Assessment and advice of Snow Crab in West Greenland 2009. Technical Report No. 80

By An Assessment and advise of snow crab in west Greenland 2010 nDorte Burmeister a Helle Siegstad By AnnDorte Burmeister TEKNISK RAPPORT NR. 80, 2009 Snow crab stock status and advisory report 2010 2 Titel: Assessment and advice of Snow Crab in West Greenland 2009 Forfatter(e): AnnDorte Burmeister Serietitel og nummer: Teknisk rapport nr. 80 Udgiver: Pinngortitaleriffik, Grønlands Naturinstitut Udgivelsestidspunkt: November 2009 Kvalitetssikring: Earl Dawe, Department of Fishery and Science, Newfoundland, Canada Oversættelse: Finansiering: Forsidefoto: AnnDorte Burmeister ISBN: 87-91214-44-0 ISSN: 1397-3657 Bedes citeret: Burmeister, AD. 2009. Asessment of snow crab in West Greenland 2009 Teknisk Rapport nr.80, Pinngortitaleriffik, Grønlands Naturinstitut Rekvireres: Rapporten er udelukkende udgivet elektronisk. PDF-fil af Rapporten findes på instituttets hjemmeside http://www.natur.gl/publikationer/tekniske rapporter Det er muligt at rekvirere en udskrift af rapporten her: Pinngortitaleriffik, Grønlands Naturinstitut Postboks 570 3900 Nuuk Grønland Tlf. +299 36 12 00 Fax. +299 36 12 12 [email protected] www.natur.gl T68nisk rapport nr. 68, 2007 Pinngortitaleriffik, Grønlands Naturinstitut Snow crab stock status and advisory report 2010 3 Assessment and advice of Snow Crab in West Greenland 2010 AnnDorte Burmeister, Pinngortitaleriffik, Greenland Institute of Natural Resources. Box 570, 3900 Nuuk. Greenland. Phone: +299 361200. E-mail: [email protected]. Introduction This report documents the scientific basis for the assessment of snow crab (Chionoecetes opilio) stocks in West Greenland. Snow crabs are patchily distributed and commercially exploited along the coast and within the fjords. The fishery is managed by quotas and assessed when data are available within the inshore and offshore of 6 management areas (Upernavik, Uummannaq-Disko Bay, Sisimiut, Maniitsoq-Kangaamiut, Nuuk-Paamiut and Narsaq-Qaqortoq. The report briefly updates and summarizes the historical background of commercial crab fishing, which includes catch, effort, CPUE and spatial distribution of the fishery, as well as the results from scientific surveys undertaken by the Greenland Institute of Natural Resources (GINR). There are no specific long-term management objectives for the snow crab resource in West Greenland. However, since 2004 the main objective of recommendations from GINR has been to stop the decline in biomass of the crab resource in the different management areas. Summary Management area Disko Bay - Uummannaq  The recommended catch level for 2010 in Disko Bay inshore is 600 tons. The quota should be divided on 200 tons in the southern part of Disko Bay, 200 tons in the Northern part of the bay and 200 tons in Vaigat.  No survey has been conducted in Disko Bay 2009 owing to technical problems with r/v Adolf Jensen. Management area Sisimiut  The recommended catch level for 2010 in Sisimiut inshore is 500 tons, divided on 300 tons in the traditionally fishing area and 200 tons in Ndr. Isortoq and Ndr. Stoemfjord.  Fishery and survey CPUE index as well as abundance index of recruits based on survey data dropped from 2008 to 2009, but remain high and are still above the series average based on available observations. If this drop and if continues in 2010 the commercial biomass might decrease might decrease over the next few years.  The recommended catch level for 2009 in Sisimiut offshore is 200 tons. In 2009 there is no sign of progression in the biomass and the previous year sign of recovery has turned into a decline in the biomass and recruitment.  Survey and fishery data indicate signs of recovery in 2007 and 2008. The increase in biomass was largely attributable to greatly reduced removals due to the large reductions in commercial catches, from 2004 up to 2007. Nevertheless, all available indexes show a significant drop from 2008 to 2009. Snow crab stock status and advisory report 2010 4 Recruitment indices for the offshore area are poor and indicate low recruitment prospects in the short term. Caution must be exercised as CPUE from the fishery and survey declining and the recruitment is at a very low level. Those results might be effects of increased removals by the fishery after the re-opening and suggesting that the biomass is/was not recovered.  It should be emphasized that re-opening of the fishery in 2007 was sustained before the re-opening criteria was met. Management area Nuuk - Paamiut  The recommended catch level for 2010 in Nuuk – Paamiut inshore is 200 tons.  The recommended catch level for 2009 in Nuuk - Paamiut offshore is 1,600 tons, and unchanged from 2008. Management area Maniitsoq - Kangaamiut  Due to the lack of survey and fishery data no recommendation is given for Maniitsoq - Kangaamiut inshore and offshore. Management area Narsaq - Qaqortoq  Due to the lack of survey and fishery data no recommendation is given for Narsaq - Qaqortoq inshore and offshore. General recommendation and advice  GINR recommends a seasonal fishery from April to July in all management areas to reduce discarding and associated mortality to soft-shelled crabs and to maximize recruitment to the stock. Such a seasonal fishery will also promote the most optimal and sustainable utilization of the crab resource. Resource status in each management area derived from fishery data An overview of GINR‟s recommendations and the imposed quota and