Sustainable harvesting of wild seaweed resources

Abstract

Macroalgae have played an important role in coastal communities for centuries. In the past, they have been harvested and gathered from shorelines around the world for traditional uses such as food, animal feed and a crude fertilizer (marine manure). Today, seaweeds are used in a multitude of applications with expanding global industries based on hydrocolloids, cosmetics and food supplements, and also as a potential biofuel source. However, of the approximately 10 000 algal species reported to exist, only a small number are commercially utilized. While representing only a small fraction of total global seaweed production, harvesting and gathering 'wild' seaweeds has had, and continues to have, an integral role in many coastal societies, often being intrinsically linked to the cultural identity of those coastal communities. Today, 32 countries actively harvest seaweeds from wild stocks, with over 800 000 t harvested annually from natural beds. It is vitally important that seaweeds are utilized sustainably and that natural resources are effectively managed by coastal communities with vested interests around the world. As the popularity of seaweeds increases and the use of less traditional species with novel applications comes to the fore, it is critically important to make certain that the sustainability of the resource is ensured given the increased pressures of harvesting. Issues exist regarding ownership of the resource and its over-exploitation, and the implementation of environmentally damaging harvesting techniques must be avoided. Resource scientists, managers, conservationists, governments, and other stakeholders need to be proactive in the sustainable management of these vulnerable, yet valuable, resources.

Translating Ecological Integrity terms into operational language to inform societies

“…Therefore, we believe that part of monitoring for EI should include triggers and responses when in situ scientific observation leads to conclusions of "something is wrong". This structure has analogies with a System Thinking, with an essential feedback component that relates the different levels of the system: 1) observable changes, 2) patterns in changes, 3) complex interactions in the system that conditions its resilience, and 4) individual perceptions of the system that collectively would trigger responses (Maani and Cavana, 2007).…”

“…Stage 1: Commercial harvesting of habitat structuring species, like kelps, is likely to produce pervasive impacts on the ecosystem they create (Mac Monagail et al, 2017). In Chile, more than 250.000 tons of the subtidal kelp Lessonia trabeculata and its intertidal congeneric L. nigrescens are harvested each year; this activity is highest in northern regions but is increasing southwards (Vásquez et al, 2012).…”

Bioextracting Polyphenols from the Brown Seaweed Ascophyllum nodosum from Québec's North Shore Coastline

“…The production of seaweed is promising since the resource is abundant, can be harvested sustainably if well monitored, and has potential for a variety of uses, such as food additives, pet food, fertilizers, biofuel, cosmetics, and medicines. [2][3][4] A lower profit is derived from producing fertilizers and animal food additives, 5 due to high volumes of biomass required for a low-value product. Some seaweed productions are used for high-value ingredients in the cosmeceutical industry, since marine algae contains polyphenol compounds, which are substances that protect the cellular structure from oxidative damage.…”

Sustainable Harvesting of the Ecosystem Engineer Corallina officinalis for Biomaterials

“…Algae are increasingly important as a potentially sustainable resource for biotechnological applications (Kim and Chojnacka, 2015;Rocha et al, 2018). Whilst microalgae are suitable for culture in bioreactors and some macroalgae, or seaweeds, are grown on frames and ropes in the open water (FAO, 2003(FAO, -2015Chung et al, 2017), other seaweeds are more efficiently harvested from the wild (McLaughlin et al, 2006;Mac Monagail et al, 2017). Wild algae can be commercially harvested either by hand or mechanically.…”

“…However, species with short or delicate thalli are not suitable for mechanical harvesting and must be harvested by hand. Manual (artisanal) harvesting of wild seaweeds has a long history in coastal communities, where they have been collected for food, medicine and as a soil improver (Reed, 1907;Morrissey et al, 2001;Mac Monagail et al, 2017;Yang et al, 2017). Manual harvesting is informed by traditional practices and hand harvesting of seaweeds is largely regarded as sustainable (McLaughlin et al, 2006;O'Toole and Hynes, 2014).…”