6.2 Occurrence in Nature
123
and is one of the species of economic importance in the northeast coast of Brazil
(Souza et al. 2018). Red algae grow in the epipelagic (sunlight) zones of the sea.
Some freshwater red algae also exist (Sheath and Vis 2015), albeit rare.
Until the 1970s, carragenophytes, mainly K. alvarezii and Eucheuma denticulatum, were obtained only from wild stocks. As the technology to cultivate
carragenophytes began in the Philippines and Indonesia where they were first cultivated, carragenophyte cultivation spread to other regions of the world where it
has become a significant source of livelihood for many seaweed farmers in countries such as Tanzania and Vietnam. Today, some carragenophytes are still harvested
from the wild. For example, the Betaphycus gelatinum is harvested in regions in
the Philippines China, Hainan Island and Taiwan Province of China, and G. skottsbergii, Sarcothalia crispata and Mazzaella laminaroides are harvested in some parts
of Chile. Gigartina skottsbergii also grows in Argentina. However, over 90% of the
carragenophytes are cultivated. In other regions such as the Prince Edward Island in
Canada, USA and France, carragenophyte commonly grown here is the C. crispus.
Gigartina canaliculata and H. musciformis grow in Mexico and Brazil, respectively.
In some cases, the occurrence of the wild-growing species can be sporabic. Chile is
one example where all of the carragenophytes produced in this region are sourced
from natural stock. Despite this reliant on naturally existing carragenophytes, there is
no report of overharvesting and sufficient aquatic space exists for further expansion
of carragenophyte cultivation.
Carrageenans yield obtained from bench-scale extractions are around 34.3%
(Manuhara et al. 2016) although the actual content of carrageenan in red algae could
be higher since the yield of extraction is highly dependent on the efficiency and
method of extraction. Seaweeds from which carrageenans are obtained are referred
to as carragenophytes. The types of red algae from which carrageenans are sourced
vary with the locations within which they exist or conditions within which they can
be cultivated. Main factors for growth include temperature, salinity, water current,
nutrients composition and water depth which in turn affect light intensity. Most
algae exist in the epipelagic zones of the water (see Chap. 2 on aquatic ecosystem
classification) where sufficient light penetrates for photosynthesis.
One of the red algae species which is the most common source of carrageenan is
K. alvarezii. This species grows in marine water where the temperature is ~21 °C and
there is sufficient bright light for growth. This species grows well in water exposed to
slow to moderate tides and rocks, sand and coral substrates. Another species which
grows in this region is the E. denticulatum prefers moderate to strong tides and B.
gelatinum grows in stronger tides close to the reef edge.
Species which grow at warmer temperatures include chondrus crispus which
grows in the littoral fringe with moderate light and large rock areas. In colder climates, it grows best in the summer periods and late spring with minimal growth in
winter. G. skottsbergii also grows in warmer seasons in the sublittoral region on the
sea. M. laminaroides and sarcothalia, G. canaliculata and H. musciformis all grow
along the seashore line while S. crispata grows in the epipelagic zone. Cultivations
in tanks and seaweed farms require mimicking these growth conditions for optimal
yield of the particular species of interest.
123
and is one of the species of economic importance in the northeast coast of Brazil
(Souza et al. 2018). Red algae grow in the epipelagic (sunlight) zones of the sea.
Some freshwater red algae also exist (Sheath and Vis 2015), albeit rare.
Until the 1970s, carragenophytes, mainly K. alvarezii and Eucheuma denticulatum, were obtained only from wild stocks. As the technology to cultivate
carragenophytes began in the Philippines and Indonesia where they were first cultivated, carragenophyte cultivation spread to other regions of the world where it
has become a significant source of livelihood for many seaweed farmers in countries such as Tanzania and Vietnam. Today, some carragenophytes are still harvested
from the wild. For example, the Betaphycus gelatinum is harvested in regions in
the Philippines China, Hainan Island and Taiwan Province of China, and G. skottsbergii, Sarcothalia crispata and Mazzaella laminaroides are harvested in some parts
of Chile. Gigartina skottsbergii also grows in Argentina. However, over 90% of the
carragenophytes are cultivated. In other regions such as the Prince Edward Island in
Canada, USA and France, carragenophyte commonly grown here is the C. crispus.
Gigartina canaliculata and H. musciformis grow in Mexico and Brazil, respectively.
In some cases, the occurrence of the wild-growing species can be sporabic. Chile is
one example where all of the carragenophytes produced in this region are sourced
from natural stock. Despite this reliant on naturally existing carragenophytes, there is
no report of overharvesting and sufficient aquatic space exists for further expansion
of carragenophyte cultivation.
Carrageenans yield obtained from bench-scale extractions are around 34.3%
(Manuhara et al. 2016) although the actual content of carrageenan in red algae could
be higher since the yield of extraction is highly dependent on the efficiency and
method of extraction. Seaweeds from which carrageenans are obtained are referred
to as carragenophytes. The types of red algae from which carrageenans are sourced
vary with the locations within which they exist or conditions within which they can
be cultivated. Main factors for growth include temperature, salinity, water current,
nutrients composition and water depth which in turn affect light intensity. Most
algae exist in the epipelagic zones of the water (see Chap. 2 on aquatic ecosystem
classification) where sufficient light penetrates for photosynthesis.
One of the red algae species which is the most common source of carrageenan is
K. alvarezii. This species grows in marine water where the temperature is ~21 °C and
there is sufficient bright light for growth. This species grows well in water exposed to
slow to moderate tides and rocks, sand and coral substrates. Another species which
grows in this region is the E. denticulatum prefers moderate to strong tides and B.
gelatinum grows in stronger tides close to the reef edge.
Species which grow at warmer temperatures include chondrus crispus which
grows in the littoral fringe with moderate light and large rock areas. In colder climates, it grows best in the summer periods and late spring with minimal growth in
winter. G. skottsbergii also grows in warmer seasons in the sublittoral region on the
sea. M. laminaroides and sarcothalia, G. canaliculata and H. musciformis all grow
along the seashore line while S. crispata grows in the epipelagic zone. Cultivations
in tanks and seaweed farms require mimicking these growth conditions for optimal
yield of the particular species of interest.