World Wildlife Fund Sustainability Works

Person hauls seaweed in from the ocean

From Sea to Table: Wild Harvested Kelp Versus Farmed Kelp

  • Date: 02 October 2023

Seaweed, although often overlooked in Western diets, has been a staple in many Asian cuisines for centuries. This rich source of vitamins, minerals and antioxidants is valued for its savory umami flavor. The cultivation of kelp, a popular type of seaweed, has a much lower environmental footprint compared to traditional agriculture on land. As climate change and increasing resource consumption create concerns over food security, kelp is gaining recognition as a food source with a low environmental impact. But many misconceptions still surround this sustainable superfood. In the first blog post of our Seaweed Explainer Series, we’ll examine the differences between wild harvested kelp and farmed kelp.

Wild harvesting involves the collection of kelp from natural kelp forests in the ocean. While this method has been practiced by coastal and Indigenous communities for generations, it is unable to sustain the rising global demand for seaweed. If wild kelp is harvested faster than it can grow back, populations can be depleted over time, eventually threatening the health of the entire kelp forest ecosystem. Overharvesting also harms the many species that depend on kelp forests for food and shelter, including sea otters, fish, octopuses and invertebrates. Not all wild kelp harvesting is unsustainable, but overharvesting is a risk in areas where the activity isn’t sufficiently regulated.

By contrast, farmed kelp offers a profitable and sustainable solution. Farming kelp involves taking just a few blades of kelp from a natural kelp bed, which produce millions of spores that can be propagated in a designated underwater area. Because these spores are grown in controlled conditions, their survival rate is significantly higher than if they were growing in the wild. Farmers then have full ownership over the new patch of kelp they’ve created, whereas wild harvesters have to negotiate with others for a limited resource. This technique can satisfy the rising demand for seaweed while reducing pressure on wild populations, so that kelp forests can recover.

Kelp is a powerful carbon sink, pulling large amounts of carbon dioxide from the atmosphere as it grows. It is one of the only foods that has a negative carbon footprint! Additionally, kelp production requires no freshwater, pesticides or fertilizers. While wild kelp harvesting may carry the risk of ecological harm, kelp farming offers a reliable option that augments the total population of kelp in the ocean. In our next blog post, we’ll explore other applications for seaweed, including livestock feed, biofuels, fertilizer, and more.


Tags And Categories