Snow Crab Chionoecetes opilio Canada Traps November 28, 2012 Daniel A. Ovando, Consulting Researcher Disclaimer Seafood Watch strives to ensure all our Seafood Reports and the recommendations contained therein are accurate and reflect the most up-to-date evidence available at time of publication. All our reports are peerreviewed for accuracy and completeness by external scientists with expertise in ecology, fisheries science or aquaculture. Scientific review, however, does not constitute an endorsement of the Seafood Watch program or its recommendations on the part of the reviewing scientists. Seafood Watch is solely responsible for the conclusions reached in this report. We always welcome additional or updated data that can be used for the next revision. Seafood Watch and Seafood Reports are made possible through a grant from the David and Lucile Packard Foundation.
2 Final Seafood Recommendation This report covers the three largest management areas (by landings) of the Canadian snow crab trap fishery: Eastern Nova Scotia (ENS), Newfoundland and Labrador (NFL), and the Southern Gulf of St. Lawrence (SGSL). Snow crab from Eastern Nova Scotia, Newfoundland, and Labrador are a Good Alternative. Snow crab from the Southern Gulf of St. Lawrence are a Best Choice. Stock Snow crab Canada/Eastern Nova Scotia Snow crab Canada/Newfoundland and Labrador Snow crab Canada/Southern Gulf of St. Lawrence Fishery Canada Eastern Nova Scotia (ENS) Trap Canada Newfoundland and Labrador (NFL) Trap Canada Southern Gulf of St. Lawrence (SGSL) Trap Impacts on the Stock Rank (Score) Green 3.83 Yellow 2.64 Green 3.83 Impacts on other Species Lowest scoring species Rank*, Subscore, Score Leatherback turtle, Northern and spotted wolffish Yellow 2.24, 2.24 Northern and spotted wolffish Red 1.92, 1.92 No other main species caught Green 5, 5 Management Rank Score Green 3.46 Yellow 3 Yellow 3 Habitat and Ecosystem Rank Score Yellow 3.12 Yellow 3.12 Yellow 3.12 Overall Recommendation Score GOOD ALTERNATIVE 3.1 GOOD ALTERNATIVE 2.62 BEST CHOICE 3.66 Scoring note Scores range from zero to five where zero indicates very poor performance and five indicates the fishing operations have no significant impact.
3 Table of Contents Final Seafood Recommendation... 2 Executive Summary... 4 Introduction... 6 Analysis... 10 Criterion 1: Stock for which you want a recommendation... 10 Factor 1.3. Fishing mortality... 15 Criterion 2: Impacts on other retained and bycatch stocks... 17 Criterion 3: Management ness... 21 Criterion 4: Impacts on the habitat and ecosystem... 30 Overall Recommendation... 36 Acknowledgements... 37 Appendix A: Review Schedule... 40 About Seafood Watch... 41 Guiding Principles... 42
4 Executive Summary This report covers wild trap fisheries for snow crab (Chionoecetes opilio). The geographic scope of this report includes the snow crab fisheries of Canada. Snow crabs caught from Canada s Atlantic regions are managed by a number of smaller management units. The size and structure of these units is guided by governance needs; biological distinctions between these units have not been clearly established. For the purposes of this assessment, however, the individual regions are assumed to be distinct. This report concentrates on the three largest management areas (by landings) of the Canadian snow crab industry: Eastern Nova Scotia (ENS), Newfoundland and Labrador (NFL), and the Southern Gulf of St. Lawrence (SGSL). Snow crabs have high inherent vulnerability to fishing pressure. Males reach sexual maturity after 4 10 years and can live up to 20 years. Females are highly fecund, producing just over 80,000 eggs on average in their lifetimes. Fertilized eggs are brooded by the females outside their bodies under an abdominal flap. Larvae are released to the water column where they spend several months before settling. Snow crabs are not broadcast spawners. As such, they may require minimum densities in order to achieve viable mating aggregations, which raises the potential for depensatory population dynamics at low population sizes. The ENS population is estimated to be above the proxy level for B msy used in this region; however, trends in catch per unit effort (CPUE) and recruitment indicate possible future declines in the fishery (though this may be a natural consequence of the currently high biomass levels). The NFL region has no firm biological reference points in place. Exploitable biomass in this region is low compared to recent highs but has recently shown signs of increasing. Nevertheless, while short-term recruitment is high, a lack of small individuals in the fishery suggests that future recruitment may be compromised. It is possible that recent declines in the NFL snow crab population are a result of prior warm water years. Biomass reference points for the SGSL indicate that the fishery is likely above the proxy of B msy used in this region. For the ENS region, fishing mortality has been consistently below F msy in the recent past. No reference points for fishing mortality exist for the NFL region. Fishing mortality has been fluctuating around the F msy proxy used in the SGSL over the past several years but has remained below this level in recent years. Evidence suggests that this current level is highly unlikely to reduce stock productivity. Bycatch rates for finfish and invertebrates are near zero for the ENS fishery. Bycatch of the threatened northern (Anarhichas denticulatus) and spotted (Anarhichas minor) wolffish have been reported in the ENS region. However, bycatch rates for these species amount to approximately 0.001% of snow crab landings in the region and are not expected to negatively impact wolffish populations. Since 2001, some encounters with leatherback turtles have been documented (fewer than 10 instances, with no observers reporting any harm to the turtle following release). The Department of Fisheries and Ocean (DFO) estimates that the snow crab trap fishery in the ENS region may account for 1 5 leatherback deaths per year. Due to their
5 high vulnerability and their endangered status under Schedule 1 of the Canadian Species at Risk Act (SARA), the leatherback turtle is the limiting stock for the ENS region. The NFL region for snow crab also has low rates of discard and byctach, but incidentally captures two wolffish species (northern and spotted) that are listed as threatened by SARA. Incidental bycatch of leatherback turtles has also been reported in the NFL region. The spotted and northern wolffish are both listed as limiting stocks for the NFL region due to their threatened status. Spotted and northern wolffish are also present in other regions of Canada, but their populations are centered on the Newfoundland and Labrador shelves. The SGSL has negligible levels of bycatch aside from sub-legal male snow crabs. The SGSL region coincides with habitat for leatherback turtles, but no interactions between the snow crab trap fishery and leatherback turtles have been reported for the region. As such, the SGSL is considered a single species fishery. Snow crab fisheries in Canada are managed using an individual quota system (IQ) together with effort controls, size limits, seasons, total allowable catches (TAC), gear restrictions, and prohibitions on the capture of females and soft-shelled males. Individual fishing management areas operate the exact structures of these tools (for example, by recommending TACs and seasons). Each region conducts annual assessments of stock status based on both fisherydependent and independent data. The extent of available data and the ability to assess the health of individual stocks vary among regions, but most Canadian snow crab populations are in good condition. Management has generally demonstrated a strong ability to respond to the fluctuations that often characterize snow crab populations. Throughout the Canadian snow crab fisheries, scientific recommendations stemming from assessments are used to suggest TACs to an advisory committee made up of industry stakeholders. A Federal Fisheries Minister sets the final TAC for each region throughout Canada. The mechanisms by which the advisory boards of each region suggest TACs to the Minister vary. Enforcement practices include mandatory logbooks, dock-side observers, on-board observers, and in some locations, VMS systems. Many of the Canadian snow crab fisheries have demonstrated strong effort to include stakeholders in management decisions. All Canadian snow crab fisheries use traps on sandy or muddy bottoms. Limited direct efforts are in place to reduce the habitat impacts of the fisheries. Little action has been taken to actively reduce effort across the Canadian snow crab fisheries; in some areas effort has been allowed to increase. Closed areas are employed to protect regions with high densities of sublegal and molting males, which also serve to prevent some habitat damage. The NFL region has also closed portions of its fishery in order to protect the overall integrity of the stock. Although no clear ecosystem-based management strategies are currently in use for snow crab, a broader integrated management approach is being developed that will foster opportunities to implement ecosystem-based management across all Canadian snow crab fisheries.
