ArticlePDF Available

The Use of Seaweeds Aquaculture for Carbon Sequestration: A Strategy for Climate Change Mitigation

Authors:
Ellyn Erlania at National Research and Innovation Agency Republic of Indonesia
Ellyn Erlania
  • National Research and Innovation Agency Republic of Indonesia
Nyoman Radiarta at Agency for Marine and Fisheries Extention and Human Resources Developmen
Nyoman Radiarta
  • Agency for Marine and Fisheries Extention and Human Resources Developmen
Download full-text PDF
Read full-text
Download citation

Abstract and Figures

Seaweed has the ability to use carbon from the environment through photosynthesis to produce biomass. The aim of this study is to estimate carbon sequestration by seaweed aquaculture as a strategy for climate change mitigation. The study was undertaken at Gerupuk Bay, Lombok Island, West Nusa Tenggara Province, Indonesia. Four seaweed variants, such as Kappaphycus alvarezii var. Tambalang and Maumere, K. striatum and Eucheuma denticulatum, were cultivated with long-line system for three cultivation periods, starting from July to November, 2013. Each cultivation period was taken about 45 days. Parameters including weight increasement and carbon content of seaweeds were measured every 15 days of culture for each cultivation period in order to calculate carbon sequestration rate. The results showed that E. denticulatum had the highest carbon sequestration rate and significantly different (P < 0.05) compared with other variants for every cultivation period. Different seaweed variants have different capacity on carbon sequestration. Optimal utilization of the potential area for seaweed aquaculture could reduce a great quantity of CO 2 from the atmosphere and help to mitigate global climate change process.
Figures - uploaded by Nyoman Radiarta
Author content
All figure content in this area was uploaded by Nyoman Radiarta
Content may be subject to copyright.
Content uploaded by Nyoman Radiarta
Author content
All content in this area was uploaded by Nyoman Radiarta on Jul 28, 2015
Content may be subject to copyright.
Journal of Geodesy and Geomatics Engineering 2 (2015) 109-115
doi: 10.17265/2332-8223/2015.06.006
The Use of Seaweeds Aquaculture for Carbon
Sequestration: A Strategy for Climate Change Mitigation
Erlania and I Nyoman Radiarta
Center for Aquaculture Research and Development, Ministry of Marine Affairs and Fisheries Republic of Indonesia, South Jakarta
12540, Indonesia
Abstract: Seaweed has the ability to use carbon from the environment through photosynthesis to produce biomass. The aim of this
study is to estimate carbon sequestration by seaweed aquaculture as a strategy for climate change mitigation. The study was
undertaken at Gerupuk Bay, Lombok Island, West Nusa Tenggara Province, Indonesia. Four seaweed variants, such as Kappaphycus
alvarezii var. Tambalang and Maumere, K. striatum and Eucheuma denticulatum, were cultivated with long-line system for three
cultivation periods, starting from July to November, 2013. Each cultivation period was taken about 45 days. Parameters including
weight increasement and carbon content of seaweeds were measured every 15 days of culture for each cultivation period in order to
calculate carbon sequestration rate. The results showed that E. denticulatum had the highest carbon sequestration rate and
significantly different (P < 0.05) compared with other variants for every cultivation period. Different seaweed variants have different
capacity on carbon sequestration. Optimal utilization of the potential area for seaweed aquaculture could reduce a great quantity of
CO
2
from the atmosphere and help to mitigate global climate change process.
Key words: Carbon sequestration, seaweed variants, cultivation, West Nusa Tenggara, Indonesia.
1. Introduction
CO
2
, the main anthropogenic greenhouse gas, if that
releasing into the atmosphere, is responsible for
increasing the greenhouse effect leading to global
warming. Climate change is caused by the massive
increase of GHG (Green House Gases) emission to the
atmosphere, for example carbon dioxide, which is
caused not only from natural factors but also from
human activities (anthropogenic factors) including the
burning of fossil fuels and deforestation [1, 2]. The
impact of climate change on marine environment is
already apparent, such as sea level rise, ocean surface
warming, changing course of currents, acidification of
surface waters, and shifting ranges of natural species
[1, 3-5].
CO
2
gas is present in considerably higher
concentrations in seawater (34-56 ml/l) than in the
atmosphere (0.3 ml/l), partially due to the ability of
Corresponding author: Erlania, M.Si., research fields:
aquaculture, environment, carbon sequestration. E-mail:
erlania_elleen@yahoo.com.
water to absorb more CO
2
than air, in equal volume
[6]. There has been a good deal of interest in the
potential of marine vegetation as a sink for
anthropogenic carbon emissions which known as Blue
Carbon. The concept of Blue Carbon or atmospheric
carbon captured by coastal ecosystems, has recently
been the focus of reports by UNEP (the United
Nations Environment Programme) and IUCN (the
International Union for the Conservation of Nature)
[7]. Seaweed is a potential marine vegetation which
can use solar energy for the bio-fixation of
concentrated CO
2
sources from atmosphere into
biomass that can be used to produce phycocolloid
compound [8]. These macroalgae have relatively
better capability on carbon sequestration than
terrestrial plants [9, 10]. Seaweeds are currently used
commercially in the production of high-value products
such as agar, carrageenan, and alginate, and also
produce for human food, animal feed, fertilizers,
biofuel, and cosmetics [11].
Mass cultivation of seaweeds can be more effective
D
DAVID PUBLISHING
The Use of Seaweeds Aquaculture for Carbon Sequestration: A Strategy for Climate Change Mitigation
110
methods for CO
2
capture and sequestration from the
environment, because CO
2
can be transformed and
become more valuable products through
photosynthesis. The rate of carbon sequestration by
seaweeds would be different; influenced by seaweed
species and environmental conditions where they were
cultivated [12, 13]. The aim of this study is to estimate
carbon sequestration by different seaweed cultured
variants as a strategy for climate change mitigation.
