Trevor Bell

Impact assessment of current and future sea-level change on coastal archaeological resources - illustrated examples from Northern Newfoundland

ABSTRACT Coastal archaeological heritage is potentially vulnerable to increased erosion resulting from predicted future sea-level rise and increased storminess. As all sites cannot be protected, it is essential that heritage managers know which sites and landscapes are most at risk so they can prioritize resources and decision-making most effectively. One method of doing so is through desk-based modeling of coastal vulnerability. This article outlines the advantages and limitations of such an approach and demonstrates the application of a desk-based model to case studies from Newfoundlands coast. The rate of future sea-level rise around Newfoundland is complicated by its glacio-isostatic recovery since the last ice age. The first step therefore in this assessment is to combine output from glacio-isostatic adjustment models with appropriate rates of global eustatic sea-level rise. Next, these data are integrated with existing information on coastal characteristics (topography, surficial geology, erosion rates) to assess coastal sensitivity to sea-level rise. Finally, overlay of known archaeological sites identifies those locations at greatest risk from destructive coastal changes. The results demonstrate the effectiveness of such models for regional-scale analyses but caution against the use of low resolution data to generate site-specific predictions.

Marine habitat mapping in support of Marine Protected Area management in a subarctic fjord: Gilbert Bay, Labrador, Canada

This paper presents an approach that allows production of benthic substrate and habitat maps in fjord environments. This approach is used to support the management of the Gilbert Bay Marine Protected Area (MPA) in southeastern Labrador, Atlantic Canada. Multibeam sonar-derived bathymetry, seabed slope, and acoustic reflectance (backscatter) were combined using supervised classification methods and GIS with ground-truthed benthic sampling in order to derive maps of the substrates and main benthic habitats. Six acoustically distinct substrate types were identified in the fjord, and three additional substrate types without a unique acoustic signature were recognized. Ordination by multidimensional scaling and analysis of similarity generalized these to four acoustically distinct habitat types. Greatest within-habitat (alpha) diversity was found in the coralline-algae encrusted gravel habitat. Greatest between-habitat (beta) diversity was found in the management Zones 1 and 2, which have the highest level of protection. The study confirmed that the zoning plan for the MPA, which was designed to protect spawning and juvenile fish habitat for a local genetically distinct population of Atlantic cod, afforded highest levels of protection to areas with highest habitat diversity.

Prehistoric cultures, reconstructed coasts: Maritime Archaic Indian site distribution in Newfoundland

We argue that variable and complex post-glacial relative sea level (RSL) in Newfoundland is linked to (1) the uneven distribution around the coastline of late Maritime Archaic Indian (MAI) sites (5500–3200 bp) and (2) the apparent absence of early MAI sites (8000–5500 bp), despite their presence in nearby southern Labrador. Three post-glacial RSL histories are described for different regions of Newfoundland: continuous emergence (type A), initial emergence followed by submergence (type B) and continuous submergence (type C). In areas characterized by type B or C curves, where the lowstand is greater than 20m water depth, late MAI sites older than 3000 bp are today submerged. In all areas other than those characterized by a type A curve, early MAI sites would be under water. The Northern Peninsula is the only region of Newfoundland described by a type A curve. If early MAI did occupy Newfoundland, we predict where on the Northern Peninsula those sites would be found.

Holocene glacimarine sedimentation and macrofossil palaeoecology in the Canadian High Arctic: environmental controls

