Follow-up re Sea urchin barrens and mini-barrens
Further to my article titled “Sea urchin barrens and mini-barrens” (http://wp.me/p4BvtZ-pZ ), Society member, David Muirhead commented, “Magazine Bay looks so nice Steve. I can see why you dived that day rather than sat on the beach reading a magazine (or waiting for one to explode)!”
David then added, “PS: the only barrens or minis I’d seen in my early diving days were in Fiji and those were uncommon, but here in SA it is only in the last few decades I’ve increasingly noticed both mini-barrens (quite common) and also larger areas, sometimes on surprisingly shallow sub-tidal rock reefs particularly in our upper Gulfs, which I can’t call barrens but which seemed sparser with regard to macro-algae and had quite high purple urchin densities.
This is pure anecdote, and as I only learned several decades ago of the now commonly accepted connect between locally high urchin densities and ‘canopy brown algal deserts’ I might simply have been overlooking such barrens for the first half of my SA diving life.
However, I do believe there is now an order of magnitude greater population of purple urchins in SA’s inshore marine, and since the worst areas so affected are almost without exception the same areas that have been accessible from early in the phase of European settlement, hence are also heavily silted from altered catchment management, historically over-fished (Note:here I use the term ‘fished’ to include rock lobster and abalone as well as target fish species) and subject to excess land-based nutrient input.
Rather like the crown-of-thorns fiasco in Queensland, the purple urchins might be an indicator of a far greater malaise rather than a main cause of our southern temperate rocky reefs deforestation.”
Later on, Anthea suggested, “If you are interested in the problem of urchin barrens you might like to look up http://www.urchinomics.com.”
According to the web page found at www.urchinomics.com , Urchinomics is “A business solely dependent on transforming ocean health. We only profit as the environment improves. We do this through:
Turning seabed ‘urchin barrens’ into flourishing kelp forests
Converting worthless urchins into luxury food
Generating value exclusively by restoring marine biodiversity
The problem: Kelp forests are one of the most productive and dynamic ecosystems on earth. They provide a habitat for marine life and are a powerful carbon sink. But right now, kelp forests are under threat.
Overfishing of their natural predators, lobster and cod, has led to the overpopulation of urchins. Urchins feed on kelp, and they’re overgrazing, turning once lush kelp forests into barren seabeds. Urchins are a delicacy around the world. But with no kelp to feed on, these urchins starve and lose nearly all of their nutritional goodness and value. They become inedible. The demand for this delicacy outstrips the supply.
The opportunity: What if we could meet that consumer demand? What if it were possible to turn this source of low-quality urchins into an abundance of high-quality food and, in doing so, restore kelp forests?
We’ve found a way. Urchinomics makes it possible to create healthy profits and environments.
Our approach: Right now, divers hand-catch urchins in the hope that they’ll be good to eat. In reality, only 1 in 5 urchins get the best prices. At Urchinomics, we provide the technology and market access to turn barren urchins into perfect urchins, and sell them at a premium to Japan.
Our licensed partners place barren urchins into our specially designed holding systems and feed them with our high-performance, 100% natural urchin feed. Within 8-12 weeks, these once inedible urchins are now ready to be enjoyed at high-end seafood restaurants around the world. Our Licensed partners profit. Kelp forests are restored. The marine ecosystem recovers. And the more this happens, the better we do as a business.
Contact: For more information and to find out about investment or partnership opportunities,
get in touch with Brian Tsuyoshi Takeda, Founder of Urchinomics: firstname.lastname@example.org .”
Our Patron (& Life Member) Scoresby Shepherd discusses urchin barrens in his memoirs (“Underwater is Paradise – memoir of a marine biologist”). He discusses the topic (starting) on pages 77 and 123.
We have copies of Scoresby’s book “Underwater is Paradise – memoir of a marine biologist” for sale for $30 each (plus costs). Contact us at email@example.com to order your copy.
Steve Reynolds is the current President of MLSSA and is a long-standing member of the Society. Steve is a keen diver, underwater explorer, photographer and is chief author of the Society's extensive back catalogue of newsletters and journals.