Potential zone for photosynthesis in natural waters is restricted to a relatively thin illuminated surface water layer. The thickness of this layer is often indirectly estimated by measuring the depth in which 1% of the photosynthetically active radiation entering the water remains. This depth is referred to as the euphotic depth. A coarser way to evaluate the underwater light penetration is to...

The stoichiometry of biological components and their influence on dissolved distributions have long been of interest in the study of the oceans. Cobalt has the smallest oceanic inventory of inorganic micronutrients and hence is particularly vulnerable to influence by internal oceanic processes including euphotic zone uptake, remineralization, and scavenging. Here we observe not only large varia...

Surveys of the California Current System in 1993 revealed high concentrations of photosynthetic pigment biomass at -200-m depth, well below the euphotic zone. The deep fluorescence feature contained an estimated 2.2 X 10J metric tons of carbon and contained -2.5 times the amount of chloroph,yll observed in surface waters directly above it. Deep phytoplankton assemblages may be a signature of wa...

As the waters of marine primary production, euphotic zone is living environment for aquatic organisms. Eddies account 90% ocean’s kinetic energy and they affect organisms’ habitats by excitation vertical velocities horizontal advection nutrients ecosystems. Satellite observations indicate that anticyclones mainly deepen depth, while cyclones do opposite. The anomalies reach 5 m on average in re...

The phylogenetic composition of the heterotrophic microbial community is depth stratified in the oceanic water column down to abyssopelagic layers. In the layers below the euphotic zone, it has been suggested that heterotrophic microbes rely largely on solubilized particulate organic matter as a carbon and energy source rather than on dissolved organic matter. To decipher whether changes in the...

Profiles of alkenone concentration, the abundance of the calcified alkenone-producing species Emiliania huxleyi and Gephyrocapsa oceanica as well as nutrient and phytoplankton pigment concentrations were measured through the euphotic zone in surface waters of the Gulf of California during cruises in two different summers (2004, 2005) and one winter (2005). As determined using a biomarker and pi...

Total gas pressure, oxygen, temperature and salinity were measured at 50m on a mooring at the Hawaii Ocean Time series (HOT) station from January through September of 1997 and 1998 using a gas tension device (GTD) and a conductivity temperature depth and oxygen (CTD-O2) sensor (GTD–CTD-O2 instrument package). Our goal was to evaluate the precision and accuracy of the in situ total gas and oxyge...

Growth-independent test characters of the generaOperculina, Planoperculina, andPlanosteginawere investigated to determine relations to water depth in form of morphoclines. All characters describing test form – thickness, initial vector of the test spiral that is correlated to proloculus size, and radius expansion rate describing test contour – are correlated. The investigated Operculina and Pla...