Octopus Farming
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MORE INFORMATION: Ross Cammilleri, 08 9314 1615, 0419 196 626, [email protected]; 16 Sagiv Kolkovski, 08 9203 0220, 0417 9404 98, [email protected] FRDC RESEARCH CODES: 2009/206, 2010/212 PHOTO: D PHOTO: E PARTM en T O F F ISH E RI E S, W Brave new world A of octopus farming a clutch of octopus (octopus tetricus) eggs. as in Mexico – and with its excellent eating Research Laboratories (WAFMRL) based at aquaculture qualities and high growth rates (up to three Hillarys Boat Harbour, north of Perth. countering territorial behaviour and the kilograms a year) O. tetricus offers real commercial The aim was to imitate commercial reality propensity of octopus to escape from possibilities,” Ross Cammilleri explains. and develop a system that could be replicated even the most securely closed tank The Cammilleris were granted an aquaculture in any country and be a profit-yielding systems have been among a number licence and lease at Garden Island, WA, enterprise. The costs of running the system – of achievements and world firsts to to ocean-ranch juvenile octopus, but Ross including equipment set-up, such as tanks and come from australian efforts to develop Cammilleri says it is not possible to source pumps, as well as resources, such as labour, aquaculture techniques for the species enough juveniles from the wild-capture fishery electricity, water and feed – were analysed. to make ranching independently commercially viable. This requires closing the life cycle of the Ranching By Rose Yeoman species and developing tank-based production Sagiv Kolkovski and his team had to solve several ctopus was once considered bycatch in the systems to breed juveniles in sufficient issues to develop the commercial tank-based o rocklobster industry and used primarily as numbers to supply ocean-based ranches. ranching system. He explains that in the wild, bait, but is now considered a gourmet seafood The dual advantages of this are the octopus exhibit territorial behaviour and will and Australian consumers just cannot get enough. preservation of wild stock and the production aggressively defend their range. In Spain and other However, wild-capture fisheries are unable to keep of controlled-sized animals (about 1.5 countries developing this type of aquaculture, up with demand, leading fishers to investigate kilograms) to meet the market. this behaviour is controlled by providing hides the aquaculture potential of the species. In order to move from ranching to a in the form of PVC tubes, so each octopus has Western Australia’s octopus fishery is whole-of-lifecycle approach in an aquaculture its own territory in which to grow and develop. relatively new; it was officially established in setting, the Cammilleri brothers approached “But these hides limited the biomass in the 1999 and targets Octopus tetricus. But even in the Department of Fisheries, WA. tank and the harvesting and maintenance. This its first few years, it was clear that demand included cleaning, which was a huge issue,” Sagiv exceeded supply. Model octopus farm Kolkovski says. “From day one, I wanted to Brothers Ross and Craig Cammilleri, who Working with the Cammilleri brothers, grow octopus as I grow fish – without a hide.” founded Fremantle Octopus Pty Ltd and its Sagiv Kolkovski was appointed the principal He and his team discovered they could subsidiary Occoculture Pty Ltd, have been the research scientist to lead a four-year, FRDC- intensively grow octopus in tanks without hides main drivers behind research into octopus supported project, which has made major when individuals were all of a similar size. “When aquaculture. The brothers were keen to move gains in understanding the behaviour and this occurred, none of the individuals displayed from octopus fishing to ‘ranching’, where wild- life cycle of O. tetricus, while analysing its aggression or cannibalism, as they inevitably caught juveniles, the bycatch of adult harvest, commercial viability for aquaculture. did in a mixed-size population. We found there are grown in land-based tanks or offshore cages. This includes the development of was an inverse relationship between octopus “Ranching is gaining popularity in Europe a 15-tank model octopus farm at the density in the tank and the degree of aggression – especially in Spain, Italy and Greece, as well Western Australian Fisheries and Marine and cannibalism. We added so many to the MarcH 2015 FISH aquaculture 17 PHOTO: DEPARTMENT OF FISHERIES, WA An octopus interacts with a researcher. PHOTO: BRADPHOTO: COLLIS Sagiv Kolkovski (front), principal researcher for the octopus aquaculture study, developed a 15-tank model octopus farm at the WA Fisheries and Marine Research Laboratories based at Hillarys Boat Harbour. tanks that we had to install flat PVC sheets so positioned a few centimetres above the perimeter the most difficult aspect of closing the life cycle. they