6 Introduction Scope of the analysis and ensuing recommendation This report covers wild trap fisheries for the snow crab (Chionoecetes opilio). The geographic scope of this report covers the snow crab fisheries of Canada. Snow crabs caught from Canada s Atlantic regions are managed by a number of smaller management units. The size and structure of these units is guided by governance needs; biological distinctions between these units have not been clearly established. For the purposes of this assessment, the individual regions are assumed to be distinct. This report concentrates on the three largest management areas (in terms of landings) of the Canadian snow crab industry: Eastern Nova Scotia (ENS), Newfoundland and Labrador (NFL), and the Southern Gulf of St. Lawrence (SGSL). Species overview Ecology of snow crabs (C. opilio) Snow crabs are disc-shaped crabs reaching widths of up to 15 cm and living up to 20 years (Turnock & Rugolo 2011). In the North Pacific, snow crabs are found throughout the continental shelf of the Bering, Chukchi, and Beaufort Seas, as well as in the Sea of Okhotsk (the snow crab population in the Sea of Japan consists of a subspecies, Chionoecetes opilio elongates). In the Atlantic, they are found along the eastern seaboard of North America as far south as Maine and as far north as Greenland (NOAA 2012) (Fig. 1). They have four pairs of legs and one pair of large claws that become disproportionately larger once the males reach their final molt at approximately 4 15 cm in width, by which time they have also generally developed functional sperm (DFO 2012a). Snow crabs grow by molting, undergoing several molts before reaching a terminal molt. After each molt, the crab s new shell is soft (during which time they are called soft crab), making it vulnerable to handling, predation, and environmental hazards. Snow crabs feed on a wide variety of material such as fish, crustaceans (including other crabs), algae, and even sponges on occasion. Snow crabs are preyed upon by fish, seals, sea otters, and octopus, usually when the crabs are smaller in size (NOAA 2012).
7 Figure 1. Geographic distribution of snow crabs, C. opilio. Figure from FAO (2012a). Snow crabs are also reported in the Barents Sea. Snow crabs typically inhabit temperatures from -1 to 5 degrees C (Weston 2011). Adult males generally live along mud or silt bottoms at depths less than 200 m where they can burrow and feed. Adult females live in habitats apart from the adult males for much of the year (Poulsen 2012). During mating, females form large mounds, and the largest males generally participate in mating. After mating, females can brood fertilized eggs on their abdomen outside their body for nearly one year (females living in extremely cold water may even brood their embryos for two years). Eventually, larvae are released to the water column where they spend several months undergoing molts until they reach sufficient size to settle to the ocean floor (Choi & Zisserson 2012). Juveniles live in shallower protected waters where they can bury themselves in fine sediments to provide better protection from predators. Snow crab fisheries are marked by strong boom-bust dynamics in which periods of high productivity are followed by phases of low recruitment (Sainte-Marie, Sévigny, Smith & Lovrich 1996; Turnock & Rugolo 2011). The drivers and timing of these cycles are not yet well understood, though factors such as compensatory density dependence, cod predation, and water temperature may all play roles (Boudreau, Anderson & Worm 2011; Sainte-Marie, Raymond & Brêthes 1995; Sainte-Marie et al. 1996).
8 History & management of the fishery Snow crab was initially caught in Canada as bycatch in groundfish trawls during the 1960s (Moriyasu 2011). The targeted commercial market expanded in the 1980s when it quickly became among the largest fisheries in Canada. Landings fell in the late 1980s as a result of stock failures stemming from overfishing (Moriyasu 2011), but they have since shown a generally upward trend to a peak at over 100 kilo tons (kt) in 2002, largely due to expanded fishing efforts in Newfoundland. Increased availability of snow crab is also likely due to increases in suitable cold-water bottom habitats and larval recruitment, together with decreases in populations of predatory groundfish (Moriyasu 2011). Catch levels have declined slightly since 2002 but remain at historically high levels (Fig. 2) (Pinfold 2006). Figure 2. History of commercial landings (metric tons) for Canadian snow crab (1990 2009) (DFO 2011c). Management of Canadian snow crab is divided into regional management areas based largely on geopolitical necessity, although biological distinctions between the regions are also evident. This report provides recommendations for the three most significant regions (in terms of production): the Southern Gulf of St. Lawrence (SGSL), Newfoundland and Labrador (NFL), and Eastern Nova Scotia (ENS). Production and markets Global production is dominated by the Canadian market and sold primarily to the USA and Japanese markets (Weston 2011). Consumption of snow crab in the USA exceeded 101 kt live weight in 2009. The Alaskan EBS snow crab fishery provides approximately 14% of this total. The majority of imports making up the balance of consumption in the USA comes from Canada
9 and Russia. Roughly 50% of USA snow crab landings are exported, primarily to China and Japan (Sea Fare Group 2011). Wholesale prices in the USA have fluctuated between $3.00 and $6.00 USD/lb (Seafood Market Bulletin 2012). Global production has generally increased over time, reaching a peak of over 110 kt in 2002 (FAO 2012b). Global production of snow crab has historically been dominated by Canada, with Russia and the USA also providing substantial shares (Pinfold 2006). Snow crab production in the USA dropped to historic lows during the early 2000s in response to the overfished condition of the stock. However, US production has increased since 2005, with the most recent complete season bringing in 26.2 kt (Turnock & Rugolo 2011). The USA exports snow crab predominately to Japan. The USA and Japan each account for nearly half of global snow crab consumption (Pinfold 2006). The majority of snow crab sold in the USA is in section form (four legs and a claw; other forms include live whole, frozen whole, and extracted meat). Primary markets include mid-level seafood restaurants, buffets and casinos in the USA, and luxury and sushi restaurants in Japan (Pinfold 2006). Snow crab meat is described as sweet and flaky. In the US market, prices have generally fluctuated between a low of $2.00/lb and a high of $5.00/lb, with recent US import values nearing $5.00/lb wholesale (NMFS 2012). Imports to the USA are primarily from Russia and Canada. Common market names Snow crab is also marketed as queen and spider crab. In sushi form, crab is generically referred to as kani.
