Stephen Walsh1 and Paul Winger2

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Surveys Survey Trawl Standardization in
Newfoundland, Canada

• Stephen Walsh1 and Paul Winger2
• 1Northwest Atlantic Fisheries Centre
• 2Marine Institute, Memorial University
• St. Johns, Newfoundland, Canada

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Northwest Atlantic Fisheries Centre
(NAFC) Fisheries and Oceans (DFO)
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Centre for Sustainable Aquatic Resources Marine
Institute Memorial University
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Centre for Sustainable Aquatic Resources

• CSAR provides industrial research and
  development, technology transfer, and
  education/training services to the fishing
  industry.
• Potential clients include fishers, fishing gear
  manufacturers, government groups, geophysical
  equipment manufacturers, professional divers and
  ship builders.

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Flume Tank Specifications

• Constructed in 1988 (8.5 million)
• Worlds largest flume tank
• Dimensions 8m wide x 4m deep x 22m long
• Capacity 1.7 million litres of water
• Water velocity variable speed up to 1 metre per
  second
• Moving ground plane
• Full array of electronic monitoring

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Outline

• Overview and history of several Newfoundland
  surveys
• Development a standardization program
• Modernization of the standardization program

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• Overview of several surveys conducted by
• NAFC
• NAFC Industry
• University Industry

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NAFC Stratified-Random Multi-Species Trawl Surveys

• Annual spring (1971-present) and fall surveys
  (1977-present).
• Extends from Davis Strait to the Flemish Cap and
  along the south coast to the Gulf of St.
  Lawrence.
• Surveys cover 900,000km2.
• Water depths range from 40-1500m
• Inshore bays along the coast of Newfoundland
  surveyed since 1995

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A.T. Cameron (54m)
Gadus Atlantica (80m)
1977-1995
1971-83
Teleost (63m)
Wilfred Templeman (50m)
1995-2006
1983-2006
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Typical Survey Coverage - 2001
Biological Data Collected

• Numbers weights on all commercial finfish
• shellfish
• Length, weight, sex, maturity, otoliths
• stomach contents on commercial species
• Frozen samples for lab analyses
• Bottom classification using RoxAnn system
• Oceanographic information from each tow
• using a trawl mounted CTD.

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Data Collection and Usage

• Catch rate data are used as fishery independent
  indices either separately or in catch-at-age
  models to estimate the size of the resource.
• Yearly assessments are carried out within Canada
  for stocks totally inside 200 mile EEZ and by
  NAFO, and at bilateral meetings of Canada and USA
  for trans-boundary stocks.

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Inshore Cod Surveys
Inshore juvenile cod surveys from fixed-station
bottom trawling surveys in Southern Bonavista
Bay, 1999-2006
Includes 31 stations -Newman Sound -Swale
Tickle -Chandlers Reach -Clode Sound -Goose
Bay -Sweet Bay -Southern Bay
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Objectives of this specialized inshore survey

• Determine areas of high and low abundance of
  juvenile Atlantic cod in southern Bonavista Bay,
  in addition to distribution and abundance of
  adult cod and other finfish species.
• Classify juvenile cod seabed habitats using
  acoustics and video.
• Determine distribution and abundance of juvenile
  Atlantic cod in relation to their biological and
  physical habitats.

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Types of data collected

• Trawl data cod numbers, lengths, weights,
  otoliths, and stomach
  contents
• - all other fish species
  numbers, weights and lengths.
• Trawl geometry depth, door wing distance,
  clearance opening.
• CTD temperature, salinity, density profiles
  each set
• Echosounder acoustics (selected trips) - fish
  distribution and density
• Sediment typing with acoustic seabed
  classification.

