Fruits of the sea

Umi budo literally translates as ‘sea grapes’ and is known in Australian culinary circles as ‘green caviar’.
Photo: Clive Keenan

By Melissa Marino

For an aquaculturalist, Clive Keenan has an unusual problem. Rather than ensuring his product is kept cold on its way to market, he has to ensure it stays warm.

It is a challenge he found difficult to meet over winter and the supply of his novel product, the edible seaweed umi budo (‘green caviar’), was momentarily suspended. The tropical species has a shelf life of about three weeks, but dies and turns to mush if the temperature becomes too cold.

“It was quite unexpected,” he says.

“You think you’ve solved all the problems of growing the stuff and then transport logistics comes up.”

This prized and in-demand seaweed is commonly farmed in Japan and the Philippines, but as the first and only commercial producer in Australia, Clive Keenan has become accustomed to overcoming challenges. This included figuring out how to grow umi budo – literally translated as ‘sea grapes’ and known in Australian culinary circles as green caviar.

Keeping the details a closely guarded secret, Clive Keenan does divulge that his mariculture farm Coral Coast Mariculture, in Bundaberg, Queensland, has just the right balance of salinity and tropical conditions to foster the species’ growth.

“A lot of farms aren’t suitable because in the wet season salinity levels drop below the level the plants can tolerate,” he says.

“Our farm just happens to be set up very well for maintaining high salinity levels through the wet season.”

In a very small catchment, fresh water runs past the farm for just a short period and a buffering pond further protects it from salinity dilution. Sandy-bottomed ponds also aid production, he says.

Umi budo first came onto Clive Keenan’s radar after he left his job as a fisheries researcher with the Queensland Department of Agriculture, Fisheries and Forestry and began working as an aquaculture consultant in the Philippines. There the seaweed is grown in abundance and sold in large batches at markets.  

He was also aware of the seaweed’s proliferation in Japan’s Okinawa, where it has been cultured for centuries and is known as ‘the longevity seaweed’ and linked to the population’s renowned longevity.

After finding a wild population of the species Caulerpa lentillifera growing in Queensland’s Hervey Bay, Clive Keenan decided to try his luck at home.

Starting with a small biomass he began experimenting and after two years of trials, he found the right balance.

This year he began selling the seaweed commercially, mostly to Australia’s top restaurants, and demand rose quickly to about 40 kilograms per week.

“We have been selling all we can produce,” he says.

Clive Keenan had an inkling of the seaweed’s potential as a food product, given its popularity in Japan and the Philippines.

But he was still surprised and delighted by the response when the product was launched at the Noosa International Food and Wine Festival in May this year. Only two of the thousands of people who tried it at the festival did not like it.

Tasting like caviar with a salty flavour of the sea, umi budo is one of the best edible seaweeds, he says.

“It’s got a lot of texture to it. The little sea balls ‘pop’ and release the flavour into your mouth.”

Umi budo represents about 10 per cent of his aquaculture business, which is largely dedicated to whiting production. He hopes to capitalise on the mariculture possibilities of the species, introducing it to his whiting ponds as well as his fledgling soft shell Blue Swimmer Crab enterprise.

“The whiting don’t eat it and it reduces the nutrient levels in the ponds and puts oxygen back in the water,” he says.

“We think we can integrate production so we get clean, nutrient-rich water and two products out of the same system.”  

Algae, he says, is an underused resource in Australia. He believes there is potential for the use of mass-produced marine algae in the production of biodiesel and has undertaken a ‘desk study’ into the opportunity.

“Some species of algae, if they are treated correctly, produce up to 60 per cent of their mass in oil. So that really is an opportunity for the future,” he says. “And once you extract the oil you end up with a high-protein byproduct.” 

More information

Coral Coast Mariculture, 07 4156 1600