Chapter 8 | Surface Water Quality (Organisms used as Indicators of Pollution)

Question 1

Can be used to determined the overall quality of an aquatic ecosystem

Answer 1

Biological communities (fish and freshwater macroinvertebrates)

Question 2

used to evaluate short and long-term trends in water quality

Answer 2

Biological communities (fish and freshwater macroinvertebrates)

Question 3

it show the existing status of a water body whether it is clean or polluted

Answer 3

Short-term trends

Question 4

it shows if conditions are getting better or worse over time.

Answer 4

Long-term trends

Question 5

are placed into
categories based on their tolerance to pollution and are
used as indicator organisms in evaluating the health of
streams

Answer 5

Fish and benthic macroinvertebrates

Question 6

three main categories of pollution tolerance

Answer 6

1. Intolerant
2. Intermediate
3. Tolerant

Question 7

sensitive to poor stream conditions

Answer 7

Intolerant

Question 8

moderately tolerant to degraded habitat
and water quality

Answer 8

Intermediate

Question 9

most tolerant to degraded habitat and water
quality

Answer 9

Tolerant

Question 10

not always the limiting factor in the
presence or absence of aquatic organisms

Answer 10

Water quality

Question 11

also
plays a key role in the whether an organism inhabits a water
body

Answer 11

Physical habitat

Question 12

It is indicated when the number of
tolerant organisms exceed that of intermediate species and intolerant species are absent

Answer 12

Poor water quality

Question 13

It have a larger number of species with fewer individuals per species, increased variety, and a
balanced system

Answer 13

Good quality stream

Question 14

It includes a few species with numerous individuals, lacks variety, and is unbalanced

Answer 14

Unhealthy community

Question 15

Freshwater macroinvertebrates can indicate the following:

Answer 15

•Long-term water quality trends.
•Impacts of various pollutants.
•Impact of changes to the physical habitat.
•Improvements or declines in water quality.

Question 16

Freshwater macroinvertebrates are used as indicators of water
quality for what reasons?

Answer 16

•Important component of virtually all aquatic ecosystems.
•Found in all types of aquatic habitats.
•Relatively easy to collect.
•Have different levels of tolerance to environmental disturbance.
•Most are sedentary or move over a small area.
•The kind of organisms and number present in a stream is well correlated with recent past and present conditions.
•Life cycles and taxonomy of most groups are well documented.

Question 17

Freshwater fish are used as indicators of water pollution for what reasons?

Answer 17

•Live in water for entire life and have long life spans.
•Easy to identify in the field because of established key characteristics of fish species.
•Relatively easy to collect with the proper equipment.
•Wide range of tolerance levels, from very sensitive to very tolerant of environmental
disturbance.
•Distribution, life histories, and pollution tolerances of many species are well documented.
•Fish communities are persistent and can recover from natural disturbances.

Question 18

Freshwater fish can indicate the following about water pollution:

Answer 18

•Long-term and short-term water quality trends.
•Impacts of various pollutants.
•Impact of changes to the physical habitat.
•Improvements or declines in water quality