10 Analysis Scoring guide All scores result in a zero to five final score for the criterion and the overall final rank. A zero score indicates poor performance, while a score of five indicates high performance. The full Seafood Watch Fisheries Criteria to which the following scores correspond are available on our website at www.seafoodwatch.org. Criterion 1: Stock for which you want a recommendation Guiding principles The stock is healthy and abundant. Abundance, size, sex, age, and genetic structure should be maintained at levels that do not impair the long-term productivity of the stock or fulfillment of its role in the ecosystem and food web. Fishing mortality does not threaten populations or impede the ecological role of any marine life. Fishing mortality should be appropriate given current abundance and inherent resilience to fishing while accounting for scientific uncertainty, management uncertainty, and non-fishery impacts such as habitat degradation. Summary Stock Fishery Inherent Vulnerability Snow Crab - Canada/Eastern Nova Scotia Snow Crab - Canada/Newfoundland and Labrador Snow Crab - Canada/Southern Gulf of St. Lawrence Canada - Eastern Nova Scotia (ENS) - Trap Canada - Newfoundland and Labrador (NFL) - Trap Canada - Southern Gulf of St. Lawrence (SGSL) - Trap Stock Status Fishing Mortality Criterion 1 Rank Rank (Score) Rank (Score) Rank Score High High High Low Concern (4) Moderate Concern (3) Low Concern (4) Low Concern (3.67) Moderate Concern (2.33) Low Concern (3.67) Green 3.83 Yellow 2.64 Green 3.83
11 Justification of Ranking Factor 1.1. Inherent Vulnerability: High Resilience attribute Score Rationale Source Average age at maturity Average maximum age 2 4 6 years (Sainte-Marie et al. 1995) 2 7 15 years, with 7 being a highly conservative estimate Fecundity NA More than 80,000 eggs per lifetime produced by females Reproductive 2 Eggs are fertilize and brooded by strategy female, larvae spend several months in water column (Fonseca, Sainte-Marie & Hazel 2008; Siddeek, Wade & Moriyasu 2009) (Sainte-Marie 1993) (Choi & Zisserson 2012, Sainte-Marie 1993) Density dependence 1 Steepness parameter high, little risk of Allee effects or compensatory effects Total score 1.75 High vulnerability (Siddeek et al. 2009) Factor 1.2. Stock status Snow crab ENS: Low concern No aggregate stock assessment exists for the complete ENS region. However, estimates of biomass, recruitment, egg production, size frequency distributions, effort, and landings are available. These estimates are based on fishery dependent and independent information from sub-regions throughout the ENS region, which is used to produce reference points for subregions of the ENS (DFO 2012b). Fishable biomass has been generally increasing over recent decade (Fig. 3). Recruitment has also been increasing since 2005, though recruitment patterns within individual sub-regions of the ENS have been highly variable. Trends in recruitment and substantial numbers of sub-legal sized males observed in survey data suggest strong entry to the fishery over the next several years (DFO 2012b). However, egg production is expected to decline due to small numbers of immature female crabs currently observed in the population. Reference points were established for this fishery in a prior assessment. Using these metrics,
1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 B/Bmsy 12 the fishery has been above B msy for the past several years (Fig. 6) at both the median prediction of B msy and the upper 95% estimate of B msy (using an average of B msy across all regions, weighted by the biomass in each individual region) (Choi & Zisserson 2012). The ENS snow crab fishery is managed using a precautionary approach compliant system and is currently classified as healthy (Choi & Zisserson 2012). However, while overall trends in the fishery show positive signs of increasing fishable biomass, CPUE, and recruitment prospects, in some smaller subareas of the region, managers recommend reducing fishing mortality until a more sustained increase in biomass is observed. This suggests that current population levels are not yet ideal throughout the system. Detailed rationale 1.8 1.6 1.4 1.2 1 0.8 0.6 0.4 0.2 0 95% Mean Bmsy Figure 3. Trends in snow crab biomass throughout the ENS region over time (adapted from DFO 2012a). Snow crab NFL: Moderate concern The lack of reference points with which to assess these metrics, together with recent declines in biomass and CPUE, and the uncertain prospects for long-term recruitment renders the current state of the biomass uncertain. No quantitative stock assessment is available, and therefore the NFL section of the Canadian snow crab fishery is considered to have an unknown stock status. Detailed rationale Exploitable biomass and total abundance both decreased to a recent historic low in 2003 (Fig. 4). Both indices have seen modest recovery from that period, but levels remain low relative to high periods in the mid-1990s and showed downward trends from 2009 2010 (DFO 2011a).
t x 1000/ Millions t x 1000 / millions t x 1000 / millions Resource Status, Division 2H 1999 1995 1995 2000 1997 1997 2001 1999 2002 1999 2003 2001 2001 2004 2003 2003 2005 2006 2005 2005 2007 2007 2007 2008 2009 2009 2009 2010 13 Some snow crab populations in the NFL region experienced extremely low levels during the 1980s as well (DFO 2011a). It is possible that the high period in the mid-1990s was a result of successful recruitment following a period of cold water in the early 1990s. Correspondingly, the current low period may be a response to warm waters in the late 1990s, as snow crab populations have been shown to have a lagged response to water temperature with warmer waters negatively affecting future populations (Boudreau et al. 2011). 140 120 100 80 60 40 20-2J3KLNO - Fall * Incomplete Surveys in 2004 and 2006 Exploitable Biom ass Index Abundance Index Figure 4. Trends in exploitable biomass in the NFL region (DFO 2011a). Recruitment indices have seen an increase relative to the historic low period of 2003 2004 (Fig. 5). This suggests that short-term recruitment may be high for the fishery. However, longer-term recruitment prospects remain uncertain due to declines in the smallest indices of males (Dawe et Newfoundland al. 2011). and Labrador Region 2HJ3KLNOPs4R Snow Crab 90 75 2J3KLNO - Fall * Incomplete Surveys in 2004 and 2006 60 45 30 15 - Pre-recruit Biomass Index Abundance Index 35 3LNOPs - Spring Figure 5. Trends in recruitment and abundance in the NFL * region Incomplete (DFO 2011a). Survey 30 in 2006 25 20 15 10 5 0 Trends in CPUE across three major regions of the fishery show strong fluctuations over time. Along Eastern Newfoundland, CPUE has increased from recent lows but has declined in recent years. In Northern Newfounland, CPUE has increased from its historic low and is trending upward. In the Southern Newfoundland region, CPUE is tranding upwards but is very near to historic lows (Boudreau et al. 2011). Pre-recruit Biomass Index Abundance Index Figure 5: Trends in the multi-species survey pre-recruit biomass and abundance indices for Div. 2J3KLNO during fall (above) and for Div. 3LNOPs during spring (below).
