Can We Help With Kelp
Kelp forests, one of the planet's most productive and diverse ecosystems, are under
threat due to climate change, ocean warming, and overgrazing by sea urchins. This has
led to a significant decline or complete disappearance of these forests in some regions,
such as Australia, with severe consequences for the biodiversity and economy of the
Great Southern Reef.
Various methods are being explored by scientists and conservationists to restore and
protect these crucial ecosystems. These include transplanting kelp from healthy donor
sites, selectively breeding heat-tolerant kelp strains, and deploying artificial reefs to
provide substrate and shelter for kelp and other marine life.
However, finding suitable locations and conditions for kelp growth and survival is a
challenge. While artificial reefs can offer some of the requirements, they may not always
be effective or suitable for the local environment. They can also be expensive, difficult to
install and maintain, and potentially harmful to existing marine life.
A promising approach to kelp forest restoration involves the use of man-made seaweed
reefs. These reefs, made of biodegradable mesh cubes seeded with native kelp species
and weighted with recycled rocks, mimic the natural structure and function of kelp
forests. Deployed in areas where kelp forests have been lost or degraded, they provide a
temporary scaffold for kelp growth and establishment. Over time, the kelp forms a
canopy that shades and protects the reef, creating a complex habitat for various marine
species. The mesh cubes eventually degrade, leaving behind a self-sustaining kelp forest.
This method has been successfully tested in several locations worldwide, including the
UK, Norway, and Australia, showing promising results in terms of kelp survival, growth,
and diversity. Man-made seaweed reefs are relatively low-cost, easy to deploy and
monitor, and environmentally friendly. They also have the potential to enhance the
ecosystem services and benefits of kelp forests, such as carbon sequestration, coastal
protection, and fisheries production.
However, man-made seaweed reefs are not a panacea for kelp forest restoration. They
face challenges and limitations, such as suitability for areas with high wave energy,
strong currents, or sedimentation, which can dislodge or bury the cubes. They may also
require ongoing management and protection from human activities that can damage or
disturb the reefs. Furthermore, they may not be sufficient to cope with the increasing
frequency and intensity of marine heatwaves, which can cause mass mortality of kelp
and other marine organisms.
Therefore, man-made seaweed reefs should be considered a complementary tool for
kelp forest restoration, not a replacement for natural kelp forests. They should be
accompanied by other measures, such as reducing greenhouse gas emissions,
enhancing kelp resilience and adaptation, and restoring kelp predators and herbivores,
to ensure the long-term survival and recovery of kelp forests and the Great Southern
Reef. This approach underscores the importance of a comprehensive strategy for the
restoration and preservation of these vital ecosystems.