Mercury transfer from watersheds to aquatic environments following the erosion of agrarian soils: A molecular biomarker approach

Lake St. Pierre, an important freshwater location for sports and commercial fisheries in Canada, is composed of a 120 km2 stretchof the St. Lawrence River, located at the center of the St. Lawrence Lowlands. Receiving its waters from the St. Franc¸ ois, Yamaska, Ottawa, and St. Lawrence Rivers, it is subjected to important inputs of mercury (Hg) and suspended particles eroded from its watershed. This study aims at tracing back the origin of terrigenous Hg loadings to Lake St. Pierre. The specific phenol signatures yielded by a mild oxidation of the terrestrial organic matter (TOM) carried in the water column was used as a tracer to identify the different sources of terrigenous Hg to the lake. Our results demonstrate that most of the Hg bound to suspended particulate matter (SPM-bound Hg) found in Lake St. Pierre is associated withTOM. We were also able to distinguish the relative influence that forested soils, mainly drained by the Ottawa River, and agrarian soils, located on nearby watersheds, exert on the lake’s Hg burden. Our data strongly suggest that the erosion of vast areas of agrarian soils, drained by the Yamaska and St. Franc¸ois rivers to Lake St. Pierre, greatly facilitates the transfer of Hg from the watersheds to the lake. This study stresses the need to improve the management of agrarian soils and protect them from extensive erosion in order to preserve the integrity of the fish resources harvested in Lake St. Pierre

Effects of hypoxia on benthic macrofauna and bioturbation in the Estuary and Gulf of St. Lawrence, Canada

The bottom water in the 4300 m deep Lower St. Lawrence Estuary (LSLE) is persistently hypoxic in contrast to the normoxic bottom waters in the Gulf of St. Lawrence (GSL). We photographed the seabed at 11 stations in the Estuary and Gulf of St. Lawrence (EGSL) during the summers 2006 and 2007 and analysed the images to identify bioturbation traces (lebensspuren) and benthic macrofauna. The objective was to identify the environmental variables that influence the density and diversity of benthic macrofauna and bioturbation traces, and the differences that exist among regions with high, medium and low oxygen levels in the bottom water. The bottom water oxygen concentration is the variable that best explains the densities of total-traces as well as surface-traces. However, the density of these traces was higher in hypoxic regions than in well-oxygenated regions. The higher density of traces in the hypoxic region of the LSLE is mainly due to the activities of the surface deposit feeder Ophiura sp., which occurs in large numbers in this region. Possible explanations explored are stress behaviour of the organisms in response to hypoxia and different benthic macrofauna community structures between the hypoxic regions of the LSLE and the normoxic regions of the GSL. In the former, surface deposit feeders and low-oxygen tolerant species dominate over suspension feeders and low-oxygen intolerant species

St. Lawrence River

In lieu of an abstract, below is the essay\u27s first paragraph. The boat thrust forward under the power of his arms as he pulled back the oars. Smoother, harder, faster as he went. He had no intention of stopping. He was in his own head now. Harder, faster, the oars back and forth, harder, faster. In his own head not seeing, not hearing. The ripples and the waves that he created were crying out to him, Stop! The river helplessly cried out for his attention but the river\u27s concerns were not his. Not now

Review of: Lawrence J. Kaplan & Rosemarie Tong, Controlling Our Reproductive Destiny: A Technological and Philosophical Perspective

Review of: Lawrence J. Kaplan & Rosemarie Tong, Controlling Our Reproductive Destiny: A Technological and Philosophical Perspective (The MIT Press 1994). Appendix (basic biochemistry), illustrations, index, notes, preface, series foreword by Samuel Goldberg, tables. CIP 93-38060, ISBN 0-262-11176-4 [418 pp. Cloth $29.95. 55 Hayward St., Cambridge MA 02142.

Fish or Cut Bait? Dwight D. Eisenhower and the Creation of the St. Lawrence Seaway

“Our relations with Canada, happily always close, involve more and more the unbreakable ties of strategic interdependence. Both nations now need the St. Lawrence Seaway for security as well as for economic reasons. I urge the Congress promptly to approve our participation and construction.” When President Dwight D. Eisenhower included these sentences in his State of the Union Address in January of 1954, there must have been an almost audible sigh of relief from the thousands of Seaway activists, Congressmen, and lobbyists across the country. The previous year had not been an easy one for supporters of the St. Lawrence Seaway project, but now in 1954 they had the guaranteed support of the most powerful and popular man in the nation

Long-Term Impacts of Environmental Contaminants Are ‘Generational Game Changer’

This article also appeared on pp. 5–6 of the Summer 2018 print edition.Most Formerly Used Defense Sites (FUDS) properties are in remote locations, placing a disproportionate impact on Alaska Native communities that depend upon environmental resources for their livelihood. After the 1972 closure of a U.S. Air Force base that had operated for 20 years on St. Lawrence Island, residents of the Yup'ik village of Savoonga began to experience a higher incidence of cancer, lower birth-weight babies, and higher numbers of miscarriages. The U.S. Army Corps of Engineers eventually spent $125 million cleaning up the abandoned base. But there are concerns about continued impact from environmental contamination. While state and federal health studies recommend continued reliance upon traditional foods based on locally harvested berries, fish, and wildlife, St. Lawrence Island community members fear those foods may be contributing to elevated levels of PCBs and higher cancer rates.Unequal impacts / Corps is not a health agency / Health evaluation requested / Protecting future generations / Reference