Appendix E
New England Fishery Management Council 50 WATER STREET
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NEWBURYP ORT, MASSACHUSETTS 01950
|
PHONE 978 465 0492
E.F. “Terry” Stockwell III, Chairman | Thomas A. Nies, Executive Director
|
FAX 978 465 3116
OMNIBUS ESSENTIAL FISH HABITAT AMENDMENT 2 DRAFT ENVIRONMENTAL IMPACT STATEMENT Appendix E – Synopsis of Closed Area Technical Team analysis of juvenile groundfish habitats and groundfish spawning areas
Synopsis of juvenile groundfish habitat and spawning analysis
Intentionally blank.
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Synopsis of juvenile groundfish habitat and spawning analysis
Note – this appendix is adapted from a memorandum provided to the New England Fishery Maangement Council’s Scientific and Statistical Committee on May 10, 2013. TABLE OF CONTENTS Analytical approach ........................................................................................................................ 6 Additional figures ......................................................................................................................... 14 References ..................................................................................................................................... 54 Getis-Ord Gi* statistic in ArcGIS ................................................................................................. 56 How Incremental Spatial Autocorrelation works in ArcGIS ........................................................ 59 TABLES Table 1. Selection of and weighting factors applied to juvenile groundfish hotspot data to sum hotspots across species and develop area management options. The final weighting sum was applied to the gridded hotspots for each species shaded in red. Grey shaded rows designate species that are not managed by catch shares. ................................................................................ 9 Table 2. Selection of and weighting factors applied to large spawner groundfish hotspot data to sum hotspots across species and develop area management options. The final weighting sum was applied by season to the gridded hotspots for each species shaded in red. Grey shaded rows designate species that are not managed by catch shares. .............................................................. 10 Table 3. Summary of groundfish spawning and habitat associations. .......................................... 13 Table 4. Lengths-at-maturity used to distinguish juveniles and adults in EFH designations. Juveniles are less than the specified length; adults are equal to or larger..................................... 18 Table 5. Cumulative proportion of abundance at age by species, survey, and stock area. First line of data represents an approximate L20 for each species. Second line of data represents a size that approximates the 90th percentile of age 1 fish (some species use age 2) for the predominate stock area for each species. ........................................................................................................... 20 Table 6. Cumulative number of cod caught by survey over time by size range, compared to 20 percent of total abundance. ........................................................................................................... 24 Table 7. Cumulative weight of cod caught by survey over time by size range, compared to 20 percent of total weight. ................................................................................................................. 25 Table 8. Cumulative biomass above 5 cm size ranges by species, survey, and decade, compared to 20% of total weight per tow (kg) and the size at estimated 80% maturity for females. ........... 26 Table 9. Summary of cluster analysis procedures applied to survey catch of juveniles (number) and large spawners (weight). ........................................................................................................ 33 Table 10. Summary of peak spatial autocorrelation results and alternative trial peaks in parantheses. NA = analysis not attempted due to infrequent catch or data not yet available. NP = No significant peak autocorrelation detected. NSHS = No significant hotspots of above average catches detected or produced by the hotspot analysis. IC = insufficient catch to conduct either a spatial autocorrelation or hotspot analysis. ...................................................................... 35
May 2013
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Synopsis of juvenile groundfish habitat and spawning analysis
Table 11. Summary of significant hotspots of above average catches identified by survey and species for age 0/1 juvenile (upper) and for large spawners (lower), 2002-2012......................... 40 FIGURES Figure 1. Map of indicated cod spawning areas. Circled areas indicate former spawning grounds that are no longer active. Ames, 2004.......................................................................................... 14 Figure 2. Proposed cod spawning complexes. Berlinsky, 2005. ................................................ 15 Figure 3. Summary of cod spawning areas. Deese, 2005. .......................................................... 15 Figure 4. Bathymetric map of Ipswich Bay. Black dotted rectangle highlights the elevated bathymetric feature "Whaleback". Siceloff and Howell, 2012. ................................................... 16 Figure 5. The distribution of tagged cod releases and recaptures in spawning condition, relative to closed areas and across all years. Tallack, 2008. ..................................................................... 17 Figure 6. Domain of surveys used in the hotspot analysis by season. ......................................... 21 Figure 7. Frequency distribution plots of 2002-2012 NMFS spring trawl catches of cod
|
NEWBURYP ORT, MASSACHUSETTS 01950
|
PHONE 978 465 0492
E.F. “Terry” Stockwell III, Chairman | Thomas A. Nies, Executive Director
|
FAX 978 465 3116
OMNIBUS ESSENTIAL FISH HABITAT AMENDMENT 2 DRAFT ENVIRONMENTAL IMPACT STATEMENT Appendix E – Synopsis of Closed Area Technical Team analysis of juvenile groundfish habitats and groundfish spawning areas
Synopsis of juvenile groundfish habitat and spawning analysis
Intentionally blank.
