Chapter 3: Abiotic Factors of Water Environments

hydrologic cycle

the continuous, solar-powered movement of water between the Earth's atmosphere, land, and oceans, transitioning through liquid, solid, and gaseous states

aquifer

an underground layer of water-bearing, permeable rock, gravel, sand, or silt that stores and transmits groundwater

turbidity

the cloudiness or haziness of a fluid caused by a large number of individual suspended particles, such as sediment, algae, or organic matter, that are generally invisible to the naked eye

thermal stratification

the separation of water (or air) into distinct layers based on density differences caused by temperature, typically with warmer, lighter water resting on top of colder, denser water

spring overturn

a natural, seasonal process, where a lake or pond's water column fully mixes, usually in early spring after ice melt

intertidal zone

foreshore; the dynamic coastal area covered by water at high tide and exposed to air at low tide

photic zone

sunlight zone; the top layer of a body of water that receives enough sunlight for photosynthesis

benthic zone

seafloor; lowest ecological region of a water body, including the seafloor, surface sediments, and subsurface layers, ranging from shallow coastal areas to deep ocean trenches

aphotic zone

the deep, dark portion of aquatic ecosystems, roughly below 1,000 meters in the ocean, where less than 1% of sunlight penetrates, preventing photosynthesis

pelagic zone

the "open ocean" water column, spanning from the surface to the seafloor, excluding coastal areas and the bottom itself

tides

the regular rise and fall of sea levels caused by the gravitational pull of the moon and sun, combined with the Earth's rotation

upwelling zones

ocean regions where cold, nutrient-rich deep water rises to the surface, driven by winds and Earth's rotation (coriolis effect)

dissolved oxygen

the amount of oxygen available to aquatic organisms, essential for the health of the aquatic ecosystems

1 atmosphere

pressure change for every 10 meters of depth

salinity

the saltiness or dissolved salt content of a body of water

330,000 ppm

salinity of the dead sea

>50,000 ppm

salinity of brine

35,000 ppm

average salinity of sea water

soft water

water with a low concentration of dissolved minerals, specifically calcium and magnesium, typically containing less than 61 mg per liter

hard water

water with a high concentration of dissolved minerals, primarily calcium and magnesium, picked up as it passes through deposits like limestone or chalk