Stream Ecology

substances dissolved in other substances.
In streams: C, N, P, Mg, K, Si, S, Na, Fe, Mn, Cu, B, Mo, V…
Nutrients required by organisms in large amounts to live and grow healthily. Examples: N, P, K, Si
inorganic material required for life
relating to, or derived from living organisms
not composed of organic matter
in solution
tiny subdivisions of solid matter suspended in a gas or liquid.
a positively charged polyatomic cation with the chemical formula NH+4
the biological oxidation of ammonia with oxygen into nitrite followed by the oxidation of these nitrites into nitrates
a microbially facilitated process of nitrate reduction that may ultimately produce molecular nitrogen (N2) through a series of intermediate gaseous nitrogen oxide products.
is the natural process, either biological or abiotic, by which nitrogen (N2) in the atmosphere is converted into ammonia. This process is essential for life because fixed nitrogen is required to biosynthesize the basic building blocks of life, e.g. nucleotides for DNA and RNA and amino acids for proteins
Uptake of dissolved inorganic nitrogen by autotrophs
Heterotrophs consume organic molecules
conversion of nitrate to nitrite (by nitrate reductase) is followed by a reduction to ammonia by nitrite reductase
uptake length
represented by Sw on chart; is the time it takes before nutrient is take back up or down in the benthos
nutrient spiral
the flow of nutrients in and out of the benthos in a stream
turnover length
pollutant loads
no slip condition
water in contact with a solid surface will have a 0 velocity no matter the surface texture or condition
gas or liquid, not solid
The rate of change of velocity at which one layer of fluid flows over an adjacent parallel layer, often expressed in seconds-1.
boundary layer
is equal to 99% of freestream velocity/ thickness of flow below 99% of maximum vleocity; is where the graph stops curving.
laminar sublayer
very small layer near substrate where the flow is not turbulent.
laminar flow
flow that is uniform/ where adjacent packets of water move in the same direction at the same speed without any rapid changes in relative velocity or position.
turbulent flow
adjacent packets of water move independent of one another in direction and velocity. (whirls)
Reynold’s number
Discovered by Osborn Reynolds in 1883- equal to inertial forces over viscous forces/ or velocity times length scale (avg depth) divided by viscosity. (less than 500= laminar flow/ greater than 2000= turbulent flow)
A physical property of fluids that determines the internal resistance to shear forces. “viscous forces dominate in the world of the small”
inertial forces
“dominate in the world of the large”
Examples: pressure drag, eddy diffusion
Eddy diffusion
turbulent diffusion in which substances are mixed in an eddy motion/ mix rapidly and allows quick replenishment of nutrients.
Streamlined shape
important to large organisms due to inertial forces/ minimizes flow separation at the rear of the animal.
Froude number
Discovered by William Froude a Naval Engineer- ratio of inertial and gravitational forces at a liquid-air interface, used to predict supercritical flow. Equal to velocity divided by the square root of gravity times depth dimension.
all materials that project into or out of the bottom of or sides of a river. Examples include rocks, mud, debris, logs
Wentworth scale
categorizes types of substrate by particle size/ boulder > 265mm, cobble 64-256mm, pebble 16-64mm, gravel 2-16mm, sand 0.063-2mm, silt < 0.063mm
Organic substrates
leaf packs or woody debris
organisms that prefer rocks as substrates
sand preferring organisms
organisms that prefer woody substrates
organisms that prefer plants as substrates
Unit for estimating the demand for energy required for heating or cooling. In the US, the typical standard indoor temperature is 65?F (18.3?C). For each 1?F decrease or increase from this standard in the average outside temperature one heating or cooling degree day is recorded.
organisms whose cells have nuclei
A chlorophyll-containing plastid found in algal and green plant cells.
organisms whose cells do not have nuclei such as bacteria, blue-green algae and viruses
being longer than wide; examples of filamentous algae include mugeotia
Of or relating to diatoms of the class Centrales, distinguished by their radially symmetrical form.
algae that lives in groups
mobile, free swimming, usually with a flagellum
is an organism that cannot fix carbon and uses organic carbon for growth
also called a producer, is an organism that produces complex organic compounds (such as carbohydrates, fats, and proteins) from simple inorganic molecules using energy from light (by photosynthesis) or inorganic chemical reactions
algae attached to substrates
algae suspended in the water column
Relating to a taxonomic group that includes some but not all of the descendants of a common ancestor.
is the hard and porous cell wall or external layer of diatoms. The frustule is composed almost purely of silica, made from silicic acid, and is coated with a layer of organic substance, which was referred to in the early literature on diatoms as pectin
The median groove of a diatom valve.
Cyclic recurrent polymorphism in certain planktonic fauna in response to seasonal temperature or salinity changes.
are specialized nitrogen-fixing cells formed by some filamentous cyanobacteria,during nitrogen starvation. They fix nitrogen from dinitrogen (N2) in the air using the enzyme nitrogenase, in order to provide the cells in the filament with nitrogen for biosynthesis.
a thick-walled dormant cell derived from the enlargement of a vegetative cell.[1] It serves as a survival structure. It is a resting cell of cyanobacteria and unicellular and filamentous green algae.
green pigment in chloroplasts/ a specific form of chlorophyll used in oxygenic photosynthesis. It absorbs most energy from wavelengths of violet-blue and orange-red light.[
is light-induced reduction in the photosynthetic capacity of a plant, alga or a cyanobacterium
is a toxin produced by certain cyanobacteria (blue-green algae). When produced during algal blooms, cyanotoxins can poison and even kill animals and humans. Cyanotoxins can also accumulate in other animals such as fish and shellfish
vertical migrations
diatoms migrate diurnally up and down the water column
a biological phenomenon by which an organism produces one or more biochemicals that influence the growth, survival, and reproduction of other organisms.
nutrients required by humans and other living things throughout life in small quantities to orchestrate a whole range of physiological functions, but which the organism itself cannot produce.
A body of water, such as a reservoir, made by impounding; damming of rivers and streams
transport of water for agricultural purposes
describes the emergence of discontinuities (fragmentation) in an organism’s preferred environment (habitat). Habitat fragmentation can be caused by geological processes that slowly alter the layout of the physical environment or by human activity such as land conversion
directly connected impervious area; impervious areas that are connected directly to drainage systems without flowing over pervious surfaces
point sources
A source, especially of pollution or radiation, occupying a very small area and having a concentrated output.
non-point source
pollution that occurs when rainfall, snowmelt, or irrigation runs over land or through the ground, picks up pollutants, and deposits them into rivers, lakes, and coastal waters or introduces them into ground water.
Index of Biotic Integrity; helps calculate the impact of development on streams
minimum flows and levels for streams