Upwelling in eastern boundary current systems is a primary driver of ecosystem productivity. Typically, peak upwelling occurs during spring and summer, but winter upwelling may also be important to ecosystem functions. In this study, we investigated the hypothesis that winter and spring/summer upwelling, operating through indirect trophic interactions, are important...
Seabirds have often been proposed as environmental indicators. Beached bird data may provide an additional data source and such data is efficacious because it can reliably be collected by volunteers. In addition to anthropogenic factors, such as oil spills, changes in the ocean-atmosphere can affect carcass beaching rate in 3...
The impact of mesoscale eddies on the spatial distribution of zooplankton biomass was analysed using data from the Arabian Sea and the Black Sea. The highest values of spatial variance of zooplankton biomass in the upper 100 to 150 m were found in regions with maximum available potential energy of...
During the summer of 1994, 1996, and 1997, we conducted hydrographic and plankton surveys of the upper 70 m in the nearshore, the continental shelf, and off shelf oceanic waters off Oregon, USA. Copepod densities and biomass were estimated along 4 transects from each cruise. The on shelf copepod biomass...
Unusual collections of several euphausiid, chaetognath, and copepod species help elucidate
the effects of the strong 1997/1998 El Niño off the central Oregon, USA, coast. Furcilia of Nyctiphanes simplex, a euphausiid typically found only as far north as central California, were collected in bi-weekly nearshore samples between December 1997 and...
The Moult Rate (MR) method has been used widely to derive stage-specific growth rates in juvenile copepods. It is the most common field-based method. Unfortunately, the equation underlying the method is wrong and, consequently, large errors in juvenile growth rate estimates are widespread. The equation derives growth from the mean...
We compared brood sizes among adult female Euphausia pacifica Hansen, 1911 from 3
populations in the North Pacific: Puget Sound, Washington, USA; Toyama Bay, Japan; and the Oregon coast, USA. Additionally, we used multiple linear regression models to compare the interspecific brood size as a function of female length and...
Alongshore transport was estimated from the gridded AVISO altimeter data and water level data from NOAA tide gauges (1993–2010) for the northern California Current (NCC) system. The biomass of the cold neritic copepods including Calanus marshallae, Pseudocalanus mimus and Acartia longiremis (dominants in the eastern Bering Sea, coastal Gulf of...
Gravid adult female Euphausia pacifica were collected off Newport, Oregon, USA and transferred to the laboratory, where females spawned eggs, eggs hatched, and larvae were reared at 10.5 degrees C. We fed 4 cohorts of larvae to excess with a combination of phytoplankton species and monitored them daily until they...