2. Materials and Methods
The study was undertaken from July to November,
2013 at Gerupuk Bay, Lombok Island, West Nusa
Tenggara Province, Indonesia (Fig.1). Four seaweed
variants, including Kappaphycus alvarezii var.,
Tambalang and Maumere, K. striatum and Eucheuma
denticulatum, were cultivated with long-line system
for three cultivation periods. Each cultivation period
was taken during 45 days. The size of a long-line unit
was 50 x 50 m
2
which consists of 24 lines/unit. A
long-line unit was divided into four parts for each
seaweed variant. The seeds were bound to the line
which separated about 20 cm for each other.
Sampling was conducted every 15 days from the
day 0 (initial), 15, 30, to 45 (replanting) for every
cultivation period. Parameters were measured
including weight increasement for seaweed (in situ)
and total carbon content (laboratory analysis). Six
bonds of each seaweed variant were taken every 15
days to measure weight increasement that calculated
based on different weight of seaweed samples
between sampling period (seaweed age). Estimation of
carbon sequestration rate (ton C/ha/year) was
calculated by using formula as follows [13]:
C
seq
= A x S x P-B ratio x C
cont
(1)
where:
A is a total wide area of seaweed cultivation (m
2
), S
is standing stock (g/m
2
), P-B rationis
production-biomass ratio, and C
cont
is the carbon
content (%).
Fig. 1 Research location at Gerupuk Bay, Central Lombok, West Nusa Tenggara, Indonesia.
The Use of Seaweeds Aquaculture for Carbon Sequestration: A Strategy for Climate Change Mitigation
111
Fig. 2 Range of C sequestration by four seaweed variants cultured in Gerupuk Bay, West Nusa Tenggara, Indonesia: (a) K.
alvarezii var. Maumere; (b) K. alvarezii var. Tambalang; (c) E. denticulatum; (d) K. striatum.
Table 1 ANOVA and Duncan Teston minimum and maximum values of C sequestration rate of four seaweed variants.
Different letters indicate significant differences of the results (P < 0.05).
Source of Variation
Means of C sequestration rate (ton C/ha/year)
Seaweed variants
K. alvarezii var. Tambalang
E. denticulatum
K. striatum
Minimum values
610
a
648
a
184
b
Maximum values
2,310
b
4,769
a
1,937
b
Cultivation periods
2nd
3rd
Minimum values
72,675
a
17,675
b
Maximum values
3,560
a
1,265
b
Data of carbon sequestration rate were analyzed
using descriptive statistic methods then presented as
graphs. ANOVA (Analysis of Variance) with
completely randomized factorial design and Duncan
Test were used to observe the different response of
carbon sequestration rate which influenced by
different variants of seaweeds in different cultivation
periods and sampling periods.
3. Results and Discussion
3.1 Carbon Sequestration by Seaweed Cultivation
Capability of four seaweed variants on carbon
sequestration was described with the range of C
sequestration rate (Fig. 2). Analysis of variance and
Duncan Test showed that seaweed variants indicated
significant difference (P < 0.05) in influencing
seaweed ability on carbon sequestration, either the
The Use of Seaweeds Aquaculture for Carbon Sequestration: A Strategy for Climate Change Mitigation
112
maximum or minimum values (Fig. 2, Table 1). K.
striatum had the lowest minimum value of carbon
sequestration than E. denticulatum, K alvarezii var.,
Maumera and Tambalang about 0.12–4.03 ton
C/ha/year.
While, E. denticulatum showed the highest
maximum value of carbon sequestration rate which is
significantly different from the other three variants
(Table 1). E. denticulatum has the highest rate of C
sequestration rate based on maximum values which
range about 16.08–68.43 ton C/ha/year; while other
variants have relatively similar values (Fig. 2).
Carbon sequestration rate has a direct correlation
with internal factors of seaweed, including pigment
content and growth rate [10]. Whereas, growth rate is
influenced by seaweed variants, location, and seasonal
cultivation periods [14]. Study on different seaweed
variants, K. alvarezii, E. denticulatum, and K. striatum,
shows that E. denticulatum has the highest daily
growth rate which is significantly different from
others [15].
Different capability of seaweeds on carbon
sequestration rate was also indicated in different
cultivation periods (Fig. 2). Statistic analysis result
showed significant different carbon sequestration rate
(P < 0.05) among three cultivation periods during this
study (Table 1). The first and second cultivation
periods indicated a higher rate, and significantly
different than the third period, either minimum or
maximum values (Table 1). Seaweeds cultivation
which held during different seasonal cultivation
periods would be influenced by temporal variabilities
of environmental factors [12]. Seaweeds are exposed
to seasonal variations of abiotic factors that influence
their metabolic responses, including photosynthesis
and growth rate [16]. Seaweeds absorb CO
2
from
waters through photosynthesis process then
transformed to carbohydrate compound [6, 10]. Good
environmental conditions would give higher
opportunities to absorb more CO
2
from the
environment. The more higher CO
2
absorbed by
seaweed, the more productive seaweeds cultivated.
Trends of carbon sequestration rate were influenced
by different seaweed variants. Generally, E.
denticulatum has higher sequestration rate than the
other three seaweed variants (Fig. 3). Analysis of variance
The Use of Seaweeds Aquaculture for Carbon Sequestration: A Strategy for Climate Change Mitigation
113
Fig. 3 Trend of C sequestration by four seaweed variants cultured in Gerupuk Bay, West Nusa Tenggara, Indonesia: (a)
Kappaphycus alvarezii var. Maumere; (b) Kappaphycus alvarezii var. Tambalang; (c) Eucheuma denticulatum; (d) K. striatum.
Table 2 ANOVA and Duncan Test on trend of C sequestration rate of four seaweed variants. Different letters indicate the
significant difference of the results (P < 0.05).
Source of Variation
Means of C sequestration rate (ton C/ha/year)
Seaweed variants
K. alvarezii var. Maumere
K. alvareziivar. Tambalang
E. denticulatum
K. striatum
1,203
ab
1,282
a
2,329
a
920
b
Cultivation periods
1st
2nd
3rd
1,853
a
1,773
a
674
b
Days of culture
Day-15
Day-30
Day-45
2,293
a
1,448
ab
559
b
and Duncan Test showed significant difference (P <
0.05) on trend of carbon sequestration rate among
seaweed variants (Table 2). Gracilaria gigas showed
almost 300% carbon sequestration rate was higher
than K. alvarezii which was cultured in Gerupuk Bay
with the same method of cultivation [10].
