Aquatic Species Monitoring 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 Aquatic Species Monitoring flashcards as text
Which otolith preparation technique allows fisheries biologists to determine daily age increments in larval fish?
Answer: Whole otolith transmitted light microscopy after polishing to the primordium
Daily growth increments in larval otoliths are visible under transmitted light after grinding the otolith to expose the inner primordium layer.
In a multi-pass depletion electrofishing survey, population size is estimated by observing that catch decreases with each pass. Which statistical model is used to estimate the original population?
Answer: Zippin removal model
The Zippin removal model uses the declining catches across successive passes to estimate population size and capture probability.
What is the primary advantage of using eDNA (environmental DNA) sampling over traditional netting for detecting rare or cryptic aquatic species?
Answer: Higher detection sensitivity with less physical disturbance to the habitat
eDNA methods can detect species presence from shed cells and mucus in water with high sensitivity without disturbing the organism or habitat.
A fisheries biologist calculates a relative stock density (RSD) of 15 for a largemouth bass population. What does this low value indicate?
Answer: Few fish have reached quality size relative to the number of stock-size fish
A low RSD indicates that a small proportion of stock-size fish have grown to quality size, suggesting potential stunting or high predation on larger fish.
When using fyke nets to monitor fish assemblages in wetlands, which factor most strongly biases catch composition?
Answer: Water temperature affecting fish activity and movement
Water temperature drives fish activity levels and migration behavior, strongly influencing which species and size classes are captured in passive gear like fyke nets.
A biologist is monitoring a mussel bed and needs to determine population density. Which method provides the most accurate density estimate for sessile bivalves?
Answer: Stratified random quadrat sampling
Stratified random quadrat sampling accounts for habitat heterogeneity and provides unbiased density estimates for sedentary organisms like freshwater mussels.
Which metric best describes the temporal stability of a fish community at a monitoring site across multiple years?
Answer: Bray-Curtis similarity index calculated between annual samples
The Bray-Curtis similarity index quantifies compositional overlap between two community samples, enabling assessment of year-to-year community change.