Dogfish, Lesser Spotted

Scyliorhinus canicula

Method of production — Caught at sea
Capture method — Beam trawl
Capture area — North East Atlantic (FAO 27)
Stock area — North Sea, Skagerrak and Kattegat, eastern English Channel, West of Scotland, Irish Sea and southern Celtic Seas
Stock detail

3a, 4, 7d


Picture of Dogfish, Lesser Spotted

Sustainability rating four info

Sustainability overview

Lesser spotted dogfish populations have been increasing over time with a slight decrease in the past year. There is very little monitoring and management for the stock. More research and reporting of demersal sharks (catshark, nursehound and spurdog) by species, is required to ensure they are properly managed. Beam trawling is associated with discarding of unwanted fish and sometimes catch ETP species but dogfish capture rates can be reduced with appropriate gear modifications. Beam trawls have the potential to cause significant damage to the seafloor.

Biology

Lesser spotted dogfish or catshark belongs to one of the largest families of sharks, the dogfishes or Scyliorhinidae. Most commonly encountered around the coasts of northern Europe it is a bottom dwelling shark most usually found over sand, mud, algae, and rocky bottoms in coastal waters down to depths of 400 m. Like many elasmobranchs, the catshark often aggregates by size and sex.

In the North East Atlantic females reach first maturity at around 52 cm, with 50% of individuals mature by 57 cm (8 years) and all are expected to be mature by 69 cm. Males reach first maturity at around 49 cm, with 50% of individuals mature by 53.5 cm (6 to 7 years) and all mature 62 cm. Females lay their eggs during spring and early summer. The shark embryos are enclosed in cases (called ‘mermaids’ purses) whilst they develop and mature, a period of 5-11 months depending on sea temperature.

Catsharks can grow up to 1 metre in length, but rarely seen larger than 80 cm. Maximum age is reported as 12 years. They are also marketed as dogfish.

Stock information

Criterion score: 0.5 info

Stock Area

North Sea, Skagerrak and Kattegat, eastern English Channel, West of Scotland, Irish Sea and southern Celtic Seas

Stock information

Catshark (dogfish or lesser spotted dogfish) is common and widespread all around the coasts of Britain and Ireland. It is likely the most frequently caught elasmobranch in European waters. Lesser spotted dogfish reproduce relatively quickly compared to other sharks.

Their populations were steadily increasing until 2013 and their populations have been fluctuating since with declines. It is unknown if fishing levels are appropriate for the species.

Scientists advise that landings should be no more than 3380 tonnes in 2018 and 2019 each (2016 landings were estimated to be just under 3000 tonnes).

Discarding rates are known to be very high. Many dogfish survive discarding but it is unknown to what level.

Historical records show that lesser-spotted dogfish was previously far abundant in the southern North Sea. The species has strongly increased in its populations since the 1970s and 1980s. Their populations have increased because of warming waters, new habitats and reduced competition with skate species (many dogfish feed upon other discarded species from trawl fisheries).

Management

Criterion score: 0.75 info

There is no specific management plan or precautionary management plan for lesser spotted dogfish. There is no quota available and therefore, their catch rates are often not reported.

Some Inshore Fishery Conservation Authorities (IFCAs) have implemented management measures e.g. minimum mesh sizes in fixed nets.
When Lesser spotted dogfish catches are reported, they are often entered as generic categories as “dog fish and hounds”. There are a lack of data available for the species, though some fishery-independent surveys have been conducted. This makes it difficult to evaluate the stock

Catshark are caught as bycatch by many types of fishing gears (bottom trawl, gillnet, trammel net, and longline fisheries). Generally the species is of low commercial value and discard rates are high (up to 98%!) but equally, when caught and handled responsibly, their discard survival rates are also high. If it is not discarded, it is often used for bait in pot fisheries to catch whelk (Buccinum undatum) and crustaceans.

Capture Information

Criterion score: 0.75 info

Bycatch
Lesser spotted dogfish are mostly caught in bottom trawls. There is a higher retention rate of dogfish in otter trawls. There is a lack of information available on other bycatch species but in the southern North Sea, common bycatch in bottom trawls include mixed crabs, urchins, lesser spotted dogfish, nursehound, dragonet, starry ray, smelt. ETP species are occasionally caught (Angelshark and Common skate (both critically endangered (IUCN)). Invertebrates such as crabs and urchins are vulnerable to damage.

Discards
Trawling is also associated with discarding of unwanted fish, i.e. undersized and/or non-quota and/or over-quota species but their capture rates can be reduced for example by inserting a square-mesh panel into the net. Since dogfish have very rough skin, they can harm other species caught in trawl nets and therefore reduce their potential survival rates if discarded. Projects are on-going to try and allow shark species to escape from trawls e.g. by having square-mesh panels and LED lights to help by-caught sharks escape nets.

Habitat
Bottom trawling has the potential to cause significant impact to habitat such as removing or destroying physical features and reducing biota and habitat complexity. Therefore, the recovery time of the seabed after trawling varies greatly and depends on the fishing gear, the substrate, intensity of the trawl and accustomed the seabed is to natural disturbance. Fishing occurs over a mixture of seafloor types. IFCAs ensure bottom trawling occurs in areas where there will be minimal damage to habitats such as mobile sands, however, dogfish are bycatch are caught over a mixture of substrate types, and by a mixture of bottom trawls.

Alternatives

Based on method of production, fish type, and consumer rating: only fish rated 2 and below are included as an alternative in the list below. Click on a name to show the sustainable options available.

Basa, Tra, Catfish or Vietnamese River Cobbler
Bass, seabass (Farmed)
Bream, Gilthead (Farmed)
Cod, Atlantic Cod
Cod, Pacific Cod
Coley, Saithe
Haddock
Hake, Cape
Hake, European
Pollock, Alaska, Walleye
Sturgeon (Farmed)
Tilapia
Whiting

References

Shark Trust 2010. An illustrated Compendium of Sharks, Skates, Rays and Chimaera. Chapter 1: The British Isles and Northeast Atlantic. Part 2: Sharks www.sharktrust.org

ICES 2017d. Lesser-spotted dogfish (Scyliorhinus canicula) in Subarea 4 and in divisions 3.a and 7.d (North Sea, Skagerrak and Kattegat, eastern English Channel). Version 2: 24 October 2017 DOI: 10.17895/ices.pub.3190. Available at: http://ices.dk/sites/pub/Publication%20Reports/Advice/2017/2017/syc.27.3a47d.pdfdf

Sguotti, C., Lynam, C. P., Garcia-Carreras, B., Ellis, J. R. and Engelhard, G. H. 2016. Distribution of skates and sharks in the North Sea: 112 years of change. Glob Change Biol, 22: 2729-2743. doi:10.1111/gcb.13316

ICES. 2017a. Report of the Workshop to compile and refine catch and landings of elasmobranchs (WKSHARK3), 20-24 February 2017, Nantes, France . ICES CM 2017/ACOM:38. 119 pp.