Muraoka [13] also reported that several important
genera of seaweed along the coasts of Japan included
Laminaria, Ecklonia, Sargassum, Gelidium, and
others indicated different carbon sequestration rate:
1156, 562, 346, 17, 103 thousand ton C/year,
respectively.
The trend of carbon sequestration was also different
between cultivation periods. K. alvarezii var.
Maumere had close connection trend with E.
denticulatum at the first and second periods (Fig. 3 (a);
(c)), likewise K. alvarezii var. Tambalang and K.
striatum (Fig. 3 (b); (d)). However, different trends
occur only at the third cultivation period for every
seaweed variant (Fig. 3). Statistical analysis caused
significant difference (P < 0.05) on trend of carbon
sequestration between cultivation periods. The first
The Use of Seaweeds Aquaculture for Carbon Sequestration: A Strategy for Climate Change Mitigation
114
and second periods showed higher carbon
sequestration rate than the third period (Table 2).
Study on seaweeds growth which cultured in Gerupuk
Bay, showed that the first and second periods
(July–August and September–October, 2013) were
categorized as the productive period for seaweed
cultivation, but the third (November–December) was
non-productive period [15]. This could be indicated
that seaweeds capability on carbon sequestration rate
is correlated to cultivation productivity.
Generally, K. alvareii var. Maumere and E.
denticulatum showed the same decreasing trend of
carbon sequestration pattern during cultivation. It was
at a high rate at the beginning (day-15) then decrease
at the end of cultivation (day-45) on every cultivation
period (Fig. 3 (a); (c)). The first cultivation period of
K. alvarezii var. Tambalang and K. striatum also had
the same tendency with K. alvareii var. Maumere and
E. denticulatum, but at the second period they showed
different patterns, lower rate at day-15, and increase at
day-30 then decrease again at day-45 (Fig. 3 (b); (d)).
ANOVA and Duncan Test indicated significant
differences (P < 0.05) of carbon sequestration pattern
between seaweed age at day-15, 30 and 45 of culture
(Table 2). Erlania and Radiarta [12] reported that
seaweed K. alvareziivar. Maumere caused the highest
carbon sequestration rate at the beginning of culture
about the first 15 days on each cultivation period.
Similar trend was also found for K. alvarezii var.
Maumere in this study (Fig. 3a). Whereas, K. alvarezii
var. Tambalang and K. striatum showed different
tendencies at the second cultivation period and the
highest carbon sequestration rate was found at day-30
of culture (Fig. 3 (b); (d)).
3.2 Climate Change Mitigation through Seaweed
Aquaculture Activity
Seaweed cultivation can positively contribute to
reducing CO
2
from the atmosphere regarding to the
role of ocean ecosystem on blue carbon context [10,
17]. Marine and Fisheries Industrialization Program
was launched by Ministry of Marine Affair and
Fisheries, Indonesia for national production
enhancement including seaweed from aquaculture.
Development of seaweeds aquaculture not only can
increase national production, but also enhance
economic level of coastal people and improve
environmental conditions through its carbon
sequestration capability. It is interesting to note that
3.5 tons of algae production utilizes 1.27 tons of
carbon and about 0.22 tons of nitrogen and 0.03 tons
of phosphorus [18].
Carbon sequestration capability positively
correlated with seaweed aquaculture productivity [12].
The main aspect that very important in influencing of
seaweed aquaculture productivity is seasonal
cultivation period. Moreover, seasonal aspect will
differentiate physical and chemical conditions of
water quality parameters, the physical and chemical
factors affecting the growth of these plants [19]. The
quantity of seaweeds production is in line with carbon
sequestration volume by seaweed aquaculture [10].
Other important aspects are selection of seaweed
species/variants which are suitable for different
specific locations with different environmental
conditions. Evaluation of seaweed growth is very
important for species suitability selection based on
location and planting period [14]. Age of seaweed also
influences its performance during cultivation process.
K. alvarezii and Gracilaria gigas showed the highest
daily growth rate at the beginning of cultivation [10,
12].
Much consideration is needed to arrange a strategy
for developing of seaweeds aquaculture in order to
make this activity become efficient both economically
and environmentally. Implementation strategy for
climate change mitigation has to consider at least
these three important aspects on seaweeds aquaculture
development scheme. Seasonal cultivation periods
will be different between different areas; different
seaweed variants could not always be suitable in any
different cultivation areas; and different age of
The Use of Seaweeds Aquaculture for Carbon Sequestration: A Strategy for Climate Change Mitigation
115
seaweed will be different on carbon sequestration rate.
Indonesia has great potential areas to develop
seaweed aquaculture activity for coastal people
economic enhancement. Optimal utilization of the
potential area for seaweed aquaculture could reduce a
great quantity of CO
2
from the atmosphere and help to
mitigate global climate change process. Planning and
implementation processes of policy and management
of coastal carbon ecosystems for climate change
mitigation require that stakeholders and community
engaged in both climate change mitigation and coastal
activities [20]. Therefore, government should play a
significant role in managing and regulating a way to
combine seaweed aquaculture activity as one of
coastal community livelihood with awareness of
people to do this activity not only for economic
interests, but also for environmental concern.
4. Conclusions
Seaweed capability on carbon sequestration could be
influenced by seaweeds variants, cultivation periods,
and seaweed age (day of culture). E. denticulatum had
the highest carbon sequestration rate and K. striatum
had the lowest. Seasonal cultivation periods were also
influence capabilities of seaweed on carbon
sequestration. These were caused by variabilities
conditions of environmental factors between different
cultivation periods. Implementation strategy for
climate change mitigation has to consider at least three
important aspects on seaweeds aquaculture
development scheme. Seasonal cultivation periods
will be different in any areas; different seaweed
variants could not always grow well in any
different cultivation area; and different age of seaweed
would have different capability on carbon
sequestration.
