Major areas of activity of the LIBFISH Aquaculture component relate to what the Project Document (ProDoc) defines as Immediate Objective 2, which is to 'Develop the capacity of the Marine Biology Research Centre, by the end of the Project, to provide effective technical advisory and management services in marine resource utilization and aquaculture to the Secretariat of Marine Wealth.' An extensive agendum of aquaculture-related practical work and in-service training activities is tied to the operation within the Centre of experimental hatchery, live and pelleted feed, fry production, and tank facilities as well as laboratories in environment, fish diseases, and fish nutrition. Major rehabilitation of existing plant and facilities was planned to take place in conjunction with this programme, and indeed was a required condition for it. The ProDoc accordingly specifies design work for and supervision of rehabilitation of MBRC aquaria and experimental tanks as one area of responsibility for the Aquaculture Advisors.1
Aside from the need for repairing pumps, corroded pipes, and cracked concrete tanks, it was noticed that although it is possible with the existing system to recirculate seawater in order to facilitate temperature control, there is no system of water treatment. Waste water is presently sent back to the main seawater network, which of course is not suitable.
2.1 Seawater Intake
The seawater intake has never been completed. A short pipe (diameter: 10 cm) allows one pump (the second one is broken down) to suck water from a pool only 30 cm deep (Annex Ia). In summer, the temperature can be as high as 36°C and in winter it is impossible to pump water when the sea is rough (very turbid water, broken pipe). Two design proposals have been prepared, as shown in Annex I:
A 20 cm semi-rigid pipe should be extended from the pump house to 100 metres from the shore, in order to draw water from at least a 4 metre depth.
A sedimentation tank should be built near the pump house to receive water by gravity through a one-metre-deep trench.
Two new pumps should be fitted, each with a capacity of 20m3 per hour. New seawater pipes need to be placed (diameter: 200mm) leading from the pumps to the main building with drainage points placed at intervals to allow cleaning with chemicals from time to time. All existing seawater pipes should be cleaned with chemicals in order to remove internal fouling.
A new 400m3 concrete seawater tank should be built outside the MBRC building in order to increase storage capacity of the system and to allow supply to the main aquaculture facilities by gravity feed.
The new seawater tank and the existing 30m3 tank situated on the building roof should be protected from direct sunlight to avoid high temperatures in summer.
2.2 Seawater Circuit
A suggested layout for an improved seawater circuit inside and outside the building is shown in Annex II. This new circuit includes:
a new seawater tank outside the building in order to increase the capacity of the circuit to feed additional fattening tanks;
a filter to treat drainage water before it is recirculated to the main circuit; and
two filters, one sand and one membrane, to provide suitable water for the live feed unit and the hatchery.
Drainage of the ground floor facilities should be modified so that it works by gravity. The recirculation circuit and drainage (basement tanks) need to be fully separated. A gravel/sand filter should be included in the recirculation circuit. All metal fittings should be replaced with PVC.
The seawater cooling system operates through the main cooling system (air conditioning) for the whole building, and thus will have to be rehabilitated as part of an overall programme for the entire MBRC complex. Actually, for the time being, it would be better to disconnect the inter-cooler system in order to avoid diffusion of toxic metallic salts in the sea water circuit.
Substantial works are needed if MBRC pilot aquaculture and display aquaria facilities are to be operated successfully.
As indicated in Annex III, provision should be made for the remodelling of existing aquaria installations into several sections, as follows:
Together these sections would comprise a pilot aquaculture system with the following functions:
A variety of new equipment will also be required, as listed in Annex IV, with accompanying Figures 1 through 4.
3.1 Public Aquarium
3.1.1 Repair work
Many visitors come to the MBRC to see the museum and display aquaria. The latter is in a very sad condition, with broken glass panels on several of the tanks, cracks in concrete, turbid water, few fishes, etc. Works needing urgent attention are as noted below.
Repair all sections of concrete with serious cracking; clean iron bars and protect from corrosion with new concrete plaster.
Replace all broken/cracked glass panels and provide 2cm thick silicone joints so that possible distortions of comers are not transmitted to the panels; clean all metal corners and protect from corrosion.
Remove old paint from tank interiors; concrete walls should be thoroughly washed with fresh water; when dry, all surfaces in contact with sea water should be coated with polyester.
The existing aquarium compressed air piping network should be disconnected from the general compressed air circuit and fitted with two rotary blowers so that it can operate independently.
Individual plastic foam filters should be installed in each display aquarium so that they can work as semi-closed circuits as until the main sea water circuit rehabilitation is complete,
3.1.2 Fishes
Fishes can be caught locally or on live capture cruises using the RV NOUR. Equipment requirements arc simple in either case. On live capture cruises holding tanks must be available onboard. Local live capture can be carried out using tranquilliser (quinaldine), a small boat or dinghy, and plastic buckets and other minor equipment readily available at the Centre. Holding tanks will need to be ready to receive live-captured fish before eventual transfer to display aquaria.
3.2 Brood Stock Unit
Brood stock can be accomodated within existing tanks in the public aquarium and the westside groundfloor aquaculture service room and the basement aquaria service room. Until selected broodstock is available from reputable sources experiments can be carried out using sexually mature specimens obtained from local fishers.
3.3 Hatchery and Live Feed Laboratory
This laboratory is needed for preparations related fish and shrimp reproduction as well as artemia, rotifer and algae cultures. It has to be dust-free and air conditioned with fully regulated temperature.
3.4 Hatching/Larvae and Live Feed Production Units
There do not seem to be any suitable rooms presently available within the MBRC building to serve as a hatching/larvae and live feed units. Two rooms of at least 35 m2 are required. As it might prove difficult to build or through subdivision create new rooms immediately adjoining existing aquaculture/ aquaria facilities, the possibility should be considered of placing two trailers or portable cabins just outside of the MBRC building on the north. The requirements for the hatching and larvae units are:
absolutely clean and dust free environment;
controlled temperature; and
connections with seawater and air supply systems and gravity drainage to the main pipe.
3.5 Fingerling Unit
The westside groundfloor room with fibreglass tanks could easily be adapted to serve as a fingerling farming unit, Fry coming from the hatchery would be received here and grown to a size of about 10 cm before being transferred to the fattening unit, or to other fish farms, as the case may be.
3.6 Pelleted/Balanced Feed Unit
Preparation of artificial feed for fingerling and bigger fish will be an important activity of the MBRC pilot aquaculture facility. It will require a specialised manufacturing workshop and a store for raw materials and finished product. The main equipment for the workshop should consist of a grinder, a mixer, a pelletiser, and a weighing scale. Since pellet production involves considerable odour and noise, it is advisable to install the workshop at an isolated site, away from the main building.
3.7 Fattening Unit
This unit could consist of a long row of 4m3 fibreglass or concrete tanks placed along seaward side of the drive that parallels the northern wall of the MBRC building, and connected to the main seawater and air supply lines and drainage system.
The design work presented in this report was undertaken as a priority activity early on in the Project in order that the rehabilitation process would not be delayed. Designs and recommendations were prepared on the basis of a thorough inspection of the existing MBRC seawater intake and pump house, seawater circuit, display aquarium, and aquaculture hall as well as a review of what would be needed to complete the various Aquaculture component tasks identified in the ProDoc.
