LEMON SOLE UK. Microstomus kitt. Sometimes known as Lemon Dab, Mary Sole, Sweet Fluke SUMMARY

LEMON SOLE UK Microstomus kitt Sometimes known as Lemon Dab, Mary Sole, Sweet Fluke SUMMARY Lemon Sole is a medium sized flatfish found along the northern European coast on coarse gravelly and rocky bottoms at depths ranging from 40 to 200 m. They mature relatively quickly and live up to nine years. Lemon Sole appear to be at medium levels of abundance, although information about population size is somewhat limited. In the United Kingdom, they are generally taken by beam and otter trawls as bycatch in mixed whitefish fisheries that target cod, haddock, and whiting. Bottom trawls can damage the seafloor. Management of Lemon Sole in the United Kingdom is limited and bycatch levels are mostly unknown. Criterion Points Final Score Color Life History 2.75 2.40-4.00 Abundance 2.25 1.60-2.39 Habitat Quality and Fishing Gear Impacts 0.50 0.00-1.59 Management 1.00 Bycatch 2.25 Final Score 1.75 Color

LIFE HISTORY Core Points (only one selection allowed) If a value for intrinsic rate of increase ( r ) is known, assign the score below based on this value. If no r-value is available, assign the score below for the correct age at 50% maturity for females if specified, or for the correct value of growth rate ('k'). If no estimates of r, age at 50% maturity, or k are available, assign the score below based on maximum age. 1.00 Intrinsic rate of increase <0.05; OR age at 50% maturity >10 years; OR growth rate <0.15; OR maximum age >30 years. 2.00 Intrinsic rate of increase = 0.05-0.15; OR age at 50% maturity = 5-10 years; OR a growth rate = 0.16 0.30; OR maximum age = 11-30 years. 3.00 Intrinsic rate of increase >0.16; OR age at 50% maturity = 1-5 years; OR growth rate >0.30; OR maximum age <11 years. Lemon Sole is a medium sized flatfish that becomes sexually mature in three to four years for males and four to six years for females (FishOnline 2011). Size at maturity for both sexes occurs between 20 and 30 cm, and in the North Sea all fish above 27 cm are considered mature (FishOnline 2011). Females grow significantly quicker than males, but the maximum age for both sexes is about 9 years (Mahe et al. 2010). Lemon Sole typically grow to 65 centimeters (26 inches) in length and weigh around 3 kilograms (6.6 lbs) (Picton and Morrow 2005). Growth rate (K) was estimated at 0.177 for females and 0.173 for males (Mahe et al. 2010). Overall, we awarded a score of three because Lemon Sole mature quickly and are relatively short lived. Points of Adjustment (multiple selections allowed) -0.25 Species has special behaviors that make it especially vulnerable to fishing pressure (e.g., spawning aggregations; site fidelity; segregation by sex; migratory bottlenecks; unusual attraction to gear; etc.). Lemon Sole have been shown to demonstrate a high site fidelity to particular areas. For example, 47% of 1,098 adult Lemon Sole tagged in the English Channel in April and May 1970 were recaptured at their original capture location in 1974 (Jennings et al. 1993). Hinz et al. (2006) also found that Lemon Sole areas of consistently high abundance were grouped relatively close together and restricted to a very small number of locations in deep water ranging from 28 to 50 m with a narrow range of salinity and low water temperatures.

