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Phytoplankton, ice algae, and benthic microalgae are the three sources of primary production in the western Beaufort Sea in winter and spring. Phytoplankton levels in winter are low with chlorophyll a levels near the limit of detection. Microflagellates are the most abundant organisms present in the water column along with a few diatoms. Low chlorophyll a , standing stock, and primary productivity continue into June when the ice breaks up. Cells are present in sea ice from the time it forms in the fall and are generally scattered throughout the ice thickness. Microflagellates are the most abundant organisms, but some diatoms, mostly pennate species, are also present. Cells concentrate in the bottom few cm of ice during March-April in response to increasing light levels. Growth continues until late May-early June when maximum production and standing stock occur. Benthic microalgal production was barely detectable in spring although chlorophyll a levels were high, perhaps left from the previous production season. Light is apparently the major factor controlling production in the spring, with the ice algae being able to take advantage of increasing light levels early in spring. This community shades both the water column and benthos so that production in those habitats does not increase until after the ice algae disappear in early June, but the ice community may be inhibited by layers of sediment in the ice. During this study, the ice algae provided about two-thirds and the phytoplankton one-third of the spring primary production; the benthic community contribution was negligible.

On the U.S. west coast, the main toxin-producing algal species are dinoflagellates in the genus Alexandrium that cause paralytic shellfish poisoning (PSP) and diatoms in the genus Pseudo-ni,zschia that produce domoic acid and cause domoic acid poisoning (DAP). Other harmful species, including the raphidophyte Heterosigma uknshiwo and the diatoms Chaetoceros convolutus and Chaetoceros concavicornis, kill fish at aquaculture sites, but arc not harmful to humans. Water discolorations (red tides) caused by nontoxic dinoflagellates also occur throughout the area. Early records, partially based on local native lore, suggest that algal toxins have been present along this coast for hundreds of years, but actual scientific information is sparse. WC review what is now known about harmful algal blooms in this vast area, including the hydrographic regimes that induce and(or) support blooms, bloom dynamics, and the biology of the causative species.

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.

The relationship among Pseudo-nitzschia distributions, particulate toxin levels in seawater, and the energetic and highly variable water masses of an upwelling-dominated region are explored using data collected during summer cruises off the Washington coast in 1997 and 1998. In the early summer of both years, an area of maximum domoic acid (DA) accumulation was located approximately 50 km off the coast within a counterclockwise, cold feature known as the Juan de Fuca eddy. The stations in the eddy with the highest domoic acid concentrations coincided with high numbers of Pseudo-nitzschia pseudodelicatissima (Hasle) Hasle (2.7 g DA equivalents L Ϫ1, up to 0.6 ϫ 10 6 cells L Ϫ1 in 1997 and 0.2 g DA equivalents L Ϫ1 , up to 0.2 ϫ 10 6 cells L Ϫ1 in 1998), a species known to produce toxin in this region. Other known toxin-producing species were sometimes present, but at Ͻ5% of the total Pseudo-nitzschia population when Ͼ0.1 g DA equivalents L Ϫ1 were measured. In 1998, large-scale surveys indicated that high levels of particulate DA in seawater persisted at least until 1 October, covering a maximum area of 100 km 2 off the Washington coast in midsummer. The appearance of high levels of DA (up to 2.7 g DA equivalents L Ϫ1 ), coincident with high numbers of P. pseudodelicatissima (up to 15.4 ϫ 10 6 cells L Ϫ1 ) at Kalaloch beach on the central coast in late September, was followed by the accumulation of record levels of toxin in razor clams. This toxic episode was preceded by a downwelling-favorable wind event, with associated onshore transport in near-surface layers. We suggest that the Juan de Fuca eddy may be one source of DA to the Washington coast. The duration of upwelling and the exact timing of fall storms likely play an influential role in the intensity of the bloom and the movement of toxic cells from the eddy to the coast.The neurotoxin domoic acid (DA) was first measured in razor clams and Dungeness crabs on the Washington coast in 1991 (Horner and Postel 1993;Horner et al. 1993;Wekell et al. 1994). Razor clam toxification on the Washington coast in 1991 was preceded by the death of seabirds in Monterey Bay due to ingestion of toxic planktivorous fish earlier that summer (Buck et al. 1992;Fritz et al. 1992;Work et al. 1993). More recently, in May and June 1998, the first confirmed death of a marine mammal species due to DA poisoning was documented in sea lions along the central California coast (Gulland et al. 1999;Scholin et al. 2000). By late September, high levels of DA were again measured in 1 Corresponding author (vera.l.trainer@noaa.gov). AcknowledgmentsThis work was funded in part by grants NA66FD0113, NAA86FD0393, and 40ABNC801574 from the NOAA to the University of Washington and by the Monitoring and Event Response to Harmful Algal Blooms initiative through the National Center for Coastal Ocean Science. We thank E. Bowlby and G. Galasso of the Olympic Coast National Marine Sanctuary and the captain and crew of the NOAA research vessel McArthur, the captain and crew of the UNOLS vessel New ...

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A large part of the Pacific Arctic basin experiences ice-free conditions in summer as a result of sea ice cover steadily decreasing over the last decades. To evaluate the impact of sea ice retreat on the marine ecosystem, phytoplankton in situ observations were acquired over the Chukchi shelf and the Canadian basin in 2008, a year of high melting. Pigment analyses and taxonomy enumerations were used to characterise the distribution of main phytoplanktonic groups. Marked spatial variability of the phytoplankton distribution was observed in summer 2008. Comparison of eight phytoplankton functional groups and 3 size-classes (pico-, nano- and micro-phytoplankton) also showed significant differences in abundance, biomass and distribution between summer of low ice cover (2008) and heavy ice summer (1994). Environmental parameters such as freshening, stratification, light and nutrient availability are discussed as possible causes to explain the observed differences in phytoplankton community structure between 1994 and 2008

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