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Pots / Traps / Baskets Gear & Effort / Total Catch

Pots / Traps / Baskets Gear & Effort / Total Catch. http://coastalvoices.blogspot.com/2009_09_01_archive.html. http://www.wildlifenews.alaska.gov. Objectives. Describe 3 components of pot gear List 2 types of specialized equipment you may encounter on pot vessels

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Pots / Traps / Baskets Gear & Effort / Total Catch

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  1. Pots / Traps / BasketsGear & Effort / Total Catch http://coastalvoices.blogspot.com/2009_09_01_archive.html http://www.wildlifenews.alaska.gov

  2. Objectives Describe 3 components of pot gear List 2 types of specialized equipment you may encounter on pot vessels Demonstrate your ability to complete the Gear Description and Total Effort / Total Catch forms

  3. What is pot/trap fishing? Pots/traps – use bait to attract fish in on or near bottom Fishing occurs on continental shelf or slope Schoolmeester & Baker 2009

  4. What is pot/trap fishing? Pots/traps – use bait to attract fish in on or near bottom Fishing occurs on continental shelf or slope Primary targets: fish, crab, octopus, shrimp

  5. What is pot/trap fishing? Pots/traps – use bait to attract fish in on or near bottom Fishing occurs on continental shelf or slope Primary targets: fish, crab, octopus, shrimp Bait = fish or squid depending on target

  6. What is pot/trap fishing? Hook & line gear – uses bait to attract fish on or near bottom Usually on continental shelf & slope Primary targets: gadoids, sharks Bait = fish or squid depending on target Fishery impacts – cetacean entanglement John Calambokidis, Cascadia Research http://wildwhales.org/ http://www.americanreef.org/news.html

  7. Data collection priorities Estimate effort and total catch for each gear deployment; Identify every individual caught on each randomly selected set (or subsample within the set) and estimate percent retained; Collect biological information on target and other species as requested; Record all sightings and interactions with marine mammals and sea turtles; Record vessel and fishing gear characteristics.

  8. Fishing with Pots / traps / baskets Groundline / Longline of baskets Single pots Longline of pots Image: Hanrahan et al. (1997)

  9. Gear components – gear markers Drawing modified from Hanrahan et al. 1997

  10. http://store.vernondeon.com/ http://williamsmarineltd.ca/Manfacturing.html

  11. Gear components - pots Funnel / opening www.seattlemarine.net

  12. http://coastalvoices.blogspot.com Traps Nova Scotia, 2009 K. Dietrich Gear components - pots http://delamersailssouth.blogspot.com

  13. Gear – hauling devices • Line hauler http://www.mustad-autoline.com/ • Groundline drum http://www.qmarine.com http://www.mustad-autoline.com/

  14. How is gear fished? Strategies Deployment (videos – 1, 2)

  15. How is gear fished? Strategies Deployment Retrieval

  16. Gear Description - Traps • 1 form per trip

  17. Pot shapes

  18. Traps – Effort / Total Catch Entry for every day on board 1 entry for each set Fishing effort – time & amount of gear fished Catch per unit effort (CPUE)

  19. Defining a set • Longline of baskets – total baskets connected by one line • Deployed individually – coordinate w/ Captain • 1 set of 18 • 3 sets of 6 ◘ ◘ ◘ ◘ ◘ ◘ ◘ ◘ ◘ ◘ ◘ ◘ ◘ ◘ ◘ ◘ ◘ ◘

  20. Choosing a set to sample • Same general rules as for demersal longline • Use random sample table if necessary

  21. Total Catch Estimation Total catch must be estimated for every set.   Weigh entire catch (method 1) Captain / vessel estimate (method 5) Catch / effort ratio (method 6) - unsampled Catch / effort ratio (method 7) – tally sample Σ Sample weights from similar sets Σ Tallied pots from similar sets Sample weight (kg) Pots in sample X Total pots in unsampled set X Total pots in set

  22. References Hanrahan, J., D. J. Melindy, and J. V. Pelrine. 1997. At-sea Observer Program Operations Manual: A Training Aid and Field Reference. National At-sea Fisheries Observer Program, Department of Fisheries and Oceans, Ottawa, Canada. Slack-Smith, R. J. 2001. Fishing with traps and pots. FAO Training Series No. 26, FAO, Rome. Watson, R., E. Hoshino, J. Beblow, C. Revenga, Y. Kura, and A. Kitchingman. 2004. Fishing Gear Associated With Global Marine Catches. Fisheries Centre Research Reports 12.

  23. http://www.fao.org/fishery/vesseltype/230/en Courtesy of Joël Prado - FAO/FIIT

  24. Vessel features

  25. Choosing pots (baskets) to sample • Population: all baskets in 1 set • Sampling unit: single basket • Decide on how much to sample (e.g. 1/3 of baskets) – spatial sample frame • Choose sample method - random or systematic random • Select random numbers • Count/weigh everything from baskets sampled ◘ ◘ ◘ ◘ ◘ ◘ ◘ ◘ ◘ ◘ ◘ ◘ ◘ ◘ ◘ ◘ ◘ ◘

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