HANDBOOK ON EUCHEUMA
CULTIVATION IN FIJI
LIST OF CONTENTS
ROBERTO FOSCARINI and JAYANT PRAKASH
Associate Professional Officer, Fisheries Officer,
Aquaculturist, FAO/South Pacific Seaweed Specialist,
Aquaculture Development Project, Fiji Fisheries Division,
Suva, Fiji Suva, Fiji
May 1990, Suva, Fiji
MINISTRY OF PRIMARY INDUSTRIES, FISHERIES DIVISION
SOUTH PACIFIC AQUACULTURE DEVELOPMENT PROJECT
FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS
The designations employed and the
presentation of material in this publication
do not imply the expression of any opinion
whatsoever on the part of the Food and
Agriculture Organization of the United
Nations concerning the legal or
constitutional status of any country,
territory, city or area or of its authorities, or
concerning the delimitation of its frontiers
We wish to express our sincere gratitude to Dr. Tim Adams,
Principal Fisheries Officer. Fiji Fisheries Division, for his critical
review of the manuscript and his valuable suggestions.
We also would like to acknowledge Mr. Sashi Kumar, Graphic Artist,
University of the South Pacific, Suva, for the illustrative drawings.
The production of this handbook on Seaweed Cultivation is timely when the aspiration of the Ministry of
Primary Industries on behalf of the Government, is taken into account. Seaweed farming as a part of
mariculture or aquaculture in its general sense is the emphasis for the current decade.
With its simplicity and clarity the handbook is an inspiration to eager farmers. As such, we as a Ministry
wish to encourage all who are planning to take up seaweed farming to study this handbook and with the
help of the Fisheries Division attempt to get going on what is indeed a potential income generating activity
for the coastal populace.
The Ministry is grateful to the FAO/South Pacific Aquaculture Development Project for making available
funds for the handbook's publication. We also congratulate the Fisheries Division and the officers
involved for their valuable contribution to the preparation of the document.
As we reaffirm our commitment to encourage seaweed farming in Fiji may we wish all who are actively
involved in all spheres of the Industry the very best that the future may bring for the good of all.
Deputy Permanent Secretary (Operations)
Ministry for Primary Industries & Cooperatives
Eucheuma seaweed culture is widely practiced in South-East Asia at present in order to create cash
income to the subsistence village fishermen. Eucheuma culture also seems feasible to the Pacific Island
countries due to the low technology required for its culture and particularly the low shipping cost which is
the most important factor for sustainable development of export-oriented fisheries industry in the Pacific.
Eucheuma culture has been already proved technically feasible in the Pacific, and its quality has been
well assessed by the industry. The South Pacific Aquaculture Development Project (SPADP) has been so
far very supportive in promoting marketing development of cultured Eucheuma.
Fiji was the major producer of Eucheuma in the Pacific and about 200 mt of dried Eucheuma was
exported in 1986. It was unfortunate that Eucheuma culture in Fiji deteriorated afterwards mainly due to
marketing constraints with the withdrawal of the sole buyer in 1988.
Since then, however, a new marketing channel of Eucheuma was developed in 1989. The SPADP has
organized a workshop on Eucheuma culture and marketing in November 1989 in association with the Fiji
Fisheries Division and the FMC Marine Colloids Division. The workshop was aimed at promoting a
restoration of Eucheuma culture in Fiji and in the Pacific region by disseminating updated information of
world marketing situation and enhanced culture methods.
This time, the SPADP has supported the production of this manual aiming at some contribution towards
economic development of Fiji and other Pacific nations. It would be quite an honor for me if this
publication would be of use for this purpose.
Project Manager, South Pacific Aquaculture Development Project,
Food and Agriculture Organization of the United Nations
Hyperlinks to non-FAO Internet sites do not imply any official endorsement of or responsibility for the
opinions, ideas, data or products presented at these locations, or guarantee the validity of the information
provided. The sole purpose of links to non-FAO sites is to indicate further information available on related
This electronic document has been scanned using optical character recognition (OCR) software. FAO
declines all responsibility for any discrepancies that may exist between the present document and its
original printed version.
What is seaweed ?
Seaweed is a plant that grows in the sea. There are thousands of different kinds of seaweed all over the
world. Like plants that are grown on land, some seaweeds are also farmed to give you both food and
For example sea grapes, known as Nama, is farmed in the Philippines. In Taiwan, glassweed,
Lumiwawa, and maidenhair, Lumicevata, are the most commonly farmed seaweeds.
One seaweed species is particularly well known in Fiji. Its name is Eucheuma.
In Fiji, Eucheuma has been farmed now for several years by coastal villagers. Some of them have been
successful and are cultivating seaweed as their main source of income.
What does Eucheuma seaweed look like ?
As you can see from the figure below, Eucheuma has a very characteristic shape.
Photo of a mature Eucheuma plant. Note its size compared to that of a cigarette packet
Eucheuma seaweed can grow in different colors. You can find some plant to be either green or brown.
Despite their different colors, these plants give the same end-product.
Eucheuma seaweed has no roots but some of its branches can attach to corals and grow. Even though
seaweed grows in all directions, most of its branches grow up toward the sea surface. The branches can
grow in many different forms depending where the seaweed is planted. Do not be surprised to see your
seaweed looking different during the year.
In the warmer months, your seaweed might grow thick with a few branches only, whereas in the cooler
months, you might see plenty of shoots growing. This is because of the lower sea water temperature
during winter, together with a moderate water movement and increased amount of plant food in the water.
How fast does seaweed grow ?
Seaweed grows better and faster during the winter season, but it can be successfully grown all year
around. Just to give an idea of how fast seaweed grows, imagine that the weight of your seaweed can
become 10 times heavier in 6 to 8 weeks. In other words, if you have a 150 gram plant to start, after 6 to 8
weeks that plant will weigh about 1.5 kilograms. Thus, Eucheuma seaweed has a very fast growth; a clear
advantage for the farmers!
