Dab | FishOnline | The in-depth guide to sustainable seafood

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Common name - Dab

Scientific name - Limanda limanda

Rating

Caught at sea Demersal otter trawl, Danish seine

Capture Area North East Atlantic FAO 27

Stock Area All Areas

Stock Detail I-IX

Summary

The stock status of dab is not formally assessed, but recent studies suggest that dab is the most abundant fish species in the North Sea, after sandeel. Management varies, with Minimum Landing Sizes stipulated by local byelaws, and a joint TAC in the North Sea with flounder. More data is required for the species, including more frequent onboard sampling, and information on biological parameters. Dab are often discarded due to low commercial value and poor market demand, although limited experiments suggest they do have a good survival rate. As a relatively abundant species, dab is potentially a more sustainable alternative to long-lived and vulnerable and overfished flatfish species, such as plaice. Seine-netted dab is the most sustainable option, as this method causes less damage to seabed and catch is of better quality than that taken in a demersal trawl. Avoid eating immature fish below the size at which they breed (26cm) and fresh (not previously frozen) fish caught during or prior to the breeding season (April - June). Cornwall, North Wales and Northwestern Seafisheries Districts currently offer the best local management, whereas the Norwegian and North Sea fisheries are also a good choice as they are regulated by TAC. As an under-utilised species it is ranked by Cefas as one of the most tolerant of over-fishing and therefore one of the better ones for consumers to eat.

Biology

Dab is a widespread demersal species on the Northeast Atlantic shelf and distributed from the Bay of Biscay to Iceland and Norway; including the Barents Sea and the Baltic. Dab is one of the most abundant demersal species in the North Sea with its centre of distribution in the Southern North Sea. Dab is a right-eyed flatfish (both eyes are on the right side of the body) related to the plaice, flounder and sole. It can reach a length of about 40cm and an age of 10-12 years. Spawns in January to August, earliest off Britanny and southern England, later in the North Sea (April to June) and in the Barents Sea (June-July). In the Baltic Sea they spawn in April-August. In the North Sea the males become sexually mature at 2-3 years when 10-20cm long, the females at 3-5 years when 20-25cm. Because of its sedentary nature, dab has proved to be a valuable indicator in eco-toxicological studies.

Stock Information

Distributed throughout the northeast Atlantic dab is an abundant fish on shallow, sandy grounds off coasts of northern Europe. Due to lack of data no reliable stock assessment for the species is carried out and no reference points have been defined. However, recent studies suggest that dab is the most abundant fish species in the North Sea, after sandeel. Abundance indices show an increase in dab abundance in the long term, with recent abundance being very high. Length composition of catch has also been stable and an increase in the range of sizes has been noted in recent years. Currently six stocks have been declared under the EU data collection framework, these consist of: IIIa North; IIIa South & III b-d; VIId; IV & VIId; II, V, VI, VII (excluding d), VIII, IX, X, XII, XIV. Effort for the main fleet with dab bycatches (beam trawls) in the North Sea and Skagerrak has declined 40% between 2003 and 2009. ICES advise no increase in catches for this area. Dab is considered an under-utilised species. Under-utilised species are ones that fishermen don't catch their full quota of; or they catch them but then discard the fish because no one wants to buy them. CEFAS have compiled a list of these species using quota and discard information, expert advice and local knowledge and chose around 50 under-utilised species to study. To determine their sensitivity to over-fishing CEFAS has developed a system, the Relative Life History Sensitivity Analysis, to study the risk. It uses biological information like growth and breeding strategies to see how increased fishing pressure might damage each species. They then ranked the species by how tolerant they are to being over-fished. For a full list of the species that are most under-utilised AND most tolerant of over-fishing and therefore the best ones for consumers to consider choosing see www.cefas.defra.gov.uk/our-science/fisheries-information/marine-fisheries/under-utilised-species.aspx

Capture Information

Seine netting causes less damage to the seabed than trawling. It is also less fuel intensive and the catch of a better quality, as it is not bumped along the seabed as with trawling. Demersal otter trawling is often associated with discarding of unwanted fish, i.e. undersized and/or non-quota and/or over-quota species. Dab catches are generally discarded based on the availability of target species and market price, dab has a low commercial value. However the limited survival data available suggests that dab have a high survival rate (77-88% depending on trawl duration and processing time). There is no minimum landing size specified for dab in EU waters, therefore there is potential for landing of immature fish. In the Cornwall and North Western & North Wales Sea Fisheries Districts, landing dab below 15cm is prohibited. Dab mature at a range of sizes between 13-29cm, but the average size of a mature Dab is is 26cm. There is a joint TAC for dab and flounder in the North Sea and the Norweigan Sea. However, it is recommended that this is separated so that there is a single TAC for each of these species.

Alternatives

(Based on method of production, fish type, and consumer rating: only fish rated 3 and below are included.)

Dab
Flounder
Halibut, Atlantic
Halibut, Pacific
Megrim
Plaice
Sole, Dover sole, Common sole
Sole, Lemon
Turbot
Yellowfin sole

Read what the consumer pages of the Good Fish Guide say about this species.