CFP Aquatic Species Monitoring 4

Question 1

In radio telemetry studies of fish movement, which factor most reduces detection efficiency of a stationary receiver array?

Accepted Answer

High background electrical conductivity attenuating signal range

Answer

Elevated specific conductance increases signal attenuation in water, reducing the effective detection range of fixed hydrophone or radio receiver arrays.

Question 2

When designing a long-term population monitoring program for a stream fish species, which sampling approach best controls for temporal variation in gear efficiency?

Accepted Answer

Standardized sampling protocols applied at fixed sites during the same season annually

Answer

Standardizing protocols, sites, gear, and seasonal timing removes many confounding sources of variation and makes year-to-year comparisons valid.

Question 3

A fisheries manager finds elevated mercury concentrations in piscivorous fish at a reservoir. Which monitoring approach would best identify the trophic pathway of mercury bioaccumulation?

Accepted Answer

Stable nitrogen isotope (δ15N) analysis of fish and prey across trophic levels

Answer

Stable nitrogen isotopes enrich predictably with each trophic step, allowing researchers to link mercury concentrations to trophic position across the food web.

Question 4

Which stream fish sampling method is best suited for estimating the total biomass of a cryptic benthic species such as sculpin?

Accepted Answer

Three-pass depletion electrofishing with removal

Answer

Depletion electrofishing removes fish across successive passes, allowing capture probability and total population size (and thus biomass) to be estimated for species difficult to detect otherwise.

Question 5

A biologist calculates weight-at-length residuals for a sample of bluegill to generate a relative weight (Wr) index. What does a Wr value of 85 indicate?

Accepted Answer

Fish are below average condition relative to the standard weight equation

Answer

A Wr below 100 means the observed weight is less than the standard weight for fish of that length, indicating below-average condition.

(CFP) Certified Fisheries Professional Practice Test

(CFP) Certified Fisheries Professional Practice Test

CFP Aquatic Species Monitoring 4