Durban - THE South African Association for Marine Biological Research (Saambr) has used the sardine run to investigate the movement of sharks.
Saambr announced this week that during winter on the KwaZulu-Natal coast there was an influx of sharks associated with the sardines (Sardinops sagax, or pilchards).
These include dusky sharks (Carcharhinus obscurus), blacktip sharks (Carcharhinus limbatus), spinner sharks (Carcharhinus brevipinna) and others.
Saambr spokesperson Anne Kunz said, “We know they make the most of winter in KZN to feed on the sardines, but it is still unclear what all these sharks do for the rest of the year.”
Saambr has been making the most out of one of the best sardine runs on record in KZN.
“We fit them with acoustic tags that ping a coded ID to underwater receivers located along our coastline from Cape Town to the Mozambique border. We are then able to follow their movements for six to eight years as they migrate along our coast.”
For some sharks, such as the endangered dusky shark, Saambr hoped to be able to improve their conservation by understanding more about areas that are critical for them.
“The KZN coastline remains an important nursery area for juvenile dusky sharks, but we don’t know much about their movements as they mature, which may take up to 25 years. We hope that by tagging a range of juveniles and adult sharks we are able to find out more about this species and discover which areas on our coast are most important to them. We can then design effective conservation strategies for the species.”
As sharks are increasingly under threat from fisheries, South Africa remains an important “shark hot spot”.
“We need to ensure these top predators continue to thrive and support healthy, balanced marine ecosystems.”
Greg Thompson, KwaZulu-Natal Sharks Board acting head of operations, said this had been one of the best and most consistent sardine runs experienced in many years. Thompson said the combination of a healthy biomass of sardines, a good following of associated predators and good sea and weather conditions had contributed.
Daily News