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Fishing gear vessel

• Modified Yankee 36 shrimp trawl
• 4 x 7 225 kg doors
• Wings, square, bellies and codend all 40mm
• Codend liner 12.7mm
• Rockhopper footgear 6 discs
• 10 minute tows
• Monitored with SCANMAR

Shamook
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Other NAFC Surveys

• Inshore pot/trawl surveys for snow crab
• Offshore capelin acoustics on the Grand Bank
• Offshore sea scallops on St. Pierre Bank
• Trinity Bay acoustics/ecosystem surveys
• Offshore marine salmon drift net surveys

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NAFC-Industry Surveys

• Yellowtail flounder grid survey on Grand Bank,
  1996-2004 using commercial vessel and gear
• Stratified random multi-species surveys of St.
  Pierre Bank using commercial vessel and gear
  1997-2006
• Stratified random shrimp surveys off eastern
  Labrador 2005 using commercial vessel Campelen
  trawl
• Sea cucumber grid survey on St. Pierre Bank since
  2004

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Sea Cucumber

• Emerging fishery throughout the province
• Inshore dive harvests in NAFO 3K and 3L
• Offshore harvest in NAFO 3Ps using mobile drags
• All product processed and shipped to China and
  Japan

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Fishery-independent data is collected during an
annual pre-fishery grid survey. Fishery-dependent
data collected during the commercial fishery
through logbooks and observer coverage.
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University-Industry Surveys

• Hagfish (slime eels)
• Toad crab
• Soft shelled clam

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Hagfish
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Gulf of Maine Experience Fishery started
1993 No trap selectivity work - no escape
holes or very small escape holes (3/8) Day
trip fishery sort in plant discards (offal)
of up to 50 or higher Landings 1 (1993) to
6.8 (2000) million lbs 5 (2001) to 31 (1997)
vessels Fishery in trouble by 2003-4 lower
catches expanding fishing area Available
Science Oldest living vertebrate line 250
million years jawless fish Adapted to live
in sediments blind, lateral line, gill pore,
sense of smell Juvenile hermaphroditic phase
but sexes separate as adult Low
reproductive potential 1-30 eggs/female
Reproductive cycle unknown 1 or 2 years for
eggs to mature? Growth unknown body of
cartilage - no hard parts to age Only females
captured in baited traps Discard mortality
likely to be high intolerant of salinity and
temperature Produces copious amounts of slime
avoid predation Scavenger but also actively
preys on shrimp and critters in mud Predators
thought to be few in adult phase of life-cycle
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Newfoundland Experience Historically a
nuisance scavenging in gillnet and longline
fisheries on south coast from Codroy to Harbour
Breton. Abundant during exploratory inshore
fishery in 3Pn conducted in 1996, but too
small. Little is known of extent of
distribution, but commercial quantities are
likely to mirror that of commercial populations
of Monkfish, White Hake, and Haddock on the
southwest slope of Grand Bank, St. Pierre Bank,
and into Laurentian and Esquiman Channel in the
Gulf of St. Lawrence.
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Biomass Estimates Distribution Fishery
Independent
Fishery Independent Science Survey is conducted
yearly over 5-consecutive years to establish
trends in hagfish biomass and distribution.
Conducted prior to any commercial fishing for the
season and employing standardized fleet of gear
and method of fishing.
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Biomass Estimates Distribution Fishery
Dependent
Logbooks 100 Observer Coverage Monitor
5-year Trend in Catch Effort Collect Samples
for Science Document Bycatch Hagfish Packed
and Frozen at Sea Trap Limits No Bulk
Removals From Any Block Trip Catch Limits
Dockside Monitoring Program
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History of NAFC offshore survey gears
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History Offshore Research Survey Gears

• Stratified random surveys
• Yankee 41.5 otter trawl 1971-83.
• Engel 145 otter trawl, 1984-1994
• Yankee 41.5 shrimp trawl 1985-1994
• Campelen 1800 shrimp trawl 1995-2005

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A major portion of variability in survey
abundance estimation by fishing can be attributed
to the human factor 1991 Proceedings of the
International Workshop on Survey Trawl
Mensuration, NAFC, St. Johns, Newfoundland
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Before Standardization

• From 1983 the Gadus Atlantic and Wilfred
  Templeman were using identical Engel 145 high
  lift otter trawls.
• In the absence of standardized construction and
  rigging practices unregulated changes in trawl
  specifications occurred up to 1992.

Engel 145 high lift otter trawl
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Differences in Engel 145 trawl What happens when
you dont have a trawl standardization program
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Differences in survey gear resulted because

• Multiple versions of ambiguous and erroneous net
  plans.
• Inconsistent quality and specification of parts.
• RV crews did not understand difference between
  fishing for science and fishing for commerce.
• Scientific staff not trained or unwilling to
  share in ownership of the survey trawl
  (scientific tool).
• Nobody was checking to see that the gear was
  constructed correctly.
• Absence of clearly defined and written protocols
  that everybody understood.

