply of food for piscivorous groundfish, such as Atlantic cod. Overfishing, water pollution, altered food webs, dams, and habitat degradation each played a role in the precipitous decline of river herring populations, and the consequent decline of coastal fisheries. Currently, only the Kennebec and Damariscota rivers produce river herring in any abundance.
Our research seeks to understand the ecological and socioeconomic influences on recovery of our rivers, estuaries, and coastal marine environments. With funding support from the Maine-EPSCoR program of the University of Maine-Orono, we have identified key ecological changes occurring in the combined Kennebec-Androscoggin river-estuary-nearshore marine ecosystem, but we do not have a complete understanding of the current state of the ecosystem nor of the ecological factors limiting further recovery. Similarly, we have identified important socioeconomic forces that have led to ecological change over the past three centuries, but we do not yet know how they may constrain, or respond to, further ecological recovery. To understand the reciprocal interactions and feedbacks between the human and ecological dimensions of these systems, we are gathering the available ecological and socioeconomic information about Maine’s waterways and neighboring communities. This information will be supplemented with more detailed analyses of the Kennebec-Androscoggin system to understand the biophysical and social constraints that dictate the nature, pace, and ultimate extent of ecological recovery. Habitat, food web, and predatory fish diet studies will contribute to our understanding of biophysical constraints on recovery, as well as to the indirect economic benefits – primarily commercial and recreational fisheries – which might emerge from enhancement of river herring populations. Retrospective studies using information collected from retired fishermen inform our understanding of the ecological dependence of nearshore marine ecosystems on anadromous fish. We are administering a contingent choice survey to characterize public understanding and appreciation of ecological principles, qualitative attitudes toward restoration efforts, and quantitative willingness to engage in tradeoffs – monetary and otherwise – to bring about recovery. We will complement this survey with an inventory of institutions which have been and which continue to be influential in dictating actions surrounding river restoration. Our forward-looking analysis will combine market analysis, bioeconomic modeling coupled with food-web analyses, and hedonic analysis of property values to ascertain a plausible range of values for the net benefits of further recovery. Our study of institutions will allow us to examine potential feedbacks between ecological and social change. This project will provide both context-specific and broadly applicable insight into the role of socioeconomic drivers in determining ecosystem state, and in turn how ecosystem status influences human communities.
Our research is a collaborative project which brings together scientists from Bowdoin College, Bates College, the University of Southern Maine, and the Penobscot East Resource Center. Members of our team have long and significant experience working on environmental issues related to Maine’s rivers and coastal waterways. Each scientist brings unique expertise and experience to the research. The natural scientists have experience reconstructing historical fish populations (Ames 2004), conducting aquatic food web (Wilson et al. 2006) and vegetation studies (Camill et al. 2010, Lichter et al. 2011), analyzing fish stomach contents for diet studies (Willis 2009), and performing statistical and spatial analyses. The social scientists have contributed to our understanding of the economic benefits of dam removal (Robbins and Lewis 2008, Lewis et al. 2008); the implications of ecological interactions and spatial dynamics for the management of commercial fish populations (Herrera 2006, 2007, Herrera and Holland 2010); and the potential for economic development in rural Maine (Vail 2004, 2010). E. P. (Ted) Ames, of the Penobscot East Resource Center is a lifelong commercial fisherman, fisheries scientist, and advocate for policy reform that matches the scale of fisheries management with the relevant ecological scale of groundfish populations. His work reconstructing historical groundfish populations based on interviews with retired fishermen has provided insight into the community ecology and food-web dynamics of nearshore groundfish populations before they collapsed in the mid-20th century (Ames 2004). In 2005, Ted’s accomplishments were recognized with a MacArthur Fellowship. Our research team has been convening over the past few years to integrate our interdisciplinary research. In 2009, we were awarded a grant from the Maine EPSCoR program to begin a detailed study of the Kennebec-Androscoggin rivers and their common estuary and nearshore marine ecosystem.
References Ames, E. P. 2004. Atlantic cod structure in the Gulf of Maine. Fisheries 29:10-28. Camill, P., L. Chihara, J.B. Adams, G. Rafert, A. Barry, C. Andreassi, M. Mandell. (2010) Early life history transitions and establishment of Picea mariana in thawed permafrost peatlands. Ecology 91:448-459. Herrera, G.E., 2007. Dynamic use of closures and imperfectly enforced quotas in a metapopulation. American Journal of Agricultural Economics 89(1):176-189. Herrera, G.E., 2006. The benefits of spatial regulation in a multispecies fishery. Marine Resource Economics 21(1):249-261. Holland, D. and G.E. Herrera, 2010. The benefits and risks of increased spatial resolution in management of fishery metapopulations under uncertainty. Natural Resource Modeling 23(4):494-502. Lewis, L. Y., C. Bohlen and S. Wilson. 2008. “Dams, Dam Removal and River Restoration: A Hedonic Property Value Analysis,” Contemporary Economic Policy. April 26(2), 175-186. Lichter, J., M. E. H. Burton, S. L. Close, J. M. Grinvalsky, and J. Reblin. 2011. Habitat change over five decades in a freshwater tidal ecosystem in mid-coast Maine. Northeastern Naturalist, in press. Robbins, J. and L. Lewis. 2008. “Demolish it and They will Come: Dam Removal and the Ex-post measurement of Fisheries Benefits,” Journal of the American Water Resources Association 44(6), 1488-1499. Vail, D. 2004. Tourism in Maine’s expanding service economy. Changing Maine 1960-2010. R. Barringer, ed. Edmund Muskie School of Public Service. University of Southern Maine. Tilbury Press. Pp 429-449. Vail, D. 2010. Prospects for a rural population rebound: can quality of place lure immigrants? Maine Policy Review 19:16-25. Willis, T. V. 2009. How Policy, Politics, and Science Shaped a 25-Year Conflict over Alewife in the St. Croix River, New Brunswick Maine in A. Haro, Smith, Katherine L. , Rulifson, Roger A. , Moffitt, Christine M. , Klauda, Ronald J. , Dadswell, Michael J. , Cunjak, Richard A. , Cooper, John E. , Beal, Kenneth L. , Avery, Trevor S. , editor. Challenges for Diadromous Fishes in a Dynamic Global Environment. American Fisheries Society, Bethesda, MD. Wilson, K. A., J. J. Magnuson, D. M . Lodge, A. M. Hill, T. K. Kratz, W. L. Perry, and T. V. Willis. 2004. Long-term effects of rusty crayfish (Orconectes rusticus) invasion: dispersal patterns and community changes in a north temperate lake. Canadian Journal of Fisheries and Aquatic Sciences 61:2255-2266.