Whiting (Merlangius merlangus)
|Size||Adult body length: up to 50 cm|
Not subject to specific protection, but listed by the International Council for the Exploration of the Seas (ICES) as below Safe Biological Limits (SBL).
The whiting is similar in appearance to its larger relatives the cod, the haddock, the coley and the pollack. It has three dorsal fins separated by small gaps, the third fin extending almost to the tail fin. The tail is not forked, having almost a square end. The two anal fins are very close together, nearly touching one another and, together with the anterior fin, are elongated. The pectoral fin is also long and projects beyond the base of the anal fin. The whiting’s upper jaw projects slightly beyond the lower, and the lateral line is continuous along the length of the body. In colour, individual fish vary quite a lot, and there is often a small dark blotch at upper base of the pectoral fin.
The whiting ranges from the eastern North Atlantic to the south eastern Barents Sea, and from Iceland to Portugal. It is also found in the Black Sea, Aegean Sea, and Adriatic Sea, but is uncommon in the northwestern Mediterranean.
This fish is a bottom-dweller in water no deeper than 200 metres. It prefers mud and gravel beds but is also recorded on rocky bottoms. The young fry spend about a year in much shallower waters of no more than 30m depth, before migrating to the adult feeding grounds.
The fish matures at between three and four years of age, and spawning takes place at a depth of 20 to150m. The time of the spawning varies from location to location: from January to spring in the Mediterranean; from January to September in the area between the British Isles and the Bay of Biscay; and throughout the year in the Black Sea. A large female can produce up to one million eggs. The eggs float in the open ocean and the larval whiting swim with other sea plankton until they have attained a length of around 10 cm. The fish grow quickly, with females growing faster than males, and can live to about ten years of age. The diet of the whiting consists of bottom-living organisms, such as crabs, shrimps, small fish, molluscs, worms, squid and cuttlefish.
The biggest threat to this species is over-harvesting by the fishing fleets of many nations. Although the whiting is still a fairly numerous species, in common with a number of other commercially important fish it is now feared that there are more being caught by trawlers than reproduce annually. Domestic pressure on governments to support their fishing industries has led to the situation where overfishing takes place, and agreed quotas are exceeded.
The whiting is listed in the UK Biodiversity Grouped Action Plan for commercial marine fish. Being a species that is found in international waters, it has proved very difficult to impose restrictions on the number of fish that can be harvested from the sea without reducing fish stocks below the important Safe Biological Limits (SBL) figure. The whiting is listed in the part of the UK Grouped Action Plan dealing with fish stocks in the Celtic Sea, and the total allowable catch (TAC) figure for this region was cut to 35% in 2001. At the moment, it appears that elsewhere the whiting’s populations have not dropped below the SBF.
It remains to be seen whether implementation of the rules and recommendations in the current Common Fisheries Policy (CFP) will allow population levels to stabilise and recover. One side effect of the original CFP has been to remove inefficient fishing boats from the fleets, allowing heavy overfishing by the ‘factory’ trawlers. This, coupled with the pressure on individual governments to support their country’s own fishing fleets, has led to the harvesting of ‘black fish’, catches above and beyond a country’s legal quota.
For more on fishes see Fishbase:
Information supplied by English Nature.
- Dorsal fin: the unpaired fin found on the back of the body of fish, or the raised structure on the back of most cetaceans.
- Larval: of the stage in an animal’s lifecycle after it hatches from the egg. Larvae are typically very different in appearance to adults; they are able to feed and move around but usually are unable to reproduce.
- Lateral line: a row of receptors that can detect movement via vibrations in water. The receptors are typically embedded in the skin, and in fish they form a line along the sides of the body.
- Pectoral fins: in fish, the pair of fins that are found one on each side of the body just behind the gills. They are generally used for balancing and braking.
- Plankton: aquatic organisms that drift with water movements; may be either phytoplankton (plants), or zooplankton (animals).