Seafloor mapping for fisheries management: MSA requirements and the NEFMC

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Seafloor mapping for fisheries management MSA
requirementsand the NEFMCs SASI model

• Chad Demarest
• Integrating Seafloor Mapping Benthic Ecology
  Into Fisheries Management
• Portland, ME
• April 15, 2009

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Objective

• Describe the NEFMCs use of seafloor maps and
  benthic ecology in meeting the MSAs requirements
  to minimize to the extent practicable the adverse
  effects of fishing on EFH

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• The MSA requires FMPs to
• Describe and identify essential fish habitat
  (EFH) for every fishery
• Minimize to the extent practicable the adverse
  impacts of fishing on EFH
• List the major prey species for the species in
  the FMU and discuss their location
• Identify non-fishing activities that may
  adversely affect EFH

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What is EFH?

• The term essential fish habitat means those
  waters and substrate necessary to fish for
  spawning, breeding, feeding or growth to
  maturity.
• MSA, 2006

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The Final Rule

• Adverse effect means any impact that reduces
  quality and/or quantity of EFH
• Councils must act to prevent, mitigate, or
  minimize any adverse effects from fishing, to the
  extent practicable, if there is evidence that a
  fishing activity adversely affects EFH in a
  manner that is more than minimal and not
  temporary in nature.

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More Guidelines

• Loss of prey may be an adverse effect on EFH
  Therefore, actions that reduce the availability
  of a major prey species, either through direct
  harm or capture, or through adverse impacts to
  the prey species habitat that are known to cause
  a reduction in the population of the prey
  species, may be considered adverse effects on EFH
  if such actions reduce the quality of EFH

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And yet more Guidelines

• Adverse effects may include direct or indirect
  physical, chemical, or biological alterations of
  the waters or substrate and loss of, or injury
  to, benthic organisms, prey species and their
  habitat, and other ecosystem components, if such
  modifications reduce the quality and/or quantity
  of EFH.
• Adverse effects to EFH may result from actions
  occurring within EFH or outside of EFH and may
  include site specific or habitat-wide impacts,
  including individual, cumulative, or synergistic
  consequences of actions.

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NEFMC Objectives

• Identify all major fishing threats to the EFH of
  those species managed by the Council
• Identify and implement mechanisms to protect,
  conserve, and enhance the EFH of those species
  managed by the Council to the extent practicable.
• Define measurable thresholds for achieving the
  requirements to minimize adverse impacts to the
  extent practicable
• Integrate and optimize measures to minimize the
  adverse impacts to EFH across all Council managed
  FMPs

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The SASI model
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Model components

• Tow distance
• Effective linear gear width
• Gear component contact index
• Gear component sensitivity index

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• Tow distance and gear widths are modeled for nine
  primary gear types based on empirical data
  (observer, VTR, VMS)
• Contact indices are categorically defined
• Sensitivity indices are calculated as a function
  of habitat and gear-specific susceptibility and
  recovery values

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Sensitivity indices

• Sensitivity is defined here as a combination of
  the effects of a fishing gear on the functional
  value provided by a unit of habitat
  (Susceptibility), and the recovery in functional
  value that unit of habitat will experience after
  the gear effect has passed (Recovery)
• Sensitivity ƒ (Susceptibility, Recovery)
• where Susceptibility and Recovery are known to
  vary across
• Habitats
• Energy environments
• Fishing gears

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• Habitats
• Consistent with literature review of fishing gear
  impacts
• Substrate as primary impact surface
• Inferred features consistent with underlying
  substrates
• Energy environments
• Classified high or low based on
• critical shear stress model
• depth
• Fishing gears
• Gear types and area swept based on
  spatially-delineated commercial fisheries data

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Assessment matrices

• All cells assessed (hypothetical interactions)
• Susceptibility independent of energy, but
  recovery not

