Benguela (Southern) - Key Species
Horse Mackerel (Trachurus trachurus capensis)
Horse mackerel are commonly known as maasbanker in South Africa. Juvenile horse mackerel are pelagic, feeding on zooplanktonic prey and thus often shoaling with anchovy and sardine, hence caught in the purse seine fishery (but managed by means of an upper precautionary catch limit). Larger horse mackerel are more piscivorous, feeding more in the midwater, on fish such as lanternfish, lightfish and gobies, but also eat polychaete worms and bottom-dwelling as well as planktonic crustaceans. Larger horse mackerel are caught in the directed midwater trawl fishery. Horse mackerel are considered to be moderately fished off South Africa.
Sardine (Sardinops sagax)
Sardine are locally called pilchard, and by virtue of their size, are the preferred small pelagic fish species as they are suitable for canning purposes. Juvenile sardine often shoal with juvenile anchovy, resulting in a bycatch of juvenile sardine in anchovy-directed fishing operations. Sardine is predominantly a filter feeder, consuming small sized zooplankton and some phytoplankton. Sardine abundance was at a low in the 1970s and 1980s but began to increase again in the late 1990s. Sardine off southern Africa is considered to be fully exploited (FAO).
Anchovy (Engraulis encrasicolus)
In South African waters, anchovy is predominantly a particulate feeder, concentrating on larger zooplankton prey than sardine. Anchovy are mostly caught as recruits (6 month old fish) and are commercially important for the reduction fishery producing fish meal. Anchovy sustained the purse seine fishery on small pelagics through the low sardine abundance period of the 1970s and 1980s, are still currently considered fully exploited (FAO).
Redeye round herring (Etrumeus whiteheadi)
Redeye round herring for the third of the small pelagic fish trio in the southern Benguela, and like anchovy, they are used for fish meal. They are caught as bycatch in sardine-directed operations and also in directed operations, although in smaller quantities than anchovy and sardine, and are considered to be moderately fished (FAO). Redeye tend to school closer to the sea bed during the day than anchovy and sardine and are thus not as available to diving seabird predators.
Snoek (Thyrsites atun)
The predatory fish, snoek, is a fast-swimming large pelagic fish caught along the South African west coast. Being a highly popular eating fish in the Cape, snoek is prized by handline fishermen and are also caught in bottom trawls. Being an opportunistic predator, and the availability of snoek to fishermen is strongly dependent on the distribution of prey such as anchovy, sardine, redeye round herring, hake, lightfish, lanternfish, as well as planktonic crustaceans such as euphausids and mantis shrimps. Snoek is considered to be fully exploited off the South African coast.
Deep-water Cape Hake and Shallow-Water Cape Hake (Merluccius paradoxus, Merluccius capensis )
The hake fishery is the single most important fishery operating off South Africa, and hake are probably the most commonly consumed fish species in South African households. They are caught near the sea bed by means of bottom trawl nets during the day. Two species of hake are found off Southern Africa, deep-water and shallow-water Cape hake, named according to the depth of water they tend to inhabit. The species are treated separately in the provision of scientific management advice, but not differentiated in landings. Although hake are largely considered to be bottom-dwelling (benthic) fish, they spend a substantial part of their time in near-surface waters, rising from the bottom at dusk to feed, particularly on small pelagic fish. Juvenile hake are pelagic in life style, feeding on planktonic crustaceans just like small pelagic fish, and thus competing with them. Large shallow-water Cape hake are found in the same areas as small deep-water Cape hake, and prey heavily on these, although large individuals eat smaller ones of the same species as well. They are highly opportunistic predators, adapting their diet seasonally and spatially to the availability of fish prey. Data suggest that hake are fished to their maximum sustainable level off South Africa. Demersally-trawled hake are considered to be sustainably fished, whereas hake caught in the South African demersal longline fishery are cause for concern (www.wwf.org.za/sassi).
Kingklip (Genypterus capensis)
Kingklip is a highly valuable groundfish species off South Africa, taken as bycatch in the hake trawl and longline fisheries. Being opportunistic scavengers feeding on the bottom, kingklip predominantly lie in wait in burrows or rocky crevices for suitable prey items to come along. The species is overexploited and consumers are being encouraged to make alternative choices in restaurants, although fishery improvement projects are underway (The Southern African Sustainable Seafood Initiative www.wwf.org.za/sassi/).
Monkfish (Lophius vomerinus)
Monkfish, also known as anglerfish, are taken as bycatch in the hake fishery and are of high commercial value. By virtue of their similarity in taste to that of crayfish, monkfish are often called mock crayfish and are particularly good in seafood cocktails, but also enjoyed as whole eating fish. Monkfish are relatively sedentary fish, using an extension of their dorsal fin as a lure to entice prey, mainly benthic fish, towards them. Internationally, monkfish is overexploited, although South African catches have been stable. Consumers are cautioned to think twice when purchasing South African monkfish (See here).
Chokka Squid Loligo (Loligo reynaudi)
Chokker squid is targeted by the South African squid jig fishery, operating off the south-east coast of South Africa, and is also caught as by-catch in the demersal trawl fishery. The species is characteristic of the warmer Agulhas Bank region, where they spawn in large aggregations, rather than the Benguela upwelling area on the west coast. Squid are fairly heavily preyed upon by several fish and mammals, and themselves, at least when mature, consume small fish such as anchovy, thus likely playing an important trophic role in the ecosystem. The species is considered to be fully exploited (FAO).
Cape fur seal (Arctocephalus pusillus pusillus)
The Cape fur seal population declined as a result of seal harvesting in the early 1800s and most of the 1900s. Seal pups aged 7-10 months were prized for their pelts. Sealing was stopped in South Africa in 1990 but is still permitted in Namibia, where bull seals are also harvested as a source of aphrodisiacs for the Asian market. Seals are commonly viewed as a menace by fishermen, as they interfere with fishing operations, although scientific studies have shown that competition between seals and hake fishing operations is limited. Seals eat sardine, anchovy, horse mackerel, hake and squid. Seals are a protected species off South Africa.
Marine birds
Fifteen species of seabirds breed on islands or at mainland sites off south-western Africa, all of which enjoy legal protection in South Africa: African penguin Spheniscus demersus, Cape gannet Morus capensis, four species of cormorant, three species of gull, five species of tern, and the white pelican. African penguin and Cape gannet are important for the ecotourism industry, yet, on the basis of their large population declines, they have been classified as Vulnerable species of conservation concern according to The World Conservation Union (IUCN) criteria, highlighting the urgency for effective management measures. Because marine birds and mammals are confined to the vicinity of terrestrial localities for breeding, they are especially influenced by the availability of prey fish within their restricted foraging ranges during the breeding season. The halving of the African penguin breeding population off South Africa in recent years (2002-2006) is thought to be at least partly due to the southward and eastward shift in sardine, an important and nutritious prey for penguins. Measures to ensure sufficient pelagic fish prey available to penguins in the vicinity of breeding islands are currently being actively investigated.