COMMON DAB ICELAND. Limanda limanda. Sometimes known as Dab, Sand Dab SUMMARY

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1 COMMON DAB ICELAND Limanda limanda Sometimes known as Dab, Sand Dab SUMMARY Common Dab is a small species of flatfish that grows fast and becomes sexually mature within four years. Dab is found on shallow, sandy bottoms throughout the Northeast Atlantic, and in Iceland they are found all around the country. Common Dab is mostly caught with Danish seines in Icelandic waters, which cause little to moderate damage to the seafloor. In Iceland, catches peaked at 8,000 tons in the mid 1990s but have declined sharply over the past decade to under 1,000 tons, indicating low abundance. In response to this decline, management has restricted the amount of Common Dab that can be landed so that the total commercial catch does not exceed the number of Dab that are taken as bycatch in other fisheries. Criterion Points Final Score Color Life History Abundance Habitat Quality and Fishing Gear Impacts Management 2.25 Bycatch 2.25 Final Score 2.20 Color

2 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 Intrinsic rate of increase <0.05; OR age at 50% maturity >10 years; OR growth rate <0.15; OR maximum age >30 years Intrinsic rate of increase = ; OR age at 50% maturity = 5-10 years; OR a growth rate = ; OR maximum age = years Intrinsic rate of increase >0.16; OR age at 50% maturity = 1-5 years; OR growth rate >0.30; OR maximum age <11 years. Dab is relatively small compared to other commercially caught Icelandic flatfish species, reaching between 20 and 30 cm in length. In Iceland, the largest recorded individual was 48 cm (Jónsson 1992), which is also the world record (Valtysson 1998). Females grow faster than males and live longer, sometimes as long as 14 years. Sexual maturity is attained in 2 to 3 years for males and 3 to 4 years for females (IIMFA 2010a). Their growth is fast before reaching maturity, but slows after becoming mature. Published growth rates (k) for Dab range from 0.3 to 0.6 (Fishbase 2010), although these values should be interpreted cautiously as they are not specific to Iceland. Overall, we awarded a score of 3 because Dab is relatively fast growing and matures early. Points of Adjustment (multiple selections allowed) 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.) 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) 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). Dab has a relatively moderate range, with the species restricted to the eastern North Atlantic. In Iceland, Dab is more abundant in the warmer waters along the south and west

3 coasts but can be found all around the country (IIMFA 2010a). Overall, Dab have a medium distribution range so no points were subtracted Species exhibits high natural population variability driven by broad-scale environmental change (e.g. El Nino; decadal oscillations). Water temperature during Dab spawning has been demonstrated to affect their egg mortality (Lange and Greve 1997; Henderson 1998). This suggests that, if mortality during the egg stage is high, changes in Dab recruitment and distribution could impact the population. However, it is unclear if changes in water temperature have affected Dab populations in Iceland, so no points were subtracted 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). Dab live in very shallow water and this makes them less vulnerable to most types of commercial fishing gear, except Danish seines. For example, no bottom trawls are allowed in areas occupied by Dab (anonymous 2011) 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). Dab likely spawn all around Iceland, starting from mid April off the southeast coast and spreading clockwise around the country until about the middle of June (IIMFA 2010a). They exhibit moderate fecundity (~33,000 to 280,000 eggs per female per year depending on size of the female (Jastania 1995) and relatively fast growth rates, but not to the extent that these life history characteristics would make them especially resilient to heavy fishing pressures. Therefore, no points were added Species is distributed over a very wide range (e.g., throughout an entire hemisphere or ocean basin; e.g., swordfish; tuna; Patagonian toothfish) Species does not exhibit high natural population variability driven by broad-scale environmental change (e.g., El Nino; decadal oscillations) Points for Life History

