FAO FISHERIES DEPARTMENT

STANDARD INTERNAL DISTRIBUTION
OF PROJECT DOCUMENTS

FI: CPR/88/077 Field Document 10 October 1991

A report prepared for the project
Fisheries Development in Qinghai Province

by

David Edwards

CTA/Coldwater Fish Culture Specialist

This report was prepared during the course of the project identified on the title page. The conclusions and recommendations given in the report are those considered appropriate at the time of its preparation. They may be modified in the light of further knowledge gained at subsequent stages of the project.

The designations employed and the presentation of the material in this document do not imply the expression of any opinion whatsoever on the part of the United Nations or the Food and Agriculture Organization of the United Nations concerning the legal or constitutional status of any country, territory or sea area, or concerning the delimitation of frontiers.

FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS
Rome, 1991

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TABLE OF CONTENTS

1. TERMS OF REFERENCE

2. CONSULTANT'S VISITS

2.1 Lake Fisheries Management Specialist
2.2 Limnologist

3. NATIONAL PROJECT STAFF

4. TRIPARTITE REVIEW MEETING

5. FELLOWSHIPS AND STUDY TOURS

6. TROUT FARM DESIGN, CONSTRUCTION AND OPERATION

6.1 Rainbow Trout Hatchery and Fingerling Production Unit

6.1.1 Construction work
6.1.2 Hatchery operation

6.2 On-growing Units

6.2.1 Concrete raceways
6.2.2 Floating cage unit
6.2.3 Earth ponds

7. NAKED CARP HATCHERY CONSTRUCTION AND OPERATION

7.1 Construction
7.2 Operation

8. RAINBOW TROUT FEEDS

9. MONEY AND EQUIPMENT

10. CONCLUSIONS

1. TERMS OF REFERENCE

The Chief Technical Advisor/Coldwater Fish Culture Specialist consultant to project CPR/88/077 undertook his third mission from 23 January to 25 June 1991. His terms of reference for the four-year project are:

1. To coordinate the activities of other consultants in partnership with the National Project Director (NPD).

2. To prepare progress reports for consideration by tripartite review meetings, and to write the project terminal report.

3. To be responsible for planning, building and operating the trout farms and the experimental naked carp hatchery, working in close cooperation with the NPD and consultants specialized in fish feed technology, aquaculture engineering etc.

4. To take a major part in the in-service training of national staff.

2. CONSULTANTS' VISITS

In addition to the CTA/Coldwater Fish Culture Specialist, two other experts were assigned to the project for periods during the first half of 1991, as follows:

2.1) Dr. Ian Dunn, Specialist in Lake Fisheries Management, was assigned for two months from 4 April until 10 June 1991. He will return again for a further two months in August of the same year.

2.2) Mr. Colin Smith, Consultant in Limnology, worked one month in Qinghai from April 6 until May 7. During that time he completed commissioning of equipment for the Qinghai Lake study group, and trained staff in use of laboratory equipment. No further assignments for limnology consultants are budgeted during this project, apart from a technical backstopping mission by an experienced limnologist from FAO headquarters which will be fielded later this year.

The above consultants submitted reports following their visits in the normal way, and their findings and recommendations will therefore not be repeated here.

3. NATIONAL PROJECT STAFF

The number of counterpart staff assigned to the project was substantially increased during 1991, reflecting the additional workload resulting from full implementation of all project activities. A full list of project staff employed by the Bureau of Aquatic Products, Qinghai Provincial Government, is as follows:

a) Administrative and service personnel:

In addition, several staff were employed by the Huzhu County Government as a contribution to staffing the Nanmenxia trout hatchery, and others by the Longyangxia Hydro-Power Company for the project's floating cage culture site for trout on-growing. Including part-time workers, the total number of counterpart staff assigned to this project is now around 40.

