Navigating Challenges in the Sea Urchin Conundrum

By: IAAS Secretariat

In the temperate waters of New South Wales and various coastal regions of Australia, a significant shift in the population dynamics of the long-spined sea urchin, a keystone species, is causing concern among marine ecologists. The surge in their numbers, attributed to rising ocean temperatures, has set off a ripple effect, leading to imbalances in marine ecosystems.

These sea urchins thrive in waters with temperatures above 12 degrees Celsius during winter. With global ocean temperatures rising at an alarming rate of 4 degrees Celsius per century, sea urchins are finding new territories to repopulate, particularly from eastern Victoria down to Tasmania, creating marine deserts.

The long-spined sea urchin primarily feeds on kelp. However, their overabundance in a kelp forest transforms it into an urchin barren, where kelp struggles to regrow, rendering the area uninhabitable. This poses an imminent threat to Australia’s great Southern reef and kelp forests.

Remarkably, sea urchins are considered a delectable delicacy worldwide, from Southeast Asia to the Mediterranean. Valued at around $100 per kilogram, the potential for urchin fisheries presents itself as a viable solution.

While these fisheries have the capacity to remove large quantities of urchins at a relatively low cost across expansive areas, challenges arise in the labor-intensive extraction process of the edible gonads and variations in urchin quality due to overgrazing. Additionally, specifics about processing and market access are often closely guarded, hindering transparency. Nonetheless, the Tasmanian government has thrown its support behind urchin fisheries, recognizing their potential to mitigate overabundance and confine the sea urchins within their habitat.

Another avenue involves introducing natural predators of sea urchins. The Tasmanian East Coast Rock Lobster Rebuilding Strategy attempted to boost wild rock lobster numbers while addressing the sea urchin issue. However, challenges emerged as rock lobsters showed a preference for local prey like abalone, limiting their ability to restore barren areas and diminishing their appeal for recreational or commercial fishing.

In facing these challenges, creative solutions have emerged, positively impacting economies beyond the marine realm. A burgeoning urchin fishery has the potential to generate numerous jobs, and processors gain financial stability, fostering confidence in business investment. This not only boosts regional economies but also contributes to reducing urchin barrens.