Exploitation rate in year of fishery 14 Snow crab SGSL: Low concern Reference points are available for both biomass and exploitation in the SGSL (Fig. 9). Reference points are based on the precautionary principle and estimates of biomass during historically productive periods, where a B msy proxy (B pmsy ) is estimated as the maximum biomass observed during a productive period of the fishery (DFO 2012b). For the SGSL fishery, this value was estimated to be 51.7 kt over the period of 1997 2008. The upper stock reference point (B usr ) was estimated to be 80% of B msy, and the limit reference point (B lim ) was estimated to be the lowest biomass of commercial sized hard-shelled male crabs (10 kt) that produced acceptable numbers of recruits (DFO 2012b). The most recent biomass values for the SGSL snow crab stock indicate a biomass above B usr, and trends indicate that the population is increasing (Fig. 6). This increase follows a decrease in fishing effort, though the fishery appears to be in a period of high recruitment as well (DFO 2012a). The available biomass for the 2012 fishery, derived from the 2011 survey, is within the healthy zone of the Precautionary Approach framework (DFO 2012a). After the fishery survey of 2010, the biomass of commercial-sized adult crabs was estimated at 30,500 t (27,400 to 33,700 t), an increase of 17% from 2009, but below B usr (34,000 t). The residual biomass (13,500 t) from the 2010 survey increased by 26% over 2009 (DFO 2012b). Recruitment to the fishery (soft shell, commercial-sized adult males) increased by 10% relative to the 2009 estimate. In addition, the abundance of mature females increased in 2010 relative to values during 2005 2009 (DFO 2012b). It is anticipated that fishable biomass will be above B usr by 2013; however, because B usr is set at 80% of B msy, there is some uncertainty in appropriate biomass levels. Detailed rationale 1 B Lim = 10,000 t B USR = 41,400 t 0.8 0.6 2009 2002 F Lim = 0.346 0.4 2001 2008 2007 2004 2005 2010 2011 2000 2006 0.2 1999 1998 2003 2012 0 0 20000 40000 60000 80000 100000 120000 Biomass (t) before the fishery in year - 1 Figure 6. Trajectory of fishing effort and biomass in the SGSL region (DFO 2012b)
15 Factor 1.3. Fishing mortality Snow crab ENS: Low concern The regional exploitation rate (weighted by the fishable biomass in each region) follows the trend of exploitation rates between 10% and 30% (Fig. 10, Choi & Zisserson 2012). For the whole ENS region, as F has been consistently both lower than F msy and within the bounds of the adaptive harvest strategy, it is unlikely that overfishing is occurring. However, the use of F msy as a reference point has been questioned for Canadian snow crab (Choi & Zisserson 2012) and inherent fluctuations occur in the productivity of the stock. Detailed rationale Fishing mortality has fluctuated over time, with a peak in 2004 and high and upwardly trending values as of 2010 (the most recent data available). Low abundance of very old crabs in both fishery and survey-based data may suggest that fishing levels are high for the fishery, as few crabs are able to reach this age group. It is also possible, however, that natural mortality is simply high. Significant bycatch in the fishery is limited to sub-legal males. The impact of sublegal or soft-shelled bycatch can be significant. Management has recently taken efforts to minimize bycatch of soft-shelled males by shifting fishing seasons as well as through an observer program that can quickly shut down fishing in regions where significant numbers of soft-shelled individuals are observed. Alternative reference points for fishing mortality are available for the ENS region. Standard estimates of F msy are available for all three sub-regions of ENS. While subregions NENS and CFA4X have fluctuated well above F msy at times, current estimates of F are below F msy. The largest sub-region (in both landings and fishable biomass) of ENS is SEN, which has consistently been lower than F msy, as has the weighted average of F/F msy across all regions. However, the suitability of F msy as a reference point has been questioned for Canadian snow crab (Choi & Zisserson 2012) given the inherent fluctuations in the productivity of the stock. An alternative strategy is to set fishing mortality at the turnover rate of fishable biomass. This has been estimated at approximately 20% of fishable biomass (assuming a longevity of five years for terminally molted male snow crabs), though this number can fluctuate, generally between 10% and 30%, as guided by the current status and outlook of the stock (Choi & Zisserson 2012, Fig. 7). While the NENS and CFA4X regions have greatly exceeded these guidelines in the past (only CFA4X is currently estimated to be above 30%), the SENS region, and hence the bulk of the fishery, has consistently remained between 10% and 30%.
1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 Exploitation Rate 16 70% 60% 50% 40% 30% 20% 10% 0% SENS CFA4X NENS Weighted Average 10% 20% 30% Figure 7. Trends in snow crab fishing exploitation rate, relative to reference points, in the ENS region (adapted from Choi & Zisserson 2012). Snow crab NFL: Moderate concern No reference points for are available for sustainable exploitation rates. As such, estimation of the effect of current exploitation levels on the stock is not possible. Snow crab SGSL: Low concern Under the relatively new (2010) precautionary approach outlined by the DFO (2012a), the fishing effort limit (here designated as F lim ) is set as the average fishing effort over the productive period during which estimates of B msy are derived. Fishing mortality has been fluctuating around F lim over the past several years, though it has been below F lim since 2011 (F 2012 is not currently known) (Fig. 9). However, if landings remain comparable to recent years (~10 kt), or even increase closer to 20 kt, the most recent stock assessment for the region indicates that the population is unlikely to drop below B usr, although there is some uncertainty associated with this (DFO 2012a). Efforts have been taken to minimize bycatch of soft-shelled crabs through a program called the soft shell monitoring protocol. This allows fishing to be shut down in regions where high densities of soft-shell crabs are observed. Fishing mortality is likely at a sustainable level, as evidenced by the upward population trends and low probability of population decrease under current fishing pressure. Nevertheless, in the absence of an explicit model, uncertainty remains in the use of the new provisional estimate of F msy (F lim = 0.401, the average exploitation rate over the 1998 2009 fishing seasons).