Photo of a seaweed seed on the left and of a mature plant after 8 weeks growth on the right.
How does Eucheuma seaweed reproduce ?
In the seas where seaweed grows naturally, waves and strong currents occasionally break seaweed
branches. These branches, drift away and eventually settle between corals or on sandy sea bottoms.
Here, they anchor and start to grow again. A new seaweed patch has been formed. In this way seaweed
has spread to many parts of the world.
Because of the way this seaweed reproduces, it is easy for the farmer to cultivate it. The only thing you
have to do to grow your seaweed, is to cut the young branches, and re-plant them.
What will be the benefit of farming seaweed for my village ?
Farming seaweed is a new job opportunity for you and your fellow villagers. It will bring money and give
you the possibility to improve your standard of living. At the same time, farming seaweed will not stop you
from performing other activities such as fishing or cutting copra. You still have plenty of time for those.
If you compare seaweed farming with other activities, you will find out that seaweed can assure you a
continuous and constant earning all year around. What other jobs can give you this?
Your wife and the other women of your village will be also benefitting from farming seaweed, in fact for
them, working in a seaweed farm will be a rare chance to earn money. Your kids can also participate by
helping you prepare the lines, cut raffia strings, tie seaweed seeds, etc. All easy jobs. In other words you
will be able to work with your family and enjoy your work.
We would like to bring to your attention another important point. Seaweed farming is not harmful to the
environment. Different kinds of fishing have already caused serious damage to the sea. Remember when
beche-de-mer were everywhere? Today it seems difficult to find a place with plenty of them. The same
happened for a lot of marine species. Seaweed farming will not take away anything from the sea. You are
just cultivating it. In fact, places where seaweed is farmed, become a sheltered area for other valuable
marine organisms such as beche-de-mer, cockles, sea snails, small fish and many others. So your
farming activity will be of benefit to the sea as well.
Are there any laws I should know about seaweed farming ?
No. Unlike other fishing activities which have size or volume restrictions, seaweed farming is free from
any limitations. You can plant and harvest as much as you want. However, you should know that there
are some customary traditions concerning the use of land and sea resources.
In Fiji, as in other Pacific island countries, the land and sea rights are held by the local villages. In other
words, you cannot plant your seaweed anywhere.
If you have intention to start cultivating seaweed, we suggest you seek written permission from the
customary owners or whoever holds the rights for the use of the area you have selected. This is very
important to avoid friction amongst villages or individuals. We want to work in peace!
In some cases, however, it might happen that you need to settle some disputes with your neighbouring
village. The local authority and the Native Fisheries Commission can help you to discuss problems and
Please, try your best to avoid unpleasant situations. Find out who holds the rights on the area you choose
before you take any step.
How seaweed is used by food and other industries ?
Through industrial processing of the seaweed you cultivate, many edible and non-edible items can be
The most important component of seaweed, in terms of industrial use, is a substance called carrageenan
also commonly known as seaweed flour.
From your dried seaweed, about 25% of the weight is carrageenan. This can be extracted through a
complicated industrial process.
Carrageenan, in its semi-refined or refined form, is used to manufacture food items, both for human and
To give you an idea of what can be done with carrageenan, this substance is used in the manufacture of
ice cream, chocolates, custards, cake topping and fillings, milk shakes, yogurts, dessert gel, canned
foods, fish gel, sauces, and many others. As you can see, it has a large number of applications for a sole
chemical substance. But that is not all!
Carrageenan is also used in the manufacture of waterbased paints, toothpastes, lotions, shampoos, and
beer. You will also find carrageenan to be an essential component in several pharmaceutical products as
In some overseas countries, such as Indonesia and Philippines, Eucheuma seaweed is also eaten raw.
People like to eat it fresh in salads. Why don't you try it? But remember, the main reason for you to
cultivate seaweed is not to eat it, but to make money!
2. GROWING SEAWEED
Where can I place my seaweed farm ?
Locating a suitable site is the key to success in cultivating Eucheuma seaweed. Numerous factors
influence the growth of Eucheuma and should be considered while choosing a farming area. These are
A water temperature ranging form 25 °C to 30 °C is best for growing Eucheuma. In shallow waters near
the beach, the water temperature can become quite high especially during a sunny day. Such an area is
not suitable for planting seaweed. In fact, even though you might think that the shallow sandy bottom is
good for securing your stakes, the high water temperature will kill your plants.
So, we suggest that you set your farm away from the lowest tide mark (spring low tide limit). A good area
is the one between the spring low tide limit and the reef edge or an area which does not dry up during
these big low tides occurring during full or new moon.
Minimum water salinity required is about 28 ppt (parts per thousand) or more. Salinity is the term used to
indicate the amount of salt you can measure in sea water. Do not worry! By tasting a few drops of salt
water in your mouth, you can feel the difference in salinity. Brackish water at the river mouth will taste less
salty than ocean flowing water. Be sure that you do not plant your seaweed in front of a river mouth or in
fresh water, as fresh water will kill the seaweed.
In the drawing is represented a bad situation. Do not set your farm in front of a river mouth.
A white sandy bottom with the presence of a limited amount of natural seaweed, is probably the best
place to cultivate Eucheuma. If the bottom is covered with seagrass, Eucheuma will not grow very well.
This is because other seaweeds might compete, absorbing the nutrients from the water leaving your
Eucheuma plants starving. In this situation, your plants might be covered with unwanted seaweeds and
as a result, silt will quickly deposit on them.
A sea bottom with hard coral formations and coral heads is not a good site to establish your farm. In such
areas it is difficult to secure your stakes. In addition, plant eating fish generally live and aggregate around
coral heads. From here, they move out from time to time to graze on your seaweed. As a result, they
damage your plants.