-0.25 Species has a strategy for sexual development that makes it especially vulnerable to fishing pressure (e.g., age at 50% maturity >20 years; sequential hermaphrodites; extremely low fecundity). Lemon Sole spawn from April to August (FishOnline 2011), but specific spawning sites have not yet been fully identified (Seafish 2011). In the UK, Lemon Sole spawn in the northwest area of the North Sea in April and spawning spreads north and east throughout the season (ICES 2011). Reliable estimates of fecundity are unknown, so no points were subtracted. -0.25 Species has a small or restricted range (e.g., endemism; numerous evolutionarily significant units; restricted to one coastline; e.g., American lobster; striped bass; endemic reef fishes). Lemon Sole is widely distributed in northern European waters from the White Sea and Iceland (Albert et al. 1998) to the Bay of Biscay (Mahe et al. 2010). In the UK, Lemon Sole are frequently found in the North Sea and around the British Isles, especially the Celtic Sea, western English Channel, and Irish Sea (Pawson 1995; ICES 2007). These flatfish can be found in deep offshore waters ranging from 40 to 200 m deep over coarse gravelly and rocky substrate (Bennet 1965; Rae 1965; Jennings et al. 1993; Hinz et al. 2006; ICES 2007; Mahe et al. 2010). We consider this a medium range, so no points were removed. -0.25 Species exhibits high natural population variability driven by broad-scale environmental change (e.g. El Nino; decadal oscillations). +0.25 Species does not have special behaviors that increase ease or population consequences of capture OR has special behaviors that make it less vulnerable to fishing pressure (e.g., species is widely dispersed during spawning). +0.25 Species has a strategy for sexual development that makes it especially resilient to fishing pressure (e.g., age at 50% maturity <1 year; extremely high fecundity). +0.25 Species is distributed over a very wide range (e.g., throughout an entire hemisphere or ocean basin; e.g., swordfish; tuna; Patagonian toothfish). +0.25 Species does not exhibit high natural population variability driven by broad-scale environmental change (e.g., El Nino; decadal oscillations). 2.75 Points for Life History

ABUNDANCE Core Points (only one selection allowed) Compared to natural or un-fished level, the species population is: 1.00 Low: Abundance or biomass is <75% of BMSY or similar proxy (e.g., spawning potential ratio). 2.00 Medium: Abundance or biomass is 75-125% of BMSY or similar proxy; OR population is approaching or recovering from an overfished condition; OR adequate information on abundance or biomass is not available. In Europe, annual landings of Lemon Sole increased from approximately 8,000 tons in the early 1970s to a peak of 14,504 tons in 1984. Landings subsequently decreased before peaking again at 15,506 tons in 2001. Since 2001, however, annual landings have decreased to approximately 10,000 tons (ICES 2007). In the UK, catch levels indicate that Lemon Sole abundance has declined in the Irish and Celtic Sea since 2003, has been variable in the English Channel, and has increased slightly in the North Sea (Seafish 2011). English and Welsh beam trawlers had relatively high Lemon Sole CPUE in the early to mid-1980s of about 4 kg/h, but this declined in most areas to approximately 1 kg/h by 1990 (ICES 2007). In other areas, CPUE indices increased slightly during the 90 s. Unlike beam trawlers, otter trawlers have less consistent CPUE values for all areas surveyed (ICES 2007). This likely occurs because otter trawlers target a variety of species, whereas beam trawlers primarily target Lemon Sole resulting in more constant effort. Catches in the UK Scottish fleet peaked in 1991 at 3,121 tons, but then declined to a low of 644 tons in 2004 (ICES 2007). Although there is insufficient data to fully assess population status (ICES 2007), and landings can vary over time and fishing locations (FishOnline 2011), abundance of Lemon Sole appears to be at medium levels. 3.00 High: Abundance or biomass is >125% of BMSY or similar proxy. Points of Adjustment (multiple selections allowed) -0.25 The population is declining over a generational time scale (as indicated by biomass estimates or standardized CPUE). Landing data from several locations in the UK seem to suggest a declining long-term trend (ICES 2011). However, CPUE data is variable in both time and space and it is unclear if the population, as a whole, is declining over a generational time scale, so no points were removed.

