Chapter 24: Aquatic Ecosystems

Question 1

Pertaining to flowing water

Answer 1

lotic

Question 2

Pertaining to standing water, such as lakes and ponds;

A population is limited by the lowest amount needed of an essential nutrient

Answer 2

lentic

Question 3

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

Answer 3

littoral zone

Question 4

Aquatic animals that are able to move at will through the water

Answer 4

nekton

Question 5

Deep zone in aquatic ecosystems, below the limnetic zone (beyond the depth of effective light penetration)

Answer 5

profundal zone

Question 6

A place of intense biological activity where decomposition of organic matter takes place

Answer 6

benthic zone

Question 7

4 types of zones found in ponds and lakes

Answer 7

• Littoral zone
• Limnetic zone
• Profundal zone
• Benthic zone

Question 8

Small, floating plant life in aquatic ecosystems;

Planktonic plants

Answer 8

phytoplankton

Question 9

Floating or weakly swimming animals in freshwater and marine ecosystems;

Planktonic animals

Answer 9

zooplankton

Question 10

A condition of lake water when it is too acidic and poor in oxygen to support life, resulting from excessive humus content

Answer 10

dystrophy

Question 11

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

Answer 11

dystrophic

Question 12

Nutrient enrichment of a body of water

Answer 12

eutrophication

Question 13

When is eutrophication called cultural eutrophication?

Answer 13

It is called cultural eutrophication when accelerated by introduction of massive amounts of nutrients from human activity

Question 14

Condition of being nutrient-rich

Answer 14

eutrophy

Question 15

Nutrient-poor condition

Answer 15

oligotrophy

Question 16

A sequence in a flowing stream that develops as a stream’s hydrological flow structure alternates from areas of relatively shallow to deeper water

Answer 16

riffle-pool sequence

Question 17

The sites of primary organic production in the stream;

Shallow with fast, turbulent water running over rocks

Answer 17

riffles

Question 18

The sites of decomposition in the stream;

Deep with slow water (the velocity of the current slows enough for organic matter to settle)

Answer 18

pools

Question 19

___, the major sites of carbon dioxide production during the summer and fall, are necessary for maintaining a constant supply of bicarbonate in solution.

Answer 19

pools

Question 20

Without ___, photosynthesis in the ___ would deplete the bicarbonates and result in smaller and smaller quantities of available carbon dioxide downstream.

Answer 20

pools / riffles

Question 21

A partially enclosed embayment where freshwater and seawater meet and mix

Answer 21

estuary

Question 22

2 main divisions of the ocean

Answer 22

• pelagic zone

- benthic zone

Question 23

Zone referring to the open sea / whole body of water

Answer 23

pelagic zone

Question 24

Zone referring to the area of the sea or lake bottom / bottom region of water

Answer 24

benthic zone

Question 25

2 provinces of the pelagic zone

Answer 25

• neritic province

- oceanic province

Question 26

Marine environment embracing the regions where landmasses extend outward as a continental shelf;

Water that overlies the continental shelf

Answer 26

neritic province

Question 27

Referring to regions of the sea with depths greater than 200 m that lie beyond the continental shelf

Answer 27

oceanic province

Question 28

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

Answer 28

photic zone (or epipelagic zone)

Question 29

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

Answer 29

nanoplankton

Question 30

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

Answer 30

microbial loop

Question 31

Animals and plants living on the bottom of a lake or sea, from the high-water mark to the greatest depth

Answer 31

benthos

Question 32

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

Answer 32

hydrothermal vent

Question 33

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

Answer 33

white smokers

Question 34

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

Answer 34

black smokers

Question 35

Colorful, rich oases within the nutrient-poor seas

Answer 35

coral reefs

Question 36

3 basic types of coral reefs

Answer 36

• fringing reefs
• barrier reefs
• atolls

Question 37

Type of coral reef that grows seaward from the rocky shores of islands and continents

Answer 37

fringing reef

Question 38

Type of coral reef that parallels shorelines of continents and islands and is separated from land by shallow lagoons

Answer 38

barrier reef

Question 39

A ring of coral reefs and islands surrounding a lagoon, formed when a volcanic mountain subsides beneath the surface

Answer 39

atoll

Question 40

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

Answer 40

dead zones (especially Gulf of Mexico)

Question 41

Why do dead zones occur?

Answer 41

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

Question 42

What can be done to minimize the Gulf dead zone?

Answer 42

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