Biological Significance

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Biological Significance

• B.S. is ..a model which provides a relative
  score of the biological risk, or biological
  significance, of not providing remediation for
  fish passage at road crossings.
• It is a component of a more comprehensive model
  that facilitates fish passage remediation
  management decisions.

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Biological Significance (BS)Factors
Biological Significance is composed of 10
factors..
1. Area of fish habitat impeded upstream of
crossing.
2. Average stream gradient of fish habitat
upstream of crossing.
3. Macro pool frequency of fish habitat upstream
of crossing
4. Proportion of the design flow that design
fish are unable to move upstream through the
crossing.Barrierity
5. Access to habitat upstream of crossing from a
Fish Reservoir
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Biological Significance (BS)Factors (cont.)
Biological Significance is composed of 10
factors..
6. Proportion of fish habitat upstream of xing
that is Class I habitat.
7. Proportion of watersheds Class I habitat
obstructed by xing.
8. Proportion of watersheds Class II habitat
obstructed by xing.
9. Proportion of watersheds Class I habitat
obstructed by all Red xings in the watershed.
10. Proportion of watersheds Class II habitat
obstructed by all Red xings in the watershed
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Quantifying Biological Significance

• Biological Significance is quantified by
  calculating individual factor scores for the 10
  factors and then multiplying them by each other.
• The fish habitat area factor has a score
  equivalent to the number of square meters of fish
  habitat located upstream.
• All other factors each have a score between 0 and
  1. A higher score indicates a condition more
  conducive for remediation action.
• Since all factor scores, besides habitat area,
  are equal to or less than 1 the overall BS
  maximum score for a crossing is equal to the
  number of square meters located upstream of the
  crossing. The other factors only have the
  potential of reducing this value.

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Fish Habitat Area Score
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Stream Gradient Score
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Pool Frequency Score
If x lt 0.5 then y (0.4)(x) 0.8 If x gt 0.5
then y 1
1 if palustrine total pool length/reach length
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Barrierity Score
Passage refers to passage within design flow
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Barrierity Score
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Proportion of Habitat Obstructed by Xing that is
Class I
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Fish Reservoir

• A fish reservoir is defined as a relatively
  productive source for fish recruitment downstream
  of the crossing. It is believed that the value of
  adjacent habitat is related to the vicinity of
  this reservoir and the ease of movement upstream
  through the intervening stream reach.

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Fish Reservoir

• The following are considered fish reservoirs
• All floodplain channels (FP1 - FP5)
• Wide, moderate gradient, mixed control, channels
  (MM2)
• All estuarine channels (ES1 ES4, ES8)
• Lakes
• Saltwater

Must be within 500 meters to have significance
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Fish Reservoir Access Score Adjustment for Type
of Intervening Channel
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Fish Reservoir Access
If x gt 500 then y 0.9 If x lt 500 then y
-0.0002(x)1
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Proportion of Watersheds Class I Obstructed by
Xing
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Proportion of Watersheds Class II Obstructed by
Xing
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Proportion of the Watersheds Class I Obstructed
by All Red Xings in the Watershed
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Proportion of the Watersheds Class II Obstructed
by All Red Xings in the Watershed
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Pilot Site
5 miles
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Habitat Area vs. Score Mitkof Pilot Sites
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Gradient Score vs. Xing Score Mitkof Pilot Sites
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Pool Frequency Score Vs. Xing Score Mitkof Pilot
Sites
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Barrierity Score Vs. Xing Score Mitkof Pilot
Sites
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Proportion of Watersheds Class I Obstructed by
Xing Score Vs. Xing Score Mitkof Pilot Sites
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Proportion of Watersheds Class II Obstructed by
Xing Score Vs. Xing Score Mitkof Pilot Sites
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Proportion of Fish Habitat Upstream of Xing that
is Class I Habitat Score Vs. Xing Score Mitkof
Pilot Sites
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Reservoir Access Score Vs. Xing Score Mitkof
Pilot Sites
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Proportion of Watersheds Class I that is
Obstructed by All Red Xings in Watershed Score
Vs. Xing Score Mitkof Pilot Sites
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Proportion of Watersheds Class II that is
Obstructed by All Red Xings in Watershed Score
Vs. Xing Score Mitkof Pilot Sites
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Gradient () vs. Gradient ScoreMitkof Pilot Sites
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Pool Frequency VS. Pool Frequency ScoreMitkof
Pilot Sites
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Adult and Juvenile Barrierity VS. Barrierity
ScoreMitkof Pilot Sites
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Proportion of Watersheds Class I Obstructed by
Crossing VS. ScoreMitkof Pilot Sites
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Proportion of Watersheds Class II Obstructed by
Crossing VS. ScoreMitkof Pilot Sites
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Proportion of Watersheds Class I Obstructed by
All Red Crossings in the Watershed VS.
ScoreMitkof Pilot Sites
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Proportion of Watersheds Class II Obstructed by
All Red Xings in the Watershed VS. ScoreMitkof
Pilot Sites
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Proportion of Maximum ScoreMitkof Pilot Sites
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How well does Mitkof represent the Tongass?
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How well does Mitkof represent the Tongass?
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Discussion Issues

• Issue whether or not to include the factor
  proportion of habitat obstructed by a xing that
  is Class I habitat in the BS model vs outside of
  it.
• Anthropocentric Factor

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Discussion Issues

• Issue whether or not to include the factor
  proportion of the watersheds habitat that is
  obstructed by all Red xings in a watershed in
  the BS model vs outside of it.

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250 m

250 m
1
2
All obstructed habitat/total habitat
500 m
proportion of one xing changes from 500/1000
(0.5) to 250/1000 (0.25) if decision to fix other
xing is made.