year review of EBS Crab EFH

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1 The evaluation of adverse impacts from fishing on crab essential fish habitat NMFS and NPFMC staff discussion paper, March year review of EBS Crab EFH EFH Final Rule requires that a review and revision of EFH components be completed every 5 years MSA requirement Focus: new information since last review, update of best available science CPT 5 year review of EFH provisions highlighted issues with effects of fishing evaluation on EFH. Specific EFH components are included in each of 5 Council FMPs EFH descriptions and identification fishing activities (MSA and non MSA) that may adversely affect EFH, and cumulative impacts EFH conservation and enhancement recommendations 2 1

2 Council request: Develop a discussion paper to a) re evaluate fishing effects on crab EFH b) Assess importance of protecting southwest Bristol Bay habitat for spawning red king crab (perhaps as a HAPC) Discussion paper: the evaluation of adverse impacts from fishing on crab EFH 1) Are appropriate habitat parameters important for crab captured (e.g., oceanic parameters, pelagic habitat)? 2) Are conclusions about EFH appropriate without information about crabs habitat needs unknown. 3) Is there adverse effects in southwest Bristol Bay where there has recently been an increase in the red king crab population and increase in trawling activity. 4) If crab populations have shifted distribution in recent years is the the red king crab savings area effective? 2

3 Background EFH description for red king crab Habitat needs for crab stocks 2005 EFH EIS effects of fishing Red King Crab habitat linkages Fishing impact conclusions Improved methodology for evaluating adverse impacts Red king crab distribution Importance of southwestern Bristol Bay Changing distribution of red king crab Research Questions Council action options Background EFH description for red king crab Habitat needs for crab stocks 2005 EFH EIS effects of fishing Red King Crab habitat linkages Fishing impact conclusions Improved methodology for evaluating adverse impacts Red king crab distribution Importance of southwestern Bristol Bay Changing distribution of red king crab Research Questions Council action options 3

4 2005 EIS on EBS EFH for crabs Fisheries do have long term effects on habitat but they are minimal final action: Describe and identify EFH Minimize adverse effects of fishing on EFH protect habitat for sponge, coral, and other important habitat. new measures adopted for AI and GOA in 2005 and in EBS in Focus on SMBKC and SC including info on egg bearing females, post larval distribution, and historical trawl effort. EBS Crab EFH Analyses Provide habitat descriptions and quantify effects of fishing 1) Intensity of fishing 2) Sensitivity of habitat features 3) Recovery rates of habitat features 4) Long terms effects Index (distribution of effort relative to habitat) LEI higher on living structure in sand/mud and slope habitat (11% affected by fisheries most of which were pollock and flatfish trawls) No EBS Species rely on living structure on sand/mud habitat 4

5 Description of Red king crab EFH (page 2) Eggs: inferred form the general distribution of egg-bearing female crab. Larvae: No EFH Description Determined. Insufficient information is available. Early Juveniles: No EFH Description Determined. Insufficient information is available. Late Juveniles & Adults: general distribution area for this life stage w/ rock, cobble, and gravel and biogenic structures such as boltenia, bryozoans, ascidians, and shell hash. 5

6 Habitat needs for crab stocks King Crab Life Cycle Egg Day 1 Egg Day 395 Prezoea Zoea 1 Zoea 2 Zoea 3 Zoea 4 Glaucothoe Crab Instar 1 Molting, mating and extrusion Red King Crab Life History ADULTS Embryo development Hatching JUVENILES Zoeal stages Glaucothoe stage Metamorphosis and settlement Jan Feb March April May June July Aug Sept Oct Nov Dec 6

7 Background EFH description for red king crab Habitat needs for crab stocks 2005 EFH EIS effects of fishing Red King Crab habitat linkages Fishing impact conclusions Improved methodology for evaluating adverse impacts Red king crab distribution Importance of southwestern Bristol Bay Changing distribution of red king crab Research Questions Council action options Effects of EFH Issue Spawning/breeding Feeding Growth to maturity Evaluation MT (Minimal, temporary, or no effect) U (Unknown effect) MT (Minimal, temporary, or no effect) CPT discussed increasing the effect to substantial. However, data limitations prevent an evaluation beyond unknown. Applies to all crab species. 7

