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Manayunkia speciosa, a fresh water polychaete, is the definitive host of Ceratomyxa shasta, a salmonid parasite endemic to the Klamath River. Little is known about the survival of this host under various environmental conditions. This study investigated the survival of M. speciosa under varying water temperature regimes and following drying in two of the primary substrates for this host, cladophora and a mixture of sand and silt. The polychaete was able to survive 24 h when water was removed, and survival was higher at lower temperatures. These effects were seen in both substrate types. Water temperature also had an effect on C. shasta actinospores, with actinospore morphology maintained longer at cooler temperatures. In challenge trials as few as 5 actinospores were capable of causing lethal infections in susceptible fish.

Ground penetrating radar (GPR) records of groundwater surface (GWS) reflections have been analyzed from 40 across-barrier profiles, totaling 50 km in combined length, taken from barrier spits and beach plains of the Columbia River littoral system. The barriers and beach plains host shallow fresh-water aquifers in the prograded beach deposits and abandoned foredune ridges, totaling 10–30 m in thickness. Study results demonstrate that GWS reflections could be traced continuously at subsurface depths of 1–15 m with the GPR 100 MHz and 50 MHz antennae using 400 V and 1000 V transmitters. Boreholes (62 in number) and lake water levels (24 in number) provide ground-truthing of the across-barrier GWS trends interpreted from the GPR profiles. The GWS rises in elevation (4–8 m above base level) under high, broad foredune-ridges and drops under interdune ridge valleys (1–3 m above base level). Continuous profiles of GWS demonstrate that lakes, ponds, and bogs of the barriers and beach plains are “windows” into the shallow coastal aquifer. The GPR records demonstrate that the GWS slopes either to seaward (0.003–0.04 gradient) or to landward (0.001–0.05 gradient) from divides under the largest, shore-parallel dune ridges in the barriers. The GWS gradients indicate that subsurface contaminant transport from the developed dune ridges will be intercepted by intervening lakes and ponds in the interdune-ridge valleys. The GPR records also establish the effect of drainage ditches in lowering GWS elevations (1–2 m) in sensitive wetlands located 100s of meters in distance from the constructed ditches.

Floating, mixed-valent Fe films have been observed worldwide in wetlands, ferrous iron-rich seeps, and in seasonally reduced soils, but are usually misidentified as oil or biofilms. There has been little characterization or explanation of their formation. Along the Oregon coast such films were found on ephemeral pools where Fe(II)-rich groundwater (~100 μM Fe) has been discharged at the base of Pleistocene sand dunes. Fe(II) oxidized to Fe(III) at the air-water interface to form ~100–300 nm thick films. Analyses indicated that the films contained both Fe(III) and Fe(II) in a ratio of 3:1; Si was the other main cation; OH was the main anion and some C was also identified. The film morphology was flat under optical and electron microscopy with some attached floccules having a string-like morphology. Energy-filtered electron diffraction patterns showed three diffraction rings at 4.5, 2.6 and 1.4 Å in some places and two rings (2.6 and 1.4 Å) in others. Upon further oxidation the films became 2-line ferrihydrite. We are proposing the name ‘schwimmeisen’ for the floating, mixed-valent Fe film.

The sea otter has experienced a dramatic population decline caused by intense human harvesting, followed by a century of recovery including relocation efforts to reestablish the species across its former range in the eastern Pacific. Although the otter was historically present along the coast in Oregon, there are currently no populations in this region and reintroduction efforts have failed. We examined the mtDNA genotypes of 16 pre-harvest otter samples from two Oregon locations in an attempt to determine the best genotypic match with extant populations. Our amplifications of a 222 base-pair portion of the control region from otters ranging in age from approximately 175–2000 years revealed four genotypes. The genotypic composition of pre-harvest otter populations appears to match best with those of contemporary populations from California and not from Alaska, where reintroduction stocks are typically derived.

Ceratomyxa shasta is a myxozoan parasite identified as a primary contributor to salmon mortality in the Klamath River. The parasite has a complex life cycle involving a freshwater polychaete host, Manayunkia speciosa. The ecological requirements of this polychaete influence the severity of infection in fish. An understanding of what contributes to high densities and infection of this host may provide management opportunities to reduce the parasite effects. A laboratory based flow experiment showed that a high flow facilitated the greatest polychaete densities, whereas experimentally induced polychaete infection prevalence was higher at the slower flow. Infected rainbow trout at the slower flow rate had a shorter mean day to death, indicating a higher infectious dose than at the faster flow. Thus, at least under slow flow conditions, increased water velocities may decrease C. shasta infection severity in the fish and infection prevalence in the polychaete host.

Indian Point appears to represent a winter village of the Kathlamet, a Chinookan people who lived upstream from the Clatsop at the mouth of the Columbia River estuary. Small-scale excavations in 1978, in dense cultural deposits averaging 1.4 m deep, encountered evidence of occupation spanning the late prehistoric and early historic periods. The artifact and faunal assemblages recovered from Indian Point provide a record of the resources exploited by Native peoples in the upper portion of the Columbia River estuary. The faunal assemblage as a whole is strongly estuarine and riverine in orientation, reflecting adaptation to an environment transitional between that inhabited by the Clatsop along the coast and other Chinookan peoples farther upstream in the Columbia River Valley.