fishing status (open or closed) of the management areas in 2010 are given in Table 1. Snow crab stock status and advisory report 2010 5 Table 1. Summary of catch recommendations for the crab fishery in 2010 from the Greenland Institute of Natural Resources and total catch from 2008 (catch statistics for 2009 are incomplete at this time). Recommended catch Inshore 2010 in tons Recommended catch Offshore 2010 in tons Catch in tons 2008 Inshore Catch in tons 2008 Offshore Disko Bugt 600 130 531 96 Sisimiut 500 200 765 214 Maniitsoq No advice No advice 19 111 Nuuk-Paamiut 200 1,600 200 418 Recommended catch in all 1,300 1,930 1,515 839 Snow crab stock status and advisory report 2010 6 Species biology Snow crab habitat include sites were bottom is covered by mud/sand and rock. Their diets include brittle stars, shrimp, younger stages of snow crab (cannibalism), clams, polychaete worms and other crustaceans. Predators are various groundfish, snow crab and human. Snow crab hatching their broods in spring and larvae undergo two planktonic larval stages and settle to bottom during fall. Benthic juveniles snow crab males as well as females molt frequently and become sexually mature from > 50 mm carapace width (CW) depending on bottom temperature. Snow crabs tend to molt during spring and continue until terminal molt at adulthood is reached within a size range of 50 – 130 mm CW for males and 40 – 95 mm CW for females. At the terminal molt males developing enlarges claws improving their mating ability. Only a portions of any given cohort recruit to the fishery at 100 mm CW, where the males is approx. 9 to 10 years. Recruitment is periodic or episodic and varies considerably over a cycle of 8 to 12 years. After the molt to adulthood legal sized males remain soft/new shelled having low meat yield for the rest of the year. In the following year, meat yield would have increased to a suitable level for the industry. Discard of soft shell and new-shelled, due to their low yield contents is resources wastage. Historical fishery background Snow crabs are distributed along the West coast of Greenland and are commercially exploited primarily from Disko Bay in the North (up to 71 30N) to Paamiut in the South (60 45N). Commercial fishery for snow crab began primarily in inshore areas (within basis-line) in the mid1990s and from 1999, also included offshore areas (outside basis-line). Since 2004, the crab resource in Greenland has been managed in 6 areas (from North to South - Upernavik, Uummannaq-Disko Bay, Sisimiut, Maniitsoq-Kangaamiut, Nuuk-Paamiut and Narsaq-Qaqortoq, see Fig. 1). The fishing fleet is made up of two components; small vessels (less than 75 GRT), which have exclusive rights for fishing inshore within the basis-line as well as offshore. Small vessels are, however, restricted to fishing in only 2 management area during the year. Large vessels (greater than 75 GRT) may only fish in all offshore areas (outside the basisline), but not within the “Crab Boxes”. Quota restrictions have been imposed to each of the 6 management area since 1995 and individual quotas to vessels larger > 75 GRT, but have only limited the catch in 2004. Management decisions allow increasing quota in each of the 6 management area, when the catch achieved the first fixed quota. Un-used quota from larger vessels is re-allocated to the inshore fleet (small vessels < 75 GRT). Basically, there is now quota restriction for the small vessel. The fishery is regulated by prohibitions to land females and undersized males (<100 mm CW), logbooks for all vessels larger than 10 meters and closure of the fishery north of 64°N for 3 months (1 January to 31 March). There is also a regulation that states movement of the fishing effort when soft-shelled crabs exceed 20% of the catch, however the term “movement” is not specific and this is not monitored. From 2005 to 2007, the offshore crab fishery was closed in the management areas Maniitsoq-Kangaamiut and from 2005 to August 2007 in the offshore area of Sisimiut except for dispensation to 1 vessel that was allowed to fish in 2005. Only in 2006, the fishery was closed for 2½ months (July 1 to September 15) in all areas except UumannaqDisko Bay (closed only 1 month from July 1 – August 3) to protect soft-shelled crabs. Snow crab stock status and advisory report 2010 7 The number of vessels with licenses to participate in the snow crab fishery increased by more than a factor of 3 from approx. 120 to 374 boats from 1999-2002. Since then the number of both large and small vessels have decreased substantially as the abundance of the resource has also declined. In 2008 the number license holders amounted 74 in all management areas an 80% reduction compared to 2002. In 2009 number of license increased to 117. Greenland Institute of Natural Resources (GINR) provide stock assessment and total allowable catch (TAC) advice for the stock both inshore and offshore within each management area when sufficient data is available. The decision to give advice for both inshore and offshore areas was based on the assumption that snow crab migration is limited (tagging studies have indicated approx. 