4. TRIPARTITE REVIEW MEETING

The second tripartite review meeting for the project was held in Xining City, Qinghai Province, on June 7, 1991. The meeting was attended by a representative from FAO Rome, and one representative each from the Beijing offices of FAO, UNDP, CICETE and the Ministry of Agriculture. The NPD and Deputy NPD, CTA and Lake Management Consultant, were also present. Prior to the meeting, the group toured the project's trout hatchery at Nanmenxia Reservoir in Huzhu County, the experimental naked carp hatchery outside Xining, the floating cage culture site for on-growing rainbow trout at Longyangxia Hydro-Power Reservoir, and the fishery base used by the lake study team at Qinghai Lake.

A Project Performance Evaluation Report (q.v.) was written by the CTA in the standard format and circulated to all participants in advance of the meeting. In addition, the NPD's report was distributed in written form during the meeting. Minutes of the meeting will be circulated to concerned parties in the normal way, and need not be reiterated here.

The meeting concluded that good progress had been made during the past year, and that the implementation of project CPR/88/077 to the date of the TPR was satisfactory.

5. FELLOWSHIPS AND STUDY TOURS

The study tour in Lake Fishery Management was undertaken from 11 November to 12 December 1990. Six team members: Mr. Qiu Benchen (NPD), Mr. Wang Jilin (Scientific Leader of the Lake Study team), Mr. Yang Hongzhi (Deputy Leader of the lake group), Mr. Da Renqing, Mr. Chen Yuan, and Mr. Zhao Yimin (Interpreter), travelled.

Most of the group's tour was hosted by Humberside International Fisheries Institute, University of Hull, UK, where the team worked from 11 November until 2 December. The course of instruction included both theoretical and practical training, combined with field visits. A full programme for the course was given in CTA Edwards' 1990 report (Field Document 7).

From 2 to 7 December 1990, the study group visited sites of importance for lake management in the Netherlands, hosted by that country's Ministry of Agriculture, and from 7 to 12 December undertook a similar tour of Czechoslovakia with Ministry of Agriculture representatives from Prague. Throughout the study tour, the group was accompanied and assisted by Dr. Ian Cowx of Humberside International Fisheries Institute. (Dr. Cowx is also a consultant to FAO.)

On 12 December, four members of the team returned to Beijing. However the NPD Mr. Qiu, and Interpreter Mr. Zhao, travelled to FAO headquarters Rome, where they received four days familiarization with the organization's procedures, before returning to China.

Following the tour, the team produced a detailed report on its trip (q.v.), from which it was clear that many valuable lessons had been learned from this study tour.

The study tour completed all the overseas training budgeted under this project, and no further fellowships or study tours are planned.

6. TROUT FARM DESIGN, CONSTRUCTION AND OPERATION

6.1) Rainbow trout hatchery and fingerling production unit

6.1.1) Construction work

Hatchery building. The shell of the 40 × 15m hatchery building was completed before the onset of winter 1990. Construction is of brick under a concrete roof waterproofed with pitch and roofing felt. Floors are concrete, sloping to integral drainage channels. Single-phase electricity supplies waterproof lights.

Imported plastic pipework and fibreglass incubators and fry tanks were not delivered until winter 1990–1. They were installed during February 1991 in time for the first intake of trout eggs planned for March (see below, section 6.1.2). 16 × 3.5m long incubator troughs (each holding 7 egg boxes), and 20 2 × 2 × 0.4m deep fry tanks were installed, all supplied with water by plastic pipes and valves from a 3 × 2 × 1m deep fibreglass head tank situated 2.2m above floor level inside the building.

In accordance with Government's wishes, the hatchery building was designed large enough to allow for future expansion considerably above the requirements of the project. Thus there is currently a lot of spare space inside the building, enough to accommodate sufficient extra tanks to double the hatchery's current fry production capacity. It is planned to fill part of this space with specially-constructed small concrete raceways in time for the 1992 fry season. Plenty of water is available via the existing pipeline to supply this expansion.