Acknowledgments
The authors acknowledge the National Seaweed
Center, Central Lombok, West Nusa Tenggara. The
authors greatly appreciate the field assistance by
Buntaran, M.Si., Rusman, M.Si., and Seme. This
project was financed by the Government of Indonesia
through DIPA 2013.
References
[1] Maslin, M. 2004. Global Warming: A Very Short
Introduction. New York: Oxford University Press Inc.
[2] IPCC. 2007. “Summary for Policymakers.” In Climate
Change 2007: The Physical Science Basis. Contribution
of Working Group I to the Fourth Assessment Report of
the Intergovernmental Panel on Climate Change, edited
by Solomon, S., Qin, D., Manning, M., Chen, Z., Marquis,
M., Averyt, K. B., Tignor, M., and Miller, H. L.
Cambridge: Cambridge University Press.
[3] European Commission. 2007. “Climate Change: What
Impact on Fisheries?” Fisheries and Aquaculture in
Europe 35: 4-6.
[4] Harley, C. D. G., Hughes, R. A., Hultgren, K. M., Miner,
B. G., Sorte, C. J. B., Thornber, C. S., Rodriguez, L. F.,
Tomanek, L., and Williams, S. L. 2006. “The Impacts of
Climate Change in Coastal Marine Systems.” Ecol. Lett.
9 (2): 228-41.
[5] Callaway, R., Shin, A. P., and Grenfell, S. E. 2012.
“Review of Climate Change Impact on Marine
Aquaculture in the UK and Ireland.” Aquatic
Conservation: Marine and Freshwater Ecosystem 22 (3):
389-421.
[6] Dawes, C. J. 1981. Marine Botany. Canada: John Wiley
and Sons. Inc.
[7] Nellemann, C., Corcoran, E., Duarte, C. M., Valdés, L.,
De Young, C., Fonseca, L., and Grimsditch, G. 2009.
Blue Carbon: The Role of Healthy Oceans in Binding
Carbon. A Rapid Response Assessment. United Nations
Environment Programme. GRID-Arendal. Birkeland
Trykkeri AS. Norway. 78.
[8] Kaladharan, P., Veena, S., and Vivekanandan, E. 2009.
“Carbon Sequestration by a Few Marine Algae:
Observation and Projection.” Journal of the Marine
Biological Association of India 51(1): 107-10.
[9] Chung, I. K., Beardall, J., Mehta, S., Sahoo, D., and
Stojkovic, S. 2011. “Using Marine Macroalgae for
Carbon Sequestration: A Critical Appraisal.” J Appl
Phycol 23:877-86.
[10] Erlania, Nirmala, K., and Soelistyowati, D. T. 2013.
“Carbon Absorption in Seaweeds Aquaculture
Kappaphycus Alvarezii and Gracilaria Gigasin Gerupuk
Bay, Central Lombok, West Nusa Tenggara.” Jurnal
Riset Akuakultur 8 (2): 287-97. (in Indonesian, abstract in
English).
[11] McHugh, D. J. 2003. A Guide to the Seaweed Industry.
FAO Fisheries Technical Paper 441. Food and
The Use of Seaweeds Aquaculture for Carbon Sequestration: A Strategy for Climate Change Mitigation
116
Agricultural Organization, 106.
[12] Erlania, and Radiarta. I. N. 2014. “Difference of Seaweed,
Kappaphycus Alvarezii, Cultivation Cycles on Variability
of Carbon Sequestration Rate.” Jurnal Riset Akuakultur 9
(1): 111-24. (in Indonesian, abstract in English).
[13] Muraoka, D. 2004. “Seaweed Resources as a Source of
Carbon Fixation.”Bull. Fish. Res. Agen. Supplement1:
59-63.
[14] Parenrengi, A., and Rachmansyah, Suryati, E. 2011.
Cultivation of Carraginophyte Seaweed. Research
Institute for Coastal Aquaculture, Minsitry of
Marine Affairs and Fisheries Republic of Indonesia.
Jakarta, 54. (in Indonesian).
[15] Erlania, Radiarta, I. N., and Sugama, K. 2014. “Seasonal
Cultivatian Periods of Four Eucheumatoids Seaweeds
Variants Performance in Gerupuk Bay, West Nusa
Tenggara.” Jurnal Riset Akuakultur 9 (2): 331-42. (in
Indonesian, abstract in English).
[16] Banerjee, K., Ghosh, R., Homechaudhuri, S., and Mitra,
A. 2009. “Seasonal Variation in the Biochemical
Composition of Red Seaweed (Catenella Repens) from
Gangetic Delta, Northeast Coast of India.” J. Earth Syst.
Sci. 118 (5): 497-505.
[17] Nellemann C., Corcoran, E., Duarte. C. M., Valdés. L.,
De Young. C., Fonseca. L., and Grimsditch, G. (eds.).
2009. Blue carbon: The Role of Healthy Oceans in
Binding Carbon. A Rapid Response Assessment. United
Nations Environment Programme, GRID-Arendal.
Birkeland Trykkeri AS, Norway, 78.
[18] Sinha, V. R. P., Fraley, L., and Chowdhy, B. S. 2001.
“Carbon Dioxide Utilization and Seaweed Production.”
In Proceedings of NETL: First National Conference on
Carbon Sequestration, 6.
[19] Ask, E. I., and Azanza, R. V. 2002. “Advances in
Cultivation Technology of Commercial Eucheumatoid
Species: A Review with Suggestions for Future Research.”
Aquaculture 206: 257-77.
[20] Herr, D., and Pidgeon, E. 2012. “Guidance for National
Blue Carbon Activities: Fast-Tracking National
Implementation in Developing Countries.” Brief of Third
Workshop of International Blue Carbon Policy Working
Group—The Blue Carbon Initiative.