10 km per year) and therefore the resource in different areas is considered to be spatially independent. Commercial fishery data Logbooks from the large vessels >75 GRT have been mandatory since 1999 in conjunction with the start of offshore fishing with vessels of this size. Logbooks for the small vessels (<75 GRT) were first mandatory from July 2002, and thus first covered the annual fishery in 2003. Only landing statistics are available from boats less than 10 meters as they are not required to report catches in logbooks. Catch, Effort and CPUE The historical development of the crab fishery in Greenland is shown in Figure 2. Landings increased from approx. 1,000 tons in 1995 to a peak of approx. 15,000 tons (Quota 26,800 tons) in 2001 (based on landings from small vessels and catch from logbook data from large vessels >75 GRT). From 2001 to 2007 total catch decreased by approx. 89% to 2,189 tons (Quota 4,380 tons). Landings increase to 2,354 tons (Quota 4,200 tons) in 2008 and preliminary data indicate an additional increase in landings in 2009 (2,412 tons ultimo September 2009, Quota 4,225 tons). The ratio of total landings to logbooks landing varies between management areas. As well as in 2008, 2009 quota was increased from 500 tons to 800 tons in the management area Sisimiut and from 700 tons to 1000 tons in Nuuk - Paamiut management area (only in 2009). The increasing quota was based on re-allocation (removing a part of the quota from five vessels > 75 GRT) allowing small vessel < 75 GRT to increase catches inshore as well as offshore. The distribution of landings and geographic distribution of the fishery in each management area in Fig. 3 and Fig. 4, show that most of the landings in 2008 have predominately come from management Sisimiut (42%), where as Disko Bay–Uummanaq and Nuuk-Paamiut amounted 27% and 26% respectively of the total landings. The total fishing effort (trap hauls) has declined by 91% since 2001 (from 3,416 to 323 thousand trap hauls during 2001-2008) (Fig. 3). The decline has been mostly due to a declining number of participants in the fishery. Preliminary and incomplete logbook data for 2009 shows total effort is 353 thousand trap hauls. The overall distribution of the fishery along the West coast of Greenland from 2003-2009, derived from available logbook data is shown in Figure 4. Research Surveys Since 1997, trap surveys have been conducted annually in inshore areas of Disko Bay and Sisimiut. In 2000, a Sisimiut offshore area (Holsteinsborg Dyb) was included in the Sisimiut trap survey. In 2002, annual offshore trap surveys were initiated in areas between Nuuk and Paamiut and in 2003 were extended north to include the offshore in the Maniitsoq-Kangaamiut management area. Snow crab stock status and advisory report 2010 8 Methods Snow crabs are sampled with Japanese-style conical traps with large (70 mm) and small (21 mm) mesh sizes. Sampling stations are at predetermined fixed positions for all years and soak times range between 14-24 hrs depending on weather conditions. Bottom temperatures are recorded at each station. For males, the carapace width (CW) and chela height (CH) are measured (± 0.01 mm) to determine size and molt status (adolescent or adult). Male snow crabs stop growing after their terminal moult. Sexually mature males are referred to as adolescents (recognized by their small claws) prior to the terminal molt and as adults after their terminal molt (large claws). Males reach legal size (100 mm CW) at about 9 years of age. The range of carapace widths defining the adolescent male groups which are presumably 1, 2 and 3 years from recruitment to legal size are: ADO-1, 82.2-100mm CW; ADO-2, 67.3-82.2mm CW and ADO-3, 53.2-67.3mm CW. For females, the CW and abdomen width (AW) are measured (± 0.01mm) to determine size and maturity. Females that have mated once and are carrying their first clutch of eggs are called primiparous, while females that are carrying their second clutch and have mated more than once are called multiparous. They are distinguishable by the number of scars on their legs caused by mating and by shell conditions. Shell condition in both males and females is determined on a scale of 1-5 according to guidelines by Sainte-Marie (1993). Data from trap survey catches of males are used to determine CPUE (kg/trap), mean CW of legalsize males, shell condition and NPUE (number- /trap) of adolescent males to assess recruitment prospects. Male and females size distributions are also described to follow the progression of size modes through the populations and determine primiparous/multiparous ratios within the female population. Inshore surveys in Disko Bay and Sisimiut In Disko Bay, 43 stations are sampled annually (Fig. 5a) and in Sisimiut, 40 stations are sampled (Fig. 5b), from May to June. The sampling gear consists of a longline of 10 large-mesh (70mm) and 2 small-mesh (21mm) conical traps fished at depths ranging from 100-600m. Traps are placed approx. 40m apart and baited with squid. Offshore surveys in Sisimiut, Maniitsoq and NuukPaamiut Fifteen stations are sampled annually in Sisimiut offshore (Fig. 5b) in June and a total of 30-60 stations are sampled in the Nuuk-Paamiut and Maniitsoq offshore areas in August-September (Fig. 5c). The sampling method in Sisimiut offshore is the same as the method used inshore in Disko Bay and Sisimiut. In 2002, the sampling in the Nuuk-Paamiut offshore survey was also the same as the method inshore. In 2003, however, the offshore sampling method used in Nuuk-Paamiut and Maniitsoq was changed such that each station was then sampled using a long line of 16 traps, eight large-meshed traps alternating with eight small-meshed traps at approx. 