Aquaculture related. Mussels culture Methods.

1. Presentation
On
Culture Method of
Mussel
Presented by
Md. Tariful Islam Fuad
ID. No.: 13207059
Marine Science
Session: 2012-13 (2nd Year)
Institute Of Marine Sciences & Fisheries,
University Of Chittagong.

2. MUSSELS
Mussels are one of the member of Mollusca

3. Cultured mussels species
Perna viridis (green mussel)
Mytilus edulis (blue mussel)
Modiolus metcalfei (brown mussel)
Perna viridis is the only species farmed commercially.

4. Culture Methods
Mussel culture, as practiced in many countries, is carried out
by using a variety of culture methods based on the prevailing
hydrographical, social and economic conditions.
Mainly there are three types of culture methods-
• Bottom culture
• Inter-tidal and shallow water culture
• Deep water culture

5. Bottom Culture
Bottom culture as the name implies is growing mussels directly on
the bottom. In this culture system a firm bottom is required with
adequate tidal flow to prevent silt deposition, removal of excreta
and to provide sufficient oxygen for the cultured animals.
Production of seeds is completely left to nature. If the natural
spatfall grounds are unsatisfactory for growing, the seedlings are
transferred by the farmer to safer and richer ground or to his
private growing plots, until the marketable size is attained.
Marketable mussels are fished from the plots and undergo
cleansing before being sold. This method requires a minimum
investment. Practiced in The Netherlands.
This methods has disadvantages
like heavy predation, poor
Growth & relatively low yields
Per unit culture area.

6. Intertidal & Shallow water
culture
The culture methods that fall under this category
are usually practiced in the intertidal zone. The
culture facilities are set in such a way that the
mussels are submerged at all times. Intertidal &
shallow water Culture methods are:
• Rack culture
• Tray culture
• Wig-wam culture
• Rope-web culture

7. Rack Culture
This is an off-bottom type of mussel culture. Rack
culture is predominantly practiced in the Philippines
and Italy where sea bottom is usually soft and muddy
and tidal range is narrow. The process involves setting
of artificial collectors on poles or horizontal
structures built over or near natural spawning grounds
of the shellfish. In the Philippines, this is called the
hanging method of mussel farming. The different
variations used are as follows:
• Hanging method
• Stake(Tulos) Method

8. Hanging Method
The process starts with the preparation of the spat collectors.
Nylon ropes or strings, are threaded with coco fiber supported
by bamboo pegs or empty oyster shells at 10 cm intervals. These
collectors are hung on horizontal bamboo poles at 0.5 m apart. A
piece of steel or stone is attached at the end of the rope to
prevent the collector to float to the surface. Setting of
collectors is timed with the spawning season of the mussels.
Spats collected are allowed to grow on the collectors until
marketable size. Mussels are harvested by taking out from the
water the ropes or strings and bringing them to the shore on a
banca. The same collectors can be re-used after being cleaned
of fouling organisms.

9. Stake (Tulos) Method
The stake method is midway between the rack and bottom
methods. Bamboo poles, 4–6 m in length are staked firmly at the
bottom in rows, 0.5–1 m apart during low tide in areas about 3.0
m deep and above.
In areas where water current is strong, bamboo poles are kept in
place by nailing long horizontal bamboo supports between rows.
Since mussels need to be submerged at all times, it is not
necessary that the tip of the poles protrude above the low water
level after staking. However, boundary poles should extend
above the high water level. In staking, enough space between
plots is allowed for the passage of the farmer's banca during
maintenance.
Collected spats are allowed to grow in-situ until marketable size,
5–10 cm after 6–10 months. It has been observed, that about
2,000–3,000 seeds attach on 1 metre of stake, 1–2 m below low
water level.

10. Stake (Tulos) Method
The mussels are harvested by pulling out the poles
and bringing them ashore on a banca. Some poles
may still be sturdy and can be re-used during the
next season.

11. Tray Culture
Tray culture of mussels is limited to detached
clusters of mussels. Bamboo or metal trays, 1.5 m ×
1 m × 15 cm sidings are used. The tray is either
hang between poles like the hanging or stake
methods or suspended on four bamboo posts.

12. Wig-wam Culture
The wig-wam method requires a central bamboo pole serving as
the pivot from which 8 full-length bamboo poles are made to
radiate by firmly staking the butt ends into the bottom and
nailing the ends to the central pole, in a wigwam fashion. The
stakes are driven 1.5 m apart and 2 m away from the pivot. To
further support the structure, horizontal bamboo braces are
nailed to the outside frame above the low tide mark. Spats
settle on the bamboos and are allowed to grow to the
marketable size in 8–10 months.
Mussels are harvested by taking the poles out of water, or in
cases that there are plenty of undersized bivalves, marketable
mussels are detached by divers.

13. Rope-web culture
The rope-web method of mussel culture was first tried in Sapian Bay,
Capiz, in 1975 by a private company. It is an expensive type of culture
utilizing synthetic nylon ropes, 12 mm in diameter. The ropes are
made into webs tied vertically to bamboo poles. A web consists of two
parallel ropes with a length of 5 m each and positioned 2 m apart.
They are connected to each other by a 40 m long rope tied or fastened
in a zigzag fashion at an interval of 40 cm between knots along each of
the parallel ropes. Bamboo pegs, 20 cm in length and 1 cm width are
inserted into the rope at 40 cm interval to prevent sliding of the crop
as it grows bigger.
In harvesting, the rope webs are untied and the clusters of mussels are
detached.

14. Deep Water Culture
There are two methods followed for deep
water culture-
• Raft Culture
• Long-line culture

15. Raft Culture
Mussel raft culture has been practiced in Spain for a long time. Mussel seeds
that settle freely on rocks or on rope collectors are suspended from a raft.
When the weight of the bivalves on a given rope exceeds a certain limit, the
rope is taken out and again distributed over a greater length until marketable
size. It is a continuous thinning of the mussel stock to provide ample space to
grow.
The raft may be an old wooden boat with a system of outrigger built around
it. Other kinds of rafts could be a catamaran-type boat carrying some 1000
rope hangings, or just an ordinary plain wooden raft with floats and anchors.
Floats can be made of plastic, wood, oil drums, etc. The raft are transferred
from one place to another using a moto-boat. Production of mussels from this
type of culture is high. From a catamaran-type raft with 1,000 rope, 6–9 m in
length, about 4,666–5,333 MT of marketable mussel can be produced
(Korringa, 1976)
Advantages : reduce predation,
utilization of planktonic food at
all levels of water & minimum siltation

16. Long-line culture
Long-line culture is an alternative to raft culture
in areas less protected from wave action. A long-
line supported by a series of small floats joined by
a cable or chain and anchored at the bottom on
both end is employed. Collected mussel spats on
ropes or strings are suspended on the line. The
structure is fairly flexible.

17. Thank you everyone.