... Over 70 % of the surface of the Earth is covered by the seas, in which the coastal vegetation saltmarsh, mangroves, seaweed, and seagrass play a substantial role in removing CO 2 from the atmosphere (Chung et al., 2011). Seaweeds have a higher capacity to store atmospheric CO 2 than terrestrial plants (Erlania, 2015), but they are also involved in the circulation of organic matter in a variety of marine environments, including deep-sea sediments, intertidal rocky regions, and shallow beaches (Chung et al., 2013). As a playing role of producers in the marine ecosystem, seaweeds are responsible for producing 80 % of organic carbon which forms the base of an entire food web from direct consumers to higher tropic levels, and they also regulate many nutrient cycles (Barbier et al., 2019) such as carbon, nitrogen, phosphorus cycles, etc. Macroalgae can preserve a substantial quantity Multiple raft longline Useful for large scale production, more economic, user friendly ...
... It would depend on the species of seaweed and environmental factors of cultivated sites (Muraoka 2004). Seaweed species are categorized into two parts as per their color and pigment contents show a direct correlation with the rate of carbon sequestration (Erlania, 2015). Additionally, seasonal fluctuations, cultivation times, location, and metabolic responses like the rate of photosynthesis and general growth affect the rate of sequestration (Banerjee et al. 2009). ...
... Additionally, seasonal fluctuations, cultivation times, location, and metabolic responses like the rate of photosynthesis and general growth affect the rate of sequestration (Banerjee et al. 2009). Abiotic factors such as turbidity, nutrients contents, the temperature of seawater, etc can determine the carbon capture potential of seaweed which is further converted into carbohydrate compounds (Erlania, 2015) and provide more biomass and higher yield. This makes such seaweed species more popular among seaweed farmers. ...
Seaweeds cultivation methods and their role in climate mitigation and environmental cleanup A R T I C L E I N F O
Article
Full-text available
  • Oct 2022
Seaweed cultivation is an emerging sector of food production that can full fill the future food demand of the growing population. Considering the importance, Asia is home to seven of the top ten seaweed-producing nations, and Asian countries contributed 99.1% of all seaweed cultivated for food. Besides, it can reduce the carbon budget of the ocean through seaweed farms and act as a CO 2 sink. In the context of climate change mit-igation, the seaweed culture is the energy crop, and during its entire life cycle can serve as a bio-filter and bio-extractor. The climate change effect can be reduced by farming seaweed on a commercial scale and it will protect the coastal area by decreasing the physical damage through damping wave energy. The seaweed can reduce eutrophication by removing excess nutrients from water bodies and releasing oxygen as a byproduct in return. The cultivation of seaweed plays an important role as the source of bioenergy for full fill the future energy requirement and it will act as clean energy through the establishment of algal biorefinery along with the seaweed cultivation site. Thus, the marine energy industrial sector moves further toward large-scale expansion of this sector by adopting energy devices to offer power for seaweed growth for biofuel operation. The current reviews provides the evidence of seaweed farming methodology adopted by different countries, as well as their production and output. To mitigate climate change by direct measures such as carbon sequestration, eutrophication risk reduction, and bioenergy, as well as through indirect measures like supplying food for cattle and reducing the strain on aquaculture. The US, Japan, and Germany lastly suggest the large-scale offshore commercial farming as a feasible climate change mitigation strategy.
View
... The capacity of seaweeds to sequester carbon is a pivotal factor that can aid in the mitigation of climate change through the extraction of carbon dioxide from the atmosphere (Hurd, 2023). Seaweeds employ carbon dioxide as a source of energy during the process of photosynthesis to generate biomass, thereby efficiently sequestering and retaining carbon inside their tissues (Radiarta, 2015). This process has the dual purpose of mitigating atmospheric carbon dioxide levels and facilitating the carbon cycle through the transfer of carbon from the atmosphere to the ocean (Mongin et al., 2016). ...
EXPLORING THE POTENTIAL OF SEAWEED FOR CARBON SEQUESTRATION AND BIOREMEDIATION
Conference Paper
Full-text available
  • Feb 2024
Seaweeds, as marine macroalgae, possess significant potential not only as sources of phycocolloids and bioactive compounds but also as critical agents in environmental sustainability endeavors. This review paper evaluates their diverse roles, particularly focusing on their contributions to bioremediation and carbon sequestration. By scrutinizing the structural complexities and functional attributes of seaweed-derived phycocolloids, the paper elucidates their effectiveness in bioremediation processes, offering sustainable strategies for pollution abatement in aquatic environments. Furthermore, it explores the less-explored yet essential aspect of seaweeds' capability for carbon sequestration, emphasizing their capacity to absorb and sequester atmospheric carbon dioxide, thereby mitigating the impacts of climate change. This paper emphasizes the essential contribution of seaweeds to environmental stewardship, suggesting avenues for their expanded use in addressing global environmental challenges.
View
... For instance, emissions due to enhanced microbial respiration during the later stages of kelp growth can offset the carbon removed from the atmosphere during early cultivation phases (Xiong et al., 2024), and emissions can offset between 61 and 90 % of the carbon potentially sequestered even in farms designs to optimize seaweed CDR (Coleman et al., 2022;Lian et al., 2023). Despite this, the emissions associated with seaweed farming are often not included in assessments of the carbon removal and climate change mitigation capacity of seaweed farming (Duarte et al., 2017;Erlania and Nyoman Radiarta, 2015;Froehlich et al., 2019;Sondak et al., 2017;Wu et al., 2020). Life Cycle Assessments, commonly known as LCAs, constitute a powerful tool to quantify the environmental impacts of products or systems during their entire life cycle in a systematic manner, and examine which processes and materials are responsible for the bulk of climate impacts (reviewed in Hasselström and Thomas, 2022). ...
View
... Seaweed aquaculture can be calculated at 2.48 million tons of CO 2 (0.68 Tg C) year −1 [27]. Erlania and Radiatra [31] stated that cultured species of K. alvarezii could absorb 27.35-158.40 ton CO 2 /ha/year. ...
