| Abstract | The trophic history of Lake Champlain's northeastern arm was assessed using a multi-proxy paleolimnological approach to provide sub-basin specific information for restoration planning. Sediment cores collected from Missisquoi Bay, St. Albans Bay, and the central Northeast Arm (Inland Sea) were analyzed for nutrients, organic carbon, carbon stable isotopes, biogenic silica, pigments, diatoms and soft algaemicrofossils. Results indicate that this arm of Lake Champlain was oligotrophic when Europeans arrived in 1609, and that clearance of N70% of catchment forest cover had minor impact on algal production. Instead, eutrophication of St. Albans Bay was concurrentwith sewer installation and expansion in early 20th century, and again with urban development in the 1960-70s. In contrast, less urbanized Missisquoi Bay remained mesotrophic until agriculture intensified after 1970. Interpretation of central Northeast Armtrophic history is complicated because road and railroad causeways built in 19th century reduced sediment input to this basin for several decades. Nevertheless, high surfacesediment concentrations of nutrients, pigments and organicmatter alongwith replacement of Cyclotella bodanica with more eutrophic Fragilaria crotonensis suggest substantial eutrophication in deep as well as shallow water after 1970. We conclude that effective restoration of the northeastern arm is possible, but will require stringent control of animal and human wastes and reduced use of crop fertilizers. |
| Authors | Levine, Suzanne N.;Lini, Andrea ;Ostrofsky, Milton L. ;Bunting, Lynda ;Burgess, Heather ;Leavitt, Peter R.;Reuter, Daun ;Lami, Andrea ;Guilizzoni, Piero;Gilles, Elizabeth |
| Text | 220254 2012 10.1016/j.jglr.2011.07.007 The eutrophication of Lake Champlain s northeastern arm Insights from paleolimnological analyses Levine, Suzanne N.;Lini, Andrea ;Ostrofsky, Milton L. ;Bunting, Lynda ;Burgess, Heather ;Leavitt, Peter R.;Reuter, Daun ;Lami, Andrea ;Guilizzoni, Piero;Gilles, Elizabeth University of Vermont, Rubenstein School of Environment and Natural Resources, Aiken Center, Burlington, VT, 05405, USA ;University of Vermont, Department of Geology, Delahanty Hall, Burlington, VT, 05405, USA ;Department of Biology, Allegheny College, Meadville, PA, 16335, USA ;Limnology Laboratory, Department of Biology, University of Regina, Regina, SK, Canada, S4S 0A2 ;University of Vermont, Department of Geology, Delahanty Hall, Burlington, VT, 05405, USA ; Science, Liberal Arts and Business Division, Paul Smith s College, Paul Smiths, NY 12970, USA ;CNR ISE, Pallanza Verbania ; The trophic history of Lake Champlain s northeastern arm was assessed using a multi proxy paleolimnological approach to provide sub basin specific information for restoration planning. Sediment cores collected from Missisquoi Bay, St. Albans Bay, and the central Northeast Arm Inland Sea were analyzed for nutrients, organic carbon, carbon stable isotopes, biogenic silica, pigments, diatoms and soft algaemicrofossils. Results indicate that this arm of Lake Champlain was oligotrophic when Europeans arrived in 1609, and that clearance of N70% of catchment forest cover had minor impact on algal production. Instead, eutrophication of St. Albans Bay was concurrentwith sewer installation and expansion in early 20th century, and again with urban development in the 1960 70s. In contrast, less urbanized Missisquoi Bay remained mesotrophic until agriculture intensified after 1970. Interpretation of central Northeast Armtrophic history is complicated because road and railroad causeways built in 19th century reduced sediment input to this basin for several decades. Nevertheless, high surfacesediment concentrations of nutrients, pigments and organicmatter alongwith replacement of Cyclotella bodanica with more eutrophic Fragilaria crotonensis suggest substantial eutrophication in deep as well as shallow water after 1970. We conclude that effective restoration of the northeastern arm is possible, but will require stringent control of animal and human wastes and reduced use of crop fertilizers. 38 Articolo in rivista International Association for Great Lakes Research. 0380 1330 Journal of Great Lakes research Journal of Great Lakes research J. Great Lakes res. piero.guilizzoni GUILIZZONI PIERO andrea.lami LAMI ANDREA TA.P02.014.002 Impatto dei cambiamenti globali sugli ecosistemi acquatici |