A muddy sea bottom, is also not advisable for your farming site because silt or mud will cover the plants
reducing the seaweed growth and some extra work will be necessary to shake and keep clean your plants.
Also murky water will limit the amount of sunlight that is supposed to reach your plants.
Now you can see why we suggest you choose a nice white sandy bottom to set your farm.
BAD GOOD BAD
Too many corals Nice clean sandy bottom Too many seaweeds
Moderate water movement is mostly preferred to strong water current like the one you can see close to
the reef edges or in its passages. If the water current is too strong, it can damage your plants and even
wash away your planted lines by pulling down the stakes. It will also slow down your work as it is difficult
work in areas with strong swift current.
However, be sure that there is a constant exchange of ocean water as the one you have with the
changing of the tides and sufficient water movement as the one created by waves. This will bring the
necessary nutrients to the plants for a healthy growth.
As for any type of farming, the supply of nutrients is an essential factor for growing your crops. This
applies to seaweed cultivation too. Therefore, remember to consider water movement as an important
factor for seaweed growth while selecting the area for your farm.
You must be sure that the farm is placed in such a direction that the water current flows into the farm and
not against it as shown in the drawing.
In this drawing you see a seaweed farm set against water current. Strong water current can bend or even
break the lines. This is not a good way to follow.
In this drawing, water current flows into the farm and not against it as above. This is a good example to
Eucheuma requires sufficient sunlight for growth. Sunlight is used by Eucheuma as a source of energy for
its growth and to manufacture carbohydrates like carrageenan, the commercially valuable substance
inside the seaweed. Thus, it is essential to have plenty of sunlight. Clear seawater allows sunlight to
penetrate more easily to the plants. This is why when seaweed is planted close to the sea surface, it
grows faster and healthier compared to that planted close to the sea bottom or in deep water.
Seaweed planted in shallow water near Seaweed planted in deep water (more
the surface (30 to 50 centimeters) than 1 meter from the sea surface)
receives plenty of sunlight and its growth does not get enough sunlight and its
will be good. growth will be poor.
At least knee deep water at spring low tide (0.5 meter) is the minimum water depth required to cultivate
Eucheuma. In shallower waters seaweed can still grow, but it might be exposed to direct sunlight and
wind. As soon as your seaweed is exposed to sun and wind, the tender tips of the plants are destroyed
and if exposed for a long time (2 to 3 hours), the whitening of the branches can be seen. This will indicate
that part of the seaweed has been killed. Eventually branches will break and drift away from the whitened
So, it is important to consider the water depth while selecting the area of cultivation.
BAD GOOD BAD
Too deep at spring Sufficient water depth at spring Too shallow at spring
low tide low tide low tide
Because Eucheuma prefers clear water and plenty of sunlight, even turbid water (muddy) will not sustain
good seaweed growth.
Chemical pollution will kill the seaweed as in the case of most marine plants and animals.
We suggest, after you select one location you think is good to grow Eucheuma, to plant several lines of
seaweed in various spots within that area and observe its growth. This will be the best way to find out the
ideal area for farming.
What methods should I use to cultivate seaweed ?
There are at least 3 methods you can use to cultivate seaweed. They are known as:
Raft or Floating
As you can see in the figure below, wooden stakes are driven into the sea bottom 20 to 25 centimeters
apart form each other in straight rows. The stakes should be 5 to 10 centimeter in diameter and 1 or 1.5
meter long. At least 0.5 meter of the stake should be driven into the sand to make them secure.
Drawing showing how a seaweed line is typically suspended in the Off-bottom Method.
A 3 millimeter thick polypropylene rope 5 meters long is firmly stretched between two stakes. Attached to
the 3 millimeter rope (line) are 30 pieces of raffia (polypropylene strings). Each of your planting material
(seed), the size of the palm of your hand (150 grams), is tied to the raffia strings. The 3 millimeter rope, is
suspended at least 20 to 30 centimeters from the sea bottom to prevent the growing seaweed from being
tossed on the sand and 20 to 30 centimeters below the water surface at low tide to avoid the seaweeds
from being exposed to direct sun light. Direct sun light will kill the exposed parts.
Stakes must be sharpened at one end so that they can be easily driven in the sand. You can use
mangrove stakes or any other bush timber which does not rot easily in sea water.
Note in the drawing above how wooden stakes are sharpened in different ways. Use the type of
sharpening as shown in the top stake.
Be sure to tie the seaweed seeds in the correct way as shown in the figure below.
Photo of seaweed seeds tied with raffia strings to a 3-millimiter line. Note the type of slip knot used.
The raffia strings, should be 20 centimeter in length with both ends knotted to prevent fraying as shown in
the previous photo. The raffia strings are firmly tied to a 3 millimeter rope in such a way that it will not
move along the rope as the seaweed grows bigger, or during rough weather.
If you are preparing your lines with seed on the shore, make sure the seaweed is covered and, when
possible, prepare your lines at night or in the shade during the day. Your seed will remain alive out of the
water, if you keep it moist.
Try your best to prepare the lines as quickly as possible and place them in sea water. Remember, the
seaweed seed will grow better if you limit the time the seaweed is kept out of the water.
Also, remember that you need to tie the raffia strings to your lines on shore before you tie your seaweed
seeds to them as shown in the photo below.
Village women preparing seaweed lines on shore. The lines can be stretched between two posts or
coconut trees. You can hammer a row of nails into the posts and easily tie the lines to them.
If you want to follow the off-bottom method to cultivate your seaweed, you can prepare the lines either on
shore, in the shallow water at low tide, or in your punt near the farm.