View
Dynamism of Carbon Sequestration in Ecosystems and Its Role in Ecological Functioning
Chapter
  • Nov 2024
Organic matter is a key component of soil because it influences its structural, chemical, and biological properties, as well as its proper functioning. Although carbon is a crucial component in soil, its elevated levels in the atmosphere since pre-industrial times are warming the Earth relatively. The mechanism of harvesting CO2 from the atmosphere is known as carbon sequestration. Enhanced SOM boosts plant productivity through improved water and nutrient retention in natural and agricultural settings. Soils hold almost three times more carbon than the atmosphere, thus becoming the largest land-based carbon pool. According to the IPCC, croplands and grasslands sequester 0.4–8.6 Gt CO2 year−1. The oceans, on the other hand, are the world’s greatest sink of atmospheric carbon. However, due to the untapped potential of the different ecosystems in order to sequester atmospheric carbon, this chapter tries to understand the dynamism of carbon sequestration among different terrestrial and aquatic ecosystems and highlights some processes and amendments in the soil that can enhance carbon sequestration and discusses its impacts on the regular functioning of ecosystems and its services.
View
Challenges and opportunities towards meeting the United Nations’ Sustainable Development Goals from coral and seaweed ecosystems in an era of climate change
Article
Full-text available
  • Nov 2024
  • Environ Dev Sustain
Global climate change scenarios due to anthropogenic responses jeopardize ecosystem sustainability and hinder progress toward achieving the United nations (UN-SDGs). Achieving “natural carbon solutions” from terrestrial ecosystems is challenging due to decreasing arable land and increasing marginal land. Marine ecosystems representing a wider “natural carbon solutions” have also been severely impacted by climate change. Among marine ecosystems, coral reefs and seaweed communities are the key ecosystem engineers that support a wide range of marine life, facilitate nutrient cycling, and provide essential ecosystem services with a pivotal role in sustaining coastal economies and livelihoods. Notably, these communities compete for space within the reef ecosystem and suffer from loss of diversity and richness due to climate change. Therefore, assessing the climate change resilience of both the corals and seaweeds is essential to evaluate and design long-term adaptation strategies, ecological innovations, and science-informed policies to conserve, restore, and sustainably manage economic services. This review article aims to highlight (1) the physiological response and resilience of corals and seaweeds to environmental changes, (2) the impact of climate change on their ecosystems and economic services, (3) their potential contributions towards the United Nations' sustainable goals, (4) progressive efforts applied for their restoration, and (5) the potential complementary value of large-scale seaweed aquaculture as a carbon sink.
View
9ff3d0a4-e3d8-4222-a1b0-0ac7d4acf37a
Chapter
Full-text available
  • Jun 2023
Chapter 9 Adoption of Climate Smart Agriculture (CSA) Technologies in Sri Lanka: Scope, Present Status, Problems, Prospects, Policy Issues, and Strategies
View
View
View
Ecological Significance of Seaweed Biomass Production and Its Role in Sustainable Agriculture
Chapter
  • Mar 2023
Seaweeds are important component in the marine ecosystem. In the global scenario, about 221 species are having commercial utility but only 10 species are being commercially cultivated and has a market value of 11.7 billion US.Amongthe10species,Eucheumasp.(35. Among the 10 species, Eucheuma sp. (35%), Laminaria japonica (27%), Gracilaria sp. (13%), Undaria pinnadifida (8%), Kappaphycus alvarezii (6%), and Porphyra sp. (4%), have a major share in global seaweed biomass production. Seaweeds are the only resources for commercially important phycocolloids such as agar, carrageenan, and alginic acid production. In 2015, seaweed’s phycocolloids production was 93,035 tons wt and had a market value of 1058 million US. Hectare level cultivation of K. alvarezii (carrageenan yielding seaweeds) can sequester 643.80 tons CO2/ha/yr, whereas Gracilaria edulis and Gracilaria debilis (agar yielding seaweeds) can sequester 10.71 tons CO2/ha/yr. Seaweeds are an excellent biosorbent for the removal of heavy metal ions. Seaweed biochar, an effective adsorbent for wastewater treatment systems. For bioremediation of eutrophicated water, green seaweeds Ulva sp., Cladophora coelothrix, and Cladophora parriaudii; red seaweeds Porphyra sp. and Gracilaria sp. are used. Seaweed has high protein content as it is being used by many of the countries like Japan, China, Korea, Malaysia, Thailand, Indonesia, Philippines, and other South East Asia. Seaweeds like Ulva sp., Enteromorpha sp., Caulerpa sp., Codium sp., Monostroma sp., Sargassum sp., Hydroclathrus sp., Laminaria sp., Undaria sp., Macrocystis sp., Porphyra sp., Gracilaria sp., Eucheuma sp., Laurencia sp., and Acanthophora sp. are used in the preparation of soup, salad and curry, salad vegetable or as garnish material for fish. Ascophyllum, Ecklonia, and Fucus are the general species sold as soil additives and functioned as both fertilizer and soil conditioner. Red seaweeds K. alvarezii, G. edulis, a green seaweed Caulerpa spp. Ulva spp., etc., have been commercially exploited for biostimulant production and increase in crop yield was found in the range of 8–25% over control.
View
Seasonal variation of biochemical composition of Sundarban seaweed species.pdf
Article
Full-text available
  • Jun 2022
  • J EARTH SYST SCI
The biochemical composition of red seaweeds, Catenella repens was investigated in this present study along with subsequent analysis of relevant physico-chemical variables. In this study, the relationship between the nutritive components of this species and the ambient environmental parameters was established. Protein content varied from 2.78 ± 0.30% of dry weight (stn.3) to 16.03 ± 0.96% of dry weight (stn.1) with highest values during monsoon. The protein levels were positively correlated with dissolved nitrate content and negatively correlated with water temperature (except stn.3) and salinity. Carbohydrate content of this species varied significantly (p < 0.05) during pre-monsoon between stations and the values showed positive relationship with salinity and surface water temperature. In contrast to carbohydrate , lipid concentration was lowest in values and varied very slightly between seasons and stations. Astaxanthin content of the seaweed species was greater in pre-monsoon than monsoon and post-monsoon in all the selected stations. Compared with the three seasons, samples of red seaweed collected in pre-monsoon has high carbohydrate-astaxanthin in contrast to protein-lipid which showed high values during monsoon. Statistical analysis computed among the environmental and biochemical parameters suggests the potential role played by the abiotic parameters on biosynthetic pathways of seaweed. This paper also highlights the influence of the nutritional quality of water that can be used for mass cultivation of Catenella repens.