Abstract Raised glacimarine sediments adjacent to Strand Bay, Axel Heiberg Island and on Fosheim Peninsula, Ellesmere Island, record sedimentation in environments proximal to tidewater glaciers and glacimarine deltas. The different styles of sedimentation during early Holocene deglaciation (ca. 8–10 ka BP) of these regions are of particular interest. In Strand Fiord, Axel Heiberg Island coarse-grained sediments deposited from high-density turbidity currents generated along the margin of tidewater glaciers, are overlain by laminated fine-grained sediments deposited by suspension settling in a shallow ice-proximal environment. The fining-upward sequence records the reduction in sediment supply as tidewater glaciers retreated onto land. In contrast, on Fosheim Peninsula, Ellesmere Island, laminated to massive fine-grained sediments were deposited from low-density turbidity currents and by suspension settling in a deep prodeltaic environment several kilometres from upland ice caps. Sediment texture coarsens-upward, reflecting increasing proximity to sediment sources as deltas prograded during early Holocene marine regression. Two macrofossil faunas, a Portlandia arctica assemblage and a Hiatella arctica-Mya truncata assemblage, occur in association with early Holocene sediments. Mid-Holocene sedimentation (ca. 4–8 ka BP) in both regions was characterized by the accumulation of laminated or massive fine-grained sediments deposited from low-density turbidity currents and by suspension settling in prodeltaic environments. Several macrofossil faunas are recorded in these sediments; a Portlandia arctica assemblage and an Astarte borealis-Mya truncata assemblage associated with laminated muds deposited in shallow water, and a deep-water Portlandia arctica assemblage associated with massive muds. Variations in sedimentation rates can be correlated with the summer-melt layer record of the Agassiz Ice Cap on Ellesmere Island. Early Holocene deglaciation coincided with a period of increased summer ablation (ca. 8.5–11.5 ka BP) that contributed to the massive influx of sediment into marine environments. The mid-Holocene ice core-record indicates a sharp decline in summer ablation (ca. 6.0–9.5 ka BP) resulting in the reduction of sediment flux to marine environments.

Evaluating climate change vulnerability assessments: a case study of research focusing on the built environment in northern Canada

Vulnerability assessments (VAs) have been widely used to understand the risks posed by climate change and identify opportunities for adaptation. Few studies, however, have evaluated VAs from the perspective of intended knowledge users or with reference to established best practices. In this paper, we identify and evaluate VAs focusing on the built environment in northern Canada. We document 16 completed VAs, which range from engineering-based studies of the vulnerability of specific infrastructural assets (e.g. building foundations, roads) to community-based assessments characterizing the vulnerability of the built environment in general in specific communities. We then evaluate projects based on the extent to which they incorporate best practices for vulnerability assessment, informed by a review of the scholarship and interviews with practitioners and knowledge users in the north (n = 21). While completed VAs have increased our understanding of the risks posed by climate change, none perform well across all evaluation criteria, and interviewees identified the need for improvement to VAs to inform decision making. Specifically, there is a need for greater emphasis on stakeholder engagement and effective communication of research findings, and interdisciplinary collaboration to capture the multiple drivers of vulnerability, cost impacts, and examine the performance of infrastructural assets under different climate scenarios.

Multitemporal Analysis of a Gravel-Dominated Coastline in the Central Canadian Arctic Archipelago

Abstract ST-HILAIRE-GRAVEL, D.; FORBES, D.L., and BELL, T., 2012. Multitemporal analysis of a gravel-dominated coastline in the central Canadian Arctic Archipelago. This study assesses the stability of Arctic gravel coasts across a range of timescales, based on field and remote-sensing studies of three coastal sites near Resolute Bay, Nunavut. It considers shore-zone sensitivity to ice, wind, and wave forcing at storm-event and annual timescales within a longer-term context, including coastal emergence resulting from postglacial isostatic uplift partially counteracted by accelerating sea-level rise. Another long-term factor associated with climate change is the potential for increased seasonal depth of thaw in the beachface and nearshore. The coast in this area is ice bound on average for 10 months of the year, but the annual duration of ice cover has decreased over the past 30 years (1979–2009) by 0.95 d/y. A longer open-water season has implications for the number and timing of storm-wave events, with increased probability of storms impacting the coast later in the season when the seasonal thaw layer is approaching maximum thickness. Overall, shoreline progradation surpassed erosion in the Resolute area between 1958 and 2006, reflecting a combination of sediment supply and emergence. The coastal impacts of storms were found to be short lived and not necessarily indicative of longer-term trends. Gravel shorelines can be resilient in the face of intermittent storm impacts, but thresholds of stability in this high-latitude setting are poorly understood. If current trends of rising sea level, increasing open-water duration, and more frequent effective wave events continue, there is a heightened potential for more rapid coastal change in the region.

