|Scientific Name:||Dalatias licha|
|Species Authority:||(Bonnaterre, 1788)|
|Infra-specific Taxa Assessed:|
Squalus licha Bonnaterre, 1788
|Red List Category & Criteria:||Near Threatened ver 3.1|
|Assessor/s:||Blasdale, T., Serena, F., Mancusi, C., Guallart, J. & Ungaro, N.|
|Reviewer/s:||Acuña, E. & Valenti, S.V. (Shark Red List Authority)|
The Kitefin Shark (Dalatias licha) is a moderate sized deepwater shark is unevenly distributed on continental and insular shelves and slopes in warm-temperate and tropical areas at depths of 37 to 1,800 m in the North and Central Atlantic, western Indian Ocean and Western and Central Pacific Ocean. This species is taken in deepwater longline and gillnet fisheries in the Northeast Atlantic. A comparison between recent Scottish trawl surveys and MAFF surveys in the 1970s shows a 94% decline in catch rate to the west of the British Isles, however, this value must be treated with caution as it is likely that other species may have been misidentified as D. licha in the 1970s and this species is at the edge of its range in this area. Directed hand line and gillnet fisheries for D. licha began off the Azores in the 1970s. Portuguese landings in this fishery increased rapidly to 896t in 1991 and then decreased steadily to <46 t from 1998 onwards. The DELASS project considered this stock depleted. Given the evidence for declines in this region and the species? limiting life-history characteristics it is assessed as Vulnerable in the Northeast Atlantic. Records of yields from the Portuguese/Azores kitefin shark fishery suggest that targeted fisheries are capable of reducing populations quite rapidly. The life history of this species is expected to result in a slow recovery after depletion. The species occurs within the range of fisheries in many areas of its range, where it is taken as bycatch. An increasing trend for fisheries to move into deeper water on continental shelves and slopes suggests that fishing pressure on this species will likely increase. The life history characteristics of this species (i.e. Slow growth, relatively large size at maturity etc) make it vulnerable to rapid declines should pressure increase throughout its range. Globally, this species is assessed as Near Threatened due to concern that it may meet the category VU A4bd in the future, given continued and increasing deepwater fishing pressure and its limited life history characteristics.
|Range Description:||Found on continental and insular shelves and slopes in warm-temperate and tropical areas (Compagno and Cook 2005). This species is found in the western and eastern Atlantic, western Indian Ocean, western Pacific and around the Hawaiian islands (Compagno in prep.).|
Native:Australia; Cameroon; Canada; Côte d'Ivoire; Japan; Mauritania; Mozambique; New Zealand; Portugal (Azores, Madeira); Senegal; South Africa; United Kingdom (Great Britain, Northern Ireland); United States (Florida, Hawaiian Is.); Western Sahara
|FAO Marine Fishing Areas:||
Atlantic – eastern central; Atlantic – northeast; Atlantic – northwest; Atlantic – southeast; Indian Ocean – eastern; Indian Ocean – western; Mediterranean and Black Sea; Pacific – northwest; Pacific – southwest; Pacific – western central
|Range Map:||Click here to open the map viewer and explore range.|
Population size is unknown; however the Kitefin Shark is believed to be relatively common yet low in abundance. There is probably little or no exchange between populations separated by the deep ocean or occurring in different ocean basins, which are considered to form distinct regional subpopulations (Compagno and Cook 2005).
