Sea grapes - organic – 100% natural food produced in Singapore

Sea grapes or green caviar is fresh, quality assured, sustainably grown, local farm at 100 Sungei Tengah Road. 

Basic farming practices is: Sea grapes is growth under seawater aquaponic to remove nutrients from fish/crustacean aquaculture. After 2 months of growing, consumable sea grapes are selected, depurated, salted and packed. The unconsumable sea grapes will be used as seed stock for the next crop. 

Sea grapes can be used as a green vegetable to make salads or to decorate. In addition, sea grapes can be used for smoothies, face masks.... 

The health benefits of sea grapes are: Beautiful skin and hair; Good for cardiovascular; Strong bones and joints. It is also help to prevention / limitation of: overweight; constipation; goiter; diabetes; hypertension. 

For consumption, the sea grapes can be combined with various sauces, vegetables, seafood and meat. Recommended is salad, boiled shrimp with sesame sauce.

 

Challenges and opportunities for eucheumatoids farming

Challenges and Prospects

The cultivation of Eucheumatoids seaweed requires a moderate investment, but is labor intensive and the profit is low. They are therefore only attractive in relatively poor areas that lack alternative economic opportunities. Not much has changed in cultivation, harvesting and post-harvest methods in the cultivation of Eucheumatoids since it was started 50 years ago (since 1970s). Seedling quality has not been improved. Planting and drying methods are still mostly manual. Many challenges and prospects have been identified along the value chain. They are presented in the Table 1.

Table 1. Challenges and prospects

Value chain	Challenges	Prospects
Input suppliers	Improper aquatic environments (damaged by predators e.g. siganid fish)	Select suitable location (water quality, biology). Proper coastal planning to avoid conflict with other economic activities
	Unfavorable weather, filamentous algae (seasonal)	Choosing favourable season
	Lack of space to expand and non-sustainable use of mangrove trees as stakes for lines	Move to offshore area and using floating system
	Possible encroachment on to coral reefs	Regulate policies that seaweed farms cannot be located near or on coral reefs or within MPAs
	Lack of quality seedlings, ice-ice syndrome	High disease resistance (coupled with good yield and carrageenan quality characteristics)
	Vegetative propagation could carry disease or reduce quality	Propagation using micropropagation or sporophyte
	Poor quality of planting materials	Use of high quality and sustainable floaters, string…
	Use of non-biodegradable planting material such as the soft plastic tie-tie	Use of bio-degradable planting materials such as cotton ties
Farmers	Labor intensive and poor seeding/post-harvest handling	Increase productivity through automation from seeding to harvesting
	Lack of drying facilities / space and access to seaweed farming area	External support for drying facilities and infrastructure to access to seaweed farming area
	Monoculture of seaweed	Implement integrated aquaculture which can include several trophic levels fish, filter feeders and seaweed
	Depended on natural nutrient in seawater	Supplementing nutrients for subjects raised in nutrient-depleted areas
	No Best Aquaculture Practices (BAqPs) is available for seaweeds.	Develop and adapt of Best Aquaculture Practices (BAqPs) for seaweeds
	Strong price fluctuations and low farm gate price of dried seaweed	Contract farming with processor via trader to ensure stable price and profit
Traders and supported actors	Not yet recognize Best Aquaculture Practices (BAqPs)	Support and willing to pay better price for sustainable seaweed practices
	Weak acceptance of farmers to new farming innovations	Organize training/workshops/seminars and study visits to successful seaweed areas/farmers and the sharing of knowledge and best practices
	Weak linkages between and amongst academia-research centers-private sector	Create national and international collaboration and networking to improved scientific knowledge and strong cooperation between public and private sectors
	Lack of financial support to recover after the natural risk (cyclone)	Develop and support aquaculture insurance to support farmers to recover
	R&D stagnated in carrageenan industry, inadequate knowledge on farming, processing and the role of seaweed	Establishment of centers of excellence in seaweed agronomy
	Controversy on health effect of carrageenan	Further study and action is needed to reduce impacts from the controversy

Combination from: (Hatch Innovation Services, 2022), (Ginigaddara, et al., 2018), (Hayashi, et al., 2010)