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Design a standardization program1992-1994
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Philosophy of Standardization

• Standardized surveys should minimize the
  variability typical in commercial fisheries data
  and thus generate more consistent indices of
  stock abundance.
• Essential feature of surveys is maintaining
  consistency from one survey to the next so that
  survey catchability (q) remains constant over
  time.
• Constancy in catchability can be achieved by
  ensuring constancy in sampling efficiency of the
  trawl which is achieved by ensuring constancy in
  construction and repairs and fishing procedures.
• Assumption is that rigid standardization of
  equipment, procedures and routines minimizes the
  effects of the variable, unknown and unseen
  underwater reality.

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The survey trawl is a scientific instrument
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Components of the Standardization Program
1993-2005

• ISO9001 standard trawl plans to ICES
  specifications
• Quality Control on Purchasing-tolerance levels
• Quality Control on Construction Repairs-Survey
  Gear Checklist
• Quality Control on Trawl Deployment, Fishing and
  Retrieval-scope ratios, trawl speed monitoring
  etc.
• Survey Trawl Monitoring
• Training of Vessel and Scientific Staff in
  operations

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Trawl Plans

• Engineering drawings describing all aspects of
  construction. ICES 1989 netting specifications.
• Trawl profile and rigging,
• body plan, footgear and
• detail drawings.
• 23 drawings used to describe Campelen 1800.

Rigging Diagram - Campelen 1800
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Body Plan - Campelen 1800

• Each component is given a part number which can
  be cross referenced with the parts list.
• Drawing version numbers are tracked.

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Lower Wing Detail - Campelen 1800

• Detail leaves no room for interpretation.
• Includes graphical information about pickups,
  tapers and joins.

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• Detail drawing of each footrope component.

Footgear Drawing - Campelen 1800
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Components of Quality Controlon Procurement

• Trawl net plans Parts list
• Tolerances levels
• Institutional purchasing organizations require
  detailed specifications. Vendors are given
  detailed requirements and held to allowable
  tolerances.
• All gear subjected to inspection (by trained
  warehouse staff) prior to delivery.
• Gear outside allowable tolerance rejected.

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Quality Control on Construction Repairs

• Survey Trawl Checklist
• Survey trawls are measured prior to each survey
  and after major gear damage. Fishing Officer
  maintains a logbook of repairs and parts
  replaced.
• Trawl mensuration is conducted by RV crew under
  supervision of SIC/TIC or his/her designate.
• The Survey Trawl Checklist is designed to ensure
  a methodical examination of the trawl and its
  components.
• Each measurement is compared to specification and
  recorded. Components outside spec. are replaced.
• Also used after major construction of trawl parts
  onshore by vessel staff

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Survey Trawl Checklist

• Consists of 5 drawings Rigging, Top/Bottom
  Sheet, Codend and Liner, Ropes and Footrope.
• Graphical context makes for ease of use.
• Requires entry of a measurement and sign-off.

Example Rigging Diagram
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Modernization Plan 2005-2007

• Need to revise update trawl plans, parts list
  and tolerances.
• Need to revamp the checklist and develop
  protocols on how to use it.
• Need trawl warp standardization calibration
  protocols.
• Need protocols for rigging, construction and
  repairs of trawls onboard.
• Need protocols for replacing worn trawl parts
  such as door shoes, footgear components, ground
  wires, main warps

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• Need protocols for attachment of trawl
  instrumentation and associated floatation
• Need Scanmar protocols for configuring, deploying
  and charging sensors
• Need Standardization of all survey trawls used in
  Atlantic Canada.
• Need training of vessel and scientific staff.

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Training Component

• RV crews needed better understanding of science
  methodology and science staff of gear technology.
• 5-8 day training course developed by Marine
  Institute featuring the flume tank, classroom,
  and full scale measuring exercises.
• 1 day training course in Scanmar deployment, use
  and repairs

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Any Questions?
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Thank You Dr. Paul Winger Director Centre
for Sustainable Aquatic Resources www.mi.mun.ca/
csar