Construction of shipping channels in the Detroit River: History and environmental consequences

Abstract

The Detroit River is one of the most biologically diverse areas in the Great Lakes basin. It has been an important international shipping route since the 1820s and is one of the busiest navigation centers in the United States. Historically, it supported one of the most profitable Lake Whitefish (Coregonus clupeaformis) commercial fisheries in the Great Lakes. Since 1874, the lower Detroit River has been systematically and extensively modified, by construction of deepwater channels, to facilitate commercial shipping. Large-scale dredging, disposal of dredge spoils, and construction of water-level compensating works has greatly altered channel morphology and flow dynamics of the river, disrupting ecological function and fishery productivity of the river and influencing Great Lakes water levels. From 1874 to 1968, major construction projects created 96.5 kilometers (60 miles) of shipping channels, removed over 46,200,000 m 3 of material, covered 4,050 hectares (40.5 square kilometers) of river bottom with dredge spoils, and built 85 hectares of above-waterline compensating works at a total cost of US$283 million. Interest by industries and government agencies to develop the river further for shipping is high and increasing. Historically, as environmental protection agencies were created, construction impacts on natural resources were increasingly addressed during the planning process and, in some cases, assessments of these impacts greatly altered or halted proposed construction projects. Careful planning of future shipping-channel construction and maintenance projects, including a thorough analysis of the expected environmental impacts, could greatly reduce financial costs and ecological damages as compared to past shipping-channel construction projects.

Portfolio theory as a management tool to guide conservation and restoration of multi‐stock fish populations

“…Unfortunately, the levels of production necessary to achieve Option 3 are orders of magnitude greater than current production from these production areas. This option may perhaps be an unrealistic target without major investment in mitigating spawning habitat degradation and solving river-to-lake connectivity issues that currently plague Lake Erie's riverine stocks (Mion et al 1998, Cheng et al 2006, Bennion and Manny 2011. If the current and continued cultural demands on these systems preclude sufficient habitat (and hence, stock) rehabilitation in western Lake Erie's spawning tributaries, then management options 4 and 5 may offer the next best targets for optimal production dynamics, as both seem attainable.…”

Egg deposition by lithophilic-spawning fishes in the Detroit and Saint Clair Rivers, 2005–14

“…Habitat alteration from excavation and maintenance of these channels in the Detroit River has been more extensive than in the Saint Clair River. At least 46.2 million m 3 of material have been dredged or excavated from the river, the spoils of which now cover an additional 4,050 hectares (ha) of river bottom (Bennion and Manny, 2011). The Livingstone Channel, which was dredged through a shallow bedrock sill, is the largest of these channel projects and concentrated a majority of the discharge from the Detroit River into a singular outflow into Lake Erie (Bennion and Manny, 2011).…”

“…At least 46.2 million m 3 of material have been dredged or excavated from the river, the spoils of which now cover an additional 4,050 hectares (ha) of river bottom (Bennion and Manny, 2011). The Livingstone Channel, which was dredged through a shallow bedrock sill, is the largest of these channel projects and concentrated a majority of the discharge from the Detroit River into a singular outflow into Lake Erie (Bennion and Manny, 2011). Twelve large islands exist in the Detroit River-many of these in the lower reaches comprise parts of the more than 2,300 ha in the Detroit River International Wildlife Refuge (Hartig and others, 2010).…”

“…1). At the turn of the 20th century, 28 native fish species spawned in the SCDRS including walleye (Sander vitreus), lake whitefish (Coregonus clupeaformis), cisco (Coregonus artedi), and lake sturgeon (Acipenser fulvescens) (Goodyear and others, 1982) that all contributed to a thriving commercial fishery (Baldwin and others, 2009); however, habitat changes from over a century of shipping channel excavation and dredging, shoreline development, and pollution cumulatively resulted in huge losses of fish spawning and nursery habitats (Edsall and others, 1988;Manny and others, 1988;Bennion and Manny, 2011). These perturbations, in combination with heavy commercial fishing pressure, led to large-scale losses of fish populations in these rivers, including the local extirpations of cisco and lake trout (Salvelinus namaycush) (Smith, 1972), the near extirpation of lake whitefish (Smith, 1915(Smith, , 1917Roseman and others, 2007), and declines in walleye (Manny and others, 2010) and lake sturgeon (McClain and Manny, 2000;Manny and Kennedy, 2002).…”

“…Following the construction of the Fighting Island Channel (1914-15) that extended from shoal areas at the base of Fighting Island to the east side of Grassy Island ( fig. 1), the commercial fishery for lake whitefish quickly collapsed and spawning runs of lake whitefish into the Detroit River disappeared (Bennion and Manny, 2011). Lake whitefish eggs have never been reported from the Saint Clair River, although several studies have recorded low densities of their larvae in that river (Goodyear and others, 1982;Hatcher and Nester, 1983;Leslie and Timmins, 1991).…”