May 2013
Page 2 of 67
Synopsis of juvenile groundfish habitat and spawning analysis
Note – this appendix is adapted from a memorandum provided to the New England Fishery Maangement Council’s Scientific and Statistical Committee on May 10, 2013. TABLE OF CONTENTS Analytical approach ........................................................................................................................ 6 Additional figures ......................................................................................................................... 14 References ..................................................................................................................................... 54 Getis-Ord Gi* statistic in ArcGIS ................................................................................................. 56 How Incremental Spatial Autocorrelation works in ArcGIS ........................................................ 59 TABLES Table 1. Selection of and weighting factors applied to juvenile groundfish hotspot data to sum hotspots across species and develop area management options. The final weighting sum was applied to the gridded hotspots for each species shaded in red. Grey shaded rows designate species that are not managed by catch shares. ................................................................................ 9 Table 2. Selection of and weighting factors applied to large spawner groundfish hotspot data to sum hotspots across species and develop area management options. The final weighting sum was applied by season to the gridded hotspots for each species shaded in red. Grey shaded rows designate species that are not managed by catch shares. .............................................................. 10 Table 3. Summary of groundfish spawning and habitat associations. .......................................... 13 Table 4. Lengths-at-maturity used to distinguish juveniles and adults in EFH designations. Juveniles are less than the specified length; adults are equal to or larger..................................... 18 Table 5. Cumulative proportion of abundance at age by species, survey, and stock area. First line of data represents an approximate L20 for each species. Second line of data represents a size that approximates the 90th percentile of age 1 fish (some species use age 2) for the predominate stock area for each species. ........................................................................................................... 20 Table 6. Cumulative number of cod caught by survey over time by size range, compared to 20 percent of total abundance. ........................................................................................................... 24 Table 7. Cumulative weight of cod caught by survey over time by size range, compared to 20 percent of total weight. ................................................................................................................. 25 Table 8. Cumulative biomass above 5 cm size ranges by species, survey, and decade, compared to 20% of total weight per tow (kg) and the size at estimated 80% maturity for females. ........... 26 Table 9. Summary of cluster analysis procedures applied to survey catch of juveniles (number) and large spawners (weight). ........................................................................................................ 33 Table 10. Summary of peak spatial autocorrelation results and alternative trial peaks in parantheses. NA = analysis not attempted due to infrequent catch or data not yet available. NP = No significant peak autocorrelation detected. NSHS = No significant hotspots of above average catches detected or produced by the hotspot analysis. IC = insufficient catch to conduct either a spatial autocorrelation or hotspot analysis. ...................................................................... 35
May 2013
Page 3 of 67
Synopsis of juvenile groundfish habitat and spawning analysis
Table 11. Summary of significant hotspots of above average catches identified by survey and species for age 0/1 juvenile (upper) and for large spawners (lower), 2002-2012......................... 40 FIGURES Figure 1. Map of indicated cod spawning areas. Circled areas indicate former spawning grounds that are no longer active. Ames, 2004.......................................................................................... 14 Figure 2. Proposed cod spawning complexes. Berlinsky, 2005. ................................................ 15 Figure 3. Summary of cod spawning areas. Deese, 2005. .......................................................... 15 Figure 4. Bathymetric map of Ipswich Bay. Black dotted rectangle highlights the elevated bathymetric feature "Whaleback". Siceloff and Howell, 2012. ................................................... 16 Figure 5. The distribution of tagged cod releases and recaptures in spawning condition, relative to closed areas and across all years. Tallack, 2008. ..................................................................... 17 Figure 6. Domain of surveys used in the hotspot analysis by season. ......................................... 21 Figure 7. Frequency distribution plots of 2002-2012 NMFS spring trawl catches of cod