-0.25 Age, size or sex distribution is skewed relative to the natural condition (e.g., truncated size/age structure or anomalous sex distribution). Fine mesh beam trawl surveys conducted from 1984 to 1991 failed to find juveniles less than 18 cm, indicating distinct habitat use at different life stages. A review of juvenile fish surveys showed that Lemon Sole less than 15 cm were rarely caught, suggesting that young individuals may occupy rocky areas from 50-100 m deep that are not accessible to common sampling methods (Jennings et al. 1993). However, it is unclear if age, size, or sex distributions of Lemon Sole in the UK are actually skewed relative to the natural condition, so no points were subtracted. -0.25 Species is listed as "overfished" OR species is listed as "depleted", "endangered", or "threatened" by recognized national or international bodies. Although catch levels from some locations in the UK suggest a declining long-term trend (ICES 2011), Lemon Sole is not listed as overfished or threatened, so no points were removed. -0.25 Current levels of abundance are likely to jeopardize the availability of food for other species or cause substantial change in the structure of the associated food web. +0.25 The population is increasing over a generational time scale (as indicated by biomass estimates or standardized CPUE). +0.25 Age, size or sex distribution is functionally normal. +0.25 Species is close to virgin biomass. +0.25 Current levels of abundance provide adequate food for other predators or are not known to affect the structure of the associated food web. Lemon Sole feed on crustaceans, mollusks, and worms (Seafish 2011). Although their population status is unclear, recent catch levels suggest that current levels of Lemon Sole abundance likely provide adequate food for large predators such as grey and harbor seals (Härkönen 1987; Hammond et al. 1994; Tollit and Thompson 1996). 2.25 Points for Abundance

HABITAT QUALITY AND FISHING GEAR IMPACTS Core Points (only one selection allowed) Select the option that most accurately describes the effect of the fishing method upon the habitat that it affects 1.00 The fishing method causes great damage to physical and biogenic habitats (e.g., cyanide; blasting; bottom trawling; dredging). Lemon Sole are caught throughout the waters of the United Kingdom, but catch methods can vary slightly between fishing regions and season. Landings are made by beam and otter trawlers during the spring and summer, whereas landings by the Scottish fleet are made by demersal pair trawl, light trawl, and seine (ICES 2007). The main catch by weight occurs when Lemon Sole are taken by beam and otter trawls as bycatch in mixed demersal whitefish fisheries that target cod, haddock, and whiting (ICES 2011; Seafish 2011). Overall, we awarded a score of one because bottom trawls can damage the seafloor. 2.00 The fishing method does moderate damage to physical and biogenic habitats (e.g., bottom gillnets; traps and pots; bottom longlines). 3.00 The fishing method does little damage to physical or biogenic habitats (e.g., hand picking; hand raking; hook and line; pelagic long lines; mid-water trawl or gillnet; purse seines). Points of Adjustment (multiple selections allowed) -0.25 Habitat for this species is so compromised from non-fishery impacts that the ability of the habitat to support this species is substantially reduced (e.g., dams; pollution; coastal development). -0.25 Critical habitat areas (e.g., spawning areas) for this species are not protected by management using time/area closures, marine reserves, etc. To our knowledge, critical Lemon Sole habitat is not protected in the UK. -0.25 No efforts are being made to minimize damage from existing gear types OR new or modified gear is increasing habitat damage (e.g., fitting trawls with roller rigs or rockhopping gear; more robust gear for deep-sea fisheries).

-0.25 If gear impacts are substantial, resilience of affected habitats is very slow (e.g., deep water corals; rocky bottoms). In the UK, Lemon Sole are found predominantly on coarse gravelly and rocky bottoms. These habitats take much longer to recover from gear impacts (Kaiser et al. 2006). Additionally, these coarser sediment types that Lemon Sole predominantly utilize are often also used as fishing grounds for scallops in the UK, and scallop dredging results in severe impacts on benthic habitats (Kaiser et al. 2006). +0.25 Habitat for this species remains robust and viable and is capable of supporting this species. In the UK, Lemon Sole are found primarily in deep offshore waters over coarse gravelly and rocky substrates. These bottom habitats are easily damaged from bottom trawls and may take a long time to recover, so no points were added +0.25 Critical habitat areas (e.g., spawning areas) for this species are protected by management using time/area closures, marine reserves, etc. +0.25 Gear innovations are being implemented over a majority of the fishing area to minimize damage from gear types OR no innovations necessary because gear effects are minimal. In the UK, bycatch reduction devices are sometimes used in mixed species bottom trawl fisheries to reduce the capture of juvenile fishes, primarily cod (WWF Scotland 2009). Other regulations include the control of mesh size and attachments to cod-ends (Scottish Government 2011). However, no points were added because these management measures are intended to protect cod and not Lemon Sole. +0.25 If gear impacts are substantial, resilience of affected habitats is fast (e.g., mud or sandy bottoms) OR gear effects are minimal. 0.50 Points for Habitat Quality and Fishing Gear Impacts

