Seal Harbour Research Articles

Biological effects of gold mine tailings on the intertidal marine environment in Nova Scotia, Canada

From 1861 to the 1940s, gold was produced from 64 mining districts in Nova Scotia, where mercury amalgamation was the dominant method for the extraction of gold from ore until the 1880s. As a result, wastes (tailings) from the milling process were contaminated by mercury and were high in naturally occurring arsenic. In 2004 and 2005, sediments, water and mollusc tissues were collected from 29 sampling stations at nine former gold mining areas along the Atlantic coastline and were analysed for arsenic and mercury. The resulting data were compared with environmental quality guidelines. Samples indicated high potential risk of adverse effects in the intertidal environments of Seal Harbour, Wine Harbour and Harrigan Cove. Arsenic in Seal Harbour was bioavailable, resulting in high concentrations of arsenic in soft-shell clam tissues. Mercury concentrations in tissues were below guidelines. This paper presents results of the sampling programs and implications of these findings.

A unique coastal watershed survey in Maine

A unique, community-based coastal watershed survey was conducted in the Stanley Brook Watershed in Seal Harbor, Maine, between June and October of 2005. The Stanley Brook Watershed Survey was specifically designed to address the pollution issues affecting Stanley Brook habitats and public health issues at Seal Harbor Beach. This novel watershed survey utilized key components of the Maine Department of Environmental Protection watershed survey process, which targets nonpoint source pollution, and the Maine Department of Marine Resources sanitary shoreline survey process, which targets point sources of bacterial pollution. The survey was coupled with water quality monitoring at Seal Harbor Beach through the Maine Healthy Beaches (MHB) program. The Stanley Brook Watershed encompasses 378 ha (935 ac) and straddles both Acadia National Park (ANP) and the village of Seal Harbor in the town of Mt. Desert on Mt. Desert Island, Maine. The headwaters of Stanley Brook begin on Day Mountain; including its tributaries, Stanley Brook is 6 km (3.7 mi) in total length, meandering through ANP before emptying into the ocean at Seal Harbor Beach. Stanley Brook is a rich habitat for local flora and fauna. Sea-run brook trout ( Salvelinus fontinalis ) have been documented in Stanley Brook (Kazyak 2011), which makes…

Two Poems

Two Poems GEORGE KALOGERIS Proteus I’m squeezing his hand, but he speaks another tongue. The word for his walking stick, like the hiss of the surf At our feet, is an eel so quick it could slither away With a single wriggle: kléetza. The breakers don’t move But the pebbles keep shifting places. If I had to guess, He must be as old as old Proteus himself. Very soon, I’m told, he’ll be going back to Greece. By now we’ve reached Seal Harbor, the end of the beach. I don’t yet know the names of the harbor islands But I think I know the myths. And the fog is lifting. I point to the islands and say the only thing I ever remember saying to him: Elláda. His name for home. He nods to me by the waves. In a week or so he’s gone. And then he’s the waves. arion 22.3 winter 2015 The Rowers Oblivious to everything but the beat of their oarlocks, Over and over they strike the dark night water’s surface Into swirls the quicksilver craft instinctively recoils from. The irresistible singers stand on a reef of bones. The rowers never look up. The doldrums are all around them. Across the Sirens’ mouths flows nightfall’s streaming hair. In the brightness bleached from their marrow the heaps of bones cry out To the writhing hero, whose wrists are cut by rawhide cords. The swaying mast is pointing to stars that sail above it. Beyond the midnight pull of the moon, the rowers bend Their rounded backs to their wooden blades. To them the currents Calling them home are dim as a kitchen’s fluorescent hum. Their ears are stopped with wax that is also the honey of Hyblos. two poems 100 ...

Gaseous mercury flux measurements from two mine tailing sites in the Seal Harbour area of Nova Scotia

During August 2004, mercury (Hg) flux-rates from surface soil were measured at an abandoned gold mining site near Seal Harbour, Nova Scotia. The Hg amalgamation process, used to isolate gold, produced areas of Hg-laden mine tailings. Diurnal measurements of the soil surface exchange of gaseous Hg to the atmosphere and meteorological data from two tailing deposit sites are discussed. These sites have different mining histories resulting in differing levels of Hg in the surface soil (0.05 µg g −1 - Site 1, 23 µg g −1 - Site 2). Site 1 showed a maximum flux-rate during mid-day at 60 ng m −2 hr −1 , declining to c. 5 ng m −2 hr −1 during evening while Site 2 had a mid-day Hg flux-rate of 1292 ng m −2 hr −1 with levels of c. 300 ng m −2 hr −1 during the evening. Mercury flux from each site has continuous diurnal Hg evasion at the soil surface. Correlations of Hg flux-rate with soil temperature, air temperature and solar radiation were evident at both sites and an Arrhenius-type relation of Hg flux with soil temperature was also evident. Data from these sites were compared to flux experiments conducted at impacted and other non-impacted sites in Nova Scotia.