8 Habitat Impacts Relative to Spawning/Breeding There is only a small area of overlap between current female red king crab distribution and areas where trawling occurs. This overlap would only occur in the areas between about 162 and 163º W, where fishing effects are generally low. Habitat Impacts Relative to Feeding Changes in growth for Bristol Bay red king crab are unknown. Most of the distribution of red king crab is to the north and east of the high fishing effects areas. Habitat Impacts Relative to Growth to Maturity There are essentially no fishing effects in areas important to juvenile red king crab. All known juvenile rearing areas are currently protected by trawl closure areas. Figure 2, Page 6. 8

9 Background EFH description for red king crab Habitat needs for crab stocks 2005 EFH EIS effects of fishing Red King Crab habitat linkages Fishing impact conclusions Improved methodology for evaluating adverse impacts Red king crab distribution Importance of southwestern Bristol Bay Changing distribution of red king crab Research Questions Council action options How might a better methodology for evaluating adverse impacts of fishing on crab EFH be devised? Conceptual modeling tools to extend the empirical data to probabilistic determinations of impacts on crab populations. (key temporal and spatial biological processes) Management Strategy Evaluation with the existing stock assessment model or more directly applied to a specific life history parameter (eg. retrospective assessment of potential losses to reproductive fitness) Coupled bio physical models to better understand the effects of temperature and currents on larval drift. 9

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13 Background EFH description for red king crab Habitat needs for crab stocks 2005 EFH EIS effects of fishing Red King Crab habitat linkages Fishing impact conclusions Improved methodology for evaluating adverse impacts Red king crab distribution Importance of southwestern Bristol Bay Changing distribution of red king crab Research Questions Council action options Distribution of red king crab population in Bristol Bay 13

14 Mature males 1.5 C 9.0 C 2001 CPUE (65 4,000 crab/nm 2 ) C 2.0 C CPUE (65 4,000 crab/nm 2 ) CPUE (65 4,000 crab/nm 2 ) Mature females 2001 CPUE (70 11,000 crab/mn 2 ) CPUE (67 19,000 crab/mn 2 ) CPUE (67 13,000 crab/mn 2 ) 14

15 Figure 3. Figure 4. 15

16 crab per sq nm Station B Degrees C Figure 5. 16

17 Adapted from Stabeno et al Nearshore Current ~ 5cm/sec 45 day pelagic stage 200 km trip before settlement COLD YEAR Stabeno

18 Nearshore Current ~ 5cm/sec 45 day pelagic stage 200 km trip before settlement WARM YEAR Stabeno 2009 Stabeno

19 Background EFH description for red king crab Habitat needs for crab stocks 2005 EFH EIS effects of fishing Red King Crab habitat linkages Fishing impact conclusions Improved methodology for evaluating adverse impacts Red king crab distribution Importance of southwestern Bristol Bay Changing distribution of red king crab Research Questions Council action options Research Questions (page 12) -build on Dew and McConnaughy, Loher and Armstrong, Zheng and Kruse. Adult distribution (tagging and observation): Dual tagging ovigerous females during the EBS Trawl Survey to locate hatching area. High resolution side scan sonar/video to locate the females to identify larval release area. Juvenile assessment: Assess juvenile crab distribution to predict likely larval release locations. (2011 research) 19

20 Research Questions Larval assessment: Intensive sampling for larval crab. Conduct a time series analysis on female egg condition and distribution (eg. Chilton et al. in press). Conduct a time series analysis of environmental conditions and red king crab abundance related to recruit abundance to assess potential stock production processes related to temperature fluctuations in the eastern Bering Sea. Options for Council action (page 13) Revise the effects of EFH evaluations. No management action, but encourage further research in this area to better understand adult, juvenile and larval distribution and habitat usage. Extend or establish trawl closure areas in the affected area as EFH conservation measures. Extend the range of the red king crab savings area to protect more of the stock. Apply a seasonal closure to protect the adult female red king crab from March to May during molting and mating. Close area southwest of Amak Island. Designate a HAPC priority for areas important for red king crab egg hatching, and consider designating this area as a HAPC. 20

21 Authors and Acknowledgements Diana Evans Robert Foy Matt Eagleton Claire Armistead Liz Chilton Jan Haaga Chris Long 21