Chapter 24: Aquatic Ecosystems Flashcards
Pertaining to flowing water
lotic
Pertaining to standing water, such as lakes and ponds;
A population is limited by the lowest amount needed of an essential nutrient
lentic
Shallow water of a lake, in which light penetrates to the bottom, permitting submerged, floating, and emergent vegetative growth;
Also shore zone of tidal water between high-water and low-water marks
littoral zone
Aquatic animals that are able to move at will through the water
nekton
Deep zone in aquatic ecosystems, below the limnetic zone (beyond the depth of effective light penetration)
profundal zone
A place of intense biological activity where decomposition of organic matter takes place
benthic zone
4 types of zones found in ponds and lakes
- Littoral zone
- Limnetic zone
- Profundal zone
- Benthic zone
Small, floating plant life in aquatic ecosystems;
Planktonic plants
phytoplankton
Floating or weakly swimming animals in freshwater and marine ecosystems;
Planktonic animals
zooplankton
A condition of lake water when it is too acidic and poor in oxygen to support life, resulting from excessive humus content
dystrophy
Term applied to a body of water with a high content of humic or organic matter, often with high littoral productivity and low plankton productivity
dystrophic
Nutrient enrichment of a body of water
eutrophication
When is eutrophication called cultural eutrophication?
It is called cultural eutrophication when accelerated by introduction of massive amounts of nutrients from human activity
Condition of being nutrient-rich
eutrophy
Nutrient-poor condition
oligotrophy
A sequence in a flowing stream that develops as a stream’s hydrological flow structure alternates from areas of relatively shallow to deeper water
riffle-pool sequence
The sites of primary organic production in the stream;
Shallow with fast, turbulent water running over rocks
riffles
The sites of decomposition in the stream;
Deep with slow water (the velocity of the current slows enough for organic matter to settle)
pools
___, the major sites of carbon dioxide production during the summer and fall, are necessary for maintaining a constant supply of bicarbonate in solution.
pools
Without ___, photosynthesis in the ___ would deplete the bicarbonates and result in smaller and smaller quantities of available carbon dioxide downstream.
pools / riffles
A partially enclosed embayment where freshwater and seawater meet and mix
estuary
2 main divisions of the ocean
- pelagic zone
- benthic zone
Zone referring to the open sea / whole body of water
pelagic zone
Zone referring to the area of the sea or lake bottom / bottom region of water
benthic zone
2 provinces of the pelagic zone
- neritic province
- oceanic province
Marine environment embracing the regions where landmasses extend outward as a continental shelf;
Water that overlies the continental shelf
neritic province
Referring to regions of the sea with depths greater than 200 m that lie beyond the continental shelf
oceanic province
Lighted water column of a lake or ocean, inhabited by plankton;
Has sharp gradients in illumination, temperature, and salinity;
Ranges from the surface to about 200 m in depth
photic zone (or epipelagic zone)
Plankton with a size range from 2 to 20 mm;
Makes up the largest biomass in temperate and tropical waters;
The major source of primary production
nanoplankton
Feeding loop in which bacteria take up dissolved organic matter produced by plankton and nanoplankton consume the bacteria;
Adds several trophic levels to the plankton food chain
microbial loop
Animals and plants living on the bottom of a lake or sea, from the high-water mark to the greatest depth
benthos
Place on ocean floor where water, heated by molten rock, issues from fissures;
Vent water contains sulfides oxidized by chemosynthetic bacteria, providing support for carnivores and detritivores
hydrothermal vent
Rising up to 13 m above the sea floor, mineralized chimneys rich in zinc sulfides that issue a milky fluid with a temperature of less than 300 degrees C
white smokers
Rising up to 13 m above the sea floor, narrow mineralized chimneys rich in copper sulfides that issue jets of clear water from 300 degrees C to more than 450 degrees C that are soon blackened by precipitation of fine-grained sulfur-mineral particles
black smokers
Colorful, rich oases within the nutrient-poor seas
coral reefs
3 basic types of coral reefs
- fringing reefs
- barrier reefs
- atolls
Type of coral reef that grows seaward from the rocky shores of islands and continents
fringing reef
Type of coral reef that parallels shorelines of continents and islands and is separated from land by shallow lagoons
barrier reef
A ring of coral reefs and islands surrounding a lagoon, formed when a volcanic mountain subsides beneath the surface
atoll
Hypoxic areas in the world’s oceans and large lakes, caused by excessive nutrient pollution from human activities coupled with other factors the deplete the oxygen required to support most marine life in bottom and near-bottom water
dead zones (especially Gulf of Mexico)
Why do dead zones occur?
Dead zones occur because of a process called eutrophication,
which results in exceedingly high levels of net primary productivity (the body of water gets too many nutrients such as phosphorus and nitrogen),
which can result in anoxia,
which results in the death of marine organisms
What can be done to minimize the Gulf dead zone?
Manage nutrients more efficiently in farm fields:
- use fewer fertilizers
- adjust the timing of fertilizer applications to limit runoff of excess nutrients into adjacent aquatic ecosystems
Restore wetlands and riparian systems:
- doing so also helps to capture nutrients and reduce runoff