Mineralogy and spectral reflectance of soils and tailings from historical gold mines, Nova Scotia

Gold was mined in 64 districts in southern Nova Scotia between 1861 and the early 1940s, followed by limited, intermittent production up to the present. There is extensive dispersion of arsenic- and mercury-bearing mine tailings in the receiving environment downstream from many of these sites. Elevated mercury concentrations, highest near old stamp mill foundations, occur because of the mercury amalgamation process used to extract gold until the 1940s. Arsenic, on the other hand, occurs naturally in arsenopyrite, which is associated with the gold-bearing quartz veins and host rocks. Tailings are composed of fine sand- to silt-sized quartz, feldspar, illite and chlorite, and represent the primary rock-forming minerals in the metasedimentary host rocks of the Cambro-Ordovician Meguma Supergroup. Carbonate and sulphide minerals occur in minor to trace amounts, along with secondary minerals such as scorodite (FeAsO 4 ·2H 2 O). The extent of tailings dispersal can be mapped through hyperspectral remote sensing methods, as these major mineral components provide an identifiable spectral signature through visible, near infrared and short-wave infrared regions. This paper examines the mineralogy of soils, tills and tailings in the Upper and Lower Seal Harbour gold districts of Nova Scotia. Ground-truthing of space-borne hyperspectral data demonstrates the potential for remote mapping of the spatial extent of these historical mine wastes.

Inclusion of soil arsenic bioaccessibility in ecological risk assessment and comparison with biological effects

The purpose of this study was to conduct an ecological risk assessment (ERA) for meadow voles ( Microtus pennslvanicus) found at three arsenic contaminated sites in Nova Scotia, Canada (as well as two background locations) and to compare the numeric results to measured biomarkers of exposure and effect. The daily intake of arsenic by meadow voles was determined by three separate calculations: estimated daily intake (EDI), bioaccessible estimated daily intake (BEDI, with bioaccessibility of soil included), and actual daily intake (ADI, which is calculated with arsenic concentrations in the stomach contents). The median bioaccessibility of arsenic in soils from the contaminated locations was significantly greater than at background locations. The bioaccessible arsenic concentration in soil from all samples (both contaminated and background) was significantly less than the total concentration. Use of site-specific bioaccessibility (hazard quotients = 38 at Upper Seal Harbour (USH); 60 at Lower Seal Harbour (LSH); and 120 at Montague tailings (MONT)) and stomach arsenic contents (hazard quotients = 2.1 at USH; 7.9 at LSH; and 6.7 at MONT) in the ERA resulted in lower numeric risk than compared to risk calculated with 100% bioavailability (hazard quotient = 180 at USH; 75 at LSH; and 680 at MONT). Further, the use of bioaccessibility on the calculation of risk was aligned with biomarker results (changes in glutathione and micronucleated erythrocytes) in voles captured at the sites. This study provides evidence that using site-specific bioaccessibility in ERAs may provide a more realistic level of conservatism, thereby enhancing the accuracy of predicting risk to wildlife receptors. Furthermore, when numeric risk assessments are combined with site-specific biological data (i.e., biomarkers of exposure and effect), both lines of evidence can be used to make informed decisions about ecological risk and site management.

Arsenic transformations in terrestrial small mammal food chains from contaminated sites in Canada

Arsenic in terrestrial contaminated sites has the potential to cause harm to residential wildlife. The aim of this study was to determine the arsenic species in wild rodents living in arsenic contaminated habitats, specifically deer mice from Yellowknife, NT and meadow voles from Seal Harbour, NS, along with co-located plants. Methanol : water (1 : 1) extractions were used to optimize the extraction of methylated arsenic(v) species. Total arsenic concentrations were substantially higher in the Yellowknife deer mice (1.7-3.2 µg kg(-1) wet weight in livers) and Seal Harbour meadow voles (0.67-0.97 µg kg(-1) wet weight in livers) living on the contaminated sites with respect to the surrounding background locations (0.12-0.34 µg kg(-1) wet weight in livers). Around 50% of arsenic could be identified in Yellowknife deer mouse tissues, but only <10% was identified in Seal Harbour vole tissues; inorganic arsenic (iii and v) and dimethylarsinic acid were all found. Monomethylarsonic acid was only detected in both the mice and voles living in the contaminated sites. In the Yellowknife food chain, methyl arsenic (v) proportions increased from plants to mouse inner organs, but the trend was not for clear as the Seal Harbour food chain. Seal Harbour voles may be sequestering arsenic in a less mobile form, rather than transforming it.

