Improve the shellfish industry
Using algae to grow larvae can reduce industry's dependence on wild larvae.
Marine scientists in Scotland have developed a "design" algae that could mark a breakthrough in how the aquaculture industry produces shellfish larvae.
The Scottish mussel industry currently produces around 8 000 tonnes of wild mussels per year and therefore relies on a successful spawning year. This approach is also a factor limiting the expansion of the industry, which has the potential to become a major part of the Scottish economy.
6-10 times more efficient than today's systems
Scientists at the Scottish Marine Science Society (SAMS) in Oban have discovered a new way to raise larvae in hatcheries, feeding the larvae with "well-designed" algae that are selected and bred in the lab for optimal growth. By providing algae with organic carbon and exposing them to varying degrees of light, scientists can control the growth, size, and composition of algae. Since it is controlled and suitable for use as mussel feed, this system is 6-10 times more efficient than current production methods for oysters or other mussel larvae.
This approach could also change the way the biotechnology industry produces microalgae.
Dr. Joe Penhaul Smith, who developed this process at SAMS, published his findings in the Journal of Biological Resources Technology Report (https://doi.org/10.1016/j.biteb.2019.100321) and Aquaculture International (https://doi.org/10.1007/s10499-020-00629-7).
"These algae are not genetically modified, but 'designers' because we can breed these species in different ways to control their nutritional status," Dr Smith said. "We use their natural evolutionary diversity to control how they grow.
"It's more like comparing a person's health: one person eats whatever they can find in the store, and the other follows a managed diet with the goal of staying healthy."
"The system we developed initially requires start-up costs, but in the long run, culturing the larvae to the desired size will save the industry money. I think there are similarities with the green-lipped mussel industry in New Zealand. In the 1990s, the government established an incubation farm at the Cawthron Institute, which now produces about 30 percent of the baby shellfish for the industry. ”
The newly developed feed combines the proportions of three algae species: Tetraselmis and Diatom Triangular Brown Finger Algae Paeaactylum and Cyclotella, all three of which have been used in aquaculture feed.
"Using these technologies is a huge advance in algal production and shellfish aquaculture," said Dr Adam Hughes, Senior Lecturer in Sustainable Aquaculture at SAMS. Harnessing the natural ability of these organisms to grow in different ways means that we can dramatically increase productivity and potentially significantly reduce industry costs. ”
