Dab

Scientific: Limanda limanda. English: Dab, common dab. Icelandic: Sandkoli. For more languages see the Marine Animal Dictionary.

Biology and distribution

Dab is small compared to other flatfishes of commercial importance in Icelandic waters, usually between 20 and 35 cm in total length. The largest individual found in Icelandic waters was 48 cm, which is a world record. Growth is fast during the first years but slows after reaching sexual maturity at the age of 2 to 3 years for males and 3 to 4 years for females. Females grow faster and reach an greater age than males or up to 14 years. Dab probably spawns all around Iceland, earliest spawning starting from the middle of April off the southeast coast then spreading clockwise around the country. The last spawners are along the east coast where spawning probably starts around the middle of June. The diet of the dab is variable, it is an opportunistic feeder and can handle large food items. Various benthic invertebrates are common in the diet, as are sandeels and capelin. Discarded intestines from fishing boats are commonly found in dab stomachs.

The dab is exclusively a shallow water fish and is common on sand or mud bottoms from 0 to 40 m all around Iceland, and is rare below 120 m. It is more abundant in the warmer waters of the south and west coasts than along the north and east coasts. It presumably does not migrate long distances but generally seeks deeper waters in winter. Dab is only found in the eastern part of the North Atlantic, from the Barents Sea to the Bay of Biscay. In the North Sea, it is among the most common fish species.

Catch and fishing gear

Until 1984 dab was not caught in large numbers in Iceland, only a few hundred tonnes were reported before that, mostly caught by English boats. However, catches by Icelandic boats increased substantially after quotas were set on other more valuable species. Catch amount reached a peak at 8,000 tonnes in the late 1990s but has declined considerably since then.

Generally, the dab cannot be caught in large quantities with gillnets, longlines, or handlines used in the shallow waters. Dab is not found in deeper waters where trawlers operate. The only fishing gear that can tackle this fish is the Danish seine. Due to its low value, it was until recently primarily a bycatch in Icelandic Danish seine fisheries, and might, in many cases, have been discarded or reported with other flatfish species. After 1984, catches have increased, mainly because Faxaflói Bay, where the main fishing grounds are located, has been opened for Danish seine fishing. The current low dab catches are evenly spread over the year but used to be concentrated in the autumn when the fishing grounds in Faxaflói bay are open.

Stock status (from the Marine Research institute)

In 2010, 610 t of dab (Limanda limanda) were landed. Between 1987 and 1997, landings of dab increased from 1 200 to 8 000 t, but have since decreased considerably. CPUE is now at a historical low. The MRI recommends that the TAC for the quota year 2011/2012 should not exceed what is considered to be bycatch in other fisheries. Considering the state of the stock, this could amount to about 500 t for the 2011/2012 quota year.

Processing and markets

Most of the dab catch is iced at sea and then processed and frozen after landing.

References and further information

References: (Jónsson, 1966), (Jónsson & Pálsson, 2006), (Óskarsson, 1997).

For full citation and further information on the main species in general see this page

Hreiðar Þór Valtýsson, University of Akureyri