would have more surface to attach to as of the tank, but the escapes continued. As Sagiv Kolkovski explains, octopus species the tank walls were completely occupied.” The solution ultimately devised is both display one of two types of egg production. In Not having hides saved up to 80 per cent of simple and elegant: a band of woven shade some species, up to 150 ‘large’ eggs (like a ball the tank cleaning and maintenance work that cloth around the perimeter of the tank. bearing) are produced and the individuals that would otherwise have been required, which Shade cloth has a porous, woven structure hatch are 1.5 to 2 centimetres and look and translated into cost savings. “It simplifies the that permits airflow. This prevents an octopus behave like miniature versions of the adult. whole system. A tank can be cleaned in just a latching on with the suckers on its tentacles, In the second form of egg production, which few seconds, so there is no marine growth or which require a vacuum to work. The solution occurs in O. tetricus, 100,000 to 200,000 very bacteria on the walls,” Sagiv Kolkovski says. completely prevents escape and has the small eggs are produced and they hatch to produce added advantage of being easy to drop down embryos (called paralarvae) with leg buds, an ink World firsts during feeding or when cleaning the tank. sac and a primitive digestive system. In nature, In Spain, the maximum biomass harvested the chances of any one paralarva from this second from aquaculture systems using hides is Breeding bottleneck group surviving to an adult are much lower than 15 kilograms per cubic metre of water. The Early in the project it became apparent that that of a juvenile octopus hatched fully developed. WA octopus farm harvested 54 kilograms per survival rates of paralarvae represented a In the ocean, O. tetricus paralarvae cubic metre, a biomass production rate never significant ‘bottleneck’ in the system and would be develop over a two-month period, and at 55 before achieved in octopus aquaculture. It was also a ‘world first’ to recognise that octopus could be tank-grown without hides and that in high-density, size-matched populations octopus behaviour was modified and switched from being individual and A territorial to behaving as a ‘school’, with A no signs of cannibalism or aggression. Another first was developing a simple mechanical method of preventing them from engaging in the kamikaze habit of hurling themselves out of the tank and onto the floor. Octopus are known to be masters ARTMENT FISHERIES, OF W ARTMENT FISHERIES, OF W EP EP D of escape and heavy steel mesh is usually D used to cover tanks to prevent this. PHOTO: PHOTO: Looking for alternatives, the research team PHOTO: first tried a low-voltage pulsing electric fence A developing octopus egg. Hatching paralarva. FISH Marc H 2015 18 aquaculture PHOTO: BRAPHOTO: rates of paralarvae increased, metamorphosis to juvenile octopus was not achieved. D Aside from nutrition, environmental factors COLLIS were also considered. The team investigated photoperiod and light intensity and found that paralarvae have a strong positive response to light in the first two weeks of life and then develop a more negative response. Light intensity was manipulated and adjusted to suit these physiological requirements as it affected feeding behaviour within the tanks. ‘Green water’, which is the addition of microalgae into the paralarvae tank, was also tested. While adding green microalgae, such as species in the genus Nannochloropsis, to finfish larvae tanks is a necessity and has become standard practice, it had no effect on octopus paralarvae survival or growth. octopus ranching tank. While the ultimate goal of closing the life cycle of O. tetricus was not fully achieved, major advances in understanding were made. to 60 days post-hatching they metamorphose Management and natural induced spawning of over 48 hours to become juveniles. octopus broodstock was achieved and eggs and Yet in an aquaculture tank, among the A paralarvae can now be produced on demand. Larval hundreds of thousands of paralarvae produced S, W systems, environmental conditions and nutrition E RI during the course of the study, only one – an E were all developed and knowledge gained in these ISH F individual nicknamed ‘Bob’ – survived to develop areas will assist in accomplishing a commercial F into a juvenile octopus. This was such a rare and T O octopus breeding program in the future. exciting event that technician Nicole Watts baked en a cake and held a birthday party in Bob’s honour. Global industry PARTM E Both Sagiv Kolkovski and Ross Cammilleri Feed efforts acknowledge the need for more research to Sagiv Kolkovski says one of the main issues D PHOTO: unlock the nutritional and environmental with rearing paralarvae is nutrition and little is a juvenile octopus. code required to close the octopus life cycle in known about their nutritional requirements.