A B S T R A C TAlong the Pacific coast of North America, from Alaska to Mexico, harmful algal blooms (HABs) have caused losses to natural resources and coastal economies, and have resulted in human sicknesses and deaths for decades. Recent reports indicate a possible increase in their prevalence and impacts of these events on living resources over the last 10-15 years. Two types of HABs pose the most significant threat to coastal ecosystems in this ''west coast'' region: dinoflagellates of the genera Alexandrium, Gymnodinium, and Pyrodinium that cause paralytic shellfish poisoning (PSP) and diatoms of the genus Pseudo-nitzschia that produce domoic acid (DA), the cause of amnesic shellfish poisoning (ASP) in humans. These species extend throughout the region, while problems from other HABs (e.g., fish kills linked to raphidophytes or Cochlodinium, macroalgal blooms related to invasive species, sea bird deaths caused by surfactant-like proteins produced by Akashiwo sanguinea, hepatotoxins from Microcystis, diarrhetic shellfish poisoning from Dinophysis, and dinoflagellate-produced yessotoxins) are less prevalent but potentially expanding. This paper presents the stateof-knowledge on HABs along the west coast as a step toward meeting the need for integration of HAB outreach, research, and management efforts.Published by Elsevier B.V.

Ecologists have advocated retaining various densities of canopy trees in harvest units in Pacific Northwest forests. In contrast to clear‐cutting, this practice may better emulate the patterns of disturbance and structural complexity typical of natural forests in the region. Several ecological attributes, including vertebrate habitat diversity, are thought to be associated with stands of complex structure. The goal of this study was to determine bird abundance in canopy retention sites relative to other common stand types in the Pacific Northwest and to develop habitat functions for extrapolating bird abundance across current and future landscapes. We used data from five previous studies in the west central Cascades of Oregon to compare bird abundance and to develop habitat functions for forest birds across a wide range of natural and managed stand structures and ages. The 67 stands included clearcuts, retention sites, young closed‐canopy plantations, mature stands, and old‐growth stands. ANOVA revealed that 18 of the 23 species included in the analysis differed significantly in abundance among the stand types, with some species being primarily associated with each of the stand types. The habitat variables used to build habitat functions included tree density by size class, mean tree diameter, and variation in tree diameter. Linear, polynomial, and various nonlinear regression models were evaluated for each bird species. Significant habitat functions were generated for 17 of the 23 bird species. The analyses identified four habitat‐use guilds among the 17 bird species: open‐canopy; open‐canopy with dispersed large trees; structurally complex closed‐canopy; and structurally simple closed‐canopy guilds. This study is the first in the Pacific Northwest to compare bird abundances across natural stands, traditionally managed plantations, and stands managed under ecological forestry approaches. The results suggested that canopy tree retention benefits many, but not all, of the bird species we studied, Moreover, the nonlinear responses of bird abundance revealed thresholds in tree density at which bird abundance changed dramatically. Knowledge of these thresholds allow managers to design stands for specific biodiversity objectives. The habitat functions presented here can be used to predict bird abundance based on habitat measurements derived from field data, remotely sensed data, or output from computer models of forest dynamics.

Domoic acid is a potent neurotoxin produced by certain marine microalgae that can accumulate in the foodweb, posing a health threat to human seafood consumers and wildlife in coastal regions worldwide. Evidence of climatic regulation of domoic acid in shellfish over the past 20 y in the Northern California Current regime is shown. The timing of elevated domoic acid is strongly related to warm phases of the Pacific Decadal Oscillation and the Oceanic Niño Index, an indicator of El Niño events. Ocean conditions in the northeast Pacific that are associated with warm phases of these indices, including changes in prevailing currents and advection of anomalously warm water masses onto the continental shelf, are hypothesized to contribute to increases in this toxin. We present an applied domoic acid risk assessment model for the US West Coast based on combined climatic and local variables. Evidence of regional-to basin-scale controls on domoic acid has not previously been presented. Our findings have implications in coastal zones worldwide that are affected by this toxin and are particularly relevant given the increased frequency of anomalously warm ocean conditions.T he Pacific Decadal Oscillation (PDO) and El Niño Southern Oscillation (ENSO) are recurring patterns of climate variability centered over the northeastern (NE) and equatorial Pacific, respectively, that fluctuate at scales of years (ENSO) to decades (PDO) (1, 2). Distinct, yet also related, these patterns can amplify or dampen each other through atmospheric teleconnection (1, 3). In the NE Pacific, they induce similar spatial patterns of sea surface temperature anomalies during positive (warm) and negative (cool) phases (4). Low-frequency physical variability attributed to the PDO and ENSO modulates large shifts in NE Pacific water temperature, ocean currents, and foodweb dynamics that can persist for months to years (2,5,6). Shifts in NE Pacific plankton communities occur as well (7-12); however, climate impacts on phytoplankton ecology in this region are relatively underexplored, largely due to a lack of phytoplankton data at sufficient scales.Decadal, regional-scale monitoring of domoic acid (DA) in shellfish can be used to investigate climate-scale impacts on phytoplankton ecology. The neurotoxin DA is produced by some species of the diatom genus Pseudo-nitzschia. It enters secondary trophic levels when suspension feeders such as shellfish and anchovies ingest toxic Pseudo-nitzschia cells. Consumption of these organisms by humans can lead to a serious neurological disorder named Domoic Acid Poisoning (DAP), also termed Amnesic Shellfish Poisoning. DAP symptoms range from gastrointestinal disturbance to seizures, memory loss, or, rarely, death (13,14).DA was first identified as a public health threat in 1987 (15). Toxin-producing Pseudo-nitzschia spp. and DA have since been identified worldwide with the greatest prevalence in, and most deleterious impacts on, productive eastern boundary upwelling systems (16). Laboratory experiments have found multiple ...

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Microplastics are an ecological stressor with implications for ecosystem and human health when present in seafood. We quantified microplastic types, concentrations, anatomical burdens, geographic distribution, and temporal differences in Pacific oysters (Crassostrea gigas) and Pacific razor clams (Siliqua patula) from 15 Oregon coast, U.S.A. sites. Microplastics were present in organisms from all sites. On average, whole oysters and razor clams contained 10.95 ± 0.77 and 8.84 ± 0.45 microplastic pieces per individual, or 0.35 ± 0.04 pieces g−1 tissue and 0.16 ± 0.02 pieces g−1 tissue, respectively. Contamination was quantified but not subtracted. Over 99% of microplastics were fibers. Material type was determined using Fourier‐transform infrared spectroscopy. Spring samples contained more microplastics than summer samples in oysters but not razor clams. Our study is the first to document microplastics in Pacific razor clams and provides important coast‐wide data to compare microplastic burden across species, seasons, and sites.