MANAGEMENT Core Points (only one selection allowed) Select the option that most accurately describes the current management of the fisheries of this species. 1.00 Regulations are ineffective (e.g., illegal fishing or overfishing is occurring) OR the fishery is unregulated (i.e., no control rules are in effect). The majority of Lemon Sole in the UK are landed as bycatch in mixed demersal whitefish fisheries that primarily target cod, haddock, and whiting (ICES 2011; Seafish 2011). Lemon Sole management in the UK is largely unregulated (Mahe et al. 2010; Seafish 2011). The one exception is in Cornish waters where the taking of Lemon Sole below 25 cm, the size at which the species becomes mature, is prohibited (FishOnline 2011). Additionally, although there is no minimum landing size for Lemon Sole with the exception of Cornish waters, and vessels may land individuals of any size, the European Commission mandates that Lemon Sole can only be sold commercially when they exceed 180 g and 25 cm (Seafish 2011). Although few specific management plans exist, Total Allowable Catch levels (TAC s) are implemented in some regions (Seafish 2011). For example, in the North Sea and Norweigan waters there is a joint TAC for Lemon Sole and Witch Flounder (ICES 2011). This was set at 6,175 tons in 2006/7, 6,793 tons in 2008/9, 6,521 tons in 2010, and 6,391 tons for 2011. The UK controls over 60% of the total TAC and in 2007, the European Union TAC for Lemon Sole was 6,175 tons, of which 3,716 tons were taken by UK fishers. The UK TAC for both 2008 and 2009 was 6,793 tons (UK Parliament 2009; MMO 2011). In contrast, there are no TAC s for the Celtic Sea, western Irish Sea, and western English Channel. We awarded a score of one because Lemon Sole are largely unmanaged in European Union waters and there are few specific management plans in place. The exceptions include two fishing grounds in the UK that have a mixed precautionary TAC, and in Cornwall where there is a minimum landing size of 25 cm (FishOnline 2011). 2.00 Management measures are in place over a major portion over the species' range but implementation has not met conservation goals OR management measures are in place but have not been in place long enough to determine if they are likely to achieve conservation and sustainability goals. 3.00 Substantial management measures are in place over a large portion of the species range and have demonstrated success in achieving conservation and sustainability goals.

Points of Adjustment (multiple selections allowed) -0.25 There is inadequate scientific monitoring of stock status, catch or fishing effort. In the UK, there is inadequate data to fully assess Lemon Sole population status (ICES 2007) and there is very little known about their biology, ecology, and abundance (Mahe et al. 2010). However, there is sufficient monitoring of catch levels and fishing effort, so no points were removed. -0.25 Management does not explicitly address fishery effects on habitat, food webs, and ecosystems. Lemon Sole feed on crustaceans, mollusks, and worms (Seafish 2011), while being an important food source for harbor seals in the North Sea (Phoca vitulina) (Härkönen 1987) as well as grey and harbor seals in Scotland (Hammond et al. 1994; Tollit and Thompson 1996). Nevertheless, the minimal management aimed at Lemon Sole does not address fishery impacts on habitat, food webs, or ecosystems. -0.25 This species is overfished and no recovery plan or an ineffective recovery plan is in place. -0.25 Management has failed to reduce excess capacity in this fishery or implements subsidies that result in excess capacity in this fishery. +0.25 There is adequate scientific monitoring, analysis and interpretation of stock status, catch and fishing effort. +0.25 Management explicitly and effectively addresses fishery effects on habitat, food webs, and ecosystems. +0.25 This species is overfished and there is a recovery plan (including benchmarks, timetables and methods to evaluate success) in place that is showing signs of success OR recovery plan is not needed. Although Lemon Sole in the UK may be exhibiting a long-term decline in some areas (ICES 2011), there is insufficient evidence to suggest that a recovery plan is currently needed. +0.25 Management has taken action to control excess capacity or reduce subsidies that result in excess capacity OR no measures are necessary because fishery is not overcapitalized. 1.00 Points for Management