Water supply pipelines. A 3m-diameter concrete sump was constructed to collect water from one of the three main springs below the Nanmenxia Dam, 3.6m above hatchery floor level. From the sump, a 30cm internal diameter concrete pipe carries water approx. 340m to the hatchery. The pipeline runs underground, emerging inside the building, where it rises through a steel pipe and gate valve to discharge into the top of the fibreglass head tank. This pipeline was completed during winter 1990–1.

During commissioning trials, it was found that the water from this spring was sometimes low in oxygen (often down to 5mg/1 at 6°C). Rainbow trout are generally thought to require a minimum of 6mg/1, and higher levels than this are preferable. Consequently an aeration device comprising a 2 × 1 × 0.3m deep wooden box, with wire mesh top and bottom, was filled with 6 000 pingpong balls and installed between the water inflow and the head tank. Incoming water falls through the box over a large surface area of the balls, picking up oxygen as it goes. By this means the oxygen concentration in the incoming water was raised to 7.5 – 8.0mg/1. Full saturation at the altitude of the hatchery (almost 3 000m above sea level) and 6°C is about 8.8mg/1, but the lack of sufficient difference in level between the intake pipe and the head tank makes it difficult to raise oxygen concentration further by mechanical means.

A second and larger water supply to the fish farm was completed during May 1991. Excess water from the above spring flows in an open earth canal to join the outflow from a second spring about 2.6m above hatchery floor level. The combined flows from the two springs are channelled via an open concrete canal to a concrete sump tank, from where the water is piped underground through a 50cm internal diameter concrete pipe to the fish farm. At the farm, the pipe rises through a steel valve to 2 × 6inch and 1 × 12inch flanges. The six-inch flanges connect to plastic pipe-runs supplying outdoor 8m diameter fibreglass tanks (see below) through 4 inch valves, whilst the large flange will provide part of the water supply to outdoor concrete raceways.

A third source of spring water runs naturally in an open earth canal close to the fish farm. It will later be diverted to provide a second water supply to raceways.

In the CTA's 1990 report (Field Document 7), some uncertainty was expressed over the flow rates of water to be expected from the three springs. This was because the dam from which the springs originate was under repair and consequently kept empty, resulting in much reduced flows. However, repairs are now complete, and the reservoir above the dam is filling. Spring flow rates have now increased to a total of around 0.5m³/sec, which is plenty to supply all the tanks and raceways planned at this fish farm.

Outdoor fingerling tanks. Eight 8m-diameter fibreglass tanks were imported during winter 1990–1, and assembled on sand bases adjacent to the hatchery building in April-May 1991. Two of the tanks are supplied with water from an 8 inch plastic pipe doubling as an overflow from the head tank in the hatchery building. The other six tanks receive water from the two 6 inch diameter plastic pipes supplied by the 50cm pipe carrying the combined water from two springs as described above. The 8m tanks discharge outflow water into a 1.5m wide concrete drainage channel, and the whole area occupied by these tanks is being covered with a light roof of corrugated plastic to provide shade.

Staff accommodation. Staff accommodation was completed during April-May 1991. The single-storey 26 × 5m block houses eight rooms. Construction is of brick under a concrete roof waterproofed with pitch and roofing felt. Internal floors are of concrete, and walls finished with plaster and paint. A 3-phase electricity supply is installed, though the fish farm frequently experiences prolonged power cuts.

6.1.2) Hatchery operation

One million eyed rainbow trout eggs were imported from Denmark on March 17, 1991. The eggs were delivered by airfreight to Beijing packed in 13 special polystyrene boxes with ice. The consignment was promptly transferred to a connecting flight to Lanzhou, then carried by road to the hatchery the same night. Mortality during transport was negligible. It is planned to import a further one million eggs from the same supplier during March 1992.

