Pots / Traps / Baskets Catch Sampling Drawing: http://www.wildlifenews.alaska.gov/index.cfm?adfg=wildlife_news.view_article&articles_id=140 Photo:http://coastalvoices.blogspot.com/2009_09_01_archive.html http://coastalvoices.blogspot.com/2009_09_01_archive.html http://www.wildlifenews.alaska.gov
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.
Objectives X Demonstrate your ability to sample and complete the Catch Composition form
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 6 sets of 3 ◘ ◘ ◘ ◘ ◘ ◘
Choosing a set to sample Same general rules as for demersal longline Use random sample table if necessary
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 ◘ ◘ ◘ ◘ ◘ ◘
Catch Composition Form
Catch Composition Form Weights Actual Average weight * total count Estimate
Activity Questions on catch composition sampling / random sampling or the form? Activity #2 Groups of 2 Sample 20% (Systematic or Random) Describe how you selected pots Tally sample & complete Catch Comp form
Tally Sampling Activity Key to “symbols” Shark Purple body Stingray Redfish Flatfish Octopus Snail Starfish 14
Pot #1 1 Shark 3 Snail 8 9 2 7 3 4 6 5 1 10
Pot #2 2 Purple body 6 Starfish 8 9 2 7 3 4 6 5 1 10
Pot #3 EMPTY 8 9 2 7 3 4 6 5 1 10
Pot #4 7 Octopus 17 Snail 1 Starfish 8 9 2 7 3 4 6 5 1 10
Pot #5 18 Snail 8 9 2 7 3 4 6 5 1 10
Pot #6 5 Redfish 2 Flatfish 2 Starfish 8 9 2 7 3 4 6 5 1 10
Pot #7 4 Shark 1 Stingray 2 Starfish 8 9 2 7 3 4 6 5 1 10
Pot #8 1 Shark 3 Flatfish 1 Octopus 8 9 2 7 3 4 6 5 1 10
Pot #9 EMPTY 8 9 2 7 3 4 6 5 1 10
Pot #10 1 Shark 1 Snail 8 9 2 7 3 4 6 5 1 10
Pot #11 2 Flatfish 5 Starfish 8 9 2 7 3 4 6 5 1 10
Pot #12 8 Starfish 8 9 2 7 3 4 6 5 1 10
Pot #13 1 Stingray 2 Starfish 8 9 2 7 3 4 6 5 1 10
Pot #14 1 Purple body 2 Snail 8 9 2 7 3 4 6 5 1 10
Pot #15 EMPTY 8 9 2 7 3 4 6 5 1 10
Pot #16 EMPTY 8 9 2 7 3 4 6 5 1 10
Pot #17 1 Shark 2 Flatfish 17 Snail 1 Starfish 8 9 2 7 3 4 6 5 1 10
Pot #18 2 Redfish 1 Octopus 8 9 2 7 3 4 6 5 1 10
Pot #19 1 Stingray 1 Redfish 4 Starfish 8 9 2 7 3 4 6 5 1 10
Pot #20 2 Shark 7 Starfish 8 9 2 7 3 4 6 5 1 10
Pot #21 4 Octopus 3 Snail 8 9 2 7 3 4 6 5 1 10
Pot #22 EMPTY 8 9 2 7 3 4 6 5 1 10
Pot #23 1 Purple body 4 Snail 8 9 2 7 3 4 6 5 1 10
Pot #24 1 Shark 1 Redfish 4 Starfish 8 9 2 7 3 4 6 5 1 10
Pot #25 1 Shark 8 Snail 8 9 2 7 3 4 6 5 1 10
Pot #26 2 Purple body 1 Starfish 8 9 2 7 3 4 6 5 1 10
Pot #27 EMPTY 8 9 2 7 3 4 6 5 1 10
Pot #28 2 Octopus 11 Snail 1 Starfish 8 9 2 7 3 4 6 5 1 10
Pot #29 12 Snail 8 9 2 7 3 4 6 5 1 10
Pot #30 4 Redfish 1 Flatfish 2 Starfish 8 9 2 7 3 4 6 5 1 10
Pot #31 4 Shark 1 Stingray 1 Starfish 8 9 2 7 3 4 6 5 1 10
Pot #32 1 Shark 1 Flatfish 5 Octopus 8 9 2 7 3 4 6 5 1 10
Pot #33 EMPTY 8 9 2 7 3 4 6 5 1 10
Pot #34 1 Shark 1 Snail 8 9 2 7 3 4 6 5 1 10
Pot #35 3 Flatfish 5 Starfish 8 9 2 7 3 4 6 5 1 10
Pot #36 7 Starfish 8 9 2 7 3 4 6 5 1 10
Pot #37 2 Stingray 3 Starfish 8 9 2 7 3 4 6 5 1 10
Pot #38 1 Purple body 2 Snail 8 9 2 7 3 4 6 5 1 10
Pot #39 EMPTY 8 9 2 7 3 4 6 5 1 10
Pot #40 EMPTY 8 9 2 7 3 4 6 5 1 10
Pot #41 4 Shark 1 Flatfish 13 Snail 1Starfish 8 9 2 7 3 4 6 5 1 10
Pot #42 2 Redfish 3 Octopus 8 9 2 7 3 4 6 5 1 10
Pot #43 1 Stingray 1 Redfish 1 Starfish 8 9 2 7 3 4 6 5 1 10
Pot #44 2 Shark 1 Starfish 8 9 2 7 3 4 6 5 1 10
Pot #45 4 Octopus 3 Snail 8 9 2 7 3 4 6 5 1 10
Pot #46 EMPTY 8 9 2 7 3 4 6 5 1 10
Pot #47 1 Purple body 7 Snail 8 9 2 7 3 4 6 5 1 10
Pot #48 1 Shark 2 Redfish 7 Starfish 8 9 2 7 3 4 6 5 1 10
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.
Large traditional potters for fishing spiny lobster off Mauritania - http://www.fao.org/fishery/vesseltype/230/en http://www.fao.org/fishery/vesseltype/230/en Courtesy of Joël Prado - FAO/FIIT