17 Criterion 2: Impacts on other retained and bycatch stocks Guiding principles The fishery minimizes bycatch. Seafood Watch defines bycatch as all fisheries-related mortality or injury other than the retained catch. Examples include discards, endangered or threatened species catch, pre-catch mortality, and ghost fishing. All discards, including those released alive, are considered bycatch unless there is valid scientific evidence of high post-release survival, and there is no documented evidence of negative impacts at the population level. Fishing mortality does not threaten populations or impede the ecological role of any marine life. Fishing mortality should be appropriate given each impacted species abundance and productivity, accounting for scientific uncertainty, management uncertainty, and non-fishery impacts such as habitat degradation. Summary Snow crab ENS Stock Inherent Vulnerability Leatherback Turtle Northern and Spotted Wolffish Rank High Medium Stock Status Rank (Score) Very High Concern (1) Very High Concern (1) Fishing Mortality Rank (Score) Very Low Concern (5) Very Low Concern (5) Subscore Score (subscore*discard modifier) Rank (based on subscore) 2.24 2.24 Yellow 2.24 2.24 Yellow Snow crab NFL Stock Inherent Vulnerability Northern and Spotted Wolffish Leatherback Turtle Rank Medium High Stock Status Rank (Score) Very High Concern (1) Very High Concern (1) Fishing Mortality Rank (Score) Low Concern (3.67) Very Low Concern (5) Subscore Score (subscore*discard modifier) 1.92 1.92 Red Rank (based on subscore) 2.24 2.24 Yellow
18 Snow crab SGSL Stock Inherent Vulnerability No other main species caught Rank Stock Status Rank (Score) Fishing Mortality Rank (Score) Subscore Score (subscore*discard modifier) Rank (based on subscore) 5.00 5.00 Green Synthesis Bycatch rates for finfish and invertebrates are near zero for the ENS fishery (Garforth et al. 2012). Bycatch of threatened (SARA 2012) northern (Anarhichas denticulatus) and spotted (Anarhichas minor) wolffish has been reported in the ENS region; however, bycatch rates for these species amount to approximately 0.001% of snow crab landings in the ENS and are not likely to jeopardize wolffish populations (Garforth et al. 2012). Since 2001, some encounters (less than 10) with leatherback turtles have been documented (though observers did not note any harm done to the turtle on release) (DFO 2012c; Garforth et al. 2012). The DFO estimates that the ENS snow crab trap fishery may account for 1 5 leatherback deaths per year (DFO 2012c). Due to their high vulnerability and endangered status under Schedule 1 of the Canadian Species at Risk Act (SARA), the leatherback turtle is the limiting stock for the ENS region. The NFL region for snow crab also has low rates of discard (0 20%) but accidently captures two threatened species of wolffish (northern and spotted). It has also reported incidental bycatch of endangered leatherback turtles (DFO 2007, 2010, 2010; Kulka Hood & Huntington 2007; SARA 2012). The spotted and northern wolffish are both listed as limiting stocks for the NFL region due to their threatened status, and risk of moderate overfishing. Spotted and northern wolffish are also present in other regions of Canada, but their populations are centered around the Newfoundland and Labrador shelves (Kulka et al. 2007). The SGSL has negligible levels of bycatch besides sub-legal male snow crab. The SGSL region coincides with habitat for leatherback turtles, but no interactions between the snow crab trap fishery and leatherback turtles have been reported for the region. As such, the SGSL is considered a single-species fishery (DFO 2012c). Justification of ranking Leatherback turtle Canada; ENS and NFL Factor 2.1. Inherent vulnerability: High vulnerability As per the Seafood Watch assessment criteria, all sea turtles are classified as having high vulnerability.
19 Factor 2.2. Stock status: Very high concern Leatherback turtles are listed as endangered under Schedule 1 of the SARA. Factor 2.3. Fishing mortality: Very low concern Fishing mortality stemming from the ENS snow crab fishery is low and unlikely to substantially contribute to leatherback population declines. The Atlantic Canada leatherback turtle population contains approximately 15,000 females and is cautiously considered stable (SARA 2012). Less than 10 encounters have been reported since 2001 in the ENS region. Of those encounters that were seen by observers, all turtles were released alive and no harm was seen to have occurred (DFO 2012c; Garforth et al. 2012). The DFO estimates annual mortality to leatherbacks from the ENS snow crab fishery at 1 5 deaths per year (DFO 2012c). In the NFL fishery, there have been no observer reports of leatherback interactions; however, from 2006 2010, there were two reports of leatherbacks entangled in snow crab pot gear (they were subsequently released alive) made to the Newfoundland Whale Release and Strandings Network (http://www.newfoundlandlabradorwhales.org/). These reports suggest that the encounter rate in this fishery may be larger than estimated observer data (DFO 2012c). While efforts should be taken to minimize any possibility of leatherback deaths from snow crab fishing activity, this mortality rate is unlikely to substantially contribute to the decline of leatherback turtle populations. Factor 2.4. Overall discard rate: 0-20% Discard rates for bycatch in the ENS are near zero (Garforth et al. 2012). Soft shell snow crabs made up less than 10% of landings on average throughout the region (Choi & Zisserson 2012). The overall discard rate for the ENS region is 0 20%. Northern and spotted wolffish Canada; NFL and ENS Factor 2.1. Inherent vulnerability: High vulnerability The FishBase score for wolffish is 80, representing it to be of high vulnerability to fishing pressure (Froese & Pauly 2000). Factor 2.2. Stock status: Very high concern Northern and spotted wolffish are classified as threatened under the Canadian Species at Risk Act (SARA), as the populations have undergone a decline of more than 90% since 1970 (DFO 2012).
20 Detailed rationale (optional): Factor 2.3. Fishing mortality ENS Very low concern NFL Low concern SGSL Not assessed Northern and spotted wolffish are listed as threatened species under SARA Section 1. Although total bycatch mortality is not available for the NFL fishery, overall bycatch mortality is believed to be the largest sources of anthropogenic mortality in the spotted wolffish fishery, though the relative magnitude and impact of this mortality on populations is unknown (DFO 2007, 2010; Kulka et al. 2007). However, the snow crab fishery contributes very little to overall bycatch rates for spotted and northern wolffish in the NFL and ENS regions (Kulka et al. 2007). Benthic trawls and dredges have been identified as primary threats to these species, not crab pots (SARA 2012). No bycatch limits are in place, but regulations require that, whenever possible, any captured northern or spotted wolffish be released live (Kulka et al. 2007). The impacts of this program on discard mortality and the trajectory of the northern and spotted wolffish populations are unclear (Kulka et al. 2007). Due to wolffish populations being centered around the Newfoundland and Labrador shelves (Kulka et al. 2007), the threatened status of these species, the possibility of overfishing, the likely low contribution to fishing mortality from the snow crab fishery, and the unclear impacts of bycatch mortality mitigation, fishing mortality for northern and spotted wolffish is classified as a low concern for the NFL fisheries. The ENS fisheries have reported northern and spotted wolffish bycatch rates that make up approximately 0.001% of snow crab landings. This low rate is not considered a primary contributor to wolffish mortality or expected to negatively impact wolffish populations. Factor 2.4. Overall discard rate: 0-20% Discard rates have declined markedly in the NFL region, averaging 0 20% across the NFL subregions (Dawe et al. 2011). Discard rates of soft-shell snow crab are 0 20% in the SGSL region and generally below 10% (DFO 2012a).