View
Blue Carbon - The Role of Healthy Oceans in Binding Carbon
Technical Report
Full-text available
  • Jan 2009
The objective of this report is to highlight the critical role of the oceans and ocean ecosys­ tems in maintaining our climate and in assisting policy makers to mainstream an oceans agenda into national and international climate change initiatives. While emissions’ re­ ductions are currently at the centre of the climate change discussions, the critical role of the oceans and ocean ecosystems has been vastly overlooked. Out of all the biological carbon (or green carbon) captured in the world, over half (55%) is captured by marine living organ- isms – not on land – hence it is called blue carbon. Continu- ally increasing carbon dioxide (CO2) and other greenhouse gas emissions are contributing to climate change. Many countries, including those going through periods of rapid growth, are increasing their emissions of brown and black carbon (such as CO2 and soot) as a result of rapid economic development. Along with increased emissions, natural ecosystems are being degraded, reducing their ability to absorb CO2. This loss of ca- pacity is equivalent to one to two times that of the annual emis- sions from the entire global transport sector. Rising greenhouse gases emissions are producing increasing impacts and changes worldwide on weather patterns, food pro- duction, human lives and livelihoods. Food security, social, eco- nomic and human development will all become increasingly jeopardized in the coming decades. Maintaining or improving the ability of forests and oceans to absorb and bury CO2 is a crucial aspect of climate change mitigation. The contribution of forests in sequestering carbon is well known and is supported by relevant financial mecha- nisms. In contrast, the critical role of the oceans has been over- looked. The aim of this report is to highlight the vital contribu- tion of the oceans in reducing atmospheric CO2 levels through 6 sequestration and also through reducing the rate of marine and coastal ecosystem degradation. It also explores the options for developing a financial structure for managing the contribution oceans make to reducing CO2 levels, including the effective- ness of an ocean based CO2 reduction scheme. Oceans play a significant role in the global carbon cycle. Not only do they represent the largest long-term sink for carbon but they also store and redistribute CO2. Some 93% of the earth’s CO2 (40 Tt) is stored and cycled through the oceans. The ocean’s vegetated habitats, in particular mangroves, salt marshes and seagrasses, cover <0.5% of the sea bed. These form earth’s blue carbon sinks and account for more than 50%, perhaps as much as 71%, of all carbon storage in ocean sediments. They comprise only 0.05% of the plant biomass on land, but store a comparable amount of carbon per year, and thus rank among the most intense carbon sinks on the planet. Blue carbon sinks and estuaries capture and store between 235–450 Tg C every year – or the equivalent of up to half of the emissions from the entire global transport sector, estimated at around 1,000 Tg C yr–1. By preventing the further loss and degradation of these ecosystems and catalyzing their recovery, we can contribute to offsetting 3–7% of current fossil fuel emis- sions (totaling 7,200 Tg C yr–1) in two decades – over half of that projected for reducing rainforest deforestation. The effect would be equivalent to at least 10% of the reductions needed to keep concentrations of CO2 in the atmosphere below 450 ppm. If managed properly, blue carbon sinks, therefore, have the po- tential to play an important role in mitigating climate change. The rate of loss of these marine ecosystems is much higher than any other ecosystem on the planet – in some instances up to four times that of rainforests. Currently, on average, be- tween 2–7% of our blue carbon sinks are lost annually, a sev- en-fold increase compared to only half a century ago. If more action is not taken to sustain these vital ecosystems, most may be lost within two decades. Halting degradation and restoring both the lost marine carbon sinks in the oceans and slowing deforestation of the tropical forests on land could result in mitigating emissions by up to 25%. Sustaining blue carbon sinks will be crucial for ecosystem- based adaptation strategies that reduce vulnerability of hu- man coastal communities to climate change. Halting the de- cline of ocean and coastal ecosystems would also generate economic revenue, food security and improve livelihoods in the coastal zone. It would also provide major economic and development opportunities for coastal communities around the world, including extremely vulnerable Small Island De- veloping States (SIDS). Coastal waters account for just 7% of the total area of the ocean. However the productivity of ecosystems such as coral reefs, and these blue carbon sinks mean that this small area forms the basis of the world’s primary fishing grounds, sup- plying an estimated 50% of the world’s fisheries. They provide vital nutrition for close to 3 billion people, as well as 50% of animal protein and minerals to 400 million people of the least developed countries in the world. The coastal zones, of which these blue carbon sinks are cen- tral for productivity, deliver a wide range of benefits to hu- man society: filtering water, reducing effects of coastal pol- lution, nutrient loading, sedimentation, protecting the coast from erosion and buffering the effects of extreme weather events. Coastal ecosystem services have been estimated to be worth over US$25,000 billion annually, ranking among the most economically valuable of all ecosystems. Much of the degradation of these ecosystems not only comes from unsus- tainable natural resource use practices, but also from poor watershed management, poor coastal development practices and poor waste management. The protection and restoration of coastal zones, through coordinated integrated manage- ment would also have significant and multiple benefits for health, labour productivity and food security of communities in these areas. The loss of these carbon sinks, and their crucial role in man- aging climate, health, food security and economic develop- ment in the coastal zones, is therefore an imminent threat. It is one of the biggest current gaps to address under climate change mitigation efforts. Ecosystem based management and adaptation options that can both reduce and mitigate climate change, increase food security, benefit health and subsequent productivity and generate jobs and business are of major importance. This is contrary to the perception that mitigation and emission reduction is seen as a cost and not an investment. Improved integrated management of the coastal and marine environments, including protection and restoration of our ocean’s blue carbon sinks, provides one of the strongest win-win mitigation efforts known today, as it may provide value-added benefits well in excess of its costs, but has not yet been recognized in the global protocols and carbon trading systems
View
View
Review of climate change impacts on marine aquaculture in the UK and Ireland
Article
Full-text available
  • May 2012
  • AQUAT CONSERV
Marine aquaculture relies on coastal habitats that will be affected by climate change. This review assesses current knowledge of the threats and opportunities of climate change for aquaculture in the UK and Ireland, focusing on the most commonly farmed species, blue mussels (Mytilus edulis) and Atlantic salmon (Salmo salar). There is sparse evidence to indicate that climate change is affecting aquaculture in the UK and Ireland. Impacts to date have been difficult to discern from natural environmental variability, and the pace of technological development in aquaculture overshadows effects of climatic change. However, this review of broader aquaculture literature and the likely effects of climate change suggests that over the next century, climate change has the potential to directly impact the industry. Impacts are related to the industry's dependence on the marine environment for suitable biophysical conditions. For instance, changes in the frequency and strength of storms pose a risk to infrastructure, such as salmon cages. Sea-level rise will shift shoreline morphology, reducing the areal extent of some habitats that are suitable for the industry. Changes in rainfall patterns will increase the turbidity and nutrient loading of rivers, potentially triggering harmful algal blooms and negatively affecting bivalve farming. In addition, ocean acidification may disrupt the early developmental stages of shellfish. Some of the most damaging but least predictable effects of climate change relate to the emergence, translocation and virulence of diseases, parasites and pathogens, although parasites and diseases in finfish aquaculture may be controlled through intervention. The spread of nuisance and non-native species is also potentially damaging. Rising temperatures may create the opportunity to rear warmer water species in the UK and Ireland. Market forces, rather than technical feasibility, are likely to determine whether existing farmed species are displaced by new ones.
