Abalone Farm - Jacobsbaai Sea Products
You hear a lot about farmed mussels, oysters and other sea foods, but as abalone farms are something of a rarity it was a great opportunity for the team at Food With A Story to cover something a bit different.
While staying near the West Coast town of Saldahna we were able to visit a local abalone farm (also known here in South Africa as perlemoen) run by a company called Jacobsbaai Sea Products. You hear a lot about farmed mussels, oysters and other sea foods, but as abalone farms are something of a rarity it was a great opportunity for the team at Food With A Story to cover something a bit different.
The first impression you get on entering the farm is the clinical nature of the set up – rows and rows of rectangular white plastic tanks and endless lengths of water pipes. It all seems quite removed from the rugged coastline of South Africa’s west coast, the wild habitat of this variety of exotic sea creatures.
But of course there is a reason for this orderly set up. Like any farm, it’s all about maximising the output of product from a given area. The farm has been carefully designed to ensure each stage of raising the abalone minimises livestock losses and maximises growth rates. Our guide for the day, Hendri Endermann (hatchery manager), informs us that they mimic the natural processes from each stage of the lifecycle so while it all seems very artificial the abalone are raised in an environment very similar to their natural habitat.
The spawning process
The first link in the chain is the spawning process. The male and female are kept in separate tanks to prevent ‘spontaneous spawning’ which can result in wasted eggs. Hendri used a plastic spatula to pull out one of the "granddaddy breeding males" from the tank; it was a massive 2kg specimen whose age Hendri was unsure of.
Spawning is induced by mimicking the conditions that occur out in nature. The tanks are first drained representing spring low tide. The animals are then exposed to the air for around 45 minutes to an hour. The next lot of water filling the tanks is heated to a temperature 2 to 4 degrees Celsius warmer than the original water – this reflects the naturally warmer water from the incoming tide. The oxygen levels of the water are also altered. This combination indicates to the abalone that it is now time to spawn.
The males release sperm in the male tanks some of which is removed and added to the female tanks. The females pick up on the chemical cue the sperm creates in the water (along with the other cues such as the spring tide and warmth) and know it is time to release their eggs.
The eggs are then syphoned out into a bucket and the sperm filled water from the male tanks (a white murky colour) is introduced to the eggs for fertilisation in the larvae room.
During the initial larval period the abalones don’t require any food and survive solely on the nutrients provided to them from the egg. They don’t need to eat for the first ten days of their lives. The water coming into the larvae tanks is filtered down to one micron, thus removing any possible contaminants or pathogens.
When they are six days old the foot of the abalone has developed to the point where it can adhere to a surface. At this stage the animal is only around 40 microns in diameter and completely translucent – it’s almost impossible to see at this point and looks like a little speck of dust in the water.
The settlement tanks
The larvae are introduced to settlement tanks where they survive on micro-algae. The algae comes into the factory by way of natural sea water that is pumped into the tanks and begins growing on any suitable surface where sunlight is present.
At around two months of age you can start to distinguish the actual shape of the animal which now has its shell. It is a grazer, feeding on the micro-algae and you can watch them moving around the provided surfaces munching their way through the food source.
The weaning section
At about three to three-and-a-half months of age the abalone are removed from the settlement tanks and taken to the weaning section where they get to experience solid food for the first time. They are fed commercially produced abalone feed building up to the point where they can eat sea kelp sustainably harvested from the west coast region.
After five months of age they begin to feed on the kelp until they are big enough for harvesting. They are generally ready for export at about four years of age, weighing between 120 to 160 grams.
Some of the animals are processed into dried abalone on the farm by deshelling them, removing their intestines and then cooking and drying them. But the vast majority of the abalone are exported live, mostly to the Far East.
Unfortunately, at this point you can’t purchase abalone from the farm here in South Africa.
Some interesting facts
- The maximum lifespan of a farmed abalone is approximately 40 years, which is longer than they would survive in the wild.
- 1.5 million litres of water is pumped into the farm every hour from the nearby bay.
- Global warming is having an effect on the farm – they have noticed an increase in the sea temperatures over the past few years. This change in temperature also changes the pH level of the water and can have an effect on the way the animals grow. In fact wild abalones are threatened extinction caused by the acidification of as the reduced pH erodes their shells. It is possible that abalones will become extinct within 100 years given the current rates of carbon dioxide production.
- The abalone has very simple vision in that it can only see light / dark and movement – it has no focusing ability. The main sense it utilises is its sense of smell which it uses to find food through changes in chemical concentrations in the water.
These abalone babies are 2.5 months old. They now have their shells and are visibility moving around the surface.
In this small section of the farm there are over 250 thousand abalone alone - tiny ones.
A male abalone - Hendri points out the sperm sac.
The larger abalone are sorted and graded regularly to separate the different sizes. When they reach between 120-160 grams, they are ready for export.
Growing abalone - 1.5 million litres of natural seawater is pumped into the farm daily to mimic their natural habitat.
A brief look at an abalone farm
Identifying male and female abalone
The abalone spawning process
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