4 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). In Iceland, English boats reportedly landed about 500 to 1,000 tons of Dab per year until World War II. After the war, catches dropped for English and Belgian trawlers (Hjörleifsson et al. 1998). In 1952, the Exclusive Economic Zone (EEZ) was extended to four miles and this greatly limited the ability of English and Icelandic trawlers to catch Dab because of their preference for very shallow water (the majority of their preferred habitat fell within the four mile EEZ). Until the early to mid 1980s, Dab were mostly landed as bycatch in Icelandic Danish seine fisheries due to their low commercial value, and in many cases Dab may have been either discarded or reported along with other flatfish species (Valtysson 1998). Dab were not commercially landed in large numbers in Iceland until 1984, when catches increased considerably after quotas were established for other more valuable species and the main fishing grounds in Faxaflói Bay were opened to Danish seine fishing. From 1987 to 1997, Dab landings increased from 1,200 to 8,000 tons in Iceland, peaking in the mid 1990s at 8,000 tons, but have since declined substantially to under 1,000 tons (IIMFA 2010a). In 2009, Iceland landed only 900 tons of Dab. Catch Per Unit Effort (CPUE) has declined considerably over the past decade and is now at historically low levels (IIMFA 2010a). Declines have been especially apparent in the southern area of the country during the past decade (Björnsson et al. 2007). We awarded a score of 1 here because CPUE in Iceland is historically low and landings have declined sharply and consistently over the past decade Medium: Abundance or biomass is % 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 High: Abundance or biomass is >125% of BMSY or similar proxy. Points of Adjustment (multiple selections allowed) The population is declining over a generational time scale (as indicated by biomass estimates or standardized CPUE). Dab landings peaked in the mid 1990s at 8,000 tons, but have since dropped to under 1,000 tons (IIMFA 2010a). CPUE is now historically low (IIMFA 2010a), indicating a substantial decline over the past 15+ years.

5 -0.25 Age, size or sex distribution is skewed relative to the natural condition (e.g., truncated size/age structure or anomalous sex distribution). It is unclear if age, size, or sex distributions of Icelandic Dab are currently skewed, so no points were subtracted Species is listed as "overfished" OR species is listed as "depleted", "endangered", or "threatened" by recognized national or international bodies. Although the Dab population in Iceland has been declining considerably over the past decade, to our knowledge the species is currently not listed as overfished or threatened/endangered. Thus, no points were subtracted 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. Dab are opportunistic feeders that can handle large food items (Óskarsson 1997). They feed on various benthic invertebrates as well as sandeels and capelin (IIMFA 2010a), and also provide a food source for seals (Prime and Hammond 1990; Hauksson and Bogason 1995). In Iceland, populations have declined and may not be high enough to maintain their role in the marine ecosystem. However, no points were subtracted because Dab play a relatively small role in the ecosystem and it is unclear if their decline has had (or will have) an appreciable impact on the marine environment surrounding Iceland The population is increasing over a generational time scale (as indicated by biomass estimates or standardized CPUE) Age, size or sex distribution is functionally normal Species is close to virgin biomass Current levels of abundance provide adequate food for other predators or are not known to affect the structure of the associated food web Points for Abundance

6 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) The fishing method does moderate damage to physical and biogenic habitats (e.g., bottom gillnets; traps and pots; bottom longlines). In Iceland, almost all commercially caught Dab are taken with Danish seine nets. Danish seines resemble a trawl in appearance but are operated differently; most notably they do not require trawl doors or otter boards to keep the seine net open. Unlike trawls, Danish seines require comparatively calmer waters and lower currents, less power to operate, and they can be used on much smaller boats (IIMFA 2010b). In Iceland, Danish seines are used primarily to target flatfishes, but these nets also catch Cod and Haddock. Approximately 40% of all commercial flatfish species are landed with Danish seines, including almost all of the Dab landings in Iceland. Danish seines are used throughout Icelandic waters, but the majority of fishing effort occurs in shallow waters (40-60 m) on the western and southwestern parts of the country. Minimum mesh size ranges from mm depending on the area. The fishing vessels utilizing Danish seines are similar in size to longline and gillnet boats, and many fishers switch gears seasonally (IIMFA 2010b). Danish Seines are comparatively much smaller than traditional bottom trawls and consequently less damaging to the environment. For example, a recent study examined benthic communities in areas open to Danish Seine fishing with a comparable area where no fishing was allowed. The study found no significant differences in the species composition between areas, although the abundance of benthic organisms tended to be greater within the closed area than in the fished area (Danish Seine Report 2010). Nevertheless, this topic is currently hotly debated in Iceland and more studies are needed (anonymous 2011), so we awarded a score of 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) 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).

