Jesse Ford

Heavy metal contamination in the Taimyr Peninsula, Siberian Arctic

The Taimyr Peninsula is directly north of the worlds largest heavy metal smelting complex (Norilsk, Russia). Despite this proximity, there has been little research to examine the extent of contamination of the Taimyr Peninsula. We analyzed heavy metal concentrations in lichen (Cetraria cucullata), moss (Hylocomium splendens), soils, lake sediment, freshwater fish (Salvelinus alpinus, Lota lota and Coregonus spp.) and collared lemming (Dicrostonyx torquatus) from 13 sites between 30 and 300 km from Norilsk. Element concentrations were low in both C. cucullata and H. splendens, although concentrations of Al, Fe, Cu, Ni and Pb were significantly higher than those in Arctic Alaska, probably due to natural differences in the geochemical environments. Inorganic surface soils had significantly higher concentrations of Cd, Zn, Pb and Mg than inorganic soils at depth, although a lake sediment core from the eastern Taimyr Peninsula indicated no recent enrichment by atmospherically transported elements. Tissue concentrations of heavy metals in fish and lemming were not elevated relative to other Arctic sites. Our results show that the impact of the Norilsk smelting complex is primarily localized rather than regional, and does not extend northward beyond 100 km.

Inorganic contaminants in Arctic Alaskan ecosystems: long-range atmospheric transport or local point sources?

The moss monitoring technique (Hylocomium splendens) for tracking environmental concentrations of atmospheric contaminants is applied to arctic Alaska. Median 1990–1992 concentrations of Pb, Cd, Cu, V, and Zn are ≤ median 1990 concentrations in northernmost parts of the Nordic/European monitoring network. Extremely low Pb concentrations (median, 0.6 μg/g) indicate that long-range atmospheric transport (LRTAP) of Pb to arctic Alaskan ecosystems is neglible. However, samples taken adjacent to a local source point (the Dalton Highway) have elevated Pb, V, and Cu. Site-specific watershed studies indicate that natural within- and between-site variability does not affect the interpretation of our Alaskan data relative to the Nordic/European network for Pb, V and Cu. Variability is greater relative to regional data for Cd and Zn, but neither LRTAP nor the Dalton Highway appear to be significant contributors to local concentrations of Cd and Zn. Pilot studies of blueberries and other selected wildlife forage foods indicate that concentrations inH. splendens are generally comparable to those in a common carbou forage lichen, but thatH. splendens may underestimate Cu and overestimate Pb, Hg, and in some cases Cd, relative to selected forage fruits. More studies of contaminants in arctic Alaskan forage foods are needed to characterize potential exposure of human and wildlife populations to airborne contaminants in this region.

Diatom assemblages as indicators of timber harvest effects in coastal Oregon streams

Abstract Spatially patchy and temporally varied cycles of timber harvest across a landscape may have subtle effects on stream conditions that are difficult, but important, to assess. The objective of our study was to examine the relationship between benthic diatom composition and timber harvest in coastal Oregon watersheds. Physical habitat conditions, water chemistry, and periphyton composition were characterized for 46 sites from 2 subbasins with different timber harvest intensities (0.3 km2/y vs 3 km2/y, between 1972–1998). Landscape variables including geology, vegetative cover types, and harvest intensity, were quantified for the watershed upstream of each sample point. Nonmetric Multidimensional Scaling analysis of periphyton composition showed that the 1st axis was primarily driven by Achnanthidium minutissimum (r = −0.91) whereas the 2nd axis was driven by Nitzschia inconspicua (r = 0.77). The 1st axis was positively correlated with % of upstream area harvested between 1972 and 1998 (r = 0.54) and water-quality variables such as total P (TP) (e.g., rTP = 0.74). A subset comparison (n = 12) between harvested (30% harvested 1972–1998, n = 6) and unharvested (0% harvested 1972–1998, n = 6) watersheds with similar geology (>80% basalts), broadleaf vegetative cover (8–35% broadleaf), and other reach-scale characteristics revealed higher total N, TP, turbidity, and conductivity in the harvested than the unharvested watersheds (p < 0.05). Shannon diversity and species richness also were higher in the harvested group (p < 0.05). Our data suggest that diatom assemblages may be useful in assessing the long-term impact of timber harvest within coastal Oregon watersheds.

Tethered Transplants for Estimating Biomass Growth Rates of the Arctic Lichen Masonhalea richardsonii

Abstract Air quality studies often take advantage of the ability of lichens and mosses to accumulate certain contaminants in their tissues. In order to evaluate the rate of contaminant accumulation from concentrations in tissues, the age of the tissue must be known. Our objective was to develop and test a method for estimating annual growth rates and thallus ages for Masonhalea richardsonii, a vagrant clonal lichen abundant throughout its Beringean range. The annual growth rate of healthy individuals from Arctic Alaska, based on the 75th percentile of a cumulative frequency distribution, was 11.6% (90% confidence interval: 11.2–13.3%). This growth rate suggests that the biomass of a healthy M. richardsonii individual doubles within a period of approximately 6.3 years (90% confidence interval: 5.6–6.5 years). Average ages for the thalli in this study were estimated at 5 to 41 years using a negative compound interest formula and assuming initial masses of thallus fragments. Calculations and their appropriate application are shown and the methodology is discussed.

Characterizing Small Subbasins: A Case Study From Coastal Oregon

A fine-grained statistically robust probability sample of stream segments is used to compare two small (<20,000 hectare) subbasins of the Tillamook watershed, north coastal Oregon. The two subbasins are matched with respect to several variables (size, coastal climates), but vary in terms of geology and consequently land use. A total of 67 wadeable + non-wadeable sites were identified for sampling in the two subbasins (combined) over two field seasons from a sampling universe consisting of the River Reach File 3 (blue lines on 1:100,000 maps). Target variables include an extensive array of physical habitat endpoints, selected water chemistry endpoints, species composition, and relative abundance of both benthic macroinvertebrates and fish. Field protocols generally followed those of the U.S. EPA’s Environmental Monitoring and Assessment Program (EMAP).