Blue Crab Traffic Light 2015 Update and Management Options. March 23, 2016

Transcription

1 Blue Crab Traffic Light 2015 Update and Management Optins March 23, 2016 Amendment 2 t the Nrth Carlina Blue Crab Fishery Management Plan adpted by the Marine Fisheries Cmmissin in Nvember 2013 incrprated the use f the traffic light stck assessment methd and adaptive management measures fr management f the Nrth Carlina blue crab stck. Amendment 2 requires annual updates t the Blue Crab Traffic Light be presented t the Marine Fisheries Cmmissin as part f the Divisin f Marine Fisheries annual Stck Status Reprt. At the Marine Fisheries Cmmissin s August 2015 meeting, the divisin stated it wuld update the Blue Crab Traffic Light early and present the results t the Marine Fisheries Cmmissin at their May 2016 meeting due t the high prbability management actin wuld need t be taken after the 2015 update t the Blue Crab Traffic Light. The Traffic Light methd synthesizes a variety f infrmatin t prvide a descriptin f the stck cnditin. The indicatr value in each year fr each data series was assigned a green, yellw, r red signal based n the state f the indicatr relative t stck cnditin. Typically, the clr green is indicative f a psitive stck cnditin, yellw f a neutral r transitining stck cnditin, and red f a negative stck cnditin. The Blue Crab Traffic Light is divided int three separate characteristics: 1) adult abundance, 2) recruit abundance, and 3) prductin. Each characteristic uses data frm several divisin bilgical surveys and sampling prgrams t determine the relative abundance f adult and recruit blue crabs in the ppulatin and varius prductin indictrs fr the stck each year. Under Amendment 2, management measures will be implemented in the blue crab fishery if certain bilgical triggers are met. Either the adult abundance r prductin characteristic f the Blue Crab Traffic Light must be at r abve the 5 red threshld fr three cnsecutive years t trigger mderate management actin and must be at r abve the 75% red threshld fr tw f three cnsecutive years t trigger elevated management actin as established in Amendment 2 (Table 1). The recruit abundance indicatr, while nt used t trigger management actin, may be used t augment any management actin taken if a trigger is activated. The three year time perid was chsen t prevent taking management actin as a result f annual variability in the blue crab stck and instead base any management respnse n the bservatin f a shrt but cntinued declining trend in the ppulatin. The Blue Crab Traffic Light has been updated with 2015 data fr stck status determinatin (Figure 1). The prductin characteristic did nt meet either threshld. Hwever, the adult abundance characteristic has met the mderate threshld f 5 red fr 2015 (adult=5 red). This is the third cnsecutive year at r abve the 5 red threshld fr the adult abundance characteristic. As such, under the adaptive management framewrk adpted by the Marine Fisheries Cmmissin as part f Amendment 2, management actin is required t imprve the cnditin f the blue crab stck using the mderate management measures specified fr the adult abundance characteristic (Table 1). The recruit abundance characteristic has als met r exceeded the 75% red threshld fr three cnsecutive years (2013=92% red, 2014=96% red, 2015=75% red). Since the adult abundance characteristic has triggered management actin, the recruit abundance characteristic can be used t augment management actin. Bth the mderate and elevated management measures specified fr the recruit abundance characteristic (Table 1) may be cnsidered. Additinal figures shwing the status f the individual traffic light indices fr each characteristic and additinal analyses can be fund in the attached Appendix.

