European Sea Bass
Sources, Quantities and Cultivation Methods
Source and Quantities
European sea bass (also known as sea bass or bass)1 is an important marine species both to commercial inshore fisheries and aquaculture. Sea bass are tolerant of a wide range of temperatures and salinities and frequent coastal inshore waters, estuaries and brackish water lagoons. Farmed European sea bass should not be confused with another farmed species often called the Asian sea bass (or barramundi) farmed in Asia, Australia and the US.
Farming of sea bass was traditionally small scale and based on the capture of wild juveniles2, but it is now predominantly undertaken intensively in net pens, largely in southern European coastal waters using hatchery-reared seed (i.e. juveniles).
Sea bass is an important aquaculture species in the Mediterranean3,4, and Greece, Turkey, Spain and Egypt are the most important farming countries, as the map shows.
World production of farmed sea bass has increased steadily5 from around 60,000 tonnes in 2003 to 191, 003 tonnes in 2016, and valued at US$1.08 billion6. Turkey and Greece combined represent around 64.5% of world production2.
Domestic Market Information 7, 8
Over the past ten years (2008 to 2018) sea bass has been the second fastest growing species (from a fairly small base) in Great British retail (i.e. in England, Scotland and Wales). Sea bass grew by value and volume 156% and 157% respectively from a base of £24 million and 1,467 tonnes in 2008. Growth remained strong in spite of having the second highest average price of any seafood in the top 10, double that of cod.
In 2018, UK retail sales of sea bass were worth £67.5m (+4.3% compared to the previous year) with a volume of 4,130 tonnes (+2.6%), average price £16.33 per kg, and ranking as the 9th most popular species by value, and moving above pangasius, in the 52 weeks to 16/06/2018 (including discounters).
In 2018, the UK imported 9,310 tonnes of sea bass, including 8,574 tonnes of chilled and 736 tonnes of frozen.
Note: the difference between the volume of sea bass sold in UK retail and that which is imported is due to its use in the foodservice industry (e.g. restaurants) (no data available) and that which is re-exported.
Production2, 3, 9
Sea bass were traditionally reared in enclosed lagoons where they fed naturally until harvested. Some of these early production systems are still operational today. The example of Atlantic salmon farming in Northern Europe, combined with a scarcity of juvenile sea bass for lagoon rearing, led to research programmes being initiated in the 1960s in order to intensify production. This enabled the start of commercial scale sea bass farming in coastal areas of the Mediterranean in the 1980s. A schematic of modern sea bass production is given opposite.
Until the 1990's sea bass production relied on wild caught broodstock to produce the seed for farms, however selective breeding programmes are now in place. These are generally part of larger integrated companies which control the entire process from reproduction to harvest, but there are still independent European sea bass hatcheries that sell juveniles (i.e. seed) to on-growing facilities. Along with feed, the purchase of seed is the biggest operating cost for sea bass farms.
Broodstock are kept under controlled conditions with spawning initiated using hormonal treatments and photomanipulation (control of lighting used to prolong the sea bass spawning cycle). Fertilized eggs are collected on the surface of spawning tanks, placed in incubator tanks, and hatch after 48 hours. Larvae lose their yolk sac six days after hatching. At this point they are given specialised diets, including live feeds such as rotifera (microscopic zooplankton) and artemia (a small crustacean).
After 40-50 days, the larvae are transferred to a weaning unit where they are fed a formulated high-protein ‘micro-diet’ (small pellets). After a further three to four weeks the fry are transferred to juvenile breeding units. Two months later, at 2-5g, they are ready for on-growing.
During on-growing fish are fed and reared in floating net-pens until harvest; this will be undertaken in either small cages in sheltered marine sites, or larger net-pens in more exposed locations. There have been attempts to raise sea bass in land-based tanks, generally using recirculation aquaculture systems (RAS) that control the water temperature and minimise water usage; an example of such a system was Anglesey Aquaculture, based in North Wales. However this system ceased producing sea bass in 2015 having found it difficult to compete with Greek and Turkish imports10.
Although producers rear a range of sizes for market, sea bass are generally harvested when they reach 300-500g, which takes from a year and a half to two years, depending on water temperature2.