Farmer preparing seaweed lines in a punt. At low tide the lines can be easily stretched standing in the
Raft or Floating Method
In the floating method, seaweed is attached to some device that keeps the seaweed floating; rising and
falling, with the tidal changes.
Following this method, be sure to keep the seaweed about 50 centimeters below the water surface.
The floating devise can be a simple frame made of bamboos, mangrove wood, or bush timber durable in
seawater. You can tie together four 2.5 meter long bamboos into a square frame and stretch 3 millimeter
ropes (lines) inside the frame.
In a 2.5 meter square frame, you can stretch up to 15 lines, 10 to 15 centimeter apart. Each line will carry
15 pieces of seaweed tied to the 3 millimeter rope with raffia.
In a frame like the one described, you can plant up to 225 pieces of seaweed.
In this method you can tie your seaweed on shore by placing the raft on a support (oil drums or wooden
posts). In this way it will be easy for you to tie your seeds to the lines.
Photo of a square floating frame built with mangrove wood.
The square floating frame, should be anchored to the sea bottom as shown in the figure. As the seaweed
starts to grow and become heavier, the frame will sink. To avoid this, be sure to attach to the frame extra
bamboos or floaters. Floaters can be simply made of styrofoam or bags filled with unhusked coconuts.
Drawing of a floating frame with additional bamboo to assure sufficient buoyancy.
You can use other float materials as shown in the drawing to assure a sufficient buoyancy.
The longline method is similar to the raft or floating method in several ways. In fact, seaweed is hung to a
rope which is suspended by floaters. In this method, however, the main rope is thicker; about 10 to 15
millimeters in diameter. This rope is tied to plastic floaters or bamboo set at 4 to 5 meters interval and
anchored at each end. The pieces of raffia holding the seaweed, can be tied to the main rope in two ways.
Simplest way. The raffia string are directly tied to the main rope.
Additional pieces of rope, 0.5 to 1 meter long, can be tied to the main line and the raffia strings can be tied
Remember that your seaweed has to be hung near the water surface to receive sufficient sunlight. You
can suspend the main line about 0.5 meter below the water surface.
As described in the first two methods, the lines can be prepared on shore. Generally, in the long line
method, if you prepare your lines on shore, it will be difficult to stretch them since they are heavy and may
tangle easily. If so, you might loose some seaweed seeds. We suggested, that you tie your seaweed
seeds to the main line once the line is already stretched and suspended with floaters. You should prepare
the lines from your punt as shown in the drawing below.
Drawing of a longline being shot from a punt.
What are the advantages and disadvantages among these three
1. Simple to construct 1. Difficult to locate a good area
You might lose your crop during rough
2. Easy to manage 2.
You can prepare your lines on
3. 3. You cannot move your farm if needed
Do not require much money to You might find more grazer fish around
start your seaweed
You can use local wood to
5. 5. You need to construct a drying rack
prepare the stakes
The farm is easy to reach at
Raft or Floating Method
Can be utilized in shallow or You might have difficulty finding
deep waters bamboo
You do not need a sandy sea
2. 2. You need to find float materials
You can move your floating The frame might break or sink during
rafts if you need to rough weather
Most of the planting can be The frame can be damaged by
done on shore motor-driven boats
You do not need to construct a You might need somebody to help you
drying rack to handle the frame
You can use local wood to
construct your frame
The seaweed seems to grow
You can set your longline
1. 1. The ropes are costly
The seaweed seems to grow Planting and harvesting cannot be
faster easily done on shore
You can move the longline to
3. 3. You need to buy expensive floaters
The longline can be damaged by
How should I handle my seaweed?
When you need to transport your seaweed seeds from one place to another, as in the case of taking your
seeds to another village or even when you want to take seaweed at home to prepare your lines, you
should consider that the seaweed is a living plant and needs particular care.
The first thing you should do, is to cover your seaweed with tarpaulin or coconut leaves. If you know that
you will be travelling for several hours moving your seaweed, it is advised to put it in jute or onion bags. It
is very important to keep the seaweed moist at all times. You can pour sea water over the bags or, when
you have a chance, dip the bags in the sea.
You can also use styrofoam boxes to transport your seaweed. In this case, make a few holes on the
upper edges of the box to facilitate aeration. Remember to keep the seaweed moist. Do not fill the box
with seawater as this will make the seaweed rot rapidly unless the sea water is constantly circulated.
Drawing of seaweed farmers pouring seawater over a jute bag and a styrofoam box filled with seaweed.
Even when you carry seaweed seeds on your punt to the farm site, keep the seeds covered to protect
them from direct sunlight. Pour some seawater over them at regular intervals. Preparing the lines from
your punt, might take several hours and if not covered and kept moist, the seaweed seeds will be spoiled.
Drawing of seaweed farmers bringing seaweed seeds to the farm site for planting.
You might wonder why you should cover and keep your seaweed moist. This is to avoid the seaweed
being exposed directly to sunlight, wind and rain. Seaweed, needs to be kept moist, cool and protected to
survive out of the water.
What can harm my seaweed ?
You should keep in mind that there are several factors that can damage your farm. These might occur
especially during the warmer months of the year, from December to April. During these months, seaweed
is more susceptible to diseases and is readily harmed by grazers. Also during this period, the growth of
Eucheuma slows down and cyclones and bad weather may cause some damage to your farm. Drying in
this period can also be difficult, as it is the wet season in Fiji.
As frequently observed, rabbit and puffer fish are the main seaweed grazers. In addition to these, sea
urchins and sea turtles are also often seen damaging the seaweed plants. Among all of these, rabbit
fishes are usually the most destructive.
During the warmer months, large schools of rabbit fish 1 to 6 centimeters in length, can be seen living
among your seaweed lines. On some occasions, these small rabbit fish have grazed seaweed to such an
extent that they have entirely destroyed seaweed farms.