40m apart and baited with squid. Input data from commercial fishery to assessment No sampling from the commercial fishery has been conducted since the fishery began in 1996. Available logbook and landing statistics is used in data analysis from the commercial fishery. Logbooks nominal catches has since 2003 covered more than 85% of the total landings in Greenland. Before 2003 less than 20% of the fishing fleet were using logbooks. In order to calculate a standardised CPUE index, a GLM analysis (multiadditive model) was carried out using haul by haul logbook information Snow crab stock status and advisory report 2010 9 including zero catches. The model includes year, month and vessel effects. Management area: Uummannaq-Disko Bay The historical catch, CPUE and effort data for the fishery in Uummannaq-Disko Bay in the inshore and offshore areas are summarized in Table 2. Data for 2009 are preliminary. One of the most important fishing areas has been Disko Bay where catches are predominately from the inshore. Total catches peaked at 4,202 tons (94% inshore) in 2001 and since then have steadily declined to 627 tons (85% inshore) in 2008, approximately 15% of the 2001 catch. Inshore - Disko Bay Fishery The distribution of the fishery in Disko Bay from 2003 to 2008, according to available logbook data is shown in Figure 6. Fishing grounds include both Vaigat, area “Disko Nord” and “Disko Syd”. The geographic distribution of the fishery has been homogeneous in the period from 2003 to 2008, although total catches, CPUE used effort has changed markedly. In contrast to the previous years, 2009 preliminary data indicate a very limit fishery in the area “Disko Nord”. The fishery in Disko Bay starts in April, peaks during the summer months (June-July) and steadily declines towards the end of the year, except in 2003 when the fishery peaked in March and May. Early season catch rates (April-May generally decreased over tome (2004-2008), perhaps because early season focused on traditional areas. Late season CPUE increased from 2004-2006, reflecting allocation of effort to new areas as the season progressed. In 2006 the fishery peaked in September, mainly due to a closure during July and August (Fig. 7). In 2008 CPUE were higher that compares to previous years, but declined to 2007 level from October to December. A standardised CPUE index (Fig. 8), show a significant dropped in CPUE from 2001 to 2003 from approx. 7.7 kg/trap to 3.8 kg/trap (F= 78.60, P < 0.0001). In the following years CPUE has remained low at a stable level. Data from 2008 and preliminary data for 2009 indicate increasing trends in CPUE (Table 2) and (Fig. 8). From 2000-2001 catches inshore increased from 2,940-3,950 tons as effort more than doubled (613-1274 thousand trap hauls, Table 2). Catches and effort have steadily decreased since 2001 by approx. 86% to 531 tons and 107 thousand trap hauls, respectively, in 2008 (Table 2 and Fig. 8). Standardised soak time index (Fig. 9), shows a significantly decrease in soak time from 2001 to 2002. Since 2003 soak time increased steadily until 2007, at a level of average 72 hour per hauls and comparable to 2001 level. Research Surveys Important: Owing to the breakdown of the main engine at the research ship Adolf Jensen, the survey has been cancelled in 2009. In 2008 survey was only conducted in the Northern part of Disko Bay. No new survey data is available for the stock assessment and advice. Trap surveys have been conducted in 2 inshore areas of Disko Bay since 1997 (See Fig. 5a for maps), despite in 2008 where only the subarea North, were investigated. CPUE of legal-size males (100mm CW) in South and North peaked in 2001 and 2000 respectively and have declined steadily by more than 50% to 2004; from 4.2-1.7 kg/trap in South and 7.5-2.3 kg/trap in North (Fig. 10). The 2004 CPUE was the lowest observed in the time series. In 2005 and 2006 CPUE in South was still considerably below the reference mean of 3.7, but increased to 4 kg/trap, marginally above the reference mean, in 2007. In North, CPUE increased from 2.3 to 6.4 kg/trap and has Snow crab stock status and advisory report 2010 16 catches in that period (Table 2). The subsequent increase in percent new-shelled males in 2009, however, may have been due to increasing recruitment into the stock, as ADO-1 had increased in 2005 to 2008. However, it is unclear to what extent the changes in shell condition ratios and CPUE are due to reduced catch versus increased recruitment. In general the increased percentage of old-shelled males and increasing CPUE are both positive signs for the stock indicating an increased abundance of older shelled males that are available to participate in reproduction. The ratio of primiparous:total mature females declined sharply from 2000-2002, then increased from 2003 to 2005 (Fig. 31). A significant drop in this ratio occurred in 2006 and continued in 2008, with a minor increase in 2009 indicating poor recruitment may be forthcoming in the future. Outlook - Offshore Sisimiut Survey and fishery data indicate signs of recovery in 2007 and 2008. The increase in biomass was largely attributable to greatly reduced removals due to the large reductions in commercial catches, from 2004 up to 2007. Nevertheless, all available indexes show a significant drop from 2008 to 2009. Recruitment indices for the offshore area are poor and indicate low recruitment prospects in the short term. Caution must be exercised as CPUE from the fishery and survey declining and the recruitment is at a very low level. Those results