BYCATCH Core Points (only one selection allowed) Select the option that most accurately describes the current level of bycatch and the consequences that result from fishing this species. The term, "bycatch" used in this document excludes incidental catch of a species for which an adequate management framework exists. The terms, "endangered, threatened, or protected," used in this document refer to species status that is determined by national legislation such as the U.S. Endangered Species Act, the U.S. Marine Mammal Protection Act (or another nation's equivalent), the IUCN Red List, or a credible scientific body such as the American Fisheries Society. 1.00 Bycatch in this fishery is high (>100% of targeted landings), OR regularly includes a "threatened, endangered or protected species." 2.00 Bycatch in this fishery is moderate (10-99% of targeted landings) AND does not regularly include "threatened, endangered or protected species" OR level of bycatch is unknown. In the UK, the majority of Lemon Sole are caught in mixed demersal whitefish fisheries that target cod, haddock, and whiting (ICES 2011), with quotas independently set for each of these three targeted species (WWF Scotland 2009). These fisheries often catch large amounts of discards, or juvenile fishes that are too small to sell and need to be thrown back (Scottish Government 2011). We awarded a score of two because bycatch levels of juvenile Lemon Sole as well as other species in these mixed demersal whitefish fisheries are unknown. 3.00 Bycatch in this fishery is low (<10% of targeted landings) and does not regularly include "threatened, endangered or protected species." Points of Adjustment (multiple selections allowed) -0.25 Bycatch in this fishery is a contributing factor to the decline of "threatened, endangered, or protected species" and no effective measures are being taken to reduce it. -0.25 Bycatch of targeted or non-targeted species (e.g., undersize individuals) in this fishery is high and no measures are being taken to reduce it. -0.25 Bycatch of this species (e.g., undersize individuals) in other fisheries is high OR bycatch of this species in other fisheries inhibits its recovery, and no measures are being taken to reduce it. In the UK, Lemon Sole are most frequently taken as bycatch in mixed trawl fisheries that target demersal whitefish species such as cod, haddock, and whiting (Henk et al. 1996;

WWF Scotland 2009). However, actual bycatch levels are unknown, so no points were removed. -0.25 The continued removal of the bycatch species contributes to its decline. The removal of benthic organisms, including immature fishes, from bottom trawls may impact some species. However, actual bycatch levels in UK bottom trawl fisheries are unknown, so no points were removed. +0.25 Measures taken over a major portion of the species range have been shown to reduce bycatch of "threatened, endangered, or protected species" or bycatch rates are no longer deemed to affect the abundance of the "protected" bycatch species OR no measures needed because fishery is highly selective (e.g., harpoon; spear). To our knowledge, bycatch of threatened, endangered, or protected species does not seem to be an issue in UK bottom trawl fisheries. +0.25 There is bycatch of targeted (e.g., undersize individuals) or non-targeted species in this fishery and measures (e.g., gear modifications) have been implemented that have been shown to reduce bycatch over a large portion of the species range OR no measures are needed because fishery is highly selective (e.g., harpoon; spear). In the UK, gear modifications are sometimes used in bottom trawl fisheries to reduce discards of juvenile fishes. Other regulations include the control of mesh size and attachments to cod-ends (Scottish Government 2011). Additionally, European Union regulations and the Cod Recovery Act mandate the use of selective gear by fisheries targeting whitefish in the cod recovery zone (WWF Scotland 2009). However, no points were added because these gear modifications are designed to reduce or avoid cod, and it is unclear if they offer any protection to Lemon Sole. +0.25 Bycatch of this species in other fisheries is low OR bycatch of this species in other fisheries inhibits its recovery, but effective measures are being taken to reduce it over a large portion of the range. +0.25 The continued removal of the bycatch species in the targeted fishery has had or will likely have little or no impact on populations of the bycatch species OR there are no significant bycatch concerns because the fishery is highly selective (e.g., harpoon; spear). 2.25 Points for Bycatch

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