Automatic destriping of Hyperion imagery based on spectral moment matching

As a pushbroom imaging spectrometer, the Hyperion sensor records each along-track image column with a single detector element in one of its area detector arrays. This image acquisition configuration is prone to exhibiting along-track striping artefacts, if the instrument has not undergone a recent, proper uniformity calibration. These defective columns must be corrected before performing further processing and quantitative analyses. Spatial moment matching (SpaMM) is currently the most commonly used method for destriping Hyperion imagery. However, since SpaMM was originally developed for dealing with remotely sensed multispectral data, the abundant spectral information embedded in hyperspectral data is not fully utilized in the method. This paper proposes a new methodology that can automatically and more accurately remove the striping artefacts from Hyperion imagery. The technique is called spectral moment matching (SpcMM) because it uses spectral autocorrelation instead of spatial autocorrelation to estimate the expected mean and standard deviation of a subscene, which is comprised of the image pixels acquired by an identical detector element (an along-track image column in the case of Hyperion data). The basis of the algorithm is the observation that there are usually highly correlated groups of bands in a hyperspectral image cube; the statistics of the subscenes measured by the corresponding detectors in a set of highly correlated bands are usually very similar. The possibility of introducing undesired side effects into the destriped images by the proposed SpcMM is minimized due to the proper estimation of the expected mean and standard deviation for each along-track column. Moreover, SpcMM can automatically destripe an entire Hyperion image cube without the manual selection of defective bands or across-track spatial regions, or the individual selection of band-specific window sizes for spatial smoothing. Two Hyperion datasets acquired over sites in Seal Harbour, Canada, and Coleambally, Australia, have been used to assess the proposed new destriping technique. Examination of the images destriped by SpcMM and SpaMM and the reflectance spectra retrieved from the destriped image cubes reveals that the presented algorithm removes various types of stripes without degrading the images and is superior to the spatial moment matching technique.

Gastrointestinal Microbes Increase Arsenic Bioaccessibility of Ingested Mine Tailings Using the Simulator of the Human Intestinal Microbial Ecosystem

It is widely accepted that the use of total metal concentrations in soil overestimates metal risk from human ingestion of contaminated soils. In vitro simulators have been used to estimate the fraction of arsenic present in soil that is bioaccessible in the human digestive track. These approaches assume that the bioaccessible fraction remains constant across soil total metal concentrations and that intestinal microbiota do not contribute to arsenic release. Here, we evaluate both of these assumptions in two size fractions (bulk and <38 microm) of arsenic-rich mine tailings from the Goldenville, Lower Seal Harbour, and Montague Gold Districts, Nova Scotia. These samples were evaluated using an in vitro gastrointestinal model, the Simulator of the Human Intestinal Ecosystem (SHIME). Arsenic bioaccessibility, which ranged between 2 and 20% in the small intestine and 4 and 70% in the colon, was inversely related to total arsenic concentration in the mine tailings. Additionally, arsenic bioaccessibility was greater in the bulk fraction than in the <38 microm fraction in the small intestine and colon while colon microbes increased the bioaccessibility of arsenic in mine tailings. These results suggest that the practice of using a constant percent arsenic bioaccessibility across all metal concentrations in risk assessment should be revisited.

Arsenic bioaccessibility and speciation in clams and seaweed from a contaminated marine environment

The bioaccessible concentration and speciation of arsenic (soluble in a gastrointestinal medium and available for absorption into the bloodstream) were determined in softshell clams ( Mya arenaria), harvested by local residents until 2005, and in seaweed ( Fucus sp.) from an arsenic-contaminated marine site in Seal Harbour, Nova Scotia, Canada. Bioaccessibility extractions to simulate the human gastrointestinal environment (pH 1.5 and glycine for 1 h followed by pancreatin, bile extract and pH adjustment to 7 for an additional 4 h) and speciation of arsenic in extracts (HPLC-HG-AAS to target inorganic arsenic species) and whole samples (XANES) were carried out. Total arsenic for the clams from the contaminated area ranged from 218 to 228 ppm wet weight, with a bioaccessible fraction of 34–46%, and the major bioaccessible species of arsenic were inorganic. The seaweed from the contaminated area contained 27–43 ppm wet weight total arsenic, with the bioaccessible fraction ranging from 63% to 81%, and inorganic arsenic was also predominant. The predominantly inorganic nature of arsenic in the whole samples was confirmed by XANES. In concurrence with the closure of the area for clam harvesting, the clams and seaweed from Seal Harbour should probably not be used for human consumption.

G. Ledyard Stebbins (1906-2000): an appreciation.

Ledyard Stebbins, born January 6, 1906, was deeply fond of nature all his life, starting with his experiences around Seal Harbor, Maine, when he was 4 years old. While he was still young, his mother contracted tuberculosis, and the family moved west to find a more healthy climate for her, first in Pasadena, then in Colorado Springs. An important formative period of Ledyard's life was spent at Cate School, in Santa Barbara, where he studied for 4 years. During those years, he was, by his own account, shy and relatively unpopular. There he learned to ride horseback, explored the Santa Ynez Mountains, and fell under the influence of botanist Ralph Hoffmann, who taught him much about the plants and natural history of that lovely area.