The island of Tasmania, located 150 miles south of Australia’s mainland, is home to many spectacular landscapes, animals, and people with over 20% of the island designated as a World Heritage Area. Tasmania is also known for producing some of the best seafood for the country of Australia, but over the last 15 years, a species of long-spined sea urchin has taken over the island’s east coast wreaking havoc on the island’s valuable ecosystems. Traveling from Australia’s mainland where the urchins are native via the East Australian Current, they have already impacted the wild abalone stocks (an edible rock-clinging gastropod mollusk) as well as the rock lobster industry.
According to John Keane of the University of Tasmania’s Institute for Marine and Antarctic Studies, the Tasmanian winter sea temperatures have risen over the last 40 years from 11 to 13 degrees Celsius. This increase in sea temperature has created the proper conditions for the long-spined sea urchin larvae to be able to develop into adults. A recent estimate revealed that there are over 18 million long-spined urchins currently in Tasmania. When these urchins reach a high enough number, as they already have, they can overgraze native kelp beds which then turns healthy reef ecosystems into barren areas of rock. Thus far, 15% of the Tasmanian reefs have become barren due to the invasive urchins.
What is Australia doing about this issue? A government-backed, multifaceted approach encouraging commercial fishing operations to help keep long-spined sea urchin numbers in check has been made with hopes to protect the country’s $218 million abalone industry. Ralph’s Tasmanian Seafood has historically been a company that exports wild-caught abalone but saw firsthand as the stocks dwindled due to the urchins. In response to this crisis, the company decided to run an experiment, so-to-speak, where they began processing the invasive sea urchins with goals of exporting roe (the edible part of a sea urchin) to the Japanese market.
What started as an experimental phase back in 2017 has since transformed into the company producing at full capacity, processing 15 to 20 tons of the long-spined sea urchin every week! The roe is being sold internationally to countries such as Japan, Malaysia, Singapore, Hong Kong, and the United States, as well as domestically to Sydney fish markets and high-end restaurants. Ralph’s Tasmanian Seafood’s primary focus remains on the international market, especially Japan, because Australians aren’t as familiar with roe. Whereas in Japan, sea urchin roe is considered a popular delicacy, especially in their sushi bars.
To ensure they were meeting Japan’s high standards, Ralph’s even hired a Japanese urchin roe technician to teach their staff how to select and pack the product correctly. Simon Leonard, a sea urchin processing manager for Ralph’s Tasmanian Seafood stated, “Basically, we see it as an opportunity to not only do something to help the environment but also turn a pest into profit.” The work Ralph’s is doing couldn’t have come at a more critical time as new research published in Pacific Conservation Biology claims invasive pests are the number one threat to Australia’s most at-risk species – above climate change, land clearing, and energy production. As with the case of the long-spined sea urchins in Tasmania however, there is a combination of threats impacting one isolated area.