2 Table 1. Mderate and Elevated management measures under the adaptive management framewrk fr the Blue Crab Traffic Light in the Nrth Carlina Blue Crab Fishery Management Plan Amendment 2. Measures shaded are thse under cnsideratin based Amendment 2 and the 2015 Traffic Light update results. Characteristic Mderate management level Elevated management level Adult A1. Increase in minimum size limit fr A4. Clsure f the fishery (seasn and/r abundance male and immature female crabs gear) Recruit abundance Prductin A2. Reductin in tlerance f sub-legal size blue crabs (t a minimum f 5%) and/r implement gear mdificatins t reduce sublegal catch A3. Eliminate harvest f v-aprn immature hard crab females R1. Establish a seasnal size limit n peeler crabs R2. Restrict trip level harvest f spnge crabs (tlerance, quantity, spnge clr) R3. Clse the crab spawning sanctuaries frm September 1 t February 28 and may impse further restrictins P1. Restrict trip level harvest f spnge crabs (tlerance, quantity, spnge clr) P2. Minimum and/r maximum size limit fr mature female crabs P3. Clse the crab spawning sanctuaries frm September 1 t February 28 and may impse further restrictins A5. Reductin in tlerance f sub-legal size blue crabs (t a minimum f 1%) and/r implement gear mdificatins t reduce sublegal catch A6. Time restrictins R4. Prhibit harvest f spnge crabs (all) and/r require spnge crab excluders in pts in specific areas R5. Expand existing and/r designate new crab spawning sanctuaries R6. Clsure f the fishery (seasn and/r gear) R7. Gear mdificatins in the crab trawl fishery P4. Prhibit harvest f spnge crabs (all) and/r require spnge crab excluders in pts fr specific areas P5. Reduce peeler harvest (n white line peelers and/r peeler size limit) P6. Expand existing and/r designate new crab spawning sanctuaries P7. Clsure f the fishery (seasn and/r gear) 2

3 Adult Abundance 2015=5 Red Recruit Abundance 2015=75% Red Prductin =44% Red 2 Green Yellw Red 5 Threshld 75% Threshld Figure 1. Adult abundance, recruit abundance, and prductin characteristics fr the 2015 Blue Crab Traffic Light update. *Nte: 2013, 2014 and 2015 represent the three years that cunt tward the three cnsecutive years needed t activate mderate management fr the adult abundance characteristic. 3

4 The Blue Crab Plan Develpment Team (PDT) discussed the mderate management measures available fr the adult abundance characteristic and the mderate and elevated management measures available fr the recruit abundance characteristic under the adaptive management framewrk in Amendment 2. The PDT put tgether examples f several specific measures that fall within the brader measures specified in the adaptive management framewrk. Due t the cnditin f the traffic light, the gal f management actin at this pint shuld be t increase the escapement f mature female crabs and imprve juvenile recruitment in the Nrth Carlina blue crab stck. Specific measures listed under each ptin are nly examples t prvide a starting pint fr discussin and may nt be all-inclusive. Adult Abundance Mderate Management Measures Increase minimum size limit fr male and immature female crabs Reductin in tlerance f sub-legal blue crabs (t a minimum f 5%) and/r implement gear mdificatins t reduce sublegal catch Reduce sub-legal tlerance t 5% by number (DE, VA, FL, TX) Reduce sub-legal tlerance t 3% by number Reduce sub-legal tlerance t by number (NJ, SC, GA, AL, MS) Remve the escape ring exemptins in Pamlic Sund and Newprt River that allws the taking f small mature female crabs (will leave in place exemptin fr peeler pts; Rule 15A NCAC 03J.0301 (g)) Increase cull ring size in crab pts 2 3/8 (VA, SC, GA, FL, TX) 2 7/16 (Ruderhausen and Hightwer 2016) 2 1/2" Increase number f cull rings in crab pts 3 (FL, LA*) 4 Require cull rings in crab pts t be placed flush with the flr f the upper chamber (Havens et al. 2009) Eliminate harvest f V-aprn immature hard crab females Prhibit the harvest f all V-aprn immature female hard crabs Recruit Abundance Mderate Management Measures Establish a seasnal size limit n peeler crabs 3 (NJ, DE, GA) 3.25 (MD, VA) Restrict trip level harvest f spnge crabs (tlerance, quantity, spnge clr) 5% tlerance n harvest f spnge crabs 3% tlerance n harvest f spnge crabs 1% tlerance n harvest f spnge crabs Clse the Crab Spawning Sanctuaries frm September 1 thrugh February 28 and may impse further restrictins 4

