PDT analysis of potential alternatives
#3a
Michelle Bachman Dr. Rachel Feeney Council Staff Habitat Committee meeting May 22, 2018
Outline (same as memo) 1. Analysis of sections of GSC HMA based on habitat and fishery attributes a) Quadrants b) Industry/AP alternative c) Cobble-boulder alternatives based on MFMGA letter
2. Evaluation of a rotational management approach for the GSC HMA 3. Evaluation of an exemption for mussel dredges May 22, 2018
Schedule • June 14: Council approves range of alternatives for analysis • Summer: PDT develops environmental assessment • Committee meeting (TBD, late August or September) • September: final action
2
Areas evaluated 1. Quadrants a) b)
Drawn by PDT Equal area
2. Industry/AP alternative (April 3 Habitat AP meeting) 3. Cobble/boulder alternative (MFMGA letter, Committee motion, drawn by PDT) a) b)
MBTG
Contiguous C-B dominated Clusters (Getis Ord G* method) of C-B dominated
4. MBTG closure taken as a given and not pooled with items 1-3 for analysis May 22, 2018
3
GIS analysis of habitat attributes • Amount of cobble- and boulder-dominated habitat within each area – Using SASI base grid (total area and percent)
• Seabed form = depression – Depressions generally correspond with gravel habitats; advantage of using seabed form as a proxy for complex habitat is that data set covers entire HMA (total area and percent)
• Sediment stability – Stable = sediments of a given grain size are not mobile at predicted water flow rates along the seabed – Stable sediments provide sites for epifauna to attach
May 22, 2018
4
Cobble- or boulderdominated habitat Area name MBTG closure Possible exemption area Northwest quad Northeast quad Southeast quad Southwest quad Eastern edge Southeast corner Total Great Rip Fishing Rip Total Great Rip G* Fishing Rip G* Total May 22, 2018
Area, percent area 98, 30% 338, 15%
97, 17% 123, 22% 69, 12% 41, 07% 62, 49% 13, 05% 74, 21% 73, 28% 63, 35% 135, 31% 99, 27% 103, 33% 203, 30% 5
Seabed form = depression Area name Possible exemption area Northwest quad Northeast quad Southeast quad Southwest quad Total Industry/AP Total Great and Fishing Rips Total Great and Fishing Rips G*
May 22, 2018
Area, percent area
981, 44%
MBTG
218, 39% 233, 42% 272, 49% 258, 46% 212, 57% 234, 54% 330, 44%
6
Sediment stability Area name % stable MBTG closure 81% Poss. exempt. 37% Total GSC HMA 44% Northwest quad 42% Northeast quad 46% Southeast quad 30% Southwest quad 32% Eastern edge 88% SE corner 15% Total 40% Great Rip 50% Fishing Rip 65% Total 57% Great Rip G* 56% Fishing Rip G* 56% Total 56% May 22, 2018
MBTG
7
Statistical analysis of proportions • Using SMAST drop-camera image data • Questions 1. How do quadrants compare to each other? 2. How does an alternative compare to the remainder of potential exemption area?