Recent climate-related terrestrial biodiversity research in Canada's Arctic national parks: review, summary, and management implications

It is now well documented that Arctic climates and ecosystems are changing at some of the fastest rates on planet Earth. These changes are significant for all Arctic biodiversity, and they are a great challenge for cooperative management boards of Canadas Arctic national parks, those legislated to maintain or improve the ecological integrity of all national parks. Owing to the inherent complexity of natural ecosystems, it is not at all clear how, nor how rapidly, these ongoing changes will affect park biodiversity and impact the traditional land-based lifestyles of Indigenous park cooperative management partners. In this context, this paper reviews and integrates recent research carried out in Canadian Arctic national parks: (1) geophysical – a reduction in glacial area and volume, active layer thickening, warming soil temperatures, and terrain instability; (2) vegetation – widespread but ecosystem-specific increases in NDVI ‘greenness’, plant biomass, shrub and herb coverage, and growing season lengths; and (3) wildlife – complex changes in small mammals and ungulate populations, very negative effects on some polar bear populations, and relatively stable mammalian predator and raptor populations at this time. This work provides a partial snapshot of ongoing and evolving ecological effects of climate change in Arctic national parks, and provides a strong foundation for prioritising future research and monitoring efforts. These evolving changes also undermine the historical paradigm of place-based conservation and necessitate a new approach for managing protected areas that involves acceptance of ongoing transformational change and adoption of a risk-based, forward looking paradigm in a changing world. It is proposed that Arctic national parks are ideal locations to focus Arctic science, especially as a component of a strategic, coordinated, and pan-Arctic approach to Arctic research that makes the most effective use of limited resources in the vast areas of Canadas north.

Environmental and potential human health legacies of non-industrial sources of lead in a Canadian urban landscape – the case study of St John's, Newfoundland

Residential soil and house dust were collected in St Johns to assess the levels of lead exposure and potential human health risk. Although St Johns does not have an identified, major point source for lead, nor is it a heavily industrialized or populated city, 51% of all analysed soil samples (n = 1231) exceeded the Canadian Council of Ministers of the Environment (CCME) residential soil lead guideline of 140 ppm, 26% exceeded the 400 ppm United States Environmental Protection Agency (US EPA) guideline for soil in childrens play areas, and 9% exceeded the 1200 ppm US EPA guideline for soil outside of play areas. High soil lead concentrations, particularly those above 1200 ppm, are clustered in the older downtown core. Samples located along exterior house walls (dripline) have the highest mean soil lead concentrations, followed by open spaces in yards (ambient) and then roadside sites. Lead in dripline soil samples from older housing stock is sourced to lead-bearing paint. Lead from both dripline and ambient samples on properties developed between the 1940s and 1980s have a mixture of sources including coal ash, paint, and leaded gasoline. Approximately 12% of analysed house dust samples (n = 96) exceeded the US EPA guidelines for lead in indoor dust, all from pre-1950s housing and all associated with dripline soil lead concentrations greater than 900 ppm. Human health risk predictions suggest that, although the wider St Johns community may not be at risk of adverse health effects, children living in pre-1970s housing may be exposed to increased risk.

Hunter-Gatherer Impact on Subarctic Vegetation: Amerindian and Palaeoeskimo Occupations of Port au Choix, Northwestern Newfoundland

This paper presents data from two ponds at Port au Choix, in northwestern New-foundland, each associated with one or more archaeological sites. Disruptions in vegetation in the ponds and surrounding areas are linked to contemporaneous human activities nearby and comparisons are made between Amerindian and Palaeoeskimo impact patterns. Whereas Amerindian occupations had a major impact on the Field Pond basin, only those Palaeoeskimo activities that took place at or in Bass Pond had an impact on its limnology. This difference is linked to site location preferences, the availability of woodland, and distance of human settlement from the pond. This study contributes to our understanding of the dynamic relationship between hunter-gatherers and their environment.

The Seismic Record of Glaciation in Nachvak Fiord, Northern Labrador

Nachvak Fiord is a 45 km long glacial trough in the Torngat Mountains of northern Labrador, Canada (Fig. 1). The fiord is 2 to 4 km wide, increasing gradually eastward to Nachvak Bay, which opens to the Labrador Sea. The sidewalls are generally steep, rising in places 1000 m vertically from sea level. Bathymetry reveals a succession of basins, four of which occur between Tasiuyak Arm and Nachvak Bay (Fig. 1). Maximum water depths in the four basins are 90, 160, 170, and 210 m from west to east. The four basins are separated by shallow barriers between 10 and 180 m below sea level. Two of these, at Kogarsok and Tinutyarvik, have many of the characteristics of riegeln or glacial steps. The fiord threshold at the entrance to the fiord is very shallow with an average depth of <50 m and numerous bedrock-cored shoals.