Creel Surveys

• Lecture Outline

• Assignments

– Management of introduced fish species pp. 345 - 374 in Inland Fisheries Management

– Second draft of paper due November 11

Objectives of creel surveys

1) Estimate the amount of angling activity

2) Estimate the harvest

Information gathered from creel surveys

1) Number of fish caught, which species, and the time of year they are caught

2) Number of fish released and the number of marked fish

3) Number of anglers and the total hours fished

4) Evaluate fish stocking

5) Method of fishing (bait/tackle/fly)

6) Document demographics of anglers (resident vs non-resident)

Setting objectives

1) Identify angler concerns

2) Define spatial and temporal dimensions of the survey

3) Specify the kind of information to be collected

Sampling designs

1) Simple random sampling

2) Stratified random sampling

3) Stratified two-stage probability sampling

4) Can use Excel to select random dates

On-site angler contact methods

• Roving survey

– Creel clerk contacts anglers and he or she moves through the fishing area

• Route completely covers the survey area

• Clerk begins the rout at a random location

• Clerk moves in a random direction

• Clerk travels at a constant speed

– Data based on incomplete fishing trip

• Requires that rate estimation is not dependent on the length of time anglers fished before the interview

• Length-of-stay bias – greater chance of encountering anglers who spend more time on the water

On-site angler contact methods

1) Access point surveys

a) Clerk positioned at an access point

b) Anglers contacted at end of trip

c) Useful when all anglers must leave from a small number of points

2) Aerial or boat surveys

a) Efficient way to cover large areas over a short time period

b) Costs and observational bias may prohibit use

Household surveys

1) Useful when trying to describe characteristics of an entire population

2) Mail

a) Hand out questionnaires on site

b) Nonresponse bias

c) Follow-up survey

3) Telephone

a) More expensive

b) Recall biases