Southern Eyre Marine Farm (SEMF) is located on the Eyre peninsula of South Australia near Port Lincoln, on the coast in the vicinity of Louth Bay. It is nestled on the land ward side of some coastal sand dunes and is around 60 meters from the sea.
SEMF specialized in Green Lip Abalone. They were marketed at a size of 75 mm for use in the food industry. Abalone fetch a very high market price. SEMF has the facilities to breed it's own stock.
A small experimental grow-out of snapper has been trialed.
SEMF was primarily an abalone farm. Green lip abalone are the only species that are farmed, however some Roei abalone that are endemic to the area somehow get into the pens as well. My opinion is that they come through the sea inlet as spat (tiny baby abalone) and are flushed into the pens through the water taps. They are almost indistinguishable from the green lip except for the fact that they grow slower. Green lip are a cold water abalone that prefer to live in deeper water than some other species. Like all abalone, they eat algae.
The animals shown in this photograph are green lip abalone at SEMF. The blue colour of their shells is caused by the use of artificial feeds. In the wild the shells are much darker in colour. The white spots on the shells are growths of coral. Photo by Brian Degger
All the farm stock is bred in the hatchery. Adult abalone are induced to spawn and the resulting eggs and sperm are mixed in a bucket (yes, that's how it's done). The spat (tiny baby abalone) are reared in the hatchery until they are ready to be placed out into the abalone pens.
Once placed into their pens the abalone take around four years to reach market size. They are fed on a synthetic food that has the strange effect of turning their shells blue. Abalone are messy and their pens require constant cleaning. The Green lip abalone grows fastest at a temperature of around 20C.
Main pumping station
Sea pipes entering the back of the pumping station
Settling tank, the heart of the farm
Sea water for the farm is pumped directly from the sea. A series of pipes have inlets that are well out from the beach, in 16 feet of water. At this depth the worst of the unwanted seaweed is avoided, and the water is cool. The pipes are buried under the beach sand and only emerge when they reach the pumping station.
The pumping station is the heart of the farm. It pushes the sea water up to a settling tank which is located on the highest point of the compound.
The settling tank holds a high volume of sea water, and allows any solid debris in the water to settle to the bottom and avoid being piped into the abalone pens. The accumulated debris at the bottom of the tank must be purged when it builds up to excess. A series of pipes allow sea water to flow by gravity into all the out-door abalone pens on the farm.
Pen drainage system
OUT-DOOR ABALONE PENS
SEMF uses several different abalone grow-out systems, however they can all be classified as 'intense' farming. All the abalone pens have a constant flow of fresh sea water entering them at one end, and a drain at the other. SEMF uses deep concrete tanks and raceways. The deep concrete tanks contain a relatively high volume of water and a low current. They are mainly used for young abalone. The larger abalone are grown in concrete and fiberglass raceways. The raceways are long and narrow, with only a shallow layer of water. Water passes through the raceways at a much faster rate, which ensures that there is no buildup of toxins.
All the drained water from the out-door pens flows through a system of ducts into a large dam.
The recycling dam provides a means by which the sea water can be safely reused. Waste from the drained pens settles to the bottom of the dam while wave action on the surface oxygenates the water. The water from the recycling dam is higher than the sea water which makes it more energy efficient to use. It is pumped into an adjacent shed that contains 14 banks of abalone raceways.
This system involves banks of abalone raceways located in a shed instead of out-doors. This avoids excess heating of the water by sunlight and reduces the mortality rate. Each bank is six raceways deep and three long. Although the shed is a relatively small part of the farm, it houses a large percentage of the stock. The drainage water from the shed disperses into two settling ponds.
The settling ponds are the last stage in the water cycle. They ensure that the water discharge from the farm is relatively clean and environmentally friendly. The final drainage from the ponds is released into the sea.
SEMF is equipped with a complete abalone hatchery that is used to breed adult animals and provide baby abalone that number in the millions.
The farm also has an office, tool shed, and backup generator.
Inside the farm compound is an old freshwater well. It was used as a source of fresh water by ships sailing from Pt Augusta to Pt Lincoln in the good old days. The well is now used as a source of water to purge the water intake pipes.
SEMF also raised Snapper, King Fish and Scallops in the dam and ponds. The Snapper quickly became tame and would take food from the hand. They also made entertaining companions when I was diving in the dams to clean the pipes. These guys were the highlight for people who visited the farm.