Iron (Fe) is an important limiting nutrient that can affect the rate of ocean primary production because it is required by phytoplankton as an enzymatic cofactor in photosynthesis, nitrogen fixation, and other essential metabolic functions. Most Fe reaches the surface of the open ocean via atmospheric dust deposition, which is...
The concentrations of filamentous diazotroph Trichodesmium spp., present as free trichomes and in colonial assemblages, were measured at approximately monthly intervals at Stn ALOHA (22°45'N, 158°00'W) between October 1989 and December 1992. The average abundance of filaments in the upper 45 m of the water column was highly variable ranging...
The potential role of the diazotrophic cyanobacterium Trichodesmium spp. In nitrogen and phosphorus dynamics of the euphotic zone of the North Pacific subtropical gyre was investigated as one component of the Hawaii Ocean Time-series (HOT) program. Experiments were conducted with natural samples collected at Stn ALOHA (22° 45’ N, 158°...
Secondary metabolites (SMs) play an integral role in the life history of most fungal species. Fungal metabolomic studies provide insights into how fungi perform certain ecological functions, how they compete and interact with other organisms, and the breadth of fungal chemodiversity. Fungal SMs have also been utilized for a variety...
The Fukushima Daiichi nuclear disaster of 2011 made it apparent that releases of fission products to marine environments is a very real possibility. Additional data on the movement of material through marine environments can be used by radioecology personnel to assist with both ecosystem protection as well as environmental cleanup...
Photosynthetic energy allocation strategies were investigated in the marine diatom, Thalassiosira pseudonana, grown under a wide range of light limitation. Steady-state, continuous cultures were established at three light-limited growth rates. Simultaneous measurements of photosynthetic activity were made that targeted different points in photosynthetic energy flow from gross to net photosynthesis....
Few studies have examined the partitioning of organic matter in upwelling systems,
despite the fact that these systems play a key role in carbon and nitrogen budgets in the
ocean. We examined the production and partitioning of phytoplankton-derived organic
matter in deck incubations off Oregon during the upwelling season. During...
Ocean Acidification (OA) has emerged as a major threat to marine ecosystems, particularly regarding calcifying organisms. A growing body of literature describing laboratory investigations into pH stress indicates broadly deleterious effects for calcifiers, but responses vary greatly across taxa and can be influenced by variations in other environmental characteristics. Scaling...
The euphotic zone below the deep chlorophyll maximum layer (DCML) at Station ALOHA (a long-term oligotrophic habitat assessment; 22º45′N, 158º00′W) transects the nearly permanently stratified upper thermocline. Hence, seasonal changes in solar radiation control the balance between photosynthesis and respiration in this lightlimited region. Combining profiles of radiance reflectance, algal...