Dewey Dunnington

• Ph.D. Student, Civil & Resources Engineering
• PhD Student at Voltron Data

Multiparameter data with both spatial and temporal components are critical to advancing the state of environmental science. These data and data collected in the future are most useful when compared with each other and analyzed together, which is often inhibited by inconsistent data formats and a lack of structured documentation provided by research...

We analyzed photos of convex upward deformation in split sediment cores to obtain reasonable parameters with which to model the effect of convex upward deformation on paleolimnological data. Using a 3-dimensional raster model, we modeled the effect of this deformation on a hypothetical dataset. Model results indicated that convex upward sediment de...

We used a paleolimnological approach at Long Lake, Nova Scotia, to construct a 10 500-year record of metal deposition in lakebed sediments and elucidate the influence of both natural and anthropogenic environmental changes. Aquatic sediment concentrations of mercury (Hg), arsenic (As), and chromium (Cr) in Long Lake fluctuated substantially and, du...

Small, temperate lakes are important to communities across Canada, but commonly lack the long-term water quality records that are required to assess the impact of development and environmental change. We measured a combination of bulk sediment geochemistry and stable isotopes of carbon and nitrogen in a ²¹⁰Pb- and ¹⁴C-dated sediment core from Alta...

Nova Scotia is a small maritime province with limited capacity to gauge its abundant water resources, but it possesses a diverse geologic setting and surface water distribution. The common engineering practice of using nearest neighbor catchments as hydrologic surrogates may be unreliable in regions such as this. Catchment classification provides a...

Reduced atmospheric acid deposition has given rise to recovery from acidification – defined as increasing pH, acid neutralization capacity (ANC), or alkalinity in surface waters. Strong evidence of recovery has been reported across North America and Europe, driving chemical responses. The primary chemical responses identified in this review were in...

This paper presents the tidypaleo package for R, which enables high-quality reproducible visualizations of time-stratigraphic multivariate data that is common to several disciplines of the natural sciences. Rather than introduce new plotting functions, the tidypaleo package defines several orthogonal components of the ggplot2 package that, when com...

Dissolved organic matter (DOM) concentrations have been increasing in parts of the northern hemisphere for several decades. This process—brownification—often accompanies increasing iron and aluminum, but the metal–DOM interactions these concurrent trends imply are poorly described. Here we used field-flow fractionation with UV and ICP-MS detection...

McGuire HE, Dunnington DW, Loder AL, Spooner IS, Mallory ML, McLellan NR, Su, C-C. 2021. Evaluating the multidecadal response of historic seawater incursion events and salinity-induced meromixis at Laytons Lake, Nova Scotia, Canada. Lake Reserv Manage. 37:378–390. Long-term monitoring data from freshwater lakes can be challenging to retrieve yet ar...

The paleolimnological method was used to decouple geogenic and anthropogenic metal(loids) contributions in a sediment stabilization basin (Boat Harbour) located in Nova Scotia, Canada. Boat Harbour has been impacted by industrial effluents discharged by a bleached kraft pulp mill (1967 to 2019) and a chlor-alkali plant (1971 to 1992). The former es...

Declining emissions of sulfur and nitrogen have curtailed acid deposition across large areas of North America and Europe. This has allowed many lakes to recover from acidification, with decreases in sulfate, increases in pH, and increases in alkalinity. But reduced acid deposition has not always coincided with chemical lake recovery. Surface waters...

Using an organic carbon removal data set (n = 500), we compared a physically based semiempirical coagulation model (Langmuir sorption-removal) and three ML modeling methods using quantitative (model performance) and qualitative (model interpretability and accessibility) criteria to identify potential barriers to adoption in water treatment. We foun...

Mass accumulation rates, tracer element ratios, enrichment factors, excess measures, and centred log-ratios are elemental measures used in paleolimnological studies when more than one source (e.g. pollution and/or erosion) contributes an element of interest to the sediment archive, or when the closure constraint results in spurious correlations bet...

We evaluated anthropogenic Pb deposition along a west-east transect from the Adirondack Mountains, New York, USA (ADIR) region, the Vermont-New Hampshire-Maine, USA (VT-NH-ME) region, and Nova Scotia, Canada (NS) region using 47 ²¹⁰Pb-dated lake sediment records. We used focus-corrected Pb inventories to evaluate cumulative deposition and breakpoin...

Five large gravitational slope deformation features (GSDFs) in the Lookout Mountain-Tablelands region of western Newfoundland exemplify bedrock slope instabilities in eastern Canada. The Lookout Hills GSDF (8.3 km³) on Bonne Bay (glacial trough) may be the largest GSDF in eastern Canada. It appears to be a post-glacial feature, has vertical total d...

The main finding of this work is that a wide range of factory-calibrated pXRF analyzers are capable of providing high-quality total concentrations for many elements in aquatic sediments.

Dunnington DW, Spooner IS, Krkošek WH, Gagnon GA, Cornett RJ, Kurek J, White CE, Misiuk B, Tymstra D. 2018. Anthropogenic activity in the Halifax region, Nova Scotia, Canada, as recorded by bulk geochemistry of lake sediments. Lake Reserv Manage. 00:1–15. Separating the timing and effects of multiple watershed disturbances is critical to a comprehe...

An understanding of the morphological stability and succession of open water and wetland ecosystems in Nova Scotia is a priority for informing the conservation management of critical habitats for a complex of nationally listed, rare, disjunct wetland species. Baltzer Bog and Big Meadow Bog in southwestern Nova Scotia contain stratigraphic records o...