IDENTIFICATION
Sardines (also called pilchards) are silver on their sides and belly and blueish-green along their backs.
They have a single dorsal fin and often have a distinct row of 10 - 15 dark spots along the body.
They have large eyes and well developed vision which is important in maintaining a shoal formation.
DISTRIBUTION
Sardines are distributed throughout the world, and are the focus of many important pelagic fisheries. They are found in the upper layers of the ocean over the continental shelf where they often form huge shoals of hundreds of thousands of individuals.
FEEDING
The diet of sardines consists chiefly of zooplankton that drift in the upper layers of the ocean. Sardines also feed on phytoplankton. They are filter feeders but can bite their food if the zooplankton is large enough to see. When feeding, the sardine closes its mouth every 1 - 3 seconds and collects food particles trapped in its gill rakers.
REPRODUCTION
Sardines take about 3 years to reach maturity at which the fish is over 20 cm in length. The main spawning grounds are located off the south western Cape although some spawning does occur off the east coast. They have a long spawning season which runs from the end of winter (August) to the end of autumn (May) and they spawn several times during the spawning season. The female can release a batch of eggs every week and fertilised eggs hatch into larvae within four days of spawning. Newly hatched larvae feed off their own yolk for the first few days of their lives during which time their eyes, muscles, digestive tract and fins become developed.
GROWTH
Sardines are small fish reaching a maximum age of 6 - 8 years and a size of about 30 cm long.
FISHERY
Economically, sardines sustain some of the largest fisheries in the world. In South Africa, sardines and anchovies are caught primarily by commercial vessels along the south and west Cape coasts and approximately 100 000 tons are harvested annually. In the early 1960's, the industry nearly collapsed due to overfishing. Since then, Marine and Coastal Management (formerly the Department of Sea Fisheries), have undertaken extensive research and implemented a process of stock rebuilding. Biomass estimates are now obtained annually before setting the Total Allowable Catch (TAC) for the industry. The annual sardine run in KwaZulu-Natal is a local phenomenon which must be witnessed to be appreciated. Huge numbers of sardines congregate close inshore along the coast during winter. These concentrations of sardine may be so high that thousands of fish get pushed into the surf zone and become washed up along the beaches. Sardine shoals are forced inshore by pockets of warm water further offshore, which is too warm to tolerate. Once the fish have been forced inshore, they are quickly located by fish, bird and mammal predators including man. Shad, garrick and geelbek migrations also coincide with the sardine run.
MANAGEMENT
- Sardine are captured through a closed commercial fishery and an open recreational fishery. (Limited number of permits).
- Commercial fishers require a permit to harvest sardine.
- Recreational anglers usually capture sardine with a permitted cast net.
- There are no size or bag limits.
- Only commercial fishers may sell their catch.
Rudy van der Elst and Bruce Mann are acknowledged for the scientific information on which this web page is based.
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