The eggs were incubated in 13 “California-type” incubators. First hatch occurred about a week after importation, but hatching was not complete until mid-April. Because water temperature remained low (6.0–6.3°c), fry were not ready for first feeding until May. For the same reason, growth continues fairly slowly, and in late June fish average a little over 0.5g. Mortality through incubation and first feeding totalled about 15%. This is a satisfactory result, and currently the hatchery holds many more small fish than should be needed to meet the project's production target of 250 000 fingerlings by spring of 1992.

Due to the high survival, indoor fry tanks are already becoming crowded. Consequently some fish have been moved outside into one of the 8m-diameter tanks. Such large tanks are, however, difficult to work and especially to keep clean when they contain such small fish. Consequently extra fry accommodation in the form of small concrete raceways will be provided indoors in time for the 1992 fry season.

Though it was not planned to keep broodfish at the hatchery until 1993, project management decided to buy-in approx. 600 parent fish in 1991. These were obtained from a commercial trout farm in Gansu Province, and transported to Nanmenxia by the project's live fish hauling truck during May. The fish are kept in one of the 8m-diameter tanks at the hatchery. The purpose of bringing forward the holding of broodstock was to allow demonstration and teaching of techniques for care of parent fish, egg stripping, fertilization and early incubation during winter 1991–2. Had the original plan been strictly adhered to, this training would not have been possible until the project's own fish became mature. This cannot be expected until winter 1993–4 for females (assuming first maturation at three years of age), after the end of the project period.

In summary, the Nanmenxia hatchery has made a fully satisfactory start to its trout production activities on schedule.

6.2. On-growing units

6.2.1) Concrete raceways

As described in CTA Edwards' 1990 report (Field Document 1), it was originally planned to construct sufficient concrete raceways at the Nanmenxia Dam site to grow-out approx. 25 tonnes of rainbow trout per year to a market size averaging 250g.

Later, doubts about the adequacy of water supplies at the site, and some administrative problems with the local Huzhu Country Government, cast doubts over the siting of raceways. However, early in 1991 it became clear that water supplies are sufficient and “political” problems not insurmountable. Project management therefore decided to go ahead with construction at the Nanmenxia site.

At the time of writing, excavation has been completed for approx. 1 100m² of raceways, and concrete bases layed. Eight raceways are being constructed in this area, in two ranks of four. The outflow water from the first (highest) rank will pass into the second (lower) rank. When these ponds are completed in approx. August 1991, it is planned to begin work on a second similar set on an adjacent site. Water supplies to the raceways come from the three springs as described above.

The raceways will be ready to accommodate fingerlings from the hatchery early in 1992 as originally planned.

6.2.2) Floating cage unit

The site at Longyangxia Hydro-Power Reservoir chosen for the project's cage culture facility was described in CTA Edwards' 1990 report (Field Document 1). The preliminary trial using a single cage stocked with trout, which was undertaken during summer 1990, two years ahead of the original plan, was outlined in Edwards' 1990 report (Field Document 7). This successful trial produced around 500kg of market-size fish, and proved the environmental suitability of the site for trout production.

During 1991, a larger trial is being conducted at Longyangxia, one year ahead of the original plan layed down in the project document.

By June 1991, four new cages have been constructed to the design of the CTA. The square cages are based on timber frames with steel-reinforced corners. Walkways 0.5m-wide all around each cage are supported by expanded polystyrene flotation. Timber rails 1m above the walkways support nylon net bags 5 × 5 × 7m deep. The nets were made fairly deep to allow fish to avoid high surface water temperatures should these occur during summer. (During summer 1990, maximum surface temperature was 21° C.) Four more cages are now under construction for use when fish require thinning out later in the year, and a total of 26 will be ready for operation during 1992 as planned. At that time the first batch of fingerlings produced by the project's Nanmenxia hatchery will be ready for transfer to the on-growing unit.