In the Mediterranean, the range of this species appears to be confined to the western and central basins (Baino et al. 2001). Biomass appears to be very low in this region (Baino et al. 2001). The GRUND project, a series of experimental trawl surveys carried out on the continental and upper slopes of the central Mediterranean suggest a positive trend in kitefin catches between 1985 and 1998, however the dataset was relatively poor in that very few specimens were caught (average 1.9 per hour) over 12 years of surveys (Relini et al. 2000). D. licha were present in <2% of bottom trawls across the Mediterranean (Relini et al. 2000). A bottom trawl fishery for red-shrimp Aristeus antennatus operating in the Gulf of Valencia collected data between 1988 and 1989 on the frequency of D. licha catches. The species was present in 28.6% of trawls carried out at 450?675 m depth, with a mean abundance of 0.06 specimens per hour of trawling (Guallart 1990). During exploratory surveys to collect data of the exploited and virgin stocks of deep-sea A. antennatus (DESEAS project), D. licha were caught in all three areas of the study (the Balearic area, the western Ionian and the eastern Ionian). Abundance decreased with depth in the Balearic area and the species was found to be more abundant between 1,000 and 1,499 m in the western Ionian and was present mainly at shallower depths in the eastern Ionian (Sion et al. 2004).
Stock identity of Kitefin Shark in Northeast Atlantic is unknown. However the species seems to be more abundant in the south area of the Mid Atlantic Ridge (ICES Area X). Elsewhere in the Northeast Atlantic, kitefin shark is infrequently recorded. For the purposes of stock assessment and management, the Azores/Mid-Atlantic Ridge population is considered to be separate from the Northeast Atlantic Slope population (ICES 2006). There is very little population information for this species over the remainder of its range. On the Chatham Rise in New Zealand, D. licha comprised less than 1% of the total shark catch in all fishing (Wetherbee 1999). The species has been captured in greater numbers, however in fishing that was conducted at shallower depths other locations in New Zealand (Clark and King 1989).
|Habitat and Ecology:||
The Kitefin Shark is a deepwater, benthic to mesopelagic species. Found on continental and insular shelves and slopes in warm-temperate and tropical areas from 37 m down to 1,800 m depth, most common below 200 m. Within the Western Mediterranean it occurs at depths of up to 1,800 m (Stefanescu et al. 1992), in the Tyrrhenian Sea it is present between 200?800 m (Baino et al. 2001) and in the Adriatic it was found at depths of up to 900 m (Ungaro et al. 2001). It is, however found primarily on the continental slopes at depths of 300?600 m (Whitehead et al. 1984).
Reproduction is via aplacental viviparity and occurs throughout the year, with greater activity during the summer and autumnal months (Bini 1976, Tortonese 1956). Produces 3?16 pups per litter, (Bauchot 1987), but usually 6?8 per litter (Bini 1976, Tortonese 1956). The size at birth is approximately 30 cm in total length (Bauchot 1987, Whitehead et al. 1984). The length of maturity for males ranges between 77-121 cm and for females, between 117?159 cm (Bauchot 1987). However, in the Adriatic a mature female was observed which was considerably smaller, measuring 96 cm in length (N. Ungaro pers. obs.). The maximum size of kitefin sharks is reported to be 180 cm in total length, however 120 cm is a more common length (Bauchot 1987).
This shark is a solitary species (Bauchot 1987). The Kitefin Shark?s diet is indicative of the water region it occupies, it preys on mesopelagic and benthic fishes, including catsharks (Galeus) and spiny dogfish (Squalus and Etmopterus), as well as cephalopods, crustaceans and polychaetes (Macpherson 1980, Bauchot 1987).
This shark has long been exploited commercially (Compagno and Cook 2005). Because of the generally deep depth at which this species appears to spend most of its time, historically it was taken primarily in deepwater directed fisheries efforts (Compagno and Cook 2005). However, with recent trends in development of deep fishing gear (especially trawl gear), and the increasing need for commercial fisheries to fish deeper in attempts to sustain harvest levels, this species and other deep-sea elasmobranchs will undoubtedly come under increased pressure in the future (Compagno and Cook 2005).
The following is taken from the ICES WGEF Report (2006) unless stated otherwise.