After the warmer months, the rabbit fish grazing becomes a minor problem. In fact, rabbit fish move away
from the seaweed. It is always a good idea to set your farm far away from coral heads, since these fishes
normally live around the corals and move out to graze on seaweed.
Do not leave rubbish (tins, unused stakes, bits of wood, etc.) as these make a very good home for rabbit
Drawing of the most common seaweed predators. Among these, rabbit fish is the most unwanted.
Even though there are no specific diseases that might affect Eucheuma, in situations where plants are
heavily grazed it is common to observe whitened areas on their branches.
Whitened areas are more exposed to fungal infection. Especially during the warmer months, fungal
infection can spread quite rapidly and the seaweed plants show large portions of discolored branches
commonly seen as white and pink areas. “Ice Ice” is the common term used to describe seaweed plants
in this condition.
Apart from occasional bad weather (rough sea and heavy rain), the effect of cyclones occurring during the
summer months can be devastating. Cyclones cannot be avoided, but what you can do is take
During the cyclone season, you should listen to the radio weather forecast regularly and carefully. If a
cyclone is expected, harvest as much seaweed as you can and keep it on shore protected from wind and
Put aside sufficient seaweed to allow you to re-start farming after the cyclone has passed by. Remember
you need to keep this seaweed in bags moist with seawater at all times. That seaweed will be your
If seaweed is kept small during this period, and not allowed to become over-mature, little damage is
expected. You might decide to harvest after 4 or 5 weeks of growth instead of waiting for 6 or 8 weeks.
Experience after going through several cyclones suggest that this strategy could limit your damage.
Also, be sure that your stakes are firmly erected otherwise the strong water currents and swells during
cyclones might wash away your effort.
After the cyclone has gone through, tangled lines should be entangled and secured again. Badly
damaged seaweed should be completely removed and replaced with new seeds.
If you are heavily hit by a cyclone but you have not lost all your seaweed, then it is possible to be back in
full business again after 8 weeks. A lot of work has to be done and done quickly, but it will worth it.
3. RUNNING A SEAWEED FARM
How much will it cost to start seaweed farming?
The amount of money necessary to start up a seaweed farm, depends on the size you have in mind. We
suggest you start your farming activity with a small set-up. Just 320 or 480 lines. After some practice, it
will be up to you to decide whether or not to expand your business. To give you a better idea of what you
need to start your farm, in the following Tables 1 and 2, are listed the materials necessary to start a 320
and a 480 line seaweed farm and their costs. Some materials such as wooden posts or stakes, can be
available to you at no cost if you decide to utilize mangrove or other bush timber, and obtain these
Table 1. List of the materials necessary to set-up a seaweed farm of 320 lines or 480 lines. The
total cost indicated, excludes the seaweed seed necessary to start farming.
320-LINE FARM 480-LINE FARM
Cost per Amount Total Amount Total
Unit Needed Cost Needed Cost
Posts (timber or mangrove
$ 1.50 each 30 $ 45.00 45 $ 67.50
7 mm rope $ 0.14/m 210 m $ 29.40 320 m $ 44.80
3 mm rope $ 0.025/m 1,700 m $ 42.50 2,500 m $ 62.50
Raffia $ 1.25/roll 30 rolls $ 37.50 50 rolls $ 62.50
U nails $ 3.00/kg 1 kg $ 3.00 2 kg $ 6.00
Galvanized Wire $ 2.80/kg 10 kg $ 28.00 10 kg $ 28.00
TOTAL EXPENSES $ 185.40 $ 271.30
The total expenses, as indicated in Table 1, can be ignored if you use a simpler way to set your farm with
each line stretched between two stakes.
You can use only mangrove or other bush timber (about 10 centimeter in diameter) and not the bigger
posts as listed in Table 1.
The lines will be simply fastened to the stakes with loops on each end. Nails and galvanized wire will
Following are the essential materials and their costs necessary for your simple farm as mentioned above.
Table 2. List of the essential materials necessary to set-up a seaweed farm of 320 lines or 480 lines in the
simplest way; one line-two stakes. The total cost indicated, excludes the seaweed seed necessary to start
320-LINE FARM 480-LINE FARM
Materials Cost per Unit Amount Needed Total Cost Amount Needed Total Cost
Stakes nil 360 nil 540 nil
3 mm rope $ 0.025/m 1,760 m $ 44.00 2,640 m $ 66.00
Raffia $ 1.25/roll 30 rolls $ 37.50 50 rolls $ 62.50
TOTAL EXPENSES $ 81.50 $ 128.50
Table 3 lists the tools you need to start your farm. Once you have bought these necessary tools, they
become your asset and you can use them whenever you need either to expand or do maintenance of
your farm. You do not need to buy new ones. Other materials such as posts or stakes, nails, raffia and
ropes, will last for at least 1 year.
Table 3. List of the tools necessary to both start and continue working at your seaweed farm.
Crowbar $ 18.00
Mall hammer $ 18.00
Pliers $ 8.00
Claw hammer $ 10.00
Bow saw $ 12.00
Mask and snorkel (2 sets) $ 54.00
Kitchen knives (2 at $.75 each) $ 1.50
Cane knive $ 7.00
TOTAL EXPENSES $ 128.50
Who can help me to start and finance my seaweed farm?
The Fiji Government, through its various Ministries can help you a lot if you decide to start cultivating
seaweed. The Fisheries Division of the Ministry of Primary Industries has staff based in numerous
stations all over the country ready to come and see you. You can discuss with them your problems and
they can suggest to you the best way to proceed. They can also help you to find some of the materials
you need to start your farm, and most important, they can give you seaweed seeds free or address you to
the closest seed supplier. They can give you technical advice and put you in touch with the seaweed
buyers. It is really a great help. Do not hesitate to seek assistance from them.