• Variables evaluated: 1. Occurrence of complex habitat @ station 2. Occurrence of long-lived epifauna @ station 3. Occurrence of cobble or boulder @ station
Note: another way to think about these data is what proportion of complex habitat/LL epifauna, or cobble boulder habitat remains outside a particular alternative May 22, 2018
8
Complex
May 22, 2018
Not complex
9
LL epifauna present
May 22, 2018
LL epifauna absent
10
Cobble or boulder present
May 22, 2018
Cobble or boulder absent
11
Analysis of proportions – significant diff. Complex
Long lived epifauna
NE (0.71) different from SW (0.31)
No significant • NW (0.48) differences between different from SW quadrants (0.19) • NE (0.54) different from SE (0.29) and SW
Quadrants
Cobble or boulder
• No significant differences between industry/AP alternative and remainder of potential exemption area • Cobble-boulder (0.71) different from remainder Alternatives (0.47) • Cobble boulder G* (0.72) different from remainder (0.45)
• Cobble-boulder (0.62) different from remainder (0.41) • Cobble boulder G* (0.65) different from remainder (0.38)
• Cobble-boulder (0.52) different from remainder (0.33) • Cobble boulder G* (0.58) different from remainder (0.29)
Fishery metrics evaluated • Logbook/Vessel Trip Report data, distributed spatially using methods in DePiper 2014 • Data from 2011-2016 • Number of permits and owners • Total estimated revenue in each area • Percent revenue to permit • Percent revenue to owner, 2014-2016
May 22, 2018
13
Estimated average revenue by area, 2011-2016 Average annual Area revenue Std dev Great South Channel HMA 6,529,424 Possible Exemption Area 6,237,847 MBTG Closure 291,188 Northwest Quadrant 3,679,617 Northeast Quadrant 1,708,836 Southwest Quadrant (NLCA overlap) 515,896 Southeast Quadrant 332,700 Industry/AP Alternative 44,937 Great Rip 2,356,216 Fishing Rip 294,868 Great Rip G* 2,781,534 Fishing Rip G* 421,927 May 22, 2018
1,911,855 1,871,172 201,012 1,004,816 847,110 90,414 254,958 9,519 762,102 341,047 823,680 405,360 14
Clam dredge revenue Evidence for spatial shift in 2016:
Sum, 2011-2016 May 22, 2018
2016 only 15
Revenue by area summary • Total revenue in exemption area peaked 2014, has declined since • Northwest quad has the most revenue, northeast second (most of southwest has been closed) • Industry/AP alternative - very little revenue • Of cobble-boulder areas, Great Rip generates much more revenue, however evidence of a west to east shift over time – substantial increase in Fishing Rip areas during 2016 May 22, 2018
16
Revenue to permit – 2011-2016 • Full exemption area: Variable by year; median values range from 80% • Industry/AP alternative: Median values less than 0.5% • Great Rip: Median values for range
Michelle Bachman Dr. Rachel Feeney Council Staff Habitat Committee meeting May 22, 2018
Outline (same as memo) 1. Analysis of sections of GSC HMA based on habitat and fishery attributes a) Quadrants b) Industry/AP alternative c) Cobble-boulder alternatives based on MFMGA letter
2. Evaluation of a rotational management approach for the GSC HMA 3. Evaluation of an exemption for mussel dredges May 22, 2018
Schedule • June 14: Council approves range of alternatives for analysis • Summer: PDT develops environmental assessment • Committee meeting (TBD, late August or September) • September: final action
2
Areas evaluated 1. Quadrants a) b)
Drawn by PDT Equal area
2. Industry/AP alternative (April 3 Habitat AP meeting) 3. Cobble/boulder alternative (MFMGA letter, Committee motion, drawn by PDT) a) b)
MBTG
Contiguous C-B dominated Clusters (Getis Ord G* method) of C-B dominated
4. MBTG closure taken as a given and not pooled with items 1-3 for analysis May 22, 2018
3
GIS analysis of habitat attributes • Amount of cobble- and boulder-dominated habitat within each area – Using SASI base grid (total area and percent)
• Seabed form = depression – Depressions generally correspond with gravel habitats; advantage of using seabed form as a proxy for complex habitat is that data set covers entire HMA (total area and percent)
• Sediment stability – Stable = sediments of a given grain size are not mobile at predicted water flow rates along the seabed – Stable sediments provide sites for epifauna to attach
May 22, 2018
4
Cobble- or boulderdominated habitat Area name MBTG closure Possible exemption area Northwest quad Northeast quad Southeast quad Southwest quad Eastern edge Southeast corner Total Great Rip Fishing Rip Total Great Rip G* Fishing Rip G* Total May 22, 2018
Area, percent area 98, 30% 338, 15%
97, 17% 123, 22% 69, 12% 41, 07% 62, 49% 13, 05% 74, 21% 73, 28% 63, 35% 135, 31% 99, 27% 103, 33% 203, 30% 5
Seabed form = depression Area name Possible exemption area Northwest quad Northeast quad Southeast quad Southwest quad Total Industry/AP Total Great and Fishing Rips Total Great and Fishing Rips G*
May 22, 2018
Area, percent area
981, 44%
MBTG
218, 39% 233, 42% 272, 49% 258, 46% 212, 57% 234, 54% 330, 44%
6
Sediment stability Area name % stable MBTG closure 81% Poss. exempt. 37% Total GSC HMA 44% Northwest quad 42% Northeast quad 46% Southeast quad 30% Southwest quad 32% Eastern edge 88% SE corner 15% Total 40% Great Rip 50% Fishing Rip 65% Total 57% Great Rip G* 56% Fishing Rip G* 56% Total 56% May 22, 2018
MBTG
7
Statistical analysis of proportions • Using SMAST drop-camera image data • Questions 1. How do quadrants compare to each other? 2. How does an alternative compare to the remainder of potential exemption area?
