Bioindicators Flashcards
These are living organisms that provide information about the health of an ecosystem
Biodindicators
Biondicators exhibit responses to these
Stressors/pollutants
Does sampling bioindicators or sampling water quality periodically give a better indication of long-term water quality?
Sampling bioindicators
What is the assumption for using bioindicators?
If conditions are suitable for indicator species, the rest of the species and state of the watershed should be suitable
What are 3 of 5 characteristics of biondicators?
- Lower food chain placement; 2. Narrow tolerance to change; 3. Native species; 4. Restricted range; 5. Public image
What are two examples of species that are known to be bioindicators?
Caddisflies and orangethroat darters
What are three levels of biondicator assessment?
- Single species; 2. Group of species; 3. Species and physical/chemical factors
What are three characteristics of benthic macroinvertebrates?
- Inhabit the benthic zone; 2. Large enough to be seen with naked eye; 3. Lack backbone
What are four reasons why benthic macroinvertebrates are one of the most commonly sampled biota?
- Indicate both aquatic and terrestrial habitat; 2. Each part of their lifecycle is spent in different habitats; 3. Lack of migration; 4. Integration of conditions over time at a specific site
What are 3 of 5 advantages of sampling benthic macroinvertebrates?
- Sensitive to point and nonpoint source pollution; 2. Short life cycles; 3. Diversity of species with range of responses; 4. Sampling methods are simple; 5. Occur in lower trophic levels
What are three disadvantages to sampling benthic macroinvertebrates?
- Not responsive to all pollution; 2. Abundance varies seasonally; 3. Require experience to identify
What are three examples of highly sensitive macroinvertebrates?
Mayflies, stoneflies, caddisflies
What are three examples of moderately sensitive macroinvertebrates?
Crayfish, dragonflies, alderflies
What are three examples of tolerant macroinvertebrates?
Black flies, leeches, aquatic worms
At what two times of year is macroinvertebrate sampling done?
Spring and fall
What part of the stream is sampled for macroinvertebrates?
Riffle
What kind of substrate is preferred for sampling macroinvertebrates?
Gravel
How many samples per stream reach are used for sampling macroinvertebrates?
1
What are three types of gear are used to sample macroinvertebrates?
Kicknet, D-net, surber sampler
This type of sampling is done to allow macroinvertebrates to colonize samplers
Leave-in-field sampling
What are two levels to use when analyzing fish?
Individual fish or fish populations
What are four things to sample from individual fish?
- Heavy metals in tissues; 2. Trace elements; 3. Altered physiology; 4. Altered behaviors
What are five things to sample from fish populations?
- Stratified locations; 2. Habitat requirements; 3. Disturbances; 4. Pollution tolerance; 5. Ecological issues
What are seven advantages of fish as bioindicators?
- Long-lived; 2. Occur in variety of habitats; 3. Extensively studied; 4. Extremely diverse; 5. Easily identified; 6. Toxicity trends; 7. Well-known/socially important
What are three disadvantages of sampling fish as bioindicators?
- Manpower; 2. Migratory/spawning behaviors; 3. Sampling bias
Can fish assemblages be compared across multiple regions?
No
What are four major ways of sampling fish?
Seining, electrofishing, gill netting, trap/hoop/fyke netting
What are two advantages of seining for fish?
Inexpensive/easy maintenance and minimal impact on fish
What are two disadvantages of seining for fish?
Less effective for larger fish and standardization is difficult
What are three advantages of electrofishing?
Time efficient, effective in many habitats, easily standardized
What are two disadvantages of electrofishing?
Selective bias for large fishes and more harmful to fish
What is an advantage of gill netting?
Minimal impact on fish population
What are two disadvantages of gill netting?
Less effective for larger fishes and bias towards fish shape
What are two disadvantages of trap/hoop/fyke netting?
Bias towards cover-loving fish and near-shore fish and can also trap non-fish
What are two important considerations for trap/hoop/fyke netting?
Mesh size and throat size
What are two extreme sampling methods used to sample fish?
Chemical dispersion and draining
Can two or more different sampling methods be compared directly?
No
These are relatively large intact sites that are self-sustaining and have not been greatly influenced by human-induced disturbances
Reference sites
Do reference sites have to be pristine?
No
Reference sites are paired with these for studies
Impacted/study sites
What are 5 characteristics to reference sites and study sites have to share?
- Same chemical processes; 2. Same functions/nutrient cycling; 3. Same structure; 4. Same riparian area; 5. Same drainage
Can indicators give insight into causation?
No
What are five elements required for successful stream monitoring?
- Control site; 2. Pre-human impact information; 3. Proper scale; 4. Replication; 5. Continued monitoring over time to develop trends