D. licha was formerly caught in targeted hand-line and gill-net fisheries in the Azores. Landings from the Azores began in the early 70s and increased rapidly to over 947 t in 1981. From 1981 to 1991 landings fluctuated considerably, following market fluctuations and peaked at 937t in 1984 and 896t in 1991. After 1991 the reported landings declined linearly, possibly as a result of economic problems related to markets. The fishery ceased at the end of the 1990s because it was not profitable. Since 1988 a bycatch has been reported from mainland Portugal with 282 t in 2000 and 119 t in 2003. D. licha from the Azores is now a bycatch from different deep-water fisheries, with landings in 2004 and 2005 of less than about 15 t (Pinho 2006). This species is also caught by longline fisheries off the Portuguese mainland.
This species has been reported in longline and gill-net fisheries directed at mixed deep-water sharks west of the British Isles. Recent emergency measures by the EC and NEAFC have closed these deep-water gill-net fisheries. It is apparently also taken in small quantities by mixed deep-water trawl fisheries west of the British Isles but quantities are unknown as shark species are not usually separated in landings statistics. According to the WGEF (ICES 2006), while the United Kingdom and Ireland have official reported landings of Kitefin Shark, these have likely been misidentified, and are more likely to be either Portuguese dogfish or leafscale gulper shark. A comparison between recent Scottish trawl surveys and MAFF surveys in the 1970s shows a 94% decline in catch rate, however, this value must be treated with caution as it is likely that other species may have been misidentified as D. licha in the 1970s (Jones et al. 2005). Furthermore this species is at the limit of its geographical range west of Scotland. In total, the WGEF estimated total landings in the ICES area to be around 47 t in 2005.
Stock assessments of the D. licha fishery were made during the 80s (Silva 1987). The stock was considered intensively exploited with the average observed total catches (809 t) near the estimated maximum sustainable yield (MSY=933 t). During the DELASS project (Heessen 2003), the stock was considered depleted based on the probability of the Biomass 2001 being less than BMSY. Preliminary assessment results suggest that the stock may be depleted, to about 50% of virgin biomass. However, further analysis is required, particularly analysing the effect of liver oil prices on the fishery.
There was a specific Kitefin Shark fishery based in the Ligurian Sea until the 1930s. Roughly ten boats worked this fishery using traditional longline gear. It is reported that each boat caught approximately twenty large individuals, which were often pregnant females (Vacchi and Notarbartolo di Sciara 2000).
Today, the Kitefin Shark is caught across the Mediterranean mainly as bycatch in bottom trawl and gillnet fisheries. In the Balearic Sea, individuals ranging from small juveniles to adults are caught by such fisheries operating on the continental slope at depths between 300 and 675 m (Guallart pers. comm.). These individuals are generally discarded, the majority of which are still alive (Guallart 1990, Guallart pers. comm. 2003). There is no information on post release survival rates for this species, however due to neutral buoyancy of its body, many of them are unable to sink again, die on the surface, and sometimes are found stranded on the coast (Guallart pers. comm. 2006).
Although little specific information is available in other areas of the species' range, it is distributed over a wide depth range and is therefore a potential bycatch in a number of deepwater fisheries. The life history characteristics of the species (i.e., slow growth, relatively large size at maturity etc.) make them vulnerable to rapid declines should pressure increase throughout their range.
Deepwater sharks are subject to management in Community waters and in certain non Community waters for stocks of deep-sea species for 2005 and 2006. The TAC for ICES areas V, VI, VII, VIII and IX for a group of deep sea shark species including D. licha is 6 763 t. In Subarea X (the Azores) the TAC is 120t and in Subarea XII 243 t. The EC has also introduced emergency measures to ban deep-water gill-netting.
The development and implementation of national management plans (e.g., under the FAO International Plan of Action for the Conservation and Management of Sharks: IPOA-Sharks) is required to facilitate the conservation and sustainable management of all chondrichthyan species in the region. The EC prepared a draft proposal for the European Community Plan of Action, which encourages research programs aimed at the assessment of the conservation status of sharks in the Mediterranean Sea (Serena et al. 2002).
|Citation:||Blasdale, T., Serena, F., Mancusi, C., Guallart, J. & Ungaro, N. 2009. Dalatias licha. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.2. <www.iucnredlist.org>. Downloaded on 10 March 2014.|
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