10,500 species of seaweeds, only six genera provide 98.9% of the production and
98.8% of the value: Saccharina, Undaria, Porphyra, Gracilaria, Kappaphycus and
Sargassum. Unfortunately, not much of that is produced in the Western World as
96.3% of seaweed aquaculture is concentrated in six Asian countries: China (with
over 54.0% of production), Indonesia, the Philippines, the Republic of Korea, Japan
and Malaysia (Chopin 2014). Currently a total of 54,000 t of seaweed have been
cultivated in the Americas and Europe with an annual value of US $51 million in
2013 (FAO 2016a, b), which is even less than the value that Korea exported to the
U.S. in the same period (US $67 million; Meekyiung Kim, Korea Agro-Trade
Center pers. comm.). Seaweed production in the Americas and Europe is still in its
early stages compared to the vast production in Asia. Although seaweed aquaculture is a fairly new industry in the Americas and Europe, the market demand is
expected to increase rapidly due to an increasing consumer demand for new protein
sources and healthy food supplements and the food industry’s interest in sustainable
textural additives (Buchholz et al. 2012).
There are some characteristics that will foster the production of seaweed
worldwide. They provide ecosystem services, which need to be recognized and
valued appropriately (Chopin 2014). One often forgotten function of seaweeds is
that they are excellent nutrient scrubbers and can be used for nutrient biomitigation
of fed aquaculture or other sources of nutrification. Seaweeds can be cultivated
without the addition of fertilizers and agrochemicals, especially in an IMTA setting,
where the fed aquaculture component provides the nutrients. Seaweed cultivation
does not require more arable soil and transformation of land for agricultural
activities with accompanying loss of some ecosystem services. If appropriately
designed, it can be seen as engineering new habitats and harboring thriving communities, and can be used for habitat restoration. Moreover, it does not need irrigation, on a planet where access to water of appropriate quality is becoming more
and more an issue. As photosynthetic organisms, seaweeds are the only aquaculture
component with a net production of oxygen. All other fed and organic extractive
components are oxygen consumers. Hence, seaweeds contribute to the avoidance of
coastal hypoxia. While performing photosynthesis, seaweeds also absorb carbon
dioxide and hence participate in carbon sequestration, even if in a transitory
manner. Consequently, they could be a significant player in the evolution of climate
change, slowing down global warming, especially if their cultivation is increased
and spread throughout the world. By sequestering carbon dioxide and increasing
pH in seawater, seaweeds could also play a significant role in reducing ocean
acidification at the coastal level (Clements and Chopin 2016).
The IMTA concept (Chopin et al. 2001; Troell et al. 2003; Neori et al. 2004;
Chopin 2006) is a good illustration of how to take advantages of the ecosystem
services provided by extractive species and fits very well within the concept of
circular economy (Pearce and Turner 1989). Moreover, seaweed production doesn’t
compete with other food productions while delivering new biomass flows for
2 Offshore and Multi-Use Aquaculture with Extractive Species…
27
98.8% of the value: Saccharina, Undaria, Porphyra, Gracilaria, Kappaphycus and
Sargassum. Unfortunately, not much of that is produced in the Western World as
96.3% of seaweed aquaculture is concentrated in six Asian countries: China (with
over 54.0% of production), Indonesia, the Philippines, the Republic of Korea, Japan
and Malaysia (Chopin 2014). Currently a total of 54,000 t of seaweed have been
cultivated in the Americas and Europe with an annual value of US $51 million in
2013 (FAO 2016a, b), which is even less than the value that Korea exported to the
U.S. in the same period (US $67 million; Meekyiung Kim, Korea Agro-Trade
Center pers. comm.). Seaweed production in the Americas and Europe is still in its
early stages compared to the vast production in Asia. Although seaweed aquaculture is a fairly new industry in the Americas and Europe, the market demand is
expected to increase rapidly due to an increasing consumer demand for new protein
sources and healthy food supplements and the food industry’s interest in sustainable
textural additives (Buchholz et al. 2012).
There are some characteristics that will foster the production of seaweed
worldwide. They provide ecosystem services, which need to be recognized and
valued appropriately (Chopin 2014). One often forgotten function of seaweeds is
that they are excellent nutrient scrubbers and can be used for nutrient biomitigation
of fed aquaculture or other sources of nutrification. Seaweeds can be cultivated
without the addition of fertilizers and agrochemicals, especially in an IMTA setting,
where the fed aquaculture component provides the nutrients. Seaweed cultivation
does not require more arable soil and transformation of land for agricultural
activities with accompanying loss of some ecosystem services. If appropriately
designed, it can be seen as engineering new habitats and harboring thriving communities, and can be used for habitat restoration. Moreover, it does not need irrigation, on a planet where access to water of appropriate quality is becoming more
and more an issue. As photosynthetic organisms, seaweeds are the only aquaculture
component with a net production of oxygen. All other fed and organic extractive
components are oxygen consumers. Hence, seaweeds contribute to the avoidance of
coastal hypoxia. While performing photosynthesis, seaweeds also absorb carbon
dioxide and hence participate in carbon sequestration, even if in a transitory
manner. Consequently, they could be a significant player in the evolution of climate
change, slowing down global warming, especially if their cultivation is increased
and spread throughout the world. By sequestering carbon dioxide and increasing
pH in seawater, seaweeds could also play a significant role in reducing ocean
acidification at the coastal level (Clements and Chopin 2016).
The IMTA concept (Chopin et al. 2001; Troell et al. 2003; Neori et al. 2004;
Chopin 2006) is a good illustration of how to take advantages of the ecosystem
services provided by extractive species and fits very well within the concept of
circular economy (Pearce and Turner 1989). Moreover, seaweed production doesn’t
compete with other food productions while delivering new biomass flows for
2 Offshore and Multi-Use Aquaculture with Extractive Species…
27