5 Currently unlawful t set r use trawls, pts, and mechanical methds fr ysters r clams r take crabs with the use f cmmercial fishing equipment frm March 1 thrugh August 31 Will result in year-rund clsure f Crab Spawning Sanctuaries Elevated Management Measures Prhibit harvest f spnge crabs (all) and/r require spnge crab excluders in pts in specific areas Prhibit harvest f spnge crabs with tlerance (NJ, DE, MD, SC, GA, FL, MS, LA, TX) Require spnge crab excluders in areas and during times with a high percentage f spnge crabs in the harvest (Ruderhausen and Turan 2006) Expand existing and/r designate new Crab Spawning Sanctuaries Expand existing Crab Spawning Sanctuaries Designate new Crab Spawning Sanctuaries Designate new Crab Spawning Sanctuaries arund all inlets statewide (same harvest and gear prhibitins wuld apply as in existing sanctuaries) Clsure f the fishery (seasn and/r gear) Gear specific clsures Dredges: Prhibit the harvest f crabs with dredges (all dredges) Trawls: mve crab trawls back t shrimp trawl lines in Pamlic and Neuse rivers Seasn clsures Prhibit harvest during peak perids f spnge crab abundance Prhibit harvest frm April 1 June 30 Prhibit harvest frm August 1 September 30 Gear mdificatins in the crab trawl fishery Increase the crab trawl tail bag minimum mesh length t 4-inches statewide Literature Cited Havens, K. J., D. M. Bilkvic, D. Stanhpe, and K. Angstadt Lcatin, lcatin, lcatin: the imprtance f cull ring placement in blue crab traps. Transactins f the American Fisheries Sciety. 138: Ruderhausen, P. J. and J. E. Hightwer Retentin prbability varies with cull ring size in traps fished fr blue crab. Nrth American Jurnal f Fisheries Management. 36: Ruderhausen, P. J. and M. J. Turan Testing a device t exclude Ovigerus blue crabs, Callinectes sapidus, frm cmmercial pts. Marine Fisheries Review. 68 (1 4):

6 Appendix 1 Ttal Abundance (Albemarle, P100) Adult Abundance (Pamlic, P120) Adult Abundance (Pamlic, P195 Fall) Adult Abundance (Suthern, P120) Adult Abundance 75% 5 25% Figure A1.1. Traffic Light representatins f individual adult abundance indicatrs and the integrated summary (bttm figure),

7 Recruit Abundance (Pamlic, P120) Recruit Abundance (Pamlic, P195 Fall) Recruit Abundance (Pamlic, P195 Summer) Recruit Abundance (Suthern, P120) Recruit Abundance 75% 5 25% Figure A1.2. Traffic Light representatins f individual recruit abundance indicatrs and the integrated summary (bttm figure),

8 Median CW (Albemarle, P100) Spawning Stck (Albemarle, P100) Freq. Mature Females (Albemarle, P100) Median CW (Pamlic, P120) Median CW (Pamlic, P195 Fall) Median CW (Pamlic, P195 Summer) Figure A1.3. Traffic Light representatins f individual prductin indicatrs and the integrated summary (bttm figure), Nte: CW is carapace width. 8

9 Spawning Stck (Pamlic, P195) Freq. Mature Females (Pamlic, P195) Median CW (Suthern, P120) Pre-Recruit Abundance (Statewide, P120) 5 Maturity (Statewide, varius) 75% Prductin 5 25% Figure A1.3. cnt. Traffic Light representatins f individual prductin indicatrs and the integrated summary (bttm figure), Nte: CW is carapace width. 9

10 Red Green+Yellw 8 Adult Abundance Hard Crab Landings Millins f Punds Landed Figure A1.4. A cmparisn f the inverted adult abundance traffic light results and cmmercial hard crab landings (millins f punds),