april2010_SNE_Recruitment_Failure_TCmemoB
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april2010_SNE_Recruitment_Failure_TCmemoB
Recruitment Failure inThe Southern New England Lobster stock40285Prepared by:American Lobster Technical Committee Atlantic States Marine Fisheries Com april2010_SNE_Recruitment_Failure_TCmemoBmmissionExecutive SummaryThe executive summary represents the consensus statements crafted during the March 23 and 24, 2010, Lobster Technical Committee meeting in New Bedford, Massachusetts. These statements have formed the basis for the larger research document contained within.Status of the stock april2010_SNE_Recruitment_Failure_TCmemoB:The Southern New England stock (SNE) is critically depleted and well below the minimum threshold abundance (25th percentile) (Figure 1). Abundance inapril2010_SNE_Recruitment_Failure_TCmemoB
dices are at or near time series lows (ASMFC 2009) and this condition has persisted (ASMFC 2006).Figure 1. Total lobster abundance as measured by the Recruitment Failure inThe Southern New England Lobster stock40285Prepared by:American Lobster Technical Committee Atlantic States Marine Fisheries Com april2010_SNE_Recruitment_Failure_TCmemoBoted.Since the release of the 2009 Assessment, additional monitoring information has been reviewed which documents that the reproductive potential and abundance of the SNE stock is continuing to fall lower than data presented in the latest assessment. The TC contends that the stock is experiencing r april2010_SNE_Recruitment_Failure_TCmemoBecruitment failure caused by a combination of environmental drivers and continued fishing mortality. It is this recruitment failure in SNE that is preapril2010_SNE_Recruitment_Failure_TCmemoB
venting the stock from rebuilding. The TC formed this conclusion only after an extensive review of a number of long-term monitoring programs which incRecruitment Failure inThe Southern New England Lobster stock40285Prepared by:American Lobster Technical Committee Atlantic States Marine Fisheries Com april2010_SNE_Recruitment_Failure_TCmemoBl years have produced indices below the median and at or below the 25" percentile relative to the 1984-2003 reference years (Figure 2-4). Larval production and settlement are inherently variable. However, sustained poor production1can only lead to reduced recruitment and ultimately to reduced year c april2010_SNE_Recruitment_Failure_TCmemoBlass strength and lower future abundance levels.Lobster Recruitment Indices for Long Island Sound (delta mean density]Figure 2. Larval indices for theapril2010_SNE_Recruitment_Failure_TCmemoB
Long Island Sound lobster population. Eastern Long Island Sound (ELIS) data are entrainment densities of lobster larvae at the Millstone Power StatioRecruitment Failure inThe Southern New England Lobster stock40285Prepared by:American Lobster Technical Committee Atlantic States Marine Fisheries Com april2010_SNE_Recruitment_Failure_TCmemoB CT DEP plankton survey at seven fixed stations in NY and CT waters of western Long Island Sound.2.001.60—.1.20■f 0.80Õ0.400.001990 1992 1994 199b 1998 2000 2002 2004 200b 2008Figure 3. Rhode Island YOY Settlement Survey. The median (yellow) and 25th percentile (red) of the 1984-2003 reference perio april2010_SNE_Recruitment_Failure_TCmemoBd are indicated.2https://khothu vien .comFigure 4. Massachusetts DMF YOY Settlement Survey in Buzzards Bay, Area 2. The median (yellow) and 25th perceapril2010_SNE_Recruitment_Failure_TCmemoB
ntile (red) of the 1984-2003 reference period are indicated.Additional evidence suggests that the distribution of spawning females has shifted away frRecruitment Failure inThe Southern New England Lobster stock40285Prepared by:American Lobster Technical Committee Atlantic States Marine Fisheries Com april2010_SNE_Recruitment_Failure_TCmemoBl survey relative abundance indices for recruit and legal size lobster are generally consistent, with a peak in the 1990’s and then a decline to low levels in recent years. Recent recruit and legal indices have generally remained at or below the 25th percentile since 2002.Impediments to Rebuilding:O april2010_SNE_Recruitment_Failure_TCmemoBverwhelming environmental and biological changes coupled with continued fishing greatly reduce the likelihood of SNE stock rebuilding. There has beenapril2010_SNE_Recruitment_Failure_TCmemoB
a widespread increase in the area and duration of water temperatures above 20L1C throughout SNE inshore waters. Long term trends in the inshore portioRecruitment Failure inThe Southern New England Lobster stock40285Prepared by:American Lobster Technical Committee Atlantic States Marine Fisheries Com april2010_SNE_Recruitment_Failure_TCmemoBWorden et al. 2006, Dove et al 2005, Crossin et al 1998), increased incidence of shell disease (Glenn and Pugh, 2006), acidosis and suppression of immune defenses in lobster (Dove et al. 2004, Robohm et al. 2005). Lobster avoid water > 19°c (Crossin et al. 1998). Loss of optimal shallow habitat area april2010_SNE_Recruitment_Failure_TCmemoB is causing the stock to contract spatially into deeper water (see Appendices A, B, and C). In Area 6, the potential expansion of chronic hypoxia undeapril2010_SNE_Recruitment_Failure_TCmemoB
r conditions of high temperature compounds the physical effects of both factors (Draxler et al. 2005) as well as additionally limiting the spatial extRecruitment Failure inThe Southern New England Lobster stock40285Prepared by:American Lobster Technical Committee Atlantic States Marine Fisheries Com april2010_SNE_Recruitment_Failure_TCmemoB(e.g. striped bass, dogfish, and scup) whose abundance has increased substantially in the last decade. The routine discarding of lobster (sublegal, egg bearing, V-notched) from traps increases the exposure of lobster to the now abundant predators as lobster sink to the bottom and seek new shelter.In april2010_SNE_Recruitment_Failure_TCmemoB Area 2, recent larval drift studies suggest that the re-distribution of spawning females into deep water areas may be causing larvae to be transporteapril2010_SNE_Recruitment_Failure_TCmemoB
d away from traditional settlement areas and potentially into less favorable areas.Recruitment Failure inThe Southern New England Lobster stock40285Prepared by:American Lobster Technical Committee Atlantic States Marine Fisheries ComRecruitment Failure inThe Southern New England Lobster stock40285Prepared by:American Lobster Technical Committee Atlantic States Marine Fisheries ComGọi ngay
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