might be effects of increased removals by the fishery after the re-opening and suggesting that the biomass is/was not recovered. Furthermore, it appears that the biomass fished upon after re-opening in 2007 may not be able to support catches as large as those landed in 20072008. It is quite possible that the biomass will not recover to the same high levels as existed initially. For unknown reasons, (eg. Ocean climate change) observations from Newfoundland shows crab productivity may never be as high as it once was (pers. Comm., Earl Dawe, DFO, St. John‟s, Newfoundland, Canada). It should be emphasized that re-opening of the fishery in 2007 was sustained before the reopening criteria was met. Recommendations for the 2010 fishery - Offshore Sisimiut In 2009 there is no sign of progression in the biomass and the previous year sign of recovery is turned to a decline in the biomass and recruitment. It is therefore recommended to reduce the TAC to 200 tons in the entire offshore area in 2010. Special comments: Harvesting should be monitored using a precautionary approached, relayed on approach for changes in catch levels, careful monitoring of the population response to the fishery and implementation of re-open /re-closure criteria. Management area: Maniitsoq-Kangaamiut The historical catch, CPUE and effort data of the fishery in Maniitsoq-Kangaamiut inshore and offshore areas are summarized in Table 2. Overall catches of snow crab from the fishery in Maniitsoq-Kangaamiut area increased from 944 tons in 2000 to 1,835 and 1,775 tons in 2001 and 2002, respectively, as effort was doubled. Catches then decreased considerably to 486 tons in 2003 and 115 tons in 2004 as the CPUE both inshore and offshore decreased to the lowest levels observed in the fishery (2.4 and 2.1 kg/trap in offshore and inshore areas). Since 2003 the inshore fishery has been less than 100 tons and from 2005 the offshore fishery has been closed, but was reopened in August 2007. Inshore Maniitsoq-Kangaamiut Snow crab stock status and advisory report 2010 17 Fishery Catches in Maniitsoq-Kangaamiut inshore peaked in 2001 and 2002 at approx. 1,000 tons both years but in the subsequent years the fishery have been very limit and in 2009 catch level amount 22 tons. CPUE remained low at 3.1 kg/trap despite large decrease in catches and effort (Table 2) and Fig. No standardised index of CPUE and soak time has been prepared, owing to the lack of data and un-regularly recurring fishery in this area. Outlook - Inshore Maniitsoq-Kangaamiut It is difficult to determine the biomass of the resource in the area, while data from the fishery are limited. There is no survey in the inshore area and comparative biomass and recruitment prospects are unknown. Recommendations for the 2009 fishery - Inshore Maniitsoq-Kangaamiut Due to the lack of survey and fishery data no advice is given for Maniitsoq-Kangaamiut inshore. Offshore Maniitsoq-Kangaamiut Fishery Catches in Maniitsoq-Kangaamiut offshore peaked in 2001 with a catch level of 826 tons and a CPUE of 5 kg/trap. A significant declined in catches to 445 tons was observed. Despite in catch and used effort CPUE remained low at 2.1 kg/trap in 2004, indicating the resource was still in a state of decline. Continued poor state of the resource biomass and confirming data from a biological survey led to the recommended and implemented closure of the offshore area in 2005 and again in 2006 to promote the recovery of the resource. In 2007 CPUE has increased to approx. 10.2 kg/trap, as well as catches and effort increased to 174 tons in 2007. In 2008 catch level declined to 111 tons and CPUE to 9.0 kg/trap. Preliminary catch for 2009 indicate an increase in catch level and declining catch rate. No standardised index of CPUE and soak time has been prepared, owing to the lack of data and un-regularly recurring fishery in this area. Research Surveys Owing to the breakdown of the main engine and continued technical problems at the research ship Adolf Jensen, the survey has been cancelled in 2007, 2008 and 2008. No new survey data is available for the stock assessment and advice. Outlook - Offshore Maniitsoq-Kangaamiut Fishery data is very sparse and those available suggest an decreasing tendency since 2007. Recommendations for the 2010 fishery - Offshore Maniitsoq-Kangaamiut No new data are available for 2009. Due to the lack of survey and fishery data no advice is given for Maniitsoq-Kangaamiut offshore. Management area: Nuuk-Paamiut The historical catch, CPUE and effort data of the fishery in Nuuk-Paamiut inshore and offshore areas are summarized in Table 2. The Nuuk-Paamiut area has been an important fishing area where total catches peaked at more than 5,000 tons in 2001 (Table 2.). However, catches the following year were approximately 50% lower (2,531 tons) despite only a 10% decrease in effort. This led to the fishery CPUE inshore and offshore decreased from 5.3 and 3.8 kg/trap respectively in 2001 to 2.8 kg/trap in 2002 in both areas. Total catches including inshore and offshore were somewhat stable around 2,300 tons during 2002-2005, partly as a result of low overall effort and more recently due to quota restrictions. Total catches decreased by 77% to 521 tons in 2007 (410 tons offshore and 111 tons inshore). Over the past two years catches have been Snow crab stock status and advisory report 2010 18 steadily increasing to a preliminary level of 743 tons in 2009 (Fig.32). Inshore - Nuuk-Paamiut Fishery Catches peaked at 4,157 tons in 2001 and then declined by more than 97% to 111 tons in 2007 (Table 2 and Fig. 33), while fishing effort declined by 98%. The catch level increased to 200 tons in 2008 and preliminary data show 216 tons in 2009. The distribution the fishery in 2004 and 2008 has been concentrated near the sub-areas FiskenæsDanasdyb and Frederikshåb-Ravnsdyb. There is, however some fishery in the northern part of the area – Godthåb (Fig. 32). From the standardised CPUE index (Fig. 33) it appears that CPUE has gradually increased during this period from a low of 1.8 kg/trap in 2000 to 7.7 kg/trap in 2006 (F= 30.4, P<0.001) and remained somewhat stable. In 2008 average soak time was approx. 