View
Using marine macroalgae for carbon sequestration: A critical appraisal
Article
Full-text available
  • Oct 2010
There has been a good deal of interest in the potential of marine vegetation as a sink for anthropogenic C emissions (“Blue Carbon”). Marine primary producers contribute at least 50% of the world’s carbon fixation and may account for as much as 71% of all carbon storage. In this paper, we analyse the current rate of harvesting of both commercially grown and wild-grown macroalgae, as well as their capacity for photosynthetically driven CO2 assimilation and growth. We suggest that CO2 acquisition by marine macroalgae can represent a considerable sink for anthropogenic CO2 emissions and that harvesting and appropriate use of macroalgal primary production could play a significant role in C sequestration and amelioration of greenhouse gas emissions. KeywordsBlue carbon–Macroalgae–Photosynthesis–CO2 sequestration
View
View
View
Global Warming: A Very Short Introduction
Article
  • Jan 2005
Global Warming: A Very Short Introduction is an informative, up to date discussion about the predicted impacts of global warming. It draws on material from the recent report of the Intergovernmental Panel on Climate Change, a huge collaborative study drawing together current thinking on the subject from experts in a range of disciplines, and presents the findings of the panel for a general readership for the first time. The book also discusses the politics of global warming and what we can do now to adapt to climate change and mitigate its worst effects.
View
Seaweed resources as a source of carbon fixation
Article
  • Jan 2004
Approximately 2 gigatons of carbon a year is estimated to diffuse across the air-sea interface into the dissolved CO 2 pool of surface ocean water. The total area of algal and seagrass beds along the coasts of Japan is 2,012 km 2 . We are currently estimat- ing the macrophyte production along the coasts of Japan by estimating the annual net production and carbon content, and it is likely to be a value of ca. 2,700,000 tons of car- bon a year. Additionally, the Japanese people have historically used seaweeds as food source. Economically important genera (Porphyra, Laminaria, Undaria etc.) are culti- vated and harvested, with an estimated annual production of cultivated seaweeds of 530,000 tons wet weight. The total amount of annual carbon absorption by seaweed cul- tivation is estimated to be approximately 32,000 tons, corresponding to 1.2 %of the an- nual macrophyte production along the coasts of Japan. It is also well known that seaweeds have a positive impact on moderately eutrophic water by absorbing nutrients from surrounding waters. Seaweed resources are an important source of carbon fixa- tion.
View
Carbon dioxide utilization and seaweed production
Article
  • Jan 2001
Stronger growth in many plants stimulated by increased CO 2 concentration should lead to greater biological productivity with an expected increase in the photosynthetic storage of carbon. Thus, the biosphere will serve as a sink for CO 2 , though it will also act as a source too, because of respiration. Normally net photosynthesis dominates in summer and removes CO2 from the atmosphere, whereas respiration dominates in winter and releases CO2 in the atmosphere. However in the tropics where day length is quite long with about 10+ or -2 hours throughout the year, net photosynthesis is expected to dominate. In this background utilization of CO2 as an industrial by-product for seaweed production holds great promise not only in acting as a significant sink, but also in meeting to some extent global food, fodder, fuel and pharmaceutical requirements, particularly in the tropics. It is interesting to note that 3.5 tons of alga production utilizes 1.27 tons of carbon and about 0.22 tons of nitrogen and 0.03 tons of phosphorus. CO2 can be utilized for stimulating the wild growth of seaweed in the sea or in culture on the shore and also possibilities exist for promoting growth of freshwater algae, fern and other submerged weed particularly Hydrilla, which is a choice feed for many fast growing fish. However, no such scientific studies have been done to evaluate this and quantify the degree of stimulation of growth and enhanced productivity through anthropogenic CO2. Culture and wild harvest of seaweed is commonly practiced in many countries in Japan, North and South Korea, China, Philippines, India and it is coming up in many Asian countries. The common seaweeds harvested and cultured are Porphyra, Undaria, Laminaria, Eucheuma and Gracilaria. Porphyra (purple laver) is the largest of the aquaculture billion-dollar industry in Japan. It is important that under the new initiative of the USA, pilot scale studies undertaken preferably at suitable institutions dealing with mariculture R&D, to evolve a package of practices to obtain optimal harvest of such aquatic weeds with anthropogenic CO 2. Considering tropical settings, institutional infrastructure, scientific capabilities and cost effectiveness a network of the institution be selected in different countries and such work should be initiated.
View