Chapter 8

Question 1

Saltwater (marine life zones)

Answer 1

(oceans and their bays, estuaries, coastal

wetlands, shorelines, coral reefs, and mangrove forests)

Question 2

Freshwater life zones

Answer 2

(lakes, rivers, streams, and

inland wetlands).

Question 3

Plankton

Answer 3

Saltwater and freshwater life zones contain several major types of organisms. One such type consists of weakly swimming, free-floating plankton, which can be divided into three groups.

Question 4

Nekton

Answer 4

A second major type of organisms is nekton,

strongly swimming consumers such as fish, turtles, and whales

Question 5

Benthos

Answer 5

The third type, benthos, consists of bottom-dwellers such as: oysters and sea stars, which anchor themselves to ocean bottom structures; clams and worms, which burrow into the sand or mud; and lobsters and crabs, which walk about on the sea floor.

Question 6

Decomposers

Answer 6

A fourth major type is decomposers (mostly bacteria), which break down organic compounds in the dead bodies and wastes
of aquatic organisms into nutrients that aquatic primary producers can use.

Question 7

Coastal zone

Answer 7

Is the warm, nutrient-rich, shallow water that extends from the high-tide mark on land to the gently sloping, shallow edge of the continental shelf (the submerged part of the continents).

Question 8

Turbidity

Answer 8

This cloudiness, called turbidity, can occur naturally, such as from algal growth, or can result from disturbances such as clearing of land, which when it rains, causes silt to flow into bodies of water.

Question 9

Estuaries

Answer 9

Are where rivers meet the sea.

Question 10

Coastal wetlands

Answer 10

Coastal land areas covered with water all or part of the year—include river mouths, inlets, bays, sounds, coastal marshes (called salt marshes in temperate zones,

Question 11

Intertidal zone

Answer 11

The area of shoreline between low and high

tides.

Question 12

Open sea

Answer 12

The sharp increase in water depth at the edge of the continental shelf separates the coastal zone from the vast volume of the ocean.

Question 13

Lakes

Answer 13

Are large natural bodies of standing fresh-
water formed when precipitation, runoff, streams, rivers, and groundwater seepage fill depressions in the earth’s surface.

Question 14

Oligotrophic (poorly nourished) lakes

Answer 14

Lakes that have a small supply of plant nutrients.

Question 15

Eutrophic (well-nourished) lake

Answer 15

A lake with a large supply of nutrients needed by producers.

Question 16

Surface water

Answer 16

Precipitation that does not sink into the ground or evaporate.

Question 17

Runoff

Answer 17

When precipitation flows into streams.

Question 18

Watershed or drainage basin

Answer 18

Is the land area that delivers runoff, sediment, and dissolved substances to a stream.

Question 19

Cultural eutrophication

Answer 19

Process in which human inputs of nutrients from the atmosphere and from nearby urban and agricultural areas can accelerate the eutrophication of lakes.

Question 20

Mesotrophic lakes

Answer 20

Many lakes fall somewhere between the two extremes of nutrient enrichment.

Question 21

Inland wetlands

Answer 21

Are lands located away from coastal

areas that are covered with freshwater all or part of the time—excluding lakes, reservoirs, and streams.

Question 22

Aquatic life zones

Answer 22

The aquatic equivalents of biomes are called aquatic life zones—saltwater and freshwater portions of the biosphere that can support life.