7 -0.25 Critical habitat areas (e.g., spawning areas) for this species are not protected by management using time/area closures, marine reserves, etc. In Iceland, there are no specific measures in place to protect Dab. However, there are specific measures in place to protect European Plaice (which include area closures on spawning grounds) and there is a wide distribution overlap between these species, especially young Dab and European Plaice (anonymous 2011). Therefore, no points were subtracted 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) If gear impacts are substantial, resilience of affected habitats is very slow (e.g., deep water corals; rocky bottoms) Habitat for this species remains robust and viable and is capable of supporting this species. In Iceland, Dab is common in shallow water (0 to 40 m) on sand or muddy bottoms, and rarely is found in depths below 120 m (Sæmundsson 1926, Jónsson 1966). These benthic habitats are more resilient to bottom damage from fishing gear and likely remain healthy enough to support populations of Dab in Icelandic waters Critical habitat areas (e.g., spawning areas) for this species are protected by management using time/area closures, marine reserves, etc 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. A recent study determined that there were no significant differences in the species composition between areas fished with Danish seines and comparable areas left alone, although the abundance of benthic organisms tended to be greater within the closed areas than in the fished areas (Danish Seine Report 2010). These results suggest that the impacts of Danish seines are likely little to moderate. However, we chose not to add points because this is currently a hotly debated topic in Iceland and further studies are necessary (anonymous 2011) If gear impacts are substantial, resilience of affected habitats is fast (e.g., mud or sandy bottoms) OR gear effects are minimal. Dab prefer muddy or sandy bottoms (IIMFA 2010a), which are more resilient to bottom gear when compared with hard or rocky bottoms Points for Habitat Quality and Fishing Gear Impacts

8 MANAGEMENT Core Points (only one selection allowed) Select the option that most accurately describes the current management of the fisheries of this species Regulations are ineffective (e.g., illegal fishing or overfishing is occurring) OR the fishery is unregulated (i.e., no control rules are in effect) 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. Iceland is committed to progressive and sustainable fisheries management, especially since a large portion of their economy depends on fishing and the trickle down effects of the country s fisheries. The current fisheries management policy advocates ecologically and economically responsible and sustainable management (IIMFA 2010c). In Iceland, the cornerstone of the country s fisheries management system is a catch limitation system that was established in The catch limitation system is based on the catch share allocated to individual vessels, where each vessel is allocated a certain share of the total allowable catch (TAC) of the targeted species. The TAC is set by the Minister of Fisheries and Agriculture and the decision is based on scientific information from the Icelandic Marine Research Institute (MRI). The MRI carries out scientific research on the status and productivity of all commercial fish populations, including Dab. The MRI also carries out long-term research on the marine environment and ecosystems around Iceland. The results of this research inform sustainable catch levels for each fishery (IIMFA 2010c). Day to day administration and enforcement of the Fisheries Act is regulated by the Directorate of Fisheries. The Icelandic Coast Guard monitors fishing activities in Icelandic waters, including surveillance of areas closed for fishing and inspection of gear (IIMFA 2010c). Additional Icelandic fisheries management regulations include time/area restrictions/closures and fishing gear restrictions. Discards are prohibited, which means that all catches must be landed. This is a very useful way of ensuring that there is adequate monitoring of undersized fish and all bycatch in the fisheries, although it is known from indirect sources that discards still occur in Iceland (anonymous 2011). For example, this might happen when a boat accidentally fishes Dab, but has finished its annual quota for the species (anonymous 2011). The Icelandic Ministry of Fisheries also mandates strict requirements for the keeping of logbooks onboard all fishing vessels and that they be made available to fishery inspectors (IIMFA 2010). In response to a 15+ year decline in landings and CPUE of Dab in Iceland, the MRI has recommended that total catch levels for 2010/2011 not exceed what is believed to be the amount of Dab caught as bycatch in other fisheries (~ 500 tons) (IIMFA 2010a). We