If you do not know anybody from the Fisheries Division working in your district, you can write to:
Director of Fisheries,
P.O. BOX 358, Suva
Institutions such as the Fiji Development Bank, the New Zealand and Australian Embassies, United
States Agency for International Development, have given in the past some assistance in terms of loans
and grants to the Fiji seaweed farmers. The assistance is given in terms of materials you need (ropes,
raffia, and in some cases small punts). Do not expect to receive cash.
It is important to know, that the Fiji Development Bank might help you with loans. They will require a
deposit of 33% of the total amount of money which you are asking for. In addition to that, you will be
asked to pay 8% annual interest to the bank. The Ministry of Rural Development, the Provincial Council,
the Ministry for Fijian Affairs or the District Officers, can also help you to some extent.
How can I organize my work at the farm?
The amount of effort you need to put into farming seaweed, the number of people that you need to help
you, and of course, the money you can earn from farming, depends on the size of your farm.
A farm size of 320 or 480 lines set following the off-bottom method, can be handled by one person.
Considering that seaweed can be harvested after 8 weeks, it is practical to divide your farm into 8 blocks.
In this way you will be able to plant and harvest one block every week.
For a 320 line farm, each block will consist of 40 lines, whereas 60 lines are suggested for a 480 line farm.
Example of a off-bottom farm divided into 8 blocks.
If you decide to work 4 days per week, you can harvest 10 to 15 lines per day, depending on the size of
In case you plan to expand your farm, say up to 800 lines, two people will be sufficient to look after the
planting and harvesting operations. For a larger farm a family of 4 to 5 members is recommended.
The diagram shown in the next page, outlines an example of work schedule that might fit your situation.
Please note that the proposed work schedule is designed for a new seaweed farmer. In this case you
might start with 10 lines, as suggested, or more. However, if you already have for example about 80
mature lines available, you can start directly to plant your 320-lines farm. In fact from one mature line of
seaweed, you can obtain enough planting material for four new lines.
If you can start your farm by planting 40 lines instead of 10 lines, as suggested in the work schedule. After
the first 8 weeks you will have sufficient seaweed to expand your farm directly to 320 lines.
Here is a suggested weekly schedule based on 4-working days.
Monday Tuesday Wednesday Thursday
Re-plant and Re-plant and Consolidate and
Harvest all your seaweed (40 lines)
tedding tedding sell
Of course, if you prefer to distribute your job over the week, here is another suggested schedule that
might fit your situation.
Monday Tuesday Wednesday Thursday Friday Saturday
Harvest 20 Harvest 20 Re-plant and Re-plant and Re-plant and Consolidate
lines lines Tedding Tedding Tedding and sell
Both examples are based on the assumption that the weather remains good and there is plenty of
sunshine to dry your seaweed.
In an established farm where seaweed is cultivated using the floating method, one person can manage to
plant and harvest 1 raft per day. Therefore, working on a four day week, you will be able to plant and
harvest 4 rafts.
What should I do to maintain my farm?
To be a productive farmer, the seaweed farm should be well attended. This means that you constantly
visit and check your farm.
Seaweed needs to be kept clean. To do this, you can shake or raise the seaweed lines to remove any
unwanted seaweeds and rubbish.
If you do not keep your seaweed clean, other seaweeds will take away the nutrients necessary for your
plants growth. As a result your plants will not grow very well.
To assure a better growth, it is advisable to remove silt or mud coating on the surface of the seaweed, by
shaking the lines. The parts of the plants showing white and pink areas, should be removed and taken to
Detached lines should be fastened and lost plants replaced.
Slow growing strains should be harvested and replaced with fast growing strains.
Fish grazers, especially the bottom and coral dwelling species, should be kept away or fished if possible.
Seaweed should be harvested as soon as it reaches its harvesting size (6 to 8 weeks), and re-planted
immediately for a continuous harvesting and re-planting cycle. Do not leave your plants to over-grow as
they will break and easily drift away. Over matured plants are difficult to dry as their branches are thicker.
To be able to successfully manage your farm, a record keeping system is an essential part of the
Such a record is the foundation for any business, especially in a farm, and through it, it is possible to find
out if your activity is profitable. If so, you might think to expand your farm.
By getting into the habit of recording daily your expenditures and income, you can rapidly see if you are
making or losing money in the seaweed business.
The record keeping will help you to see many other aspects related to your activity such as how much fuel
has been consumed in a week, or during certain months of the year you can obtain better harvests, etc.
The record book, should be filled every day. If it is left to the end of the week, there are more chances that
some payments or seaweed collected could be forgotten.
In the next page we suggest you a scheme to follow. It is just an example.
Number of hours spent farming : 6 hrs
Hours spent elsewhere (plantation, etc.) : 2 hrs
Labour (Number of people working with you) :4
Numbers of lines harvested : 40
Numbers of lines planted : 20
Weight of seaweed collected and dried : 120 kg
Amount of money earned by selling seaweed : $ 60.00
Other incomes (fish sales, etc.) : $ 25.00
Loan (FDB and others) payment :
Fuel for your motor boat :
Fuel for your car (or truck) :
Labour cost :
Food for you and your family :
School fees, etc. :
Medical expenses :
Farm costs :
TOTAL EXPENDITURES :
How much I will earn from my seaweed farm?
This is probably the point in which you are interested the most. How much you can earn.
Farming seaweed is not considered a tough job. It requires, though, a constant effort. You cannot start
cultivating and then abandon your farm for a while and expect to see good harvests. Thus, it is necessary
to work at last 4 days per week to earn sufficient money for you and your family.
Based on the current selling price of $ 0.50 per kg of dried seaweed, if you are engaged in a 320 line farm,
you can expect to earn about $ 60.00 per week. If you have a bigger farm, let's say 480 line farm, you can
earn up to $ 90.00 per week. This means $ 15.00 to $ 22.50 per each of the four working days. Not Bad!
