fisheries techniques l.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Fisheries Techniques PowerPoint Presentation
Download Presentation
Fisheries Techniques

Loading in 2 Seconds...

play fullscreen
1 / 20

Fisheries Techniques - PowerPoint PPT Presentation


  • 93 Views
  • Uploaded on

Fisheries Techniques. Zoo 511. 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

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Fisheries Techniques' - peers


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
today s outline
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 14th in Alex’s mailbox at the CFL
  • Lecture: Techniques (this is fair game for exam!)
  • Jeopardy!
slide4

Passive Gear

Standard

Nordi-mesh

Entanglement – gill nets

Considerations: habitat, depth, mesh size, mortality

slide5

Freshwater Equivalent=

Passive Gear

Entanglement -Longlining

Considerations: Habitat, by-catch, hook size, type of bait, set time, predation, finding the gear

Pelagic

Bottom

slide6

Passive Gear

Considerations: location, mesh size, funnel diameter

Entrapment- trap nets, know the parts!

Wings

Pot or Car

Funnel

Wings

Lead

slide7

Trap nets, Lots of variety

Fyke Net

Pound Net

River Trap Net

PA style trap Net

Hoop Net - river

slide8

Passive Gear – Fish Weirs

Block entire stream, catch everything going up or down

Considerations: location, high level of effort, non-target effects

slide9

Passive Gear

Minnow trap – can mean anything

Considerations: location, mesh size, funnel diameter, trap fullness = more or less caught, predation

Gee style

B style

square

Plastic style

Glass style

slide10

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

slide11

Active gear – Trawling

Considerations: depth, bycatch, habitat destruction

Tickler chains

Rockhopper

slide12

Active gear

Standing Wave

Drag/Tow – larval fish sampling – Bongo nets, Miller sampler

Considerations: depth, size of larvae, other stuff in water

Reduced Opening

slide13

Active gear - Seine

Purse seine and beach seine

Considerations: how to find fish, preventing escape, bycatch

slide14

Active gear - Electrofishing

Stream electrofishing- backpack, tow boat, bank based, electric seine

Considerations: safety – fish and researchers, not effective in all habitats

slide15

Active gear -

Boat Electrofishing

Considerations: depth, safety again

slide16

Active gear -

Toxicants – rotenone, lampricides

Considerations: Selectivity, ease of application, health concerns

slide17

Active gear -

Direct observations (underwater, camera, or viewing windows

Considerations: behavioral changes due to your presence, water clarity, can’t measure some things

slide18

Active gear - hydroacoustics

Considerations: expensive, how to determine species composition, difficult to sample fish near the bottom

gear bias
Gear Bias
  • Why certain species, sizes, or habitats are caught more or less often than their frequency in the population.
  • Every gear has bias!

A B C D

5 6 5 7

25 A

25 B

25 C

25 D

A B C D

20 4 1 15

gear bias20
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!