Can you farm sea urchins?
by Rebecca Sherratt, Production Editor, International Aquafeed
Sea urchins don"t immediately come to mind when thinking of the variety of delectable goods we farm from the seas, but they soon might be. A team of three companies, based in Canada and Norway, are researching into the perfect feed for sea urchins to make this spiny echinoderm a popular food source for consumers worldwide.
Sea urchins (Echinoidea) come in 200 different varieties, distinctive by their long spikes completely covering their hard shells, which they use to move about and trap particles of food. They dwell upon the ocean floor and coral reefs worldwide, typically preferring warmer temperatures.
They are omnivorous creatures, but mainly feed upon algae on the rocks, and sometimes treating themselves to decomposing matter such as mussels, decomposing fish, sponges and barnacles (but this is not natural for them). They can live between 15 years to an astonishing 200 and can grow between 3-10cm in size.
Japan is in fact, one of the only countries which farm and regularly eat sea urchins. Often compared to the taste of scallops, with a smooth and custard-like texture, the Japanese regularly have sea urchin (uni) sushi, and sea urchin roe, which is actually the reproductive organs of the sea urchin. Considered a delicacy, sea urchin roe can retail for over US $450 per kg, served raw as sashimi or often with soy sauce and wasabi. In the Mediterranean, people often eat sea urchin with lemon, whilst in New Zealand "kina" is the name of their raw delicacy of a sea urchin nature.
The companies behind the magic
Canadian company Green Seafoods is working with Memorial University scientists on grow-out trials for sea urchins. However, this isn"t the first time Green Seafoods have tried this. Back in 2000, the company tried similar tests, however, they came across issues when trying to use a feed which increased the roe to a marketable size.
Mark Sheppard, Operations Manager for Green Seafoods, describes the difficulty the company had in using the right kelp-based feed for the sea urchins; "Fresh kelp is difficult to gather year-round here and when we fed [sea urchins] any fish for protein, they ended up tasting like what they had just eaten. We couldn"t sell them." Despite the attempt all those years ago being a failure, Green Seafoods are now determined to try again, with the help of Norway-based Urchinomics.
Urchinomics is a global organisation that ensures the use of sea urchins in scientific testing, taste profiles and business operations are safe and sustainable. They transform specific forms of kelp into feed for sea urchins, feed which finally look like they can successfully make sea urchins marketable to an international industry.
Urchinomics has engaged fishers, ecologists and scientists and distribution partners. This 360° approach benefits from over 20 years of insight in the feed department from partners like Nofima, a Norwegian fisheries institute, who supplied an urchin feed recommendation and research to Japan"s Mitsubishi Corp, who are currently tweaking the urchin feed in preparation for commercialisation.
Urchinomics has been supplying their technology globally for grow-out trials over the past several years. At Newfoundland"s Memorial University"s Ocean Sciences Centre, they finally think they are onto a winner. Sheppard sounds especially confident, stating that, "We know that [Urchinomics feed] works in the lab. We are going to do some full-blown commercial trials."
Sheppard states that he thinks the best area for farming sea urchins is in Canada, where green urchins (Strongylocentrotus droebachiensis) swarm the area in abundance and are available throughout the year. Sea urchins are also much easier to maintain than normal fish that are farmed for aquaculture purposes, not having the same food or water flow demands that many finfish require.
The feed formulations at Urchinomics have undergone intense, detailed enhancements, to ensure that the future of sea urchin farming only continues to expand. Urchinomics President, Brian Tsuyoshi Takeda, says they are now in the process of refining the feed formulation, in order to enhance performance and ecological footprint.
"Our first major step was to replace all animal-based ingredients (fish oil and fishmeal) with sustainably harvested kelp alternatives. This makes our feed even more environmentally sustainable as we are now fishmeal and fish-oil as well as hormone and antibiotics-free", Takeda clarifies.
Among these changes, the variety of kelp utilised in the feed has also changed. The largest kelp variety that Urchinomics now use in their sea urchin feed is Japanese kombu (Laminaria japonica).
"This kelp species is naturally incredibly high in umami (savoury taste), so we have high hopes that by using the best ingredients, we can also make the best urchins", continues Takeda.
Urchinomics unique approach also benefits kelp restoration. Kelp forests are the ocean's natural nurseries for fish and marine diversity. Human overfishing of predatory species like lobsters, crabs and cod from the worlds oceans has uleashed a population explosion of sea urchins that have decimated some of the world"s most productive kelp forests. This has created the perfect conditions for the humble sea urchin to reproduce unhindered, to overgraze on the kelp forests and creating "urchin barrens"- a near lifeless environment, an empty desert void of shelter and breeding grounds for fish.
The irony is that, after destroying the kelp forests and collapsing its dependant food chain, urchins draw down on their energy stored in their roe sacs and starve. These empty urchins become unattractive for predators or human consumption as they have little or no roe in them, one of the world"s most exclusive seafood products.
If nothing is done, urchins will occupy once-productive kelp forests, keeping them barren for decades or even centuries, and likely expand to new kelp forests to ravage, making them a dangerous environmental threat that can be minimised with the development of sea urchin farming, also known as ranching, in most countries.
The Urchinomics solution is to engage fishers, ecologists, and scientists to identify and remove empty, unproductive urchins that hinder kelp forests from recovering and place them in quality ranching facilities to encourage economic gain for local communities ready for export.
The benefits to mass sea urchin ranching are plentiful. Before, when fishers would gather sea urchins when out at sea, these urchins would prove useless and void. With the introduction of a feed that renders sea urchins worthy of mass-farming, each harvest will only prove to be a success. Sea urchins are easy to farm and will be cost-effective to harvest, as they can be harvested in almost any conditions at any time.
The low-maintenance of sea urchins also makes them a desirable and prospering business. Urchinomics" sea urchin farms are only small yet provide ample space for their produce. With Urchinomics feed, even empty sea urchins with small roe"s can be fed up and enlarged in just six to 10 weeks.
Prior to the refinement of Urchinomics feed, one additional reason why sea urchins were so rarely farmed in Western markets was due to their unreliability. Wild caught sea urchins tend to vary in taste, roe yield and colour. Farmed sea urchins remove this problem, creating a healthy, desirable batch of urchins regularly and without worry.
Overfishing of sea urchins" natural predators, such as crabs, lobsters and cod, also mean that sea urchins are plentiful. By farming these spiky urchins, some alleviation will be provided for other, overfished wonders of the sea.
"We are taking barren urchins, harvesting them sustainably and using a land-based system to turn them into a high-value product that can support our Canadian labour costs", Sheppard concludes. "Given our proximity to Europe, we are going to look for markets in that direction first." Sheppard"s optimism is contagious, and as trials continue at the Marine Sciences Centre, we could all soon be seeing sea urchins on the menu.