9 awarded a score of 2 here because management measures for Dab are in place but have failed so far to produce adequate results, shown by the sharp decline in landings over the past decade and a historically low CPUE (IIMFA 2010a) 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) There is inadequate scientific monitoring of stock status, catch or fishing effort Management does not explicitly address fishery effects on habitat, food webs, and ecosystems This species is overfished and no recovery plan or an ineffective recovery plan is in place. With historically low CPUE and a decade long decline in landings, Dab appear to be overfished in Iceland. The Icelandic MRI has recommended that total catch levels for 2010/2011 not exceed what is thought to be bycatch in other fisheries (~ 500 tons) (IIMFA 2010a). However, to our knowledge no recovery plan with benchmarks, timetables, and/or methods to evaluate success is currently being implemented to address their decline Management has failed to reduce excess capacity in this fishery or implements subsidies that result in excess capacity in this fishery There is adequate scientific monitoring, analysis and interpretation of stock status, catch and fishing effort. In Iceland, the Marine Research Institute (MRI) carries out scientific research on the status and productivity of all commercial fish populations, including Dab. The MRI is responsible for conducting long-term research on the Icelandic marine ecosystem. The research results of the MRI are intended to inform sustainable catch levels for the Dab fishery. The MRI employs about 100 scientists and research assistants and uses two research vessels (IIMFA 2010c). The MRI plays a critical role in helping Iceland achieve responsible and sustainable fisheries management. Although Dab appear to be overfished in Iceland, there has been adequate monitoring of their population, catch levels, and fishing effort over the past two decades.

10 +0.25 Management explicitly and effectively addresses fishery effects on habitat, food webs, and ecosystems. Although fisheries management in Iceland addresses the marine ecosystem and impacts to it from fisheries (IIMFA 2010c), management measures do not explicitly address Dab fishery effects on habitat, food webs, or ecosystems. Thus, no points were added 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 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. Iceland controls excess capacity through the catch limitation system, which is based on the catch share allocated to individual vessels. In this system, each vessel is allowed a certain share of the total allowable catch of the targeted species. The system is effective because it provides fishers an incentive to minimize overfishing Points for Management

11 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 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. Bycatch in the Icelandic Dab fishery is unknown, largely because sampling has not been sufficient enough to warrant a satisfactory estimation (Pálsson et al. 2006). In Iceland, the minimum allowed mesh size in Danish seine nets is mm, depending on the area (IIMFA 2010b). Danish seines primarily target flatfishes, but also catch a large number of Cod and Haddock (IIMFA 2010b). Discards are prohibited and vessels are mandated to keep logbooks on board (IIMFA 2010c), although it is known from indirect sources that discards still occur in Iceland (anonymous 2011). Additionally, temporary closures are enacted when the amount of undersized fish in the catch is too high (IIMFA 2010c). Recent data from 2009 indicate that there were 10 short-term area closures for Danish seine netters because of catches of undersized fish, compared to 132 closures for longliners (Bates 2010), suggesting that bycatch of undersized fish in Danish seine fisheries is comparatively low. Nevertheless, we awarded a score of 2 here due to the lack of specific bycatch data from the Danish seine fishery 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) 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 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. In Icelandic Danish seine fisheries, area closures are implemented to protect juveniles and spawning adults (IIMFA 2010b,c). Although Iceland mandates the use of some