80 hour per hauled traps fleet (Fig. 34). Outlook - Inshore Nuuk-Paamiut There is no survey undertaken in Nuuk-Paamiut inshore thus recruitment indices and other biological parameters are not available. The commercial CPUE have been somewhat stable since 2005 as total catch and effort remain at a low level. There is concern regarding sustainability of the resource at higher catch levels, due to the lack of biological data. Recommendations for the 2010 fishery - Inshore Nuuk-Paamiut There had been indications of improvement to the resource biomass over the last several years in a scenario of decreasing fishing exploitation. It is however, difficult to determine the extent of the improvement due to the lack of other stock indices. It is therefore recommended that the catch level of 200 tons for 2010 and comparable with the commercial catch level since 2005. Offshore - Nuuk-Paamiut Fishery The distribution in the offshore fishery has changed slightly from a continuous distribution of effort along the inner edges of the offshore banks from the middle of the Nuuk-Paamiut area and northward in 2003 to effort concentrating around sub-areas Fiskenæs-Danasdyb and FrederikshåbRavnsdyb in 2004 and 2009 (Fig. 32). In 2005 and 2006 and 2009, effort has been allocated to a fishery along the outer edges of the banks (Fyllas bank) in the northern part of Nuuk-Paamiut. In 2007 there were no landings of crab from ultimo June to mid October 2007 to the main industry component (Royal Greenland) in Paamiut. Catches in Nuuk-Paamiut offshore declined from 1,339 in 2000 to 761 tons in 2002 (Table 2 and Fig. 35). Catch level more than doubled to 1,611 tons in 2003 and further increased to 2,033 tons as effort decreased to 302 thousand trap hauls in 2005. Since catches have declined and was in 2008 (418 tons) approx. 80% of the 2005 level and effort decrease by 85%. A standardised CPUE index shown gradually increase to a level of 8.1 kg/trap in 2005 (Fig. 35), followed by a two years decrease in CPUE. Data from 2008 and preliminary data for 2009 indicated some stability of CPUE at 7.9 kg/trap and 7.4 kg/trap respectively. The fishery starts in January and has the highest catch rates from February to May. Monthly trends in commercial data generally show substantial declines in CPUE during the year, suggesting the resource is being depleted as the fishing season progresses (Fig. 36). Soak time has been quite stable and varied from approx. 60 to 77 hour per hauled trap fleet from 2000 to 2008. Average soak time in 2009 is 59 hour per hauled traps fleet (Fig. 36). Snow crab stock status and advisory report 2010 19 Research Surveys Owing to the breakdown of the main engine at the research ship Adolf Jensen, the survey has been cancelled in 2007, 2008 and 2009. No new survey data is available for the stock assessment and advice. Outlook - Offshore Nuuk-Paamiut Owing to cancelled surveys, there is no fisheryindependent data, to validate the apparent increase in the exploitable biomass in this area. It is uncertain if there is a progression in biomass or the increasing catch rates is a result from a lack of interest for commercial snow crab fishery in the management area in 2007 and 2008. Recommendations for the 2010 fishery - Offshore Nuuk-Paamiut No new biological data has been available since 2006. It is recommended that the catch level for 2010 does not exceed 1600 tons, identical with the quota for 2008 and 2009. Snow crab stock status and advisory report 2010 20 Tables Table 2. Catches, catch rates (CPUE) and effort in management inshore and offshore areas from 20002009. *2009 data is preliminary and incomplete. Management Area Year Total catch (tons) Quota Inshore catch (tons) Inshore CPUE (kg/trap) Inshore effort ('000) Offshore catch (tons) Offshore CPUE (kg/trap) Offshore effort ('000) 2000 3,052 -- 2,940 4.8 613 112 5.5 20 2001 4,202 -- 3,950 3.1 1,274 252 3.6 70 Uummannaq-Diskobugt 2002 3,319 -- 2,970 3.3 900 349 3.0 116 2003 2,739 -- 2,482 3.7 679 257 2.6 97 2004 2,341 -- 2,174 3.4 632 167 3.7 45 2005 1,500 1718 1,404 3.9 363 96 4.0 24 2006 1,134 1600 1,008 4.6 221 126 6.7 19 2007 698 1530 574 4.2 138 123 5.1 24 2008 627 1400 531 5.0 107 96 5.2 19 2009* 439 700 264 5.5 48 174 5.5 32 2000 2,534 -- 491 2.8 175 2,043 6.4 319 2001 2,602 -- 327 2.9 113 2,275 4.6 495 Sisimiut 2002 2,724 -- 473 4.6 103 2,251 3.5 643 2003 1,633 -- 692 3.7 187 941 3.1 304 2004 1,432 -- 1,111 3.9 286 321 4.9 65 2005 1,125 900 891 6.5 137 234 6.4 37 2006 736 750 725 8.3 87 11 11.1 1 2007 784 850 559 7.4 75 225 12.8 18 2008 979 700+300 765 8.8 87 214 13.1 16 2009* 867 500+300 560 8.6 65 308 8.3 37 2000 944 -- 563 4.3 131 381 7.6 50 2001 1,835 -- 1009 3.7 273 826 5.0 165 Maniitsoq-Kangaamiut 2002 1,775 -- 1032 3.8 272 743 2.7 275 2003 485 -- 40 3.5 