Algal Forests - Ocean Central

Macroalgae, such as kelp, are not yet officially recognized as a Blue Carbon ecosystem under UNFCCC policies due to limited scientific data, especially regarding carbon assimilation rates and the fate of exported macroalgae. Recent studies, however, challenge this view and suggest that seaweeds are globally significant contributors to oceanic carbon sinks.

The current percentage of macroalgae falling within marine protected areas remains unclear. To safeguard these ecosystems, expanding MPAs to include algal forests is essential. One effective approach is creating “no-take” zones where fishing and harvesting are prohibited, allowing predator-prey dynamics to stabilize and enabling natural regeneration. In certain cases, areas where some regulated activities are permitted may be more practical, avoiding intensified pressures on nearby areas outside of MPAs.

The excessive population of sea urchins, due to a decline in their natural predators, is a primary cause of algal forest degradation. Restoring populations of key predators like sea otters, lobsters, and large fish helps control herbivorous sea urchins, mitigating overgrazing. In regions with low predator numbers, direct sea urchin culling may be necessary to reduce the immediate threat to algal forests.

Climate change poses a significant threat to algal forests, particularly as warming waters and ocean acidification affect their health. Global efforts to reduce carbon dioxide emissions are critical. Additionally, identifying and protecting areas where algal forests show resilience to temperature changes will help target conservation efforts, securing ecosystems that are more likely to adapt to future conditions.

Sustainable practices in fishing, tourism, and agriculture are essential to minimize pollution and habitat degradation.

Seaweed aquaculture provides an alternative source of macroalgae for industrial, pharmaceutical, and food purposes, alleviating pressure on wild forests. By expanding seaweed farming, coastal communities can simultaneously support economic development and reduce the exploitation of natural macroalgal forests.

In heavily degraded areas, active intervention may be required to restore algal forests. This can involve replanting or reseeding, either by transplanting healthy specimens or cultivating them in nurseries before outplanting. In cases where the natural rocky substrate has eroded, building artificial reefs or restoring natural substrates can encourage macroalgae to recolonize barren areas.

Nature-based solutions, such as using algal forests for coastal defense, can protect shorelines from erosion while restoring ecosystems. 

Incorporating algal forest restoration into marine spatial planning, alongside managed retreat zones and dedicated areas for seaweed farming, can ensure that restoration goals are met.

Involving local communities in the restoration process is key to long-term success.

Ongoing scientific research is vital to identify best practices for algal forest restoration. Large-scale mapping and long-term monitoring programs should track the success of restoration efforts, assessing factors such as plant growth, biodiversity recovery, sediment deposition, and the ecosystem services provided by restored algal forests.