research - aquaculture
Microalgae are an essential food for many larval and juvenile aquacultured
animals. Within Australia, target species that rely on microalgae
during their larval phase include oysters (edible and pearl), scallops,
abalone, prawns, rock lobster and various fish species.
Popular microalgal species used in their culture and supplied by
the CSIRO Microalgae Supply Service include
Isochrysis sp. (T.ISO), Pavlova lutheri, Chaetoceros
muelleri, Chaetoceros calcitrans, Nannochloropsis oculata, Skeletonema
costatum and Tetraselmis suecica. Also, in response to
industry needs, we have isolated and developed new Australian strains
that are more suited to specific Australian environments and/or
the nutritional requirements of animals. These Australian microalgae
include Pavlova pinguis, Skeletonema sp, Rhodomonas
salina and Navicula jeffreyi.
We have analysed the biochemical composition of over 50 microalgae
either currently being used, or of potential use as aquaculture
feeds, to assess their nutritional value. Most microalgae are very
rich sources of the polyunsaturated fatty acids that are essential
for marine larvae (see figure below). Other important nutrients
that we have found to be variable in microalgae include sugars,
vitamins, and sterols, with gross composition depending on species.
In addition to the biochemical screening of microalgae, we are
collaborating with the CSIRO Nutrition Project to assess the nutritional
value of microalgae to filter feeders such as oysters, scallops
and prawns, and grazing abalone. These studies include the development
and evaluation of products derived from algae, such as microalgae
concentrates or "pastes" which have a prolonged shelf-life.
We are also examining the transfer of algal nutrients (especially
polyunsaturated fatty acids and vitamins) through food chains, i.e.
microalgae to zooplankton to fish or crustacean larvae.
Last updated
18/03/09
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