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Gear type (9)1 Gear type (9)1 Gear type (9)1 Gear type (9)1 Gear type (9)1 Gear type (9)1
Substrate (5)2 Substrate (5)2 Substrate (5)2 Substrate (5)2 Substrate (5)2 Substrate (5)2
Energy (2)3 Energy (2)3 Energy (2)3 Energy (2)3 Energy (2)3 Energy (2)3
Region (2)4 Region (2)4 Region (2)4 Region (2)4 Region (2)4 Region (2)4
Feature type Feature Gear effects Susceptibility Recovery Studies considered
Geological Featureless  x, y, z  0-3  0-3  a, b, c
Geological Biogenic depressions  x, y, z  0-3  0-3  a, b, c
Geological Biogenic burrows  x, y, z  0-3  0-3  a, b, c
Geological Special-case biogenic burrows  x, y, z  0-3  0-3  a, b, c
Geological Scattered gravel  x, y, z  0-3  0-3  a, b, c
Geological Gravel pavement  x, y, z  0-3  0-3  a, b, c
Geological Gravel piles  x, y, z  0-3  0-3  a, b, c
Geological Shell debris  x, y, z  0-3  0-3  a, b, c
Biological Sponges  x, y, z  0-3  0-3  a, b, c
Biological Hydroids  x, y, z  0-3  0-3  a, b, c
Biological Anemones  x, y, z  0-3  0-3  a, b, c
Biological Anemones, burrowing  x, y, z  0-3  0-3  a, b, c
Biological Soft corals and gorgonians  x, y, z  0-3  0-3  a, b, c
Biological Sea pens  x, y, z  0-3  0-3  a, b, c
Biological Hard corals  x, y, z  0-3  0-3  a, b, c
Biological Colonial tube worms  x, y, z  0-3  0-3  a, b, c
Biological Amphipods, tube building  x, y, z  0-3  0-3  a, b, c
Biological Bivalves  x, y, z  0-3  0-3  a, b, c
Biological Bryozoans  x, y, z  0-3  0-3  a, b, c
Biological Brachiopods  x, y, z  0-3  0-3  a, b, c
Biological Ascidians  x, y, z  0-3  0-3  a, b, c
Biological Macroalgae  x, y, z  0-3  0-3  a, b, c
Biological Sea grass  x, y, z  0-3  0-3  a, b, c
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Mapping habitats for SASI

• Data sources
• usSEABED (extracted and parsed)
• SMAST video survey
• NOAA trawl survey hangs (codes 5 9)

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Substrate class Substrate subclass Particle size range (mm) Corresponding Wentworth class
Mud Clay-silt lt 0.0039 Clay
Mud Clay-silt 0.0039 0.0625 Silt
Mud Muddy-sand lt 0.0039 - 2 Clay to sand
Sand Sand/sand ripple 0.0625 2 Sand
Granule-pebble Granule-pebble 2-4 Gravel
Granule-pebble Granule-pebble 4 64 Pebble
Cobble Cobble 64 256 Cobble
Boulder Boulder gt 256 Boulder
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Vorinoi tessellations allow the size of the unit
area to vary in proportion to the density of data
available, producing irregular shaped polygons of
varying sizes
Unstructured grid
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Energy environments

• Environments with different energy
  characteristics are created by the flow of water
  over habitats
• These energy environments affect the
• nature of fishing gear impacts (i.e. loss of
  functional value)
• susceptibility of habitats to fishing gears
• habitat recovery rates

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Applying the SASI model spatially

• The model represents a quality-adjusted area of
  seabed impacted by NE gears per spatial unit
  (e.g. tms, 5k grid)
• The Sensitivity Index (e.g., So, Sc, Ss) is
  derived from matrices specific to a combination
  of gear type / habitat / energy they apply
  uniformly across gear components

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Groundfish trawl Se
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End products

• Matrices summarizing the hypothetical sensitivity
  of habitat components to fishing gears
• Maps depicting the realized vulnerability of
  habitat area units to fishing gears, as measured
  by quality-adjusted m2 and summed across all
  gears fishing in each area
• Assessment of adverse effects based on
  pre-determined thresholds

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Alternative impacts analysis

• Matrices and SASI allow PDT to quantify and
  visualize changes in quality-adjusted seabed
  impacts, enabling analysis of
• Area-based fishing restrictions (mapping
  hypothetical or re-directed fishing effort)
• Gear modifications (changing SASI contact and
  sensitivity indices)