Seaweed is an important component in regenerative coastal aquaculture. Regenerative coastal aquaculture is a climate-friendly model in which seaweed and/or shellfish, fish and crustaceans are grown in a manner that does not require fresh water, feed or fertilizer. Seaweed and shellfish can absorb excess nutrients, carbon and help reduce harmful algal blooms, deoxygenated dead zones (Figure 1). Renewable coastal aquaculture has the potential to enhance local food and nutritional security. Seaweed, shellfish can be used as food for fish, crustaceans. The regenerative coastal aquaculture model in Singapore that grows seaweed, oysters, and green mussels for lobster and crab food is yielding very positive results (Figure 2).

Figure 1. Concept of regenerative coastal aquaculture that produce human food using only seawater.

Figure 2. Trial of regenerative coastal aquaculture in Singapore

The roles of stakeholders and investment in seaweed farming and production can be summarized as in Figure 3:

Figure 3. Role of stakeholders and investors in seaweed farming

Farmer or farmer family is a place where spouses and relatives share work and income among themselves. In seaweed farming, men are often responsible for heavy works such as planting, maintenance and harvesting, while women and children are responsible for less heavy works like tying seedlings, drying and sorting dried seaweed. Seaweed farming requires a lot of seasonal labor, so job-based pay is often used. Workers often come from the same community and may be neighbors. Sometimes they work together in a group or for different farmers.

Farmer organization is organization established by farmers for the purpose of sharing resources in providing inputs, cultivation technique, marketing and selling of the seaweeds. The organization could be official such as cooperative, association and cooperative group or unofficial such as team, group or club.

Trader include collectors and exporters. Their function is not limited to (1) collecting/transporting, (2) sorting/cleaning/drying, (3) pressing and wrapping, and (4) selling or exporting raw dried seaweed for domestic or international processors. Collectors often assist seaweed farmers and buy back products.

The government, non-government organization (NGO) and other supported actors programs/projects can provide active support to farmers through training and equipment initiatives, and training on best practices directly to farmers.

Cost Benefit Analysis

Two common Kappaphycus farming methods are used for cost benefit analysis. They are floating bamboo raft and fixed-off bottom plot. The size of the analysis is for a family of three persons (8,100 m cultivation line) consist of 135 floating bamboo raft or 15 fixed-off bottom plots. 

The size of the floating bamboo raft used is 3.0 m x 3.0 m and consists of four main bamboo poles (3.6 m each) tied together by four diagonal bamboo slats (1.2 m each) in a square shape. square and a fishing net is attached underneath to prevent fish-grazing. In each raft, there are 20 three meters cultivation lines, each line sows 20 seedlings, weight about 200 g/seed. The rafts are anchored at the farming site with iron anchors (20 kg), each anchor holds a cluster of 5 rafts.

Fixed-off bottom plot (30 m × 20 m) was constructed using casuarina and bamboo poles, and a polypropylene rope was securely tied to the stakes at a distance of 0.5 m from the bottom. Approximately 200 g of seed was inserted into a loop with seed spacing of 20 cm in 30 m PP (3 mm) rope and line space of 1.0 m. Total cultivation line length is about 540m for each plot. The economic analysis for two K. alvarerzii farming models are presented in Table 2 and Table 3.

Table 2. Economic analysis for two K. alvarerzii farming models of family of three persons

Items	Unit	Total cost for 135 rafts	Total cost for 15 plots
A. Production parameters
1. Total length of lines	m	8,100	8,100
2. Size of farming plot	sqm	1,750	9,000
3. Number of cycles per year	cycle	6	6
4. Length of a cycle	days	45	45
5. Annual yield of dry seaweed	kg	21,166	18,049
6. Annual productivity	kg/m/year	2.61	2.23
7. Cycle productivity	kg/m/cycle	0.44	0.37
8. Farmgate price	USD/kg	0.34	0.34
B. Gross revenue	USD/year	7,244	6,177
C. Total annual cost	USD/year	2,300	1,766
D. Economic analysis
1. Net return (B-C)	USD/year	4,944	4,411
2. Cost of production (C/A.5)	USD/kg	0.11	0.10
3. Return on investment (D1/C)	%	215	250
4. Infrastructure cost per m of cultivation line	USD/m	0.46	0.28

