Sardine and anchovy survey shows numbers still very low

It’s troubled waters for SA’s biggest fishery — and that's bad news for people and penguins.

Coming off a decade in the doldrums, anchovy and sardine populations are still weak, the department of environment, forestry & fisheries said this week.

The R1.6b small pelagics fishery targeting anchovy and sardines is SA’s biggest in terms of catch volumes, with an average 277,000 tonnes landed annually, and it employs some 5,000 people.

The little silver fish that underpin the industry are also a fundamental part of the marine ecosystem providing food to a wide range of predators including the endangered African penguin whose numbers, it was confirmed last week, have plummeted 30-40% in the past four years, related to a shortage of prey.

Responding to questions on Wednesday, department spokesperson Zolile Nqayi said the latest annual survey of sardine and anchovy had been undertaken in November 2019.

“The sardine stock was estimated at 193,630 tonnes and the anchovy stock at 843,745 tonnes.

“For sardines, that’s higher than 2018’s estimate, but the second-lowest in the past five years. For anchovy, that’s lower than the 2018 estimate, and the lowest in the past five years.”

Small pelagic species live just three to five years, but when conditions are good they produce huge numbers of eggs and recruited juveniles can quickly swell their numbers, he said.

“The problem is that for the past 10 years conditions have not been good.

“Related to climate change and the warming of sea temperatures there have been repeated red tides, massive algal blooms which poison and starve various species including sardines and anchovies.”

Climate change had also resulted in prolonged, unseasonable southwesterly winds, he said.

“This has suppressed the plant plankton which the small pelagics feed on.”

Nqayi said that after the November assessment, provisional total allowable catch quotas had been formulated and these would be finalised by the end of April.

Pressed on this and the effect of continued fishing on the penguin, he said the department’s research showed fishing was not a major factor in reducing pelagic stocks and was only a minimal force driving the decline of the penguin.

“Under baseline sardine fishing the rate of decline over the next five years would be an annual 10.9% compared with 9.5% if there was no sardine fishing.

“The effect of any decline in penguin numbers is a consideration.

“But we also have to consider the importance of the small pelagics fishery and the huge negative effect in socioeconomic terms that complete closure of the fishery would cause.

“It is a very complex process and we take it very seriously.”

In 2008 NMU-based penguin specialist Dr Lorien Pichegru pioneered a study in consultation with fisheries authorities and the fishing industry geared around temporary no sardine fishing zones declared alternately around Bird and St Croix islands in Algoa Bay.

The study, which was published in the journal of the Royal Society of London, showed that these protected areas around each colony ensured that the penguins did not have to forage so far for food.

This improved their energy and breeding potential, and the time they had to protect their chicks and eggs from gulls — ultimately increasing penguin numbers.

Pichegru said on Wednesday she strongly disagreed with the department’s view that fishing was only a minimal force driving the decline of the penguin.

“It is a major factor and we proved it.

“The delay in implementing these findings with a system of no-sardine-fishing zones around the island colonies is leading to the demise of the African penguin.”