12 445 2.8 160 2004 116 -- 78 2.4 33 38 2.1 18 2005 73 200 (inshore) 62 4.2 15 11 3.6 3 2006 72 100(inshore)' 61 4.3 14 11 4.3 3 2007 187 300 13 2.9 5 174 10.2 17 2008 130 300 19 5.9 3 111 9.0 12 2009* 185 -- 22 3.1 7 163 6.0 27 2000 3,769 -- 2,430 5.3 458 1,339 5.4 248 2001 5,077 -- 4,157 5.3 784 920 3.8 242 Nuuk-Paamiut 2002 2,531 -- 1,770 2.8 632 761 2.8 272 2003 2,315 -- 704 3.4 207 1,611 4.2 385 2004 1,795 -- 180 4.5 40 1,615 8.0 203 2005 2,295 -- 262 8.0 33 2,033 6.7 302 2006 1,173 1,800 204 7.3 28 969 3.0 328 2007 521 1,600 111 7.2 15 410 7.4 56 2008 617 1600 200 7.2 28 418 9.1 46 2009* 743 700+300 216 7.7 28 527 8.6 62 2000 2 -- 0 -- -- 2 -- -- 2001 822 -- 822 -- -- 0 -- -- Narsaq-Qaqortoq 2002 643 -- 642 -- -- 1 -- -- 2003 133 -- 123 -- -- 10 -- -- 2004 541 -- 32 3.9 8 2 1.0 2 2005 76 -- 76 8.3 9 -- -- -- 2006 0 -- -- -- -- -- -- -- 2007 0 -- -- -- -- -- -- -- 2008 -- -- -- -- -- -- -- -- 2009* 125 -- -- -- -- -- -- -- Snow crab stock status and advisory report 2010 21 Figures Fig 1. Map of West Greenland outlining the 6 management areas as of 2004 for the snow crab fishery. Snow crab stock status and advisory report 2010 22 Figure 2. Total catch and quota size from 1995-2009. Data from 2009 is only preliminary. Fig. 3. Snow crab landings in the 4 most important management areas of West Greenland 2000-2009 and used total effort. Data for 2009 are preliminary and incomplete. Year 1994 1996 1998 2000 2002 2004 2006 2008 2010 Total quota and catch ('000 tons) 0 5 10 15 20 25 30 35 Total quota Total catch Year 2000 2002 2004 2006 2008 2010 Total catch (tons) 0 2000 4000 6000 8000 10000 12000 14000 16000 Total effort ('000) 0 1000 2000 3000 4000 Disko Bay - Uummannaq Sisimiut Maniitsoq - Kangaamiut Nuuk - Paamiut Total effort Snow crab stock status and advisory report 2010 23 Fig. 4. Distribution of the crab fishery off West Greenland within each management area from 2003 - 2009, derived from logbook data. Lines are used to separate management areas. 2003 2004 2005 2006 2007 2008 2009 Snow crab stock status and advisory report 2010 24 LL LG LH LJ LK LS LM LN LP LR LA LB LD LE LF 13 14 1715 16 18 19 24 20 21 22 23 29 25 26 27 28 3430 31 32 33 Qeqertarsuaq Aasiaat Qasigiannguit Ilulissat 61 62 63 6465 66 67 68 69 70 71 72 73 74 76 77 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 98 99 175 176 177 178 KF KG KH KJ 14 KA KB KD KE 13 1815 16 17 19 20 21 22 Sisimiut 51 52 54 55 58 60 25 26 27 28 29 32 33 34 17 18 19 20 21 1 2 3 4 5 6 7 8 9 10 11 12 35 42 44 45 46 47 48 49 50 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 Fig. 5a. Map showing the location of survey stations in Disko Bay, Area 1 (North) and Area 2 (South). Fig. 5b. Map showing the location of inshore and offshore survey stations in Sisimiut. Snow crab stock status and advisory report 2010 25 Maniitsoq-Kangaamiut Fiskenæs-Danasdyb Godthåb Nuuk-Paamiut Frederikshåb-Ravnsdyb L J M I H K NUUK G C D E F A B NUUK Offshore Survey Areas Maniitsoq-Kangaamiut Nuuk-Paamiut 0 0 Fig. 5c. Map showing the location of survey stations from Maniitsoq-Kangaamiut and Nuuk-Paamiut (and sub-areas). Snow crab stock status and advisory report 2010 32 Fig. 13. Size distribution of adolescent and adult males from survey Disko Bay South and Disko Bay North in Disko Bay from 2000-2008. Disko Bay - South Carapace width (mm) 020 40 60 80 100 120 140 160 Abundance (NPUE) 0.0 0.5 1.0 1.5 2.0 Carapace width (mm) 020 40 60 80 100 120 140 160 Abundance (NPUE) 0.0 0.5 1.0 1.5 2.0 Disko Bay - North Carapace width (mm) 020 40 60 80 100 120 140 160 Abundance (NPUE) 0.0 0.5 1.0 1.5 2.0 Carapace width (mm) 020 40 60 80 100 120 140 160 Abundance (NPUE) 0.0 0.5 1.0 1.5 2.0 Carapace width (mm) 020 40 60 80 100 120 140 160 Abundance (NPUE) 0.0 0.5 1.0 1.5 2.0 Adolescent males Adult males 2006 2007 2006 2007 2008 Snow crab stock status and advisory report 2010 33 Fig. 14. The percentage of shell conditions (1-5) of adult legal-sized male crabs (100mm CW) sampled in Disko Bay South and Disko Bay North, Disko Bay 1998 to 2008. Fig. 15. Annual trends in the ratio between primiparous and multiparous in Disko Bay South and Disko Bay North, Disko Bay 2000-2008. Disko Bay - South Year 1998 2000 2002 2004 2006 2008 Percent (%) 0 20 40 60 80 100 Disko Bugt - North Year 1998 2000 2002 2004 2006 2008 Percent (%) 0 20 40 60 80 100 SC1 SC2 SC3 SC4 SC5 Disko Bay - North Year 1998 2000 2002 2004 2006 2008 Primiparous female : (primiparous + multiparous) 0.0 0.2 0.4 0.6 0.8 1.0 Disko Bay - South Year 1998 2000 2002 2004 2006 2008 Primiparous female : (primiparous + multiparous) 0.0 0.2 0.4 0.6 0.8 1.0 Snow crab stock status and advisory report 2010 34 Fig. 16. The distribution and crab fishery in Sisimiut inshore and offshore in 2003 - 2009. The coastal line indicates the basisline separating the offshore from the inshore. Data from 2009 is preliminary and incomplete. 