Sargassum

There are over 300 species of Sargassum algae, ref a group of marine brown algae. However, there are generally two types of Sargassum (floating and non-floating) that vary in their impact to reefs and management strategies needed to address them.

Non-floating Sargassum species are a threat to coral reef ecosystems when they become overabundant on a degraded reef, inhibiting the settlement and growth of coral recruits and reducing the capacity of a reef to recover after disturbances. ref

Management strategies include the active removal of Sargassum algae either by hand or using a suction device. However, the efficacy and long-term effects of these methods are largely unknown. ref Current recommendations include: ref

• Coupling removal with effective protection and potential reintroduction of herbivores
• Removing the holdfast (root) of the Sargassum algae
• Conducting removal in the early growing season of the Sargassum
• Incorporating the effect of seasonality and climate change in the Sargassum removal plan

Floating Sargassum species form thick mats at the water’s surface. While naturally present in open waters of the Northern Atlantic, they have devastating ecological and economic impacts when they drift and smother shallow coral reef areas.

Management strategies include: ref

• Beach clean-ups either by hand or with machinery
• Barrier nets to collect the algae offshore and prevent algae from collecting on beaches

Industries may be able to commercialize collected Sargassum as it can be used as fertilizer, pharmaceuticals, bioplastic production, and even in some Asian inspired cuisine. ref