21 Criterion 3: Management ness Guiding principle The fishery is managed to sustain the long-term productivity of all impacted species. Management should be appropriate for the inherent resilience of affected marine life and should incorporate data sufficient to assess the affected species and manage fishing mortality to ensure little risk of depletion. Measures should be implemented and enforced to ensure that fishery mortality does not threaten the long-term productivity or ecological role of any species in the future. Summary Fishery Canada - Southern Gulf of St. Lawrence (SGSL) - Trap Canada - Newfoundland and Labrador (NFL) - Trap Canada - Eastern Nova Scotia (ENS) - Trap Management: Harvest Strategy Rank (Score) Moderate Concern (3) Management: Bycatch Criterion 3 Rank (Score) All species retained (N/A) Moderate Concern (3) Moderate Concern (3) Low Concern (4) Moderate Concern (3) Rank Score Yellow 3 Yellow 3 Green 3.46 Synthesis Snow crab fisheries in Canada are managed under an individual quota system (IQ) together with effort controls, size limits, seasons, total allowable catches (TAC), gear restrictions, and prohibitions on the capture of females and soft-shelled males. Individual fishing management areas operate the exact structures of these tools (for example, by recommending TACs and seasons). Each region conducts annual assessments of stock status based on both fisherydependent and independent data. However, the extent of available data and the ability to assess the health of individual stocks is variable among regions. Most Canadian snow crab populations are in good condition though, and management has generally demonstrated a
22 strong ability to respond to the fluctuations that often characterize snow crab populations. Throughout the Canadian snow crab fisheries, scientific recommendations stemming from assessments are used to suggest TACs to an advisory committee made up of industry stakeholders. A Federal Fisheries Minister sets the final TAC for each region throughout Canada. The mechanisms by which the advisory boards of each region suggest TACs to the Minister vary. Enforcement practices include mandatory logbooks, dock-side observers, on-board observers, and in some locations, VMS systems. Many of the Canadian snow crab fisheries show strong efforts to include stakeholders in management decisions. Factor 3.1. Management of fishing impacts on retained species Fishery Mgmt strategy and implementation Canada Eastern Nova Scotia (ENS) Trap Highly N/A Canada Newfoundland and Labrador (NFL) Trap Canada Southern Gulf of St. Lawrence (SGSL) Trap Moderately Moderately Recovery of stocks of concern N/A N/A Scientific research and monitoring Highly Highly Highly Scientific advice Moderately Moderately Moderately Enforcement Highly Highly Highly Track record Highly Moderately Highly Stakeholder inclusion Moderately Highly Moderately Snow Crab ENS: Low concern Management strategy and implementation: Highly Snow crab in the ENS region is managed using TACs, size limits, seasons, IBQs, license caps, gear restrictions, and prohibitions on the capture of females and soft-shelled male crabs. Voluntary adaptive closures are in place that shut down fishing in regions of ENS with observed high densities of soft-shell crabs. The ENS region is managed as three sub-regions, Northern-Eastern Nova Scotia (N-ENS), Southern-Eastern Nova Scotia (S-ENS), and the Crab Fishing Area 4X (CFA4X). However, these management divisions reflect management decisions more than established biological distinctions among the regions. The presence of clear regulations and
23 measures to protect the long-term integrity of the stock make management of the ENS snow crab fishery highly. Recovery of stocks of concern: N/A No stocks of concern are fished in the ENS snow crab fishery. Scientific research and monitoring: Highly Assessments of the state of the ENS snow crab fishery are conducted annually. Fishery dependent data are largely derived from mandatory logbooks that record location, effort, and landings. Size-frequency data are provided by at-sea observer coverage, representing between 5% and 10% of quota. Fishery-independent data are provided annually by a network of sample sites spanning the entire SGSL ecosystem; this accounts for the complex and shifting spatial dynamics of snow crab populations. This sampling provides information on size, sex, maturity, and abundance of the complete population. This is especially important for females and sublegal males that tend to inhabit different habitats than the commercially targeted males, resulting in under-reporting of these groups in fishery-dependent data. Additional data on availability of suitable habitat, measured by water temperature, are also collected. The data on catch, effort, abundance, recruitment, and habitat are incorporated into a stock assessment for each of the sub-regions of the ENS region (Choi & Zisserson, 2012). The presence of annual assessments incorporating both fishery-dependent and independent data makes scientific research and monitoring in the ENS snow crab fishery highly. Scientific advice: Moderately Using assessment data, scientists provide recommendations on the TAC to be set for the fishery. This process has been guided by informal harvest control rules, which are in the process of becoming legally codified. The ENS advisory board then evaluates the proposed TAC. In recent years, the TAC decided by the advisory board has largely conformed with scientific advice (DFO 2011b). The lack of clear control rules for translating scientific advice into TACs makes scientific advice in the ENS snow crab fishery moderately. Enforcement: Highly Comprehensive dockside observer monitoring is required in this fishery. On-board observer coverage is present for between 5% and 10% of fishing effort. VMS systems are in place in the S-ENS region, though not in the rest of the ENS sub-regions (Choi & Zisserson 2012). The strong presence of observers, both dockside and onboard, and VMS systems makes enforcement in the ENS snow crab fishery highly. Track record: Highly Given the complexities and natural fluctuations involved in managing snow crab, the ENS region has a strong track record. Biomass has been generally above B msy. Biomass has recovered from a dip below B msy during the early 2000s, though the relationship between this recovery and management actions is unclear, as catch and CPUE do not correlate closely with the trends in biomass (DFO 2011b). It is possible that the recovery is associated with reductions in sub-legal and soft-shelled bycatch mortality stemming from management actions including adjustments
24 to the fishing season (DFO 2011b). The strong history of maintaining biomass above B msy for most of the region s history gives the ENS snow crab fishery a highly track record. Stakeholder inclusion: Moderately Stakeholders are included in the management process through the advisory board. Since the ability of stakeholders to actively engage in the process is not entirely clear, stakeholder inclusion in the ENS snow crab fishery is classified as moderately. Snow Crab NFL: Moderate concern Management strategy and implementation: Moderately The NFL snow crabs are managed under an Integrated Fisheries Management Plan (IFMP), which seeks to maintain the long-term health and productivity of the NFL snow crab stock. As with all snow crab management areas, management tools include TACs, size limits, seasons, individual quotas, license caps, gear restrictions, and prohibitions on the capture of females and soft-shelled crabs. Management actively takes effort to ensure the efficacy of these programs, for example, by shifting fishing seasons in response to observed periods of high soft-shell crab bycatch. In addition, separate TACs are allocated to individual sub-regions within the NFL region in response to trends in CPUE, catch, and trends in abundance and recruitment suggested by fishery-independent surveys. The TAC levels have been adjusted both up and down in response to perceived levels of abundance. However, as the NFL snow crab fishery does not have clearly defined metrics for population health or control rules relating the health of the snow crab population to management regulations, it is not evident how TACs are set in response to data on the health of the fishery. In addition, CPUE data, which are commonly used as an indicator of population health when formal stock assessments are lacking, are somewhat uncertain in the NFL region, as CPUE is not standardized throughout the fishery over time. This makes it difficult to determine whether time trends in CPUE reflect changes in the population or year-to-year variation in fishing practices (Boudreau et al. 2011; Dawe et al. 2011; DFO 2010). Prohibitions on the capture of females and sub-legal males are in place to protect the future recruitment of the stock (DFO 2011a). The presence of strong fishery management regulations combined with the lack of clear metrics on which to judge their performance makes management strategy and implementation in the NFL snow crab fishery moderately. Recovery of stocks of concern: N/A The NFL snow crab is not a stock of concern. Scientific research and monitoring: Highly Rigorous scientific monitoring and research is conducted in the NFL region. Fisheryindependent trawls are conducted annually in the offshore regions of the fishery. Due to the difficulties of trawl surveys in the submarine terrain of the inshore portions of the fishery, trap monitoring is performed in these districts. These surveys provide estimates of abundance and recruitment for the fishery (DFO 2011a). The presence of extensive and regularly collected data
