Pots Traps Baskets Gear Effort Total Catch http
Pots / Traps / Baskets Gear & Effort / Total Catch http: //www. wildlifenews. alaska. gov http: //coastalvoices. blogspot. com/200 9_09_01_archive. html
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
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
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
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
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 http: //www. americanreef. o rg/news. html John Calambokidis, Cascadia Research http: //wildwhales. org/
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.
Fishing with Pots / traps / baskets Groundline / Longline ofof baskets pots Image: Hanrahan et al. (1997) Single pots
Gear components – gear markers Drawing modified from Hanrahan et al. 1997
http: //store. vernondeon. com/ http: //williamsmarineltd. ca/Manfacturing. html
Gear components - pots Funnel / opening www. seattlemarine. net
http: //coastalvoices. blogspot. com Gear components - pots http: //delamersailssouth. blogspot. com Traps Nova Scotia, 2009 K. Dietrich
Gear – hauling devices o Line hauler http: //www. mustad-autoline. com/ o Groundline drum http: //www. mustad-autoline. com/ http: //www. qmarine. com
How is gear fished? � Strategies � Deployment (videos – 1, 2)
How is gear fished? � Strategies � Deployment � Retrieval
Gear Description - Traps � 1 form per trip
Pot shapes
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)
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 ◘ ◘ ◘
Choosing a set to sample �Same general rules as for demersal longline �Use random sample table if necessary
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) - Σ Sample weights from similar sets X Total pots in unsampled set Σ Tallied pots from similar sets unsampled Sample weight (kg) Pots in sample X Total pots in set �Catch / effort ratio (method 7) – tally
References Hanrahan, J. , D. J. Melindy, and J. V. Pelrine. 1997. Atsea 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.
http: //www. fao. org/fishery/vesseltype/230/en Courtesy of Joël Prado - FAO/FIIT
Vessel features
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
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