Our goal was to use the CHANS Torin 1 mw approach to identify data, research needs and to set the stage for further assessment (e.g. feedbacks, time lags, surprises, sensu Liu et al., 2007) on how the socioeconomic system and the aquatic ecosystem have interacted and changed through time. Lake St. Clair (LSC), a shallow transboundary system in the Laurentian Great Lakes (Leach, 1991) (Fig. 1), connects Lakes Huron and Erie via the St. Clair River to the north and the Detroit River to the south. It is part of the Huron-Erie corridor. Lake St. Clair may seem small compared to the other Great Lakes, but it is the 11th largest lake

in surface area in the continental USA (Herdendorf, 1982 and Hunter and Simons, 2004). It also has about 1000 km of shoreline perimeter (Fig. 1). The LSC connecting channel contains three Areas of Concern as listed by the Great Lakes Water Quality Agreement, which are located in the St. Clair River, the Detroit River, and the Clinton River with a portion of the western lake shoreline (United States Environmental Protection Agency, access date see more 2 April 2012, http://www.epa.gov/glnpo/aoc/). The aggregate area of the local watersheds that drain to LSC (excluding the watershed of Lake Huron and other

upper Great Lakes) is 15,305 km2, with 59% of this area (8988 km2) on the Canadian side, and the remainder (6317 km2) on the USA side (Fig. 1). The USA and Canadian portions of the LSC watershed differ greatly in terms of land use according to recent satellite-derived land cover data. On the USA side in the year 2006, agricultural land use comprised 41% of the watershed and 32% percent was developed (Fry et al., 2011). In Canada as of 2000, land use in the watershed was dominated by agriculture (77%) with 5% cover each in forest and developed land (Agriculture and Agri-Food Canada, access date 8 April 2012, ftp://ftp.agr.gc.ca/pub/outgoing/aesb-eos-gg/LCV_CA_AAFC_30M_2000_V12). It is not likely that land cover change in the short

interval between 2000 and 2006 changed these percentages appreciably. The majority of the watershed is located within five counties on each side of the border (Fig. 1). Besides the St. Clair River, the other rivers that drain into the lake aminophylline include the Black, Belle and Clinton Rivers in Michigan and the Thames and Sydenham Rivers in Ontario. The largest portion of water entering the lake (98%) comes from the St. Clair River, which supports the largest freshwater delta in the Great Lakes system (Herdendorf, 1993), the St. Clair Flats which contains about 170 km2 of wetlands (Edsall et al., 1988). We used primary literature, state and federal governmental reports and websites as well as state and federal governmental data sources to compile our overview and to conduct new analyses about the characteristics of the lake and its watershed.