The ecological,chemical and histopathological evaluation of an oil spill site: Part I. Ecological Studies

An oil spill into Long Cove, Searsport, Maine, began on 16 March and lasted until at least 30 June 1971. It resulted in immediate and continuing soft clam mortalities which, based on before and after biological surveys, had by August 1974 exceeded 85% of the estimated 50 million market-size clams occupying the area.     

Estimating the timescale of fluvial response to anthropogenic disturbance using two generations of dams on the South River,Massachusetts, USA

Centuries-long intensive land-use change in the north-eastern United States provides the opportunity to study the timescale of geomorphic response to anthropogenic disturbances. In this region, forest-clearing and agricultural practices following EuroAmerican settlement led to deposition of legacy sediment along valley bottoms, including behind mill dams. The South River in western Massachusetts experienced two generations of damming, beginning with mill dams up to 6-m high in the eighteenth–nineteenth century, and followed by construction of the Conway Electric Dam (CED), a 17-m-tall hydroelectric dam near the watershed outlet in 1906. We use the mercury (Hg) concentration in upstream deposits along the South River to constrain the magnitude, source, and timing of inputs to the CED impoundment. Based on cesium-137 (¹³⁷Cs) chronology and results from a sediment mixing model, remobilized legacy sediment comprised % of the sediment load in the South River prior to 1954; thereafter, from 1954 to 1980s, erosion from glacial deposits likely dominated (63 ± 14%), but with legacy sediments still a substantial source (37 ± 14%). We also use the CED reservoir deposits to estimate sediment yield through time, and find it decreased after 1952. These results are consistent with high rates of mobilization of legacy sediment as historic dams breached in the early twentieth century, and suggest rapid initial response to channel incision, followed by a long decay in the second half of the century, that is likely dependent on large flood events to access legacy sediment stored in banks. Identifying sources of sediment in a watershed and quantifying erosion rates can help to guide river restoration practices. Our findings suggest a short fluvial recovery time from the eighteenth–nineteenth century to perturbation during the first half of the twentieth century, with subsequent return to a dominant long-term signal from erosion of glacial deposits, with anthropogenic sediment persisting as a secondary source. © 2020 John Wiley & Sons, Ltd.     

Side-scan sonar reveals submerged remains of the first tay railway bridge

Side-scan sonar surveys, augmented with echo-sounding, have revealed a series of columnar bodies, broken into segments, lying on the bed of the Tay Estuary at the southern end of the first Tay Railway Bridge. These are, with the aid of archive material, interpreted as the remains of 11 twin, brick uprights (Pier Nos. 4–14) that survived the infamous Tay Bridge Disaster of 1879, but were demolished after the opening of the new railway bridge. The piers in question, along with three farther to the south (Nos. 1–3), supported the southernmost 1550 feet (ca. 470 m) of the 2-mile structure, the only part of that ill-fated bridge which was built to the original plans of its designer, Thomas Bouch. They have lain forgotten on the bed of the Tay Estuary for over 100 years. © 1994 John Wiley & Sons, Inc.     

Chemical Characterisation of the USGS Reference Glasses GSA-1G, GSC-1G, GSD-1G, GSE-1G, BCR-2G, BHVO-2G and BIR-1G Using EPMA, ID-TIMS, ID-ICP-MS and LA-ICP-MS

The USGS reference glasses GSA-1G, GSC-1G, GSD-1G, GSE-1G, BCR-2G, BHVO-2G and BIR-1G were investigated by different analytical techniques. All these materials have a geological (basaltic) matrix and are therefore useful in igneous geochemistry as matrix-matched reference materials for microanalytical techniques. The new GS glasses have trace elements in groups at concentration levels of about < 0.01, 5, 50 and 500 μg g^-1. Their major element compositions have been determined by EPMA, and trace elements have been analysed by LA-ICP-MS and two isotope dilution techniques using TIMS and ICP-MS. EPMA and LA-ICP-MS analyses indicated that the USGS reference glasses are homogeneous at the μm to mm scale with respect to major (variations < 1-2%) and most trace elements (variations 1-4%). Trace element data obtained from the different analytical techniques agreed within an uncertainty of 1-5%, indicating that between method results are comparable. Therefore, the preliminary working values for the four USGS GS glasses calculated from these data have a low level of uncertainty.     

Assessing regional land‐use/cover influences on New Jersey Pinelands streamflow through hydrograph analysis

Relative baseflow volume and streamflow flashiness indices were used to assess relationships between land use/cover and streamflow regime in nine New Jersey (NJ) Pinelands streams. Baseflow index (BFI) and Richards–Baker flashiness index (RBI) were estimated on an October–September water year, with period‐of‐record changes assessed by trend analysis and differences between watersheds assessed by examining index versus land‐use/cover relationships using a data period common to all study sites. Four streams, among the more urbanized watersheds of the nine study sites, were found to have significant (α = 0·05) trends in both indices. The two most urbanized study sites showed decreasing baseflow and increasing flashiness; however, the other two streams showed the opposite trends. An apparent slowdown in urbanization towards the second half of the streamflow period of record, along with potential changes in wetland agricultural practices in the latter two watersheds, may explain their trend results. A marginally significant (α = 0·10) decreasing relationship was found between mean annual BFI and wetland agriculture, whereas a significant (α = 0·05) increasing relationship was determined between mean annual RBI and artificial lakes/reservoirs. Principal component analysis showed an association between wetland agriculture and artificial lakes/reservoirs which suggested that both of the significant index versus land‐use/cover relationships reflect wetland agricultural activities. Because these significant relationships involved land uses/covers with small spatial extents (?5%), they demonstrated that land‐use practices can have a greater impact than spatial extent on stream hydrology. This study is the first step in assessing the effect on the NJ Pinelands stream ecology by streamflow alteration due to wetland agricultural activities. Copyright © 2006 John Wiley & Sons, Ltd.     

Caught in the Currents: Pollution,Risk, and Environmental Change in Marine Space

Human interactions with the marine environment and pollution hold broad lessons for understanding environmental change. Expanding geographical inquiry beyond its traditional, land-based foci and delving deeper into marine environment and risk issues offers fruitful avenues by which to elaborate and refine our understanding of nature-society relationships. I present a case study of marine petroleum transportation risks in the Straits of Malacca to illustrate the complex history of political and economic processes across a range of scales and shaping the risks in the Straits. The inescapable tension between generalizing global social and environmental processes and recognizing the array of local differences drives ongoing policy debates in the Straits, as it does increasingly for many global environmental problems.     

Ecological impacts of air pollution from road transport on local vegetation

Motor vehicles emit a cocktail of pollutants and are a major contributor to ground-level air pollution, but little is known regarding the ecological impacts of air pollution from roads on the surrounding vegetation. Data are presented on vegetation at three sites adjacent to two major motorways in the UK, comprising two woodland sites and one blanket bog site. Surveys of oak and beech tree health (at the woodland sites) and species composition (at the blanket bog site) were undertaken along transects away from the motorway.