Detritus particulate

Outer crust. A friable outer crust forms atop the tubercle. The crust is composed of ferric hydroxide (hematite), carbonates, silicates, other precipitates, settled particulate, and detritus. Ferrous ion and ferrous hydroxide generated within the tubercle diffuse outward through fis-... 

Essentially all the dissolved organic matter in seawater can be assumed to be non-living. However, particulate organic matter can be either living or dead, with the latter often referred to as "detritus."... 

Of the remaining particulate organic matter, very little is living (> 95% detritus). 

Phytoplankton are easily sampled with fine-mesh nets. However, samples require considerable processing before analysis to remove zooplankton, detritus, or other particulates. Sampling would not measnrably affect target popnlations, even in the smallest lakes. 

Terrestrial Detritus. Variability in ecosystem response to fertilization may be attributed in part to the interaction of aquatic and terrestrial ecosystems. In contrast to the many aquatic ecosystems in which higher trophic levels are fueled almost entirely by organic matter originating in the water column, other systems are driven by inputs of particulate and dissolved organic matter from land. The importance of this land-water interaction in regulating system metabolism has been obvious to stream ecologists for some... 

Figure 4. Time course of labeling of POM (particulate organic matter, primarily phytoplankton) with tracer additions of15N in the fertilized and control sides of Lake N2. The solid line represents the predicted labeling, given the turnover time of phytoplankton. Terrestrial detritus remained unlabeled throughout the...

Use of DOM and Terrestrial Detritus. The importance of terrestrially derived organic matter (dissolved and particulate) to zooplankton... 

Fig. 1. Model depicting nitrogen flows in a kelp bed community. Primary production by macrophytes is partitioned into particulate (POM) and dissolved (DOM) components. Filter-feeders feed on detritus consisting of POM, bacteria and animal faeces. Recycling of nitrogen via the feedback loop provided by faeces is indicated by heavy lines. Fig. la) shows the model under downwelling conditions, when phytoplankton is imported with surface water from offshore. Fig. lb) shows the model under upwelling conditions when it is assumed that phytoplankton in the upwelling water is negligible and excess detritus is exported in surface water.

The seaweeds known as kelps and giant kelps (Laminariales) are built in such a way that they produce detritus more or less continuously. All are divisible into holdfast, stipe and blade (Fig. 7) and the blades normally have a growth zone at the base and a zone of erosion near the tip. They have been likened (Mann, 1972b) to "moving belts of tissue". Growth at the base compensates for erosion at the tip, and in the process large amounts of detritus, both particulate and dissolved, are released into the water. This detritus is readily colonized by bacteria (Laycock, 1974) and appears to be less resistant to digestion by animals than the detritus derived from vascular plants. 

Fenchel, T. and Harrison, P., 1976. The significance of bacterial grazing and mineral cycling for the decomposition of particulate detritus. In 3.M. Anderson and A. Macfadyen (eds), The Role of Terrestrial and Aquatic Organisms in Decomposition Processes. Blackwell Scientific Publications, Oxford, pp. 285-299. 

Detritus includes nonliving particulate, colloidal, and dissolved organic matter, and metabolically size affects only the rates of hydrolytic attack (Wetzel, 1995). Inland aquatic ecosystems collect organic matter, particularly... 

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