You may be wondering how this is possible. Follow our reasoning. From a 320-line farm, you can harvest
10 lines per day, which means that in a 4 day-week you can harvest 40 lines. Each line will weigh about
30 kg, thus totalling 1,200 kg of wet seaweed or 120 kg dry weight. If you sell your seaweed at $ 0.50 per
kg and you produce 120 kg per week, then you can earn about $ 60.00. From a bigger farm of 480 lines,
you are expected to harvest 15 lines every day. In a 4-day week you can produce 180 kg of dried
seaweed worth about $ 90.00.
Larger farms will earn you a higher income, but will also require more effort, commitment and initial
investment. You will also need more people to help you maintain the farm, unless your wife and your kids
work with you.
4. HARVESTING AND SELLING SEAWEED
What care is required after seaweed is harvested ?
Seaweed is harvested on a weekly basis after 6 or 8 weeks of growth depending on the culture method
It is the responsibility of the seaweed farmer to harvest the crop, dry the harvested seaweed and keep it in
a well protected place such as a storage shed until the buyer comes to the village to collect it.
The Farmer's Responsibility
Harvesting is a simple work to perform. It involves:
removing of the mature seaweed plants from the lines by unfastening the raffia knots, or by
breaking off the plants;
spreading the seaweed plants over a drying rack; and then
removing raffia and other unwanted materials.
The drying rack should be built in such a way, keeping in mind that air should easily circulate through the
seaweed to assure good ventilation and quick drying.
The simplest way to dry seaweed is by spreading the harvested wet seaweed over a net, a tarpaulin or
over coconut leaves on the ground. However, in this way only the seaweed exposed directly to the sun
(top portion) will dry efficiently and the remaining (lower portion) will stay wet.
Air ventilation is very limited when seaweed is dried on the ground as shown in the photo below.
Photo of seaweed drying on tarpaulin on the grass in the village backyard.
If you find it convenient and handy to dry the seaweed on the ground, be sure that the seaweed is at least
partially dried. Fresh wet seaweed, just harvested, cannot be placed directly on tarpaulin for proper
Moreover, if you dry the seaweed on the ground, sand, soil and other rubbish can mix with the wet
seaweed. The seaweed buyers will not buy a dirty product.
The best way to dry seaweed, is to use a drying rack with the drying area made of sarlon netting. The rack
can be constructed on shore or near your farm as shown in the figure below.
Photo of a drying rack placed in the shallow waters near the farm site. Note the large amount of posts,
braces and timber used.
In some cases it might be difficult to find the netting which can also be expensive. You can use reeds or
Just to give you an idea, consider that in an area of 100 square meters (20 meter by 5 meter) of sarlon
netting, you can dry approximately 80 lines of mature seaweed at one time or more.
With plenty of sunshine, let's say 8 to 9 hours a day, the drying process will take you 3 to 5 days.
Seaweed should be frequently tedded or turned for proper and quick drying. Also, for efficient drying,
make sure the seaweed is thinly and evenly spread.
Detailed drawing of a drying rack with dimensions. A drying rack as the one designed above, can be
placed in shallow water near your farm.
Drawing of a drying rack placed on shore. Shore racks are easier to construct and also cheaper.
If you weigh your seaweed before and after drying, you will find out that the original weight has decreased
by approximately 10 times. So, if you had 10 kg of wet seaweed, after 3 to 5 days of sun drying, it will
weigh only 1 kg. This is called 10 to 1 wet to dry ratio.
The minimum moisture content which is required by the seaweed buyers, is about 35 %. Don't worry! You
do not need to measure the moisture content of your seaweed before selling it. Just make sure that
seaweed is properly dried as suggested.
Well dried seaweed is covered with plenty of salt crystals and have rubber-like texture when you squeeze
it and no water should drip from it.
It is wise to cover the drying seaweed during rainy weather or at night with a tarpaulin or anything that can
prevent the seaweed from getting wet. You might have unexpected showers at night! If seaweed is
rain-washed, it will take more time to dry and you will face a further weight loss. This is a disadvantage for
the seaweed farmer as the moisture content will be lower and the seaweed will become partially rigid.
Very difficult to pack.
Rain-washed seaweed will give you less money than you might expect.
Storage of Dried Seaweed
After drying and before packing the seaweed, be sure to remove any rubbish material (raffia, pieces of
nylon ropes, plastics, other unwanted seaweeds, etc.). The people that come to your village to buy
seaweed, will appreciate a clean and well dried product.
Well dried seaweed with salt crystals on its surface can be stored for a long time; up to 2 years without
getting spoiled. The salt covering the seaweed prevents the spoilage of the carrageenan. Of course it is
important that seaweed is stored properly.
It is always a good idea to pack your seaweed in polypropylene bags soon after drying and store it in a dry
area. Polypropylene bags are the best because they do not soak up water as compared with jute bags.
In some cases you can store the packed seaweed in your house, if there is enough space. You can also
build a storage shed in the village.
It is the responsibility of the buyer to bale the seaweed and move the bales to the collection centers for
consolidation and loading of the containers. He will also take care of transporting the container to the
closest harbor with access to international routes for export. He will take charge of dealing with the
The Buyer's Responsibility
Dried seaweed already packed in bags, should be transported to collection centers in the shortest time to
allow the buyer to bale the seaweed.
A quick baling is important because it will prevent moisture being re-absorbed into the seaweed as
compared to seaweed kept loosely in bags.
In the next page are listed the advantages of baling seaweed. Do not under estimate the advantages of
baling. Even if such operation will require extra costs for material and labor, it is considered of extreme
importance for an efficient post-harvest technique.
prolonged storage time without spoilage of seaweed;
reduced space necessary for storage;
easier handling of bales compared to seaweed kept loosely in polypropylene bags;
more efficient way to export seaweed overseas.