2003 2004 2003 2005 2006 2007 2008 2008 2009 Snow crab stock status and advisory report 2010 35 Inshore Sisimiut Month 0 2 4 6 8 10 12 CPUE (kg/trap) 0 2 4 6 8 10 12 14 16 2003 2004 2005 2006 2007 2008 2009 Fig. 17. Monthly trends in CPUE (kg per trap) from the fishery in Sisimiut inshore from 2003 to 2009. Data for 2009 is incomplete. Inshore Sisimiut Year 2000 2002 2004 2006 2008 CPUE (kg/trap) 0 2 4 6 8 10 12 Total catch (tons) 0 500 1000 1500 2000 2500 CPUE (kg/trap) Upper confidence limit Lower confidense limit Total catch Fig. 18. Standardised CPUE index and total catch based on logbook information inshore Sisimiut from 20002009. Data for 2009 is incomplete. Snow crab stock status and advisory report 2010 36 Inshore Sisimiut Year 2000 2002 2004 2006 2008 GLM index soake time (hour) 0 20 40 60 80 100 120 Lsmeans Upper confidence limits Lower confidence limits Fig. 19. Standardised soak time index based on logbook information inshore Sisimiut from 2000-2009. Data for 2009 is incomplete. Sisimiut inshore Year 1996 1998 2000 2002 2004 2006 2008 2010 GLM index CPUE (kg per trap) 0 5 10 15 20 CPUE CPUE in the reference period 1999 - 2002 Fig. 20. Annual trends in CPUE (kg/trap  S.E.) of legal-size males (100mm CW) from trap surveys in Sisimiut inshore from 1997 to 2009. The mean CPUE for the reference period (1999-2002) in Sisimiut inshore is indicated with a line. Snow crab stock status and advisory report 2010 37 Year 1998 2000 2002 2004 2006 2008 Average carapace width (mm) 110 112 114 116 118 120 Sisimiut inshore Sisimiut offshore Sisimiut - Ndr. Strømfjord Sisimiut inshore - CW in the reference period 1 Sisimiut offshore - CW in the reference period Fig. 21. Annual trends in the mean carapace width (CW) for legal-size males (100mm CW) from trap surveys in Sisimiut inshore (1997-2009) and Sisimiut offshore (1999–2009). The mean CW for the reference period (1999-2002) in Sisimiut inshore and (2000–2003) in Sisimiut offshore is indicated with a line. Year 2000 2002 2004 2006 2008 Abundance (NPUE) 0 1 2 3 4 5 6 7 8 ADO1: 82.2 - 100 mm CW ADO1 in the reference period Fig. 22. Annual trends in the abundance NPUE (No. crabs per trap  S.E) of adolescent males (ADO-1: 82.2100mm CW) expected to recruit to the fishery the following year in Sisimiut inshore areas from 2000 to 2009. The mean NPUE for the reference period (1999-2003) in Sisimiut inshore is indicated with a line. Snow crab stock status and advisory report 2010 38 Sisimiut inshore Carapace width (mm) 020 40 60 80 100 120 140 160 Adundance (NPUE) 0 1 2 3 4 5 Carapace width (mm) 020 40 60 80 100 120 140 160 Abundance (mm) 0 1 2 3 4 5 Carapace width (mm) 020 40 60 80 100 120 140 160 Abundance (mm) 0 1 2 3 4 5 Adolescent males Adult males Sisimiut offshore Carapace width (mm) 020 40 60 80 100 120 140 160 Abundance (NPUE) 0 1 2 3 4 5 Carapace width (mm) 020 40 60 80 100 120 140 160 Abundance (NPUE) 0 1 2 3 4 5 Carapace widht (mm) 020 40 60 80 100 120 140 160 Abundance (NPUE) 0 1 2 3 4 5 Adolescent males Adult males 2000 2001 2002 2000 2001 2002 Snow crab stock status and advisory report 2010 39 Sisimiut inshore Carapace width (mm) 020 40 60 80 100 120 140 160 Abundance (NPUE) 0 1 2 3 4 5 Carapace width (mm) 020 40 60 80 100 120 140 160 Abundance (NPUE) 0 1 2 3 4 5 Carapace width (mm) 020 40 60 80 100 120 140 160 Abundance (NPUE) 0 1 2 3 4 5 Adolescent males Adult males Sisimiut offshore Carapace width (mm) 020 40 60 80 100 120 140 160 Abundance (NPUE) 0 1 2 3 4 5 Carapace width (mm) 020 40 60 80 100 120 140 160 Abundance (NPUE) 0 1 2 3 4 5 Carapace width (mm) 020 40 60 80 100 120 140 160 Abundance (NPUE) 0 1 2 3 4 5 Adolescent males Adult males 2003 2004 2005 2003 2004 2005 Snow crab stock status and advisory report 2010 40 Sisimiut inshore Carapace width (mm) 020 40 60 80 100 120 140 160 Abundance (NPUE) 0 1 2 3 4 5 Carapace width (mm) 020 40 60 80 100 120 140 160 Abundance (NPUE) 0 1 2 3 4 5 Carapace width (mm) 020 40 60 80 100 120 140 160 Abundance (NPUE) 0 1 2 3 4 5 Adolescent males Adult males Carapace width (mm) 020 40 60 80 100 120 140 160 Abundance (NPUE) 0 1 2 3 4 5 Sisimiut offshore Carapace width (mm) 020 40 60 80 100 120 140 160 Abundance (NPUE) 0 1 2 3 4 5 Carapace width (mm) 020 40 60 80 100 120 140 160 Abundance (NPUE) 0 1 2 3 4 5 Adolescent males Adult males 2006 2007 2008 2006 2007 2008 Snow crab stock status and advisory report 2010 41 Fig. 23. Size distribution of adolescent and adult males from surveys in Sisimiut inshore and offshore from 2000 to 2009. Fig. 24. The percentage of shell conditions (1-5) of legal-size adult males (100mm CW) sampled in trap surveys in Sisimiut inshore and offshore from 2000 to 2009. Sisimiut inshore Carapace width (mm) 020 40 60 80 100 120 140 160 Abundance (NPUE) 0 1 2 3 4 5 Adolescent Adult 2009 Sisimiut offshore Carapace width (mm) 020 40 60 80 100 120 140 160 Abundance (mm) 0 1 2 3 4 5 Adolescent Adult 2009 Sisimiut inshore Year 1998 2000 2002 2004 2006 2008 Percent (%) 0 20 40 60 80 100 SC1 SC2 SC3 SC4 SC5 Sisimiut offshore Year 1998 2000 2002 2004 2006 2008 Percent (%) 0 20 40 60 80 100 SC1 SC2 SC3 SC4 SC5 Snow crab stock status and advisory report 2010 48 Offshore Nuuk - Paamiut Year 2000 2002 2004 2006 2008 CPUE (kg/trap) 0 2 4 6 8 10 12 Total catch (tons) 0 1000 2000 3000 4000 CPUE (kg/trap) Lower confidence limits Upper confidence limits Total catch Fig. 35. Standardised CPUE index and total catch based on logbook information offshore Nuuk - Paamiut from 1999-2009. Data for 2009 is incomplete. Offshore Nuuk Paamiut Month 0 2 4 6 8 10 12 CPUE (kg/trap) 0 2 4 6 8 10 12 14 16 2003 2004 2005 2006 2007 2008 2009 Fig. 36. Monthly trends in CPUE (kg per trap) from the fishery in Nuuk-Paamiut offshore from 2003 to 2009. Data for 2009 is incomplete. Snow crab stock status and advisory report 2010 49 Offshore Nuuk - Paamiut Year 2000 2002 2004 2006 2008 GLM index soake time (hour) 0 20 40 60 80 100 120 lsmeans fishtime Lover conficence limits Upper confidence limits Fig. 37. Standardised soak time index based on logbook information offshore Nuuk - Paamiut from 19992009. Data for 2009 is incomplete.