12 bycatch reduction devices in bottom trawls, no such devices are used in Danish Seines (anonymous 2011). Nevertheless, sampling has not been sufficient to warrant a satisfactory estimation of bycatch in Danish seine fisheries (Pálsson et al. 2006). Thus, no points were subtracted 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. Bycatch of Dab in other Icelandic fisheries may be contributing to the species decline in Iceland, but bycatch estimates are currently unknown so no points were subtracted The continued removal of the bycatch species contributes to its decline. The removal of demersal fishes from Danish Seine fisheries may impact their populations. However, sampling has not been sufficient to warrant a satisfactory estimation of bycatch in Danish seine fisheries (Pálsson et al. 2006). Therefore, we chose not to subtract points 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 appear to be an issue in Icelandic Danish seine fisheries 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) 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 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) Points for Bycatch

13 REFERENCES Bates Q (2010) Policy wins over science as seine netters fall foul of policy. Gear Talk Aug Available at: Björnsson H, Sólmundsson J, Kristinsson K, et al (2007) The Icelandic groundfish surveys in March and in October Marine Research Institute Technical Report Vol. 131, 220 pp. Danish Seine Report (2010) Hafrannsóknir nr Áhrif dragnótaveiða á lífríki botns í innanverðum Skagafirði. Available at: Fishbase (2010) Common dab. Available at: Summary.php?ID=695 Hauksson E, Bogason V (1995) Occurrences of bearded seals (Erignathus Barbatus Erxleben, 1777) and ringed seal (Phoca Hispida Schreber, 1775) in Icelandic waters, in the period , with notes on their food. ICES Council Meeting Papers, 7 pp. Henderson P (1998) On the variation in dab Limanda limanda recruitment: a zoogeographic study. Journal of Sea Research 40: Hjörleifsson E, Pálsson J, Valtýsson H (1998) Catches of flatfish in Icelandic waters ). Marine Research Institute Technical Report 9801: 23 p. Icelandic Fisheries Information center of the Icelandic Ministry of Fisheries and Agriculture (IIMFA) (2010a) Main Species: Dab. Available at: fishes/dab/ Icelandic Fisheries Information center of the Icelandic Ministry of Fisheries and Agriculture (IIMFA) (2010b) Fisheries: Fishing Gear: Danish Seine. Available at: /fisheries/fishing-gear/danish-seine/ Icelandic Fisheries Information center of the Icelandic Ministry of Fisheries and Agriculture (IIMFA) (2010c) Management. Available Jastania HA (1995) Fecundity of Limanda limanda in Oxwich Bay, South Wales, U.K. JKAU Marine Sciences Journal 6: Jónsson G (1992) Icelandic fishes. Fjölvi. Reykjavík. Iceland: 568 p Jónsson G (1966) Contribution to the biology of the dab (Limanda limanda L.) in Icelandic waters. Rit Fiskdeildar, 4 (3): 36 p.

14 Lange U, Greve W (1997) Does temperature influence the spawning time, recruitment and distribution of flatfish via its influence on the rate of gonadal maturation? Ocean Dynamics 49: Óskarsson GJ (1997) Food and feeding habits of dab (Limanda limanda, linaeus, 1758)along the Icelandic coast. Hafrannsóknastofnun Fjölrit, 57: Pálsson OK, Arason A, Björnsson B, Jóhannesson G, Ottesen HBP (2006) Discards in demersal Icelandic fisheries, in Icelandic but with English summary and table and figure texts. Icelandic Fisheries - Information Centre of the Icelandic Ministry of Fisheries and Agriculture. Available at: Prime JH, Hammond PS (1990) The diet of grey seals from the south-western North Sea assessed from analyses of hard parts found in faeces. Journal of Applied Ecology Sæmundsson B (1926) Icelandic animals I: The fishes Pisces Islandea. Bokaverslun Sigfusar Eymundssonar. Reykjavik Valtysson H (1998) An assessment of Icelandic flatfish stocks. Masters Thesis, Department of Zoology, University of British Columbia, BC, Canada, 136 pp.