• Variables evaluated: 1. Occurrence of complex habitat @ station 2. Occurrence of long-lived epifauna @ station 3. Occurrence of cobble or boulder @ station
Note: another way to think about these data is what proportion of complex habitat/LL epifauna, or cobble boulder habitat remains outside a particular alternative May 22, 2018
8
Complex
May 22, 2018
Not complex
9
LL epifauna present
May 22, 2018
LL epifauna absent
10
Cobble or boulder present
May 22, 2018
Cobble or boulder absent
11
Analysis of proportions – significant diff. Complex
Long lived epifauna
NE (0.71) different from SW (0.31)
No significant • NW (0.48) differences between different from SW quadrants (0.19) • NE (0.54) different from SE (0.29) and SW
Quadrants
Cobble or boulder
• No significant differences between industry/AP alternative and remainder of potential exemption area • Cobble-boulder (0.71) different from remainder Alternatives (0.47) • Cobble boulder G* (0.72) different from remainder (0.45)
• Cobble-boulder (0.62) different from remainder (0.41) • Cobble boulder G* (0.65) different from remainder (0.38)
• Cobble-boulder (0.52) different from remainder (0.33) • Cobble boulder G* (0.58) different from remainder (0.29)
Fishery metrics evaluated • Logbook/Vessel Trip Report data, distributed spatially using methods in DePiper 2014 • Data from 2011-2016 • Number of permits and owners • Total estimated revenue in each area • Percent revenue to permit • Percent revenue to owner, 2014-2016
May 22, 2018
13
Estimated average revenue by area, 2011-2016 Average annual Area revenue Std dev Great South Channel HMA 6,529,424 Possible Exemption Area 6,237,847 MBTG Closure 291,188 Northwest Quadrant 3,679,617 Northeast Quadrant 1,708,836 Southwest Quadrant (NLCA overlap) 515,896 Southeast Quadrant 332,700 Industry/AP Alternative 44,937 Great Rip 2,356,216 Fishing Rip 294,868 Great Rip G* 2,781,534 Fishing Rip G* 421,927 May 22, 2018
1,911,855 1,871,172 201,012 1,004,816 847,110 90,414 254,958 9,519 762,102 341,047 823,680 405,360 14
Clam dredge revenue Evidence for spatial shift in 2016:
Sum, 2011-2016 May 22, 2018
2016 only 15
Revenue by area summary • Total revenue in exemption area peaked 2014, has declined since • Northwest quad has the most revenue, northeast second (most of southwest has been closed) • Industry/AP alternative - very little revenue • Of cobble-boulder areas, Great Rip generates much more revenue, however evidence of a west to east shift over time – substantial increase in Fishing Rip areas during 2016 May 22, 2018
16
Revenue to permit – 2011-2016 • Full exemption area: Variable by year; median values range from 80% • Industry/AP alternative: Median values less than 0.5% • Great Rip: Median values for range