Note: 1 raft 3 x 3m, 60m cultivation line; 1 Fixed-off bottom plot of 20 x 30 m,  540m cultivation line

Source: (Shanmugam, et al., 2017)

Table 3. Comparison of investment cost for  floating bamboo raft and off-bottom monoline culture plots methods operated by a family of three persons in US$

Items	Total cost for 135 rafts			Total cost for 15 plots
	Total investment	Economic life (year)	Annual cost	Total investment	Economic life (year)	Annual cost
Grand total of infrastructure and operational costs (A + B)	5,132		2,300	3,521		1,766
A. Insfrastructure	3,701		1,120	2,236		733
HDPE Fishing Net	1,247	3	416	1,386	3	462
1.5 mm HDPE rope	106	3	35	12	3	4
3 mm PP rope	319	3	106	213	3	71
5 mm PP rope	277	3	92
6 mm PP rope	65	3	22
10 mm PP rope	34	3	11	190	3	63
12 ft. bamboo	887	3	296
Iron anchor (20 kg)	185	3	62
Anchors (50 kg each)				41	3	14
Anchors (25 kg each)				205	3	68
Float				89	3	30
Seed cost	488	10	49	54	10	5
Transportation cost	92	3	31	46	3	15
Cost per meter of culture line	0.46	-		0.28
B. Operational cost	1,431		1,180	1,285		1,034
Storage (10 m × 5 m)	171	3	57	171	3	57
Cost of drying bed (300m2)	205	3	68	205	3	68
Cost of boat / Catamaran	684	1	684	684	1	684
Maintenance	370	1	370	224	1	224

Source: (Shanmugam, et al., 2017)

The infrastructure cost per meter of culture line for floating bamboo raft is 0.46 USD/m and fixed-off bottom plot 0.28 USD/m. Although the investment for the fixed-off bottom is lower but it is difficult to locate a good location and might lose crop during rough weather. Whereas, floating bamboo raft can be utilized in shallow or deep waters and You can move your floating rafts if need to protect from rough weather. The return on investment for both system is higher than 200%. That is high enough rate for sustainable aquaculture business.

Conclusion

In general, marine plants, such as cultivated seaweeds, will continue to sequester more CO₂ than terrestrial plants from the atmosphere (even if the capture is only for a relatively short period of time). in seaweed growth and processing cycles). Seaweed forests and enhanced future farming practices will assist in mitigating global warming beside producing food for people and animals. Cultivation of Eucheumatoids seaweed is labor intensive and low profit, therefore modifications of farming techniques and especially integration of some levels of mechanization is needed. Seed production for Eucheumatoids are vegetative propagated via cutting although some effort on micropropagation techniques have been trial. The seaweed is still susceptible to ice-ice disease and and epiphytic and epiendophytic “ infections”. It is clear that the success of eucheumatoids farming has been related to the joint-efforts of different stakeholders of the seaweed industry.

References

Ginigaddara, G., A.I.Y.Lankapura, L. R. & Bandara, A., 2018. Seaweed farming as a sustainable livelihood option for northern coastal communities in Sri Lanka. Future of Food: Journal on Food, Agriculture and Society, 6(1), pp. 57-70.

Hatch Innovation Services, 2022. Seaweed Insights. [Online]
Available at: https://seaweedinsights.com/
[Accessed 25 May 2023].

Hayashi, L. et al., 2010. Review of Kappaphycus Farming: Prospects and Constraints. In: A. Israel, R. Einav & J. Seckbach, eds. Seaweeds and their role in globally changing environments. Springer Science Business Media B.V., pp. 251-283.

Shanmugam, M. et al., 2017. Successful establishment of commercial farming of carrageenophyte Kappaphycus alvarezii Doty (Doty) in Sri Lanka: Economics of farming and quality of dry seaweed. Journal of Applied Phycology, Volume 9, p. 3015–3027.