25 on stock abundance and other fishery performance metrics make the snow crab fishery of the NFL region highly at scientific research and monitoring. Scientific advice: Moderately Scientists use the annual monitoring process to provide recommendations for upcoming TACs. These recommendations are brought before an advisory board that determines the TAC that will be used (DFO 2011a). The role of science in setting TACs combined with the lack of clear rules and metric for doing so make scientific advice in the NFL snow crab fishery moderately. Enforcement: Highly Enforcement in the fishery is performed using logbooks, dockside observers, vessel monitoring systems (VMS), and on-board observer coverage (Dawe et al. 2011). However, VMS and onboard observer coverage is much greater in the offshore sector than the inshore regions. The strong presence of observers and VMS technology makes enforcement highly in the NFL snow crab fishery. Track record: Moderately Biomass and recruitment in the fishery have recovered from lows in prior years. However, given the cyclical dynamics of snow crab populations and the lack of stock dynamics models, it is unclear to what extent improvements in fishery population are the direct effect of management. In addition, due to the lack of reference points for the fishery, it is unclear whether the levels of biomass associated with current management practices are sustainable. However, improving trends in abundance and CPUE suggest that the stock has improved over previous years (Dawe et al. 2011; DFO 2010, 2011a). Positive trends in abundance and CPUE combined with a lack of quantitative means for judging these improvements make the track record of the NFL snow crab fishery moderately. Stakeholder inclusion: Highly Stakeholders are included in the management process through the advisory board. Managers also make efforts to include representatives from different sectors of the fishery such as fishermen and processors organizations (DFO 2010). As such, stakeholder inclusion is categorized as highly. Snow Crab SGSL: Moderate concern Management strategy and implementation: Moderately Effective management is in place in the form of TACs, seasons, size limits, gear restrictions, bycatch prevention, closed areas, sector quotas, and male-only restrictions (Choi & Zisserson 2012; Dawe et al. 2011; DFO 2012a). These management efforts have successfully regulated levels of catch and reduced bycatch of soft-shelled crabs. Management has also responded to
26 historic declines in CPUE and biomass, and the stocks have for the most part seen improvements in these metrics as a result. The SGSL is currently developing a precautionary approach to determine future fishing strategies. With this approach, TACs are recommended based on a risk assessment incorporating both current estimates of biomass and biological reference points. The exact control rules that will govern the relationship between the risk assessment and the TACs are slated to be determined through a collaborative process by 2014 (Gaudet 2012). The presence of comprehensive fishery management practices and the development of a precautionary approach, together with demonstrated improvements in the fishery following a reduction in fishing effort, make management strategy. However, the mechanism used by management to respond to trends in the population is unclear, and the sustainability of the reference points established for the fishery is somewhat uncertain. Thus, management strategy and implementation is ranked as moderately for the SGSL snow crab fishery. Recovery of stocks of concern: N/A No stocks of concern are present in this fishery. Scientific research and monitoring: Highly Extensive scientific research and monitoring is undertaken in this fishery. Yearly trawl surveys provide estimates of biomass, recruitment, and size frequencies throughout the fishery regions (DFO 2009; Weston 2011). This monitoring allows for estimates of biomass-based metrics of fishery performance for areas where trawl surveys are available. Additional fishery-dependent data such as logbooks, onboard observers, dockside monitors, and VMS systems provide fishery-dependent information such as CPUE and length-frequency distributions that can be used to compliment abundance estimates (or as a proxy for estimates of biomass state when abundance estimates are unavailable). The presence of frequent assessments of fisherydependent and independent data makes scientific research and monitoring in the SGSL snow crab fishery highly. Scientific advice: Moderately Scientists interpret and present the best available assessment data (incorporating annual trawl surveys) to guide fishery management. Fishery managers and stakeholders then take these scientific assessments into consideration during the TAC setting process. However, the specific control rules for turning scientific evidence into TAC levels remains unclear. As such, scientific advice in the SGSL fishery is classified as moderately. Enforcement: Highly Enforcement measures in the SGSL region include on-board observer programs (generally with 20 25% coverage), dock-side monitors (100% coverage), and VMS systems (100% coverage), which provide a significant amount of information to annual stock assessments and a strong deterrent to illegal fishing practices. As such, enforcement in the SGSL region is classified as highly.
27 Track record: Moderately The track record of management in the SGSL snow crab region is mixed. Crab stocks naturally fluctuate in abundance and productivity, and management must be both highly adaptive and capable of accurately monitoring the current state and outlook of the population. Scientific monitoring in the Canadian system has been able to identify declines in the stock through various combinations of biomass abundance metrics and CPUE analysis. Management has also taken steps to monitor short-term prospects for the fishery by analyzing recruitment pulses and the health of the size distribution of the fishery. However, the stock did suffer sharp declines in many regions in the early 2000s. While the stock has shown signs of recovery since, it is unclear to what extent these peaks and troughs in the population are driven by management action or environmental variability (DFO 2012a). Due to the recent recovery, potentially driven by management, but also the uncertain nature of the population declines, the SGSL snow crab fishery is considered to have a moderately track record. Stakeholder inclusion: Moderately Stakeholders are included in the management process through the advisory board with expanded opportunities for participation likely coming as part of the new integrated fisheries management plan. Since the ability of stakeholders to actively engage in the process is not entirely clear, stakeholder inclusion in the SGSL snow crab fishery is classified as moderately. Factor 3.2. Management of fishing impacts on bycatch species Fishery All species retained? Critical? Mgmt strategy and implementation Scientific research and monitoring Scientific advice Enforcement Canada Southern Gulf of St. Lawrence (SGSL) Trap Yes Canada Newfoundland and Labrador (NFL) Trap No No Canada Eastern Nova Scotia (ENS) Trap No No Moderately Moderately Highly Highly Moderately Moderately Moderately Highly Snow Crab ENS: Moderate concern
28 Management strategy and implementation: Moderately Bycatch of finfish and marine invertebrates in the ENS snow crab fishery is extremely low (nearly zero) (Choi & Zisserson 2012; Garforth et al. 2012). The limiting species for the ENS region is the leatherback turtle, due to its endangered status. For other bycatch, the ENS fishery relies on large mesh sizes, the passive nature of the gear, and top entry conical structures to limit bycatch. In addition, areas with high densities of sub-legal male crabs can be rapidly closed to fishing. Currently, no specific plans are in place to minimize leatherback turtle interactions. However, the DFO has recently completed a recovery strategy for the turtles and is in the process of developing an action plan (Garforth et al. 2012). Given the lack of clear bycatch regulations combined with the limited nature of bycatch in the fishery and the recently completed recovery strategy for loggerhead turtles, management and implementation of bycatch strategy in the ENS snow crab fishery are classified as moderately. Scientific research and monitoring: Highly Extensive observer coverage has allowed for highly detailed estimations of bycatch rates in the ENS region (Garforth et al. 2012). As such, scientific research and monitoring of bycatch in the ENS snow crab fishery is classified as highly. Scientific advice: Moderately See Factor 3.1. Enforcement: Highly See Factor 3.1. Snow Crab NFL: Moderate concern Management strategy and implementation: Moderately No direct bycatch control measures are in place in the NFL snow crab fishery. However, a recovery plan is in place that seeks to understand the population dynamics and future prospects of the wolffish species caught as bycatch in the NFL snow crab fishery. In addition, this document sets strategies for minimizing human impacts on wolffish populations. These include a requirement that, whenever possible, all wolffish caught as bycatch in the snow crab fishery must be returned alive to the water (DFO 2011a; Kulka et al. 2007). As such, management of bycatch is classified as moderately. Scientific research and monitoring: Highly Observer coverage in the fishery is near 20%, allowing for adequate monitoring of bycatch rates. Efforts are underway to better understand the state of wolffish populations and the effects of fishing on the stock. However, limited information is available to date, although it
29 appears likely that current bycatch levels are not limiting recovery of the stock (Kulka et al. 2007). Due to the strong bycatch data collection and observer efforts in place for this fishery, scientific research and monitoring is classified as highly. Scientific advice: Moderately See Factor 3.1. Enforcement: Moderately See Factor 3.1. Snow Crab SGSL: N/A (All species retained) No significant bycatch exists in the SGSL region (DFO 2012a). As such, the SGSL snow crab fishery is classified as a single-species fishery.
