limiting factors 



limnetic 



lithologic 



littoral 

 la tic 



Any condition whicii approaches or exceeds the Hmits of toler- 

 ance for species. 



Pertaining to open waters of lakes, especially to areas too deep 

 to support rooted aquatic plants. 



The physical character of a rock as determined by eye or with a 

 low power magnifier, and based on color, structure, mineralogic 

 components, and grain size. 



Of, or pertaining to, the zone between high and low water marks. 

 Of, relating to, or living in running waters such as rivers or streams. 



M 



macroinvertehrates 



mcf 

 meiobenthos 



MHW 

 MLW 

 MSL 

 MWL 



Those invertebrates that are large enough to be seen by the un- 

 aided eye. 



Thousand cubic feet. 



Microscopic and small macroscopic animals inhabiting the sedi- 

 ments of water bodies. 

 Mean high water. 

 Mean low water. 

 Mean sea level. 

 Mean water level. 



nekton 

 niche 



NRR 



nutrient 



N 



Free swimming aquatic animals, essentially independent of water 

 movements. 



The functional role served by an organism in its habitat or com- 

 munity. 



Natural renewable resources. 

 An element or inorganic compound essential to life. 



O 



on lapping 



ontogenetic 



A type of overlap characterized by regular and progressive pinch- 

 ing out of strata toward the margins of a depositional basin; each 

 unit transgresses and extends beyond the point of reference of 

 the underlying unit. 



Of, relating to, or appearing in the course of development of an 

 individual organism. 



pelagic 

 perturbation 



physiography 



Pleistocene 



ppt fO/ooj 



Of, relating to, or living in the open sea. 



Any effect that makes a small modification in a physical or bi- 

 ological system. 



The topographic features of a region, as shown in the character 

 arrangement and interrelations of elements such as climate, relief, 

 soil, or land use. 



Epoch of geologic time of the Quaternary period, immediately 

 proceding the recent epoch. Also known as Ice Age:Oiluvium. 

 Parts per thousand. 



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