Concentration of sodium, potassium, magnesium, calcium, bicarbonate, carbonate, sulfate, and halides (chloride, fluoride, bromide) in water. See Dissolved Solids.


In solutions, the maximum amount of a substance that can be dissolved in a liquid without it being precipitated or released into the air.

Sea Water

Water containing from 3.0 to 3.5% total salts.


Settleable solids that form bottom deposits.


Nets used to harvest fish from ponds. Seines are usually 25% longer than the width of the pond and have a depth 25% deeper than the maximum depth of the pond.

Settleable Solids

That fraction of the suspended solids that will settle out of suspension under quiescent conditions.


Aquatic animals with shells, e.g., crustaceans (prawns, lobsters) and mollusks (e.g., oysters, scallops, clams).


Soil particles carried or deposited by moving water.


The change of height (rise) or a given distance (run). Slope is calculated as c2 = a2 + b2 where slope is c2.

Sodium Bicarbonate

A chemical compound (NaHCO3) used as a buffer in recirculating aquaculture systems.


The degree to which a substance can be dissolved in a liquid; usually expressed as milligrams per liter or percent.

Spawning (Hatchery Context)

Act of obtaining eggs from female fish and sperm from male fish.


The largest group of similar individuals that actually or potentially can successfully interbreed with one another, but not with other such groups; systematic units including geographic races and varieties, are included in a genus.


A state manifested by a syndrome or bodily change caused by some force, conditions, or circumstance (i.e., by a stressor) in or on an organism or on one of its physiological or anatomical systems. Any condition that forces an organism to expend more energy to maintain stability.

Substrate Spawners

Species of animals which spawn on substrate such as gravel, rock, perlon mats, or other material.

Suspended Solids

Non-seattleable articles retained in suspension in the water column.