30 Criterion 4: Impacts on the habitat and ecosystem Guiding principles The fishery is conducted such that impacts on the seafloor are minimized and the ecological and functional roles of seafloor habitats are maintained. Fishing activities should not seriously reduce ecosystem services provided by any fished species or result in harmful changes such as trophic cascades, phase shifts, or reduction of genetic diversity. Summary Fishery Canada - Southern Gulf of St. Lawrence (SGSL) - Trap Canada - Newfoundland and Labrador (NFL) - Trap Canada - Eastern Nova Scotia (ENS) - Trap Impact of gear on the substrate Mitigation of gear impacts Rank (Score) Rank (Score) Rank (Score) Low Concern (3) Low Concern (3) Low Concern (3) Minimal mitigation (0.25) Minimal mitigation (0.25) Minimal mitigation (0.25) EBFM Criterion 4 Moderate Concern (3) Moderate Concern (3) Moderate Concern (3) Rank Score Yellow 3.12 Yellow 3.12 Yellow 3.12 Synthesis All Canadian snow crab fisheries use traps on a sandy or muddy bottom, allowing for some impacts on marine habitats but likely having no significant impacts. Limited direct efforts are in place to reduce the habitat impacts of the fishery. Little action is evident to reduce effort throughout the fishery, and in some areas effort has been allowed to increase. Area closures are used to protect regions with high densities of sub-legal and molting males, which also serve to prevent some habitat damage. The NFL region fishery has also closed portions of the fishery in order to protect the overall integrity of the stock. No clear ecosystem-based management strategies are currently in use for snow crab. However, across the Canadian snow crab fisheries, strategies are being developed through a broader integrated management approach that will foster opportunities to implement ecosystem-based management strategies. Justification
31 Factor 4.1. Impact of the fishing gear on the substrate: Low concern The ENS, NFL, and SGSL snow crab fisheries occur on soft silty bottoms where adult males live (Choi & Zisserson 2012). Chuenpagdee et al. (2003) lists the potential habitat impact of traps as moderate, but the impacts on soft bottoms are considered a low concern according to Seafood Watch. Factor 4.2. Modifying factor: Mitigation of fishing gear impacts Snow crab ENS: Minimal mitigation Fishing effort is controlled through TAC and IBQs. However, no clear intentions to reduce fishing effort are in place, and TACs have trended upward recently. No habitat protection zones are in place specifically for the crab fishery, but closures of fishing grounds with high densities of soft-shelled males are likely to provide some ecosystem protection from fishing pressure (Choi & Zisserson 2012). In addition, MPAs are in place to protect sensitive habitats (including the Gully Marine Protected Area and the Lophelia Coral Conservation Area) in the region from fishing pressure (Fig. 8). Since fishing effort is ly controlled, but only a small amount critical habitat is protected, mitigation of fishing gear impacts is listed as minimal. Detailed rationale (optional):
32 Figure 8. Map of protected areas in the ENS region (Breeze, Horsman, Federal-Provincial Eastern Scotian Shelf Integrated Management (ESSIM). Planning Office & Canada Dept. of Fisheries and Oceans. Maritimes Region. Oceans and Coastal Management Division 2005). Snow crab NFL: Minimal mitigation The NFL snow crab fishery has some measures in place to mitigate the effects of fishing on habitat. Numerous Snow Crab Conservation Exclusion Zones (SCEZs) have been established throughout the fishery through a collaborative process with fishery stakeholders, though it is unclear what portion of the total fishing grounds these SCEZs represent (a rough estimate suggests they total near 10 km 2 ) (DFO 2010). Two large (8610 km 2 ) no trawl zones with high
33 abundances of juvenile snow crab are also enforced off the coast of southern Labrador (Mullowney, Morris, Dawe & Skanes 2012) (Fig. 9). In addition, to minimize ghost fishing and the potential impacts of lost gear moving across the seabed, damaging habitat in the process, all lost pots must be reported to the DFO within 48 hours of the loss (DFO 2010). By providing protection to some crucial habitats and reducing gear impacts, while not actively reducing effort or protecting more than 20% of all representative habitats, the NFL snow crab fishery is classified as having minimal mitigation of gear impacts. Detailed rationale (optional): Figure 9. Map of no-trawl zones near southern Labrador for the NFL region (Mullowney et al. 2012). Snow crab SGSL: Minimal mitigation Fishing effort is ly controlled through license caps and trap allocations. It is unclear whether active reductions in effort are taking place, even though TACs increased from 2010 to 2011, indicating that reductions in total fishing mortality are not occurring. The SGSL has two buffer zones where no crab fishing is permitted, though they do not cover a substantial portion of the fishing grounds (Fig. 10). In addition, portions of the fishery with fractions of soft-
34 shelled males in the catch exceeding 20% are closed to fishing, thus providing some mitigation from the habitat impacts of crab pots (DFO 2012a). Given that fishing effort is ly controlled and some critical habitats are protected, in spite of the fact that no targeted efforts are in place to further reduce physical gear impacts on the substrate, mitigation of fishing gear impacts is listed as minimal. Detailed rationale (optional): Figure 10. Map of snow crab management areas in the SGSL region. Areas B and C are buffer zones where no crab fishing is permitted (DFO 2012a). 2 Factor 4.3. Ecosystem and food web considerations Snow crab ENS: Moderate concern No exceptional species are captured in the ENS snow crab fishery. While management takes into account broader environmental variables in terms of their relative impact on the snow crab population, there are no clear efforts to place the health of the snow crab population in the broader context of the ENS ecosystem. Bycatch and ghost fishing reduction measures, together