iMare Natural

Int'l - Restorative aquaculture: know your anemones

A promising integrated multi-trophic aquaculture (IMTA) project aims to restore a threatened sea anemone to a large swathe of the southwest coast of Spain, as well as produce a range of other seafood products.

What are the main challenges to producing anemones in captivity?

Sea anemones adapt well to captive conditions, both in open and closed systems (RAS), provided that they are given the appropriate hydraulic, physical-chemical and environmental lighting conditions.

Once these appropriate conditions are in place, the results are truly amazing: adaptation to a new environment, ease of maintenance, growth and even induced healing after asexual and sexual reproduction. They can even withstand high concentrations of dissolved nitrogen compounds.

There are, however, still some bottlenecks which must be overcome in order to achieve fully sustainable anemone farming.

One of these is the year-round development of new anemones via sexual reproduction. Overcoming this would increase the numbers of anemones that we could produced, which would negate the need to capture wild broodstock. It would also reduce the time spent in the asexual reproduction by division induced. Induced asexual reproduction involves high level of stress for the animals, which can delay their growth.

A second bottleneck relates to obtaining a sustainable feed supply. Anemones’ diets are based upon fish, mussels, crustaceans and other marine invertebrates. Unlike marine fish species, they do not require large amounts of food, so production costs are relatively low. But if the sector was to scale-up, if we use a diet in which all raw materials come from capture fisheries, it would not be sustainable. We therefore need to find other formulations, with raw materials that come from sustainably cultured marine organisms, vegetable proteins, etc. In fact, one of our current research lines is the search for a diet that provides the right nutritional value, while being both economically viable and environmentally sustainable.

There are some similarities between the cultivation of sea anemones and corals: both require a good flow of water, adequate intense lighting and good water quality.

Good water quality, has great relevance because all marine invertebrates are very sensitive to the dissolved nitrogenous compounds. Similarly, other physical-chemical parameters of water (Tª, salinity, pH, phosphate, calcium, and trace elements) must be perfectly balanced to ensure the viability of farming.

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