Field Survey & Data Collection Flashcards
7 cards from real CFP practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Field Survey & Data Collection flashcards as text
A biologist needs to sample fish in a small, turbid stream where electrofishing is ineffective. Which passive gear is most appropriate?
Answer: Minnow traps baited with cat food
Baited minnow traps are effective in small streams and do not require water clarity or electrical access.
When conducting a visual snorkel survey for salmonids in a clear stream, the biologist should move in which direction?
Answer: Upstream against the current
Moving upstream prevents silt disturbance from reaching the survey area ahead and keeps fish facing the observer naturally.
The primary purpose of a fish passage survey at a culvert is to:
Answer: Determine whether the structure creates a barrier to fish movement
Fish passage surveys evaluate whether culvert outlet drop, velocity, or depth prevents upstream fish migration.
In a population mark-recapture study, which condition would cause the Lincoln-Petersen estimate to be negatively biased (underestimate true population size)?
Answer: Marked fish have higher catchability than unmarked fish
If marked fish are easier to catch, the recapture sample overrepresents marks, inflating the marked fraction and lowering the population estimate.
A biologist wants to assess the temperature regime of a stream without continuous monitoring. Which approach provides the best temporal resolution at low cost?
Answer: Continuous recording with inexpensive data loggers (iButtons or HOBO loggers)
Continuous data loggers record temperature at programmed intervals and capture diel and seasonal variation inexpensively.
When seining in a wadeable stream, the seining team should position the net so that:
Answer: The bag is downstream and the wings extend upstream to herd fish into it
Positioning the bag downstream allows the current and seine movement to guide fish into the collection bag.
Which of the following best describes the purpose of a length-frequency histogram in fisheries surveys?
Answer: To display the distribution of fish sizes and infer recruitment and cohort structure
Length-frequency histograms reveal size modes that correspond to year classes, indicating recruitment success and population structure.