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Kelp blends appear in countless agricultural products across Australia. Farmers use them for soil health, root growth and plant protection. Their popularity is clear, yet the supply of natural kelp is shrinking, raising questions about long-term sustainability.
How King Island Kelp Supports Agriculture
King Island, off Tasmania’s northwest coast, once saw bull kelp wash ashore en masse after storms. Locals collected it by hand and sold it to processors, who turned it into feed, fertiliser or ingredients for cosmetics and pharmaceuticals. Cattle even grazed directly on kelp along the rocks. The industry supported dozens of families and supplied a growing national market.
Kelp extracts provide alginates, micronutrients and organic compounds that improve soil structure and support beneficial microbes. Farmers report healthier plants and improved drought resilience when using these products.
Declining Kelp Forests Along Australia’s Southern Coast
Recent years have brought a sharp decline in kelp on King Island. Researchers from the University of Tasmania’s Institute for Marine and Antarctic Studies report a 95 percent drop in giant kelp since the 1940s, driven by warming seas. Stronger, more frequent storms tear kelp from its rocky foundations, while invasive species strip the seafloor bare. Ocean currents carry warmer water further south, slowing growth and limiting reproduction.
The Great Southern Reef, stretching over 8,000 kilometres along the southern coast, relies on these kelp forests to support more than 1,500 marine species. Declining kelp threatens these ecosystems and the industries that depend on them.
Future of Biostimulants and Sustainable Agriculture
Much of the kelp used in agriculture comes from wild harvest, not cultivation. Scarcity disrupts supply chains and increases risk for producers. Farmers face uncertainty in sourcing products with consistent composition and performance.
This raises a challenge: maintaining crop and soil benefits without overharvesting fragile ecosystems. Some companies experiment with controlled cultivation or synthetic alternatives, but few replicate the full range of compounds found in wild kelp.
At AquaBoostAG, our focus has always been to help growers improve soil and plant health in ways that are both effective and environmentally responsible. Our intensive research and development program has identified a locally sourced seagrass extract that can deliver a more potent mix of bacteria and fungi than existing kelp formulations. These next generation biostimulants are sustainable and perform consistently.
The decline of Australia’s kelp forests is a reminder that environmental and agricultural sustainability are deeply connected. The health of our oceans ultimately affects the health of our soils, our crops and the communities that depend on them.
Work is underway to translate this knowledge into new products, designed to meet growers’ needs while keeping ecosystems intact.
Sources
- Australian National Maritime Museum, Signals 135: “The Life and Loss of Kelp”
- McLennan, A., triple j Hack: “Treasure That Washes Up on the Shoreline”
- Ling, S. & Keane, J., 2024, “Climate-driven invasion and incipient warnings of kelp ecosystem collapse,” Nature Communications
- Institute for Marine and Antarctic Studies, University of Tasmania
