1. Fisheries Techniques Zoo 511

2. Today’s outline Announcements: –Final Exam next week! Format will be one section with timed stations, and one section with a total time limit for multiple questions. –Final Draft of paper due noon May 14 th in Alex’s mailbox at the CFL Lecture: Techniques (this is fair game for exam!) Jeopardy!

3. Two main types of methods: ACTIVE PASSIVE

4. Passive Gear Entanglement – gill nets Considerations: habitat, depth, mesh size, mortality Standard Nordi-mesh

5. Passive Gear Entanglement -Longlining Considerations: Habitat, by-catch, hook size, type of bait, set time, predation, finding the gear Pelagic Bottom Freshwater Equivalent=

6. Passive Gear Entrapment- trap nets, know the parts! Wings Lead Pot or Car Funnel Considerations: location, mesh size, funnel diameter

7. Trap nets, Lots of variety Pound Net Fyke Net PA style trap Net Hoop Net - river River Trap Net

8. Block entire stream, catch everything going up or down Passive Gear – Fish Weirs Considerations: location, high level of effort, non-target effects

9. Passive Gear Minnow trap – can mean anything Glass style square B style Plastic style Gee style Considerations: location, mesh size, funnel diameter, trap fullness = more or less caught, predation

10. Passive Gear Angling – sort of a weird mix between active/passive Considerations: time and place, what lure, certain types of fish more vulnerable, behavioral effects

11. Active gear – Trawling Considerations: depth, bycatch, habitat destruction Rockhopper Tickler chains

12. Active gear Drag/Tow – larval fish sampling – Bongo nets, Miller sampler Reduced Opening Standing Wave Considerations: depth, size of larvae, other stuff in water

13. Active gear - Seine Purse seine and beach seine Considerations: how to find fish, preventing escape, bycatch

14. Active gear - Electrofishing Stream electrofishing- backpack, tow boat, bank based, electric seine Considerations: safety – fish and researchers, not effective in all habitats

15. Active gear - Boat Electrofishing Considerations: depth, safety again

16. Active gear - Toxicants – rotenone, lampricides Considerations: Selectivity, ease of application, health concerns

17. Active gear - Direct observations (underwater, camera, or viewing windows Considerations: behavioral changes due to your presence, water clarity, can’t measure some things

18. Active gear - hydroacoustics Considerations: expensive, how to determine species composition, difficult to sample fish near the bottom

19. Gear Bias Why certain species, sizes, or habitats are caught more or less often than their frequency in the population. Every gear has bias! 25 A 25 B 25 C 25 D A B C D 5 6 5 7 A B C D 20 4 1 15

20. Gear Bias Gear can also be biased for size You sample and catch only one size of fish: 2 possible reasons. –The population is all one size –Your gear is biased towards one size Goal is to get least biased sample possible USE MULTIPLE GEARS!