The vast majority of organic matter in the world ocean is found in the dissolved pool. However, no evidence has been demonstrated for direct uptake of bulk dissolved organic matter (DOM) by organisms other than bacteria and some invertebrate larvae. The total organic carbon (TOC) is 10–30% higher in coral reefs than in adjacent open waters. The dissolved organic carbon (DOC) accounts for .90% o...

Allochthonous organic carbon can subsidize consumers in aquatic systems, but this subsidy may only be significant in relatively small systems with high organic matter loading. We tested the importance of allochthonous carbon to consumers in a relatively large (258,000 m2) clear-water lake by adding HCO3 daily for 56 d. Dissolved inorganic carbon (DIC) was substantially enriched in 13C by the ad...

a measured MarT of 9.4 °C. Carbon isotopes of T. giganteus were ambiguous and reveal no significant relationships with trends in nutrient concentrations (n and P), dissolved oxygen, and dissolved organic carbon, although they did exhibit more negative values concomitant with landfall of Hurricane Irene and trended to increasing values with ontogeny that could reflect migration. Carbon isotopes ...

The effects of many environmental stressors such as UV radiation are mediated by dissolved organic matter (DOM) properties. Therefore, determining the factors shaping spatial and temporal patterns is particularly essential in the most susceptible, low dissolved organic carbon (DOC) lakes. We analyzed spatiotemporal variations in dissolved organic carbon concentration and dissolved organic matte...

We investigated the effect of leaf litter on below ground carbon export and soil carbon formation in order to understand how litter diversity affects carbon cycling in forest ecosystems. 13C labeled and unlabeled leaf litter of beech (Fagus sylvatica) and ash (Fraxinus excelsior), characterized by low and high decomposability, were used in a litter exchange experiment in the Hainich National Pa...

[1] The average composition of the dissolved and particulate products of early degradation of marine phytoplankton has been established for the first time in a coastal upwelling system using a mixing analysis along isopycnal surfaces combined with a stoichiometric model. About 17–18% of the mineralized organic matter is derived from the decomposition of organic particulates, and 16–35% is from ...

In order to investigate sources and turnover rates of dissolved organic matter from Chesapeake Bay and Galveston Bay, colloidal organic matter (COM) was isolated using cross-flow ultrafiltration and subsequently characterized for its elemental (C, N, and S) and isotopic (13C and 14C) composition. Distributions of dissolved organic carbon (DOC) in Chesapeake Bay showed a non-systematic variation...

The partitioning of photosynthetically-derived organic carbon between particulate and dissolved phases has important implications for marine carbon cycling. In this study we utilized 14C-bicarbonate assimilation to quantify rates of photosynthetic production of both particulate and dissolved organic carbon (DOC) at Station ALOHA (2245N, 158W) in the North Pacific Subtropical Gyre (NPSG). At nea...

Cover figure: Atomic force microscopic image of <0.1 µm filtered water of Lake Valkea-Kotinen sampled on 6 August 1996 displaying detrital and/or viral particles. Fifty µl of the filtered water was allowed to evaporate to dryness on a crystal of mica (diameter of 1 cm). The image was taken with a multi mode atomic force microscope by the courtesy of dr. S. J. 3 To my teachers 4 CONTENTS 1. List...