I’ve received this from a friend of mine. I decided to share it for information sharing purposes. Not sure who the author is but I agree with his sentiment.
The life of a kob, Namibia’s most popular line caught fish, is a mystery to most people but very
interesting to those in the know. It’s a life fraught with danger from natural enemies throughout its
different lifecycles up to a maximum age of about 28 years. And then of course there is man
waiting with his baited hooks and nets. Silver kob (Argyrosomus inodorus) occurs along Namibia’s
1600 km long shoreline roughly from Meob Bay in the Namib Naukluft Park in the south, across
the centrally located West Coast Recreational Area to about halfway to the Kunene River in the
Skeleton CoastPark.
These facts and what follows are results obtained through the Namibian Angling Fish Tagging
Program (NAFTAP) that was initiated 20 years ago. To date almost 30 000 kob were tagged of
which 456 were recaptured giving us their size/weight ranges, growth rates, geographical
distribution and migratory cycle. Biological studies showed us what they eat, how they reproduce
and how they age. Most fish were tagged in the areas closed to shore anglers, principally to
determine to what extent those tagged fish would move into or “seed” the “open” area, the West
Coast Recreational Area which constitutes only one fifth of the coastline.
It is in this stretch of coast that about 180 000 angler outings occurs annually. And yes with
today’s modern rods & reels, GPS points and 4×4 vehicles sucha number of anglers can overfish
the kob stock if strict angling regulations are not in place. By interviewing anglers while they are
actively fishing and sampling their catch (roving kreel surveys) we can, by using a specially
designed computer model, determine how many kob are available to harvest and based on that
adapt the daily bag limit per angler in order to sustainably utilise the kob stock. Thus, in 2001 the
bag limit was lowered from 30 fish per angler to only ten.
To follow the life of a kob we have to start in the Skeleton Coast Park where the main breeding
stock lives. Here the cold Benguela Current provides a rich diet of small pelagic fish, chokka and
shrimps for them. These adult fish are between 60 to 120 cm in length in an age range of
between 5 and 28 years old. Large adults, called spawners, of 70 cm and bigger start their
annual spawning (breeding) migration southwards against the surface currents, at the beginning
of the austral summer to their main spawning grounds, Sandwich Harbour and Meob Bay, at the
southern end of their distributional range. This is also the time when the warm Angolan Front
starts pushing southwards bringing warm, saline water and sometimes tropical fish species such
as shad and garrick from mid-Angola as far south as Swakopmund.
On their way down the coast some large predators such as pelagic sharks will catch a few of
them while shore anglers at Terrace Bay and Torra Bay will catch many of them. They will also
pass though the seal colonies of Möwe Bay, Torra Bay, Toscanini and Cape Cross but seals are
more interested in the oily and tastier small pelagic shoaling fish such as pilchard or horse
mackerel which they can catch easily rather than spending a lot of energy chasing a fast
predatory fish such as kob. After feeding at Toscanini Bay they will cross into the WCRA and will
appear briefly at popular angling spots such as Horingbaai, Mile 72, Jakkalsputz and so forth
where they will feed in the shallow bays. Surprise, here hundreds of baited hooks from shore
anglers awaits them but it’s only those anglers that can cast far that will be lucky and many
spawners will end up in the bag.
In addition, between Henties Bay and Swakopmund skiboats will now hunt them just behind the
breakers and their numbers will decline further as many are hauled aboard. This is very easy
once the onboard fishfinder has located the school. Just drop the baited hook overboard and it
will instantly be swallowed by the hungry fish. Now comes the last gauntlet before the safety of
Sandwich Harbour namely the famous Paaltjies numbers 1 to 3.
The bush telegraph worked well and here hundreds of shore anglers will await their arrival, even
anglers from South Africa will arrive on short notice to take part in the feast. Fortunately the kob
keeps moving and soon the lucky ones will reach the safety of Sandwich Harbour which is closed
to angling from 25 January to 15 April each year since 1992 specifically to offer protection for
these spawners. Since 2001 when the angling permit system has been introduced, a maximum
size limit has also been introduced through which an angler may only keep two kob of 70 cm and
bigger in a further effort to protect the breeding stock.
Spawning now takes place between here and Meob Bay, 180 km further south. The females will
release their eggs in batches while the males fertilises them with their milt. Some will be caught
by the research team here for research purposes and they will be measured, weighed, tagged
and released again. This procedure takes about 1-2 minutes. By the end of March when the
water temperature decreases to about 15°C they will begin their long journey back home moving
slightly off-shore.On their way they may be caught by mid-water trawlers or purseseiners but the
high bycatch levy on kob makes the skippers think twice before hauling anyaboard. During the
winter months they were traditionally caught by lineboats on their home grounds. However, since
April 2008, lineboats may only catch snoek. This was done because their catches of kob over the
last six season has declined dramatically as they could not find the large kob on the traditional
fishing grounds. With this management measure in place we hope that the stock will recover
sufficiently.
Meanwhile the eggs will hatch and the larvae now drifts north with the current to the nursery and
juvenile grounds around Swakopmund in the WCRA. At this stage they might become the prey of
jellyfish and other small predators. Those that survive will grow rapidly and reach 30 cm within
one year and they will be hunted by larger fish such as snoek, sharks, skates and seabirds.
When these juveniles reach the age of approximately 2 years at about 40 cm, they will gradually
move north towards the adult home ground, the Skeleton Coast Park waters. This is also the size
at which about 50% of the population reaches sexual maturity. Therefore,to give them all a 50%
chance to reproduce at least once in their lifetime a minimum length of 40 cm was introduced in
2001.
Here in the relative safety of the Skeleton Coast Park they will feed and grow until they become
adults at the age of about 7 years. Now their growth will slow down to save that energy for
reproduction and to take part in the yearly spawning migration. So the life of a kob starts, comes
full cycle, and ends.
7 replies on “The life of a kob, Namibia’s most popular line caught fish!”
Very interesting and informative post!
Thank Gunnar. They have been biting well this year. I’ve only caught 2 as per the Namibian Rules. Still awesome to catch them.
Raymond,Baie dankie vir n baie insiggewende en interesante artikel.Ek was vanaf 3/11/2017 by Hentiesbaai vir kabeljou hengel en ons het baie goed gevang.Ek het al baie by Henties,sowei as Terracebaai gehengel,maar dis die eerste keer at ek ooit in November gaan en ek was eintlik geskok om te sien dat elke liewe vis vol kuite is,wat my laat wonder het of dit nie ook n geslote maand moet wees nie!
Sal die vis wat in November gevang word n noemswaardige nadelige invloed he of word te min gevang
Ek dink nie daar sal ‘n noemenswaardige verskil wees in die hoeveelhede wat by Paaltjies gaan broei nie. In November is daar meer broei vis in die water wat na Paaltjies beweeg en die rede hoekom meer kuite gesien word. Ek glo maar dat die hengelaars by hul kwotas moet bly dan sal daar meer uit broei wat daar en teen weer beter vangste oor 3 – 5 jaar sal veroorsaak.
Daar is op die oomblik baie jong vis in die water en ook mooi klas vis wat trek na hul broei velde. Die wat dat daar so baie jong vis laat my dink dat die ekologie gesond is en dat vangste baie beter gaan wees as in vorige jare.
Very informative indeed. Thank you for sharing. I wish i could get the reference as it would be helpful for my thesis. I will try to get lead maybe i will somehow be able to find something. Any kind of help will be highly appreciated.
Hi Annette, have you had a chat with Johannes Holtzhausen?
Not recently. Had a chat with him about three years ago but on a different subject. Is he the author of the article?