b. The Inorganic-organic Environment. Both the substrate and the water column 

 have nonliving organic complexities due in large measure to biotic activities. These range 

 from presence of phosphates, nitrates (and other nitrogenous compounds), and silicates, to 

 dissolved organics— the important external metabolites of earlier British authors. 



c. The Biotic Environment. The world of animal and plant life is a world of energy 

 and material transformation and of cyclic phenomena, as life is a continuum. 



The impact of engineering activities on this part of the environment has great import. 

 To be considered are life stages, breeding and feeding conditions, environmental 

 adaptations, and sustainable ranges of conditions for dwellers within and on the substrata, 

 in the ecotone layer of water immediately above the bottom and filled with life equally 

 dependent on bottom and water, or in part, in the remaining water column. Migratory 

 capacities to repopulate disturbed areas must also be considered as well as occupation of 

 niches. 



What is the import of life in the water column above the bottom? The primary source 

 of all energy is the sun. The primary producer or energy convertor is the green plant. All 

 other living things depend on plants as an energy source. In the sea most of the primary 

 energy production takes place near the surface as a result of photosynthetic activities of 

 chlorophyll-containing, microscopic, planktonic algae. These marine algae are responsible 

 for nine-tenths of the world's energy conversion. Secondary sources of conversion in 

 shallow water are attached macroscopic algae (kelps and others) and rooted higher plants 

 (eel grass and others), and to a lesser extent, (and less well-measured extent), benthic 

 bacteria. 



The algae that convert the sun's energy are consumed by small animals adrift in the 

 water; or the algae sink to the bottom where they are eaten by bottom dwellers such as 

 oysters, clams, some crustaceans, and annelid worms; or the algae are directly decomposed 

 by bacteria. Assuming they are eaten by small animals, these in turn are eaten by larger 

 consumers (predators), and so on in a complex food web with large energy losses at each 

 step. Both the producers and the consumers continually are giving off into the water 

 excretions and secretions which contribute to the organic part of what was earlier termed 

 the inorganic-organic environment. Some organic materials remain mixed or dissolved in 

 the water; much rains down on the bottom to become part of the substrate. This material 

 is particularly concentrated on the water-substrate interface and is usually measured as dry 

 weight of carbon. 



On the bottom, the material is used directly as food by bottom-dwelling animals, which 

 also continuously contribute their share of excretions and secretions. Eventually these and 

 the dead bodies of larger plants and animals— consumers and producers— will be 

 decomposed and converted by bacteria, freeing, expecially, phosphates, nitrates, and 

 silicates for use by photosynthetic algae in reinitiating the energy cycle. 



Study of plankton has, for years, fascinated marine biologists, and various collections 

 have been analyzed in attempts to typify areas. Plankton data are available from the 

 National Oceanographic Data Center, and the collections may be deposited at the 



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