CVO sole Gillnet
Certified as sustainable on 24th November 2009.
Species: Common sole (Solea solea)
Location: North Sea, ICES areas IV b & c
Fishing methods: Sole gillnets
Number of fisheries: 1
More about common sole
Common sole is a widely distributed species, extending from the Mediterranean and Northwest African coast, as far south as Senegal, to the Irish Sea, southern North Sea and Skagerrak and Kattegat. The southern North Sea (ICES area IV) where the fishery under assessment occurs is near the northern limit of the species, however these are also some of the grounds with the highest concentrations of sole, and the most important nursery grounds. The northern limit of the species in the North Sea is dictated by a steep temperature gradient separating the warmer, well mixed southern waters, with the deeper, colder, more northerly waters.
Sole generally occur in shallow, sandy and sandy /muddy habitats – typically in the depth range of 10 – 60m, and a temperature range of 8 - 24ºC. Important nursery areas are situated along the English and continental coasts in shallow waters (within the 30m contour) and on a sandy or muddy substrate.
Spawning occurs in spring, peaking in May, triggered by rising sea water temperatures. Although it has been shown that spawners return to the same spawning grounds each year, it is not known whether recruits return to the grounds where they were born. Females are batch spawners producing on average around 350,000 eggs (35cm fish) per year.
Sole are nocturnal and olfactorial feeders, spending the day buried in the sediment. The blind side of the sole has sensory organs to detect prey. Sole feed on polychaete worms (Arenicola marina, Lanice spp. and Nereis spp.), molluscs and small crustaceans.
More about the fishing methods
The fishing method employed in this fishery is a bottom set gill net. The net consists of a single netting wall (as opposed to the multiple netting layers used in trammel nets) kept more or less vertical by a float line and a weighted ground line.
The net is set on the bottom, and kept stationary by anchors on both ends. Each net is approximately 1m high (from the seabed) and 50m long with a monofilament mesh size of 92mm2. Typically lengths of nets are joined together, making long nets sometimes up to several kilometres in length. Vessels in this fleet typically carry between 100 and 300 nets. Although weighted and anchored, the nets are relatively light and can roll up into pockets or be flattened by the tide. Often the net will not be untwisted by the crew for several hauls.
The fishing season lasts from around April (when the sole first arrive on the grounds) to September (when they leave). Nets are typically shot in the late afternoon or evening, and hauled at around dawn, taking advantage of the sole’s diurnal / nocturnal feeding behaviour. All nets are hauled each day, and brought ashore when the vessel is not fishing.
168 tonnes (2008)
The main commercial market for DFO gill and tangle net sole are within the European Union.
Actual eligibility date
The actual eligibility date for the DFO gill net sole fishery is the 1st March 2009.