The figure below shows a baling machine commonly utilized to pack seaweed at the collection centers.
Photo of a baling machine and of a 100 kg seaweed bale in the foreground. This is a simple machine
operated by a screw press.
Seaweed is moved from the growing areas to the collection points for baling and consolidating enough
volume for export. From here, the bales are transported by sea or road to the closest port with access to
international shipping routes.
The industrial processing of seaweed is done in overseas countries at present, but if Fiji grows enough
seaweed, we can start to process it ourselves.
The bales can be accommodated into containers which can hold up to 20 tonnes or more of dried
How much seaweed can I harvest from my farm?
Eucheuma seaweed can be harvested after 8 weeks of growth. During the year, it is possible to achieve
at least 5 harvests; one every 2 months.
If weather remains favorable, an additional harvest can be obtained unless it is necessary to commit
some time for social and/or traditional activities.
At maturity (8 weeks), about 30 kg of wet seaweed can be harvested from each line planted with 30 seeds.
After drying the seaweed, from each line you can obtain about 3 kg of dried seaweed.
In a realistic situation, as experienced by many seaweed farmers, you will not be able to harvest on a
regular basis. Rainy weather sometimes last several days or weeks. In this condition it will a problem to
find a shade to protect your harvest form rain and dry the seaweed. You might then decide not to harvest
during this time. The seaweed will keep growing and as a result at the harvest, you will be able to obtain
more than 3 kg from each line.
Based on the work done by one man only, it is possible to harvest 10 lines of mature seaweed every day.
In a week, working only 4 days, 40 lines can be harvested giving you a total of 120 kg of dried seaweed.
If you are able to harvest seaweed 5 times over a 12-month period, you will be able to sell 4,800 kg of
How can you achieve this result? Carefully read the outline given in the next page.
30 kg of wet seaweed or 3 kg
From one seaweed line
In one working day 10 lines or 30 kg dried seaweed
In one week (4 working 40 lines or 120 kg dried
320 lines or 960 kg dried
During eight weeks cycle
1,600 lines or 4,800 kg dried
In one year (5 harvests)
These estimations are not theoretical. They are the results of observations and studies of real situations.
It should be clear though, what we have outlined applies to the most commonly used culture method: the
If you wish to culture your seaweed using the raft or floating method because is more appropriate to the
area you have selected for farming, a different production is expected.
Using the floating method, Eucheuma seaweed should grow faster because it is cultivated closer to the
water surface. Eucheuma might be ready to be harvested in 6 or 7 instead of 8 weeks. Thus, more
harvests can be obtained every year.
Each floating frame planted with 225 seeds (150 gram each), can produce about 337 kg of wet seaweed
or approximately 33 kg of dried seaweed.
One man alone can harvest up to 4 frames every week (1 every day). Owing to the shorter period
necessary to harvest mature seaweed, up to 8 harvests can be achieved in one year giving you a total
annual yield of 6,336 kg of dried seaweed.
Carefully read the illustration in the next page to find out how you can achieve this production:
337 kg of wet seaweed or 33 kg
From one frame
In one working day 1 frame
In one week (4 working
4 frames or 132 kg dried seaweed
24 frames or 792 kg of dried
In six week cycle
192 frames or 6,336 kg of dried
In one year (8 harvests)
Because the floating frame method has been introduced in Fiji recently, the figures outlined above are
The Longline Method has not yet been used in Fiji, but the Fisheries Division will be making trials in
Who is going to buy my seaweed ?
As your work progresses and you become a well established seaweed farmer, private companies working
in the seaweed business, may come to you and offer their technical expertise and help you to expand
A few years ago, a New Zealand company set up one of its branches in Fiji. The company helped
villagers to start seaweed farming. They also bought all the seaweed produced in Fiji and took care of its
Today, a newly established Fiji company, Seaweed (South Pacific) Ltd., is the sole marketing agent in Fiji.
They will buy all the seaweed you can produce.
Seaweed (South Pacific) Ltd., already has several collection centers where you can sell your dried
seaweed. These are in places like Moturiki, Kiuva, Kasavu, and Lautoka. More collection centers will be
located in new areas later on as seaweed farming develops in Fiji.
Photo of a seaweed farmer at a collection center in Kiuva. Here the farmers can sell the dried seaweed.
Photo of the shed built in Kiuva. Here the dried seaweed is consolidated and later baled for export.
What is the marketing situation for seaweed in the world ?
In countries such as Indonesia and the Philippines, seaweed farming is very common. These countries
produce most of the seaweed used by the industry in the world. In the past years they had some financial
problems when the price of seaweed dropped because of an over-production.
Today the situation has changed and the production of seaweed is lower than the amount required by the
industry every year. This is because many new products which include carrageenan have been
developed. Since the demand for carrageenan exceeds the world production, the processors are willing
to pay a higher price for your seaweed.
So, plant and cultivate more seaweed and make some extra money while the opportunity exists.
What are the prospects of the seaweed industry ?
The opinion of the experts is that, till 1992 the total volume of seaweed produced in the world will not be
enough to satisfy the needs of the processing industry and therefore the seaweed market price will not
By 1992, if enough farmers are growing seaweed, Fiji will be able to set up its own processing plant and
this will help guarantee the local price against possible future fluctuations in the world market price. New
uses are being found for carrageenan and this will keep the market expanding.
Another prospect for the future is the culture of other types of useful seaweeds, for example
agar-producer. The Fisheries Division will be researching the ways of widening and diversifying Fiji's
Remember: seaweed is a crop which requires low capital investment and has a rapid rate of return (5 or 6
crops per year). With the current high price level, this makes a very good way of making money
particularly in places where agricultural land is scarce.