7.6 Environmental Implications
157
algae blooms, well-controlled algae growth in a balanced ecosystem can be an efficient means of keeping the water bodies clean and safe. In some parts of the world,
biological methods of cleaning water bodies include the use of aquatic plants and
algae for biological nutrient uptake. The process involves an extraction system built
into the flow channel which is comprised of aquatic plants and algae. As the water
flows through the channel, it passes through the extraction system where the plants
and algae extract the nutrients and the water exits the channel cleaner than it entered.
This process of extraction of nutrients from the water can be integrated into the cultivation of biomass for the production of agar (Rocha et al. 2019). The limitation of
such systems is controlling the nutrient level in the water coming from homes and
industry to achieve the desired growth conditions for agar production and ensuring
that the agar produced is not contaminated and safe for intended applications.
Another approach of integrating seaweed cultivation is integration of integrated
multi-trophic aquaculture (IMTA). This process capitalizes on the synergy between
fish growth and algae growth and nutrient requirement. The algae take up the nutrients
produced by the fish and in turn produce the oxygen required by the fish. An example
of an IMTA system cultivates Gracilaria alongside the milkfish (Bixler and Porse
2011).
Agar production therefore adds value to red algae beyond food. This is particularly
important as outside of Asia; algae are not commonly consumed as food in other parts
of the world. There are therefore less incentives for them to be cultivated or preserved
as a natural resource. Creating awareness of the value of red algae encourages better
preservation of the resource and diversifies interest from aquatic species which are
currently being fished at unsustainable rates.
7.6.2 CO 2 Emission
While agar in itself is a biodegradable polymer with no direct adverse impact on the
environment, the process of production and the chemicals used in the production can
result in considerable generation of CO 2 , use of fossil energy and the toxification
of human and aquatic environment. The growth and cultivation of algae for the
production of agar mitigate against some of these environmental impacts as algae
remove CO 2 from the environment for the production of polysaccharides and other
organic compounds which can then be used by humans, agar being one of such.
Algae also remove nutrients from the water and are used for cleaning up polluted
water as a biological treatment method.
The cultivation of red algae removes CO 2 from the environment and can therefore
be considered as carbon negative. 260 thousand tonnes of carbon can potentially be
converted into biomass by macroalgae annually, assuming that all of this carbon is
generated from the CO 2 fixation from the environment (Chung et al. 2011; Sahho
et al. 2012). The process of extraction does not involve direct release of CO 2 into the
environment. However, other processes attached such as transportation, packaging
157
algae blooms, well-controlled algae growth in a balanced ecosystem can be an efficient means of keeping the water bodies clean and safe. In some parts of the world,
biological methods of cleaning water bodies include the use of aquatic plants and
algae for biological nutrient uptake. The process involves an extraction system built
into the flow channel which is comprised of aquatic plants and algae. As the water
flows through the channel, it passes through the extraction system where the plants
and algae extract the nutrients and the water exits the channel cleaner than it entered.
This process of extraction of nutrients from the water can be integrated into the cultivation of biomass for the production of agar (Rocha et al. 2019). The limitation of
such systems is controlling the nutrient level in the water coming from homes and
industry to achieve the desired growth conditions for agar production and ensuring
that the agar produced is not contaminated and safe for intended applications.
Another approach of integrating seaweed cultivation is integration of integrated
multi-trophic aquaculture (IMTA). This process capitalizes on the synergy between
fish growth and algae growth and nutrient requirement. The algae take up the nutrients
produced by the fish and in turn produce the oxygen required by the fish. An example
of an IMTA system cultivates Gracilaria alongside the milkfish (Bixler and Porse
2011).
Agar production therefore adds value to red algae beyond food. This is particularly
important as outside of Asia; algae are not commonly consumed as food in other parts
of the world. There are therefore less incentives for them to be cultivated or preserved
as a natural resource. Creating awareness of the value of red algae encourages better
preservation of the resource and diversifies interest from aquatic species which are
currently being fished at unsustainable rates.
7.6.2 CO 2 Emission
While agar in itself is a biodegradable polymer with no direct adverse impact on the
environment, the process of production and the chemicals used in the production can
result in considerable generation of CO 2 , use of fossil energy and the toxification
of human and aquatic environment. The growth and cultivation of algae for the
production of agar mitigate against some of these environmental impacts as algae
remove CO 2 from the environment for the production of polysaccharides and other
organic compounds which can then be used by humans, agar being one of such.
Algae also remove nutrients from the water and are used for cleaning up polluted
water as a biological treatment method.
The cultivation of red algae removes CO 2 from the environment and can therefore
be considered as carbon negative. 260 thousand tonnes of carbon can potentially be
converted into biomass by macroalgae annually, assuming that all of this carbon is
generated from the CO 2 fixation from the environment (Chung et al. 2011; Sahho
et al. 2012). The process of extraction does not involve direct release of CO 2 into the
environment. However, other processes attached such as transportation, packaging