About 20 000 rainbow trout fingerlings averaging a little over 50g were bought in from a commercial fish farm in Gansu Province, and transported to Longyangxia during May 1991. They are being fed on dry pelleted feed manufactured in Xining to the specification of the project's fish feed specialist consultant Dr. Tacon (see below, section 8). To date growth of these fish has been very good, and average weight has approx. doubled in 4–6 weeks. Currently water temperatures at the site are ideal for trout growth, ie 15–18° C at the surface.

The Longyangxia Power Company has set an arbitrary target for trout production from the cages this year of 5 tonnes, and most fish will be harvested during autumn 1991. The project's original target is for an output of 20 tonnes in autumn 1992.

6.2.3) Earth ponds

As reported above, the quantity of water available at the Nanmenxia site is now seen to be adequate for both fingerling production and for on-growing trout to market size. Management has therefore decided to build the project's earth ponds also at the same location. In fact two large earth ponds already exist adjacent to the fish farm. They were built earlier for experiments in carp reproduction. It is planned to modify these ponds for trout culture by building dividing walls of earth longitudinally within them. Water supply has already been constructed from the new concrete canal carrying water from two of the springs described above. The ponds are big enough to achieve the project's modest target for trout production using this method, ie. 5 tonnes of market fish per year beginning in 1992. Pond modification will be done during autumn 1991.

In addition to the ponds at Nanmenxia, it is possible that ponds in other parts of Qinghai Province, eg at Golmud and in Guide Country, will be supplied with fingerlings from the project's hatchery. A final decision on this depends on the numbers of fish actually produced by the hatchery in future months.

7. NAKED CARP HATCHERY CONSTRUCTION AND OPERATION

7.1) Construction

Most construction work on the naked carp hatchery was completed before winter 1990, as described in CTA Edwards' 1990 report (Field Document 7), to the design detailed in the report of Aquaculture Engineering consultant Muir (Field Document 6). Final installation of incubators and fry tanks was completed early in 1991, so that the hatchery was ready to begin operating on schedule during spring this year.

7.2) Operation

The project is fortunate to have secured the services of Mr. Qu Weiliang of the Heilingjiang Fisheries Research Institute as a national consultant to manage the naked carp hatchery during spring 1991. Mr. Qu is probably the most experienced person in China (and therefore the world) in artificial culture of this species. He began his 3-month contract with the Qinghai Bureau of Aquatic Products in mid-May.

This year, adult naked carp began their spawning migration up the Buha River (the Buha is the biggest spawning stream for the species, running into the western side of Qinghai Lake) following rains at the beginning of June. Project staff immediately began electric-fishing on the river, and succeeded in catching about 300 broodfish (200 female, 100 male). These were returned alive to the hatchery for spawning experiments.

It will be recalled that this species is a serial spawner, and that during 1990 attempts to strip eggs from females on the river bank were only partially successful (see Edwards 1990, Field Document 7). However, it was known from previous experiments that ovulation rates can be improved by the use of hormone injections. This year's work is therefore concentrating on refining and improving the methodology for inducing ovulation, as well as for incubation of eggs and subsequent rearing of larvae, fry and fingerlings.

Already this year substantial progress has been made. Using three hormone injections administered on three successive days, ovulation rates of up to 95% have been obtained. The most successful dosage so far found was a “cocktail” of 5 I.U.(international units) per kg of LHRH together with 100 IU/kg of HCG. At a water temperature of 17° C, eggs were ready for stripping 12–24h after the last injection. Males gave milt freely without induction.

To date, 150 000 fertile eggs have been produced, of which 50 000 have already hatched. Hatching occurred 10 days after fertilization at 17° C, and swim-up required a further 10 days thereafter. Work is continuing towards an arbitrary production target of one million eggs per year by 1992.

It was additionally found that brooders transferred to the hatchery lost their ability to produce viable eggs within a week after transport. Presumably this is because environmental conditions of temperature, water flow and chemistry at the hatchery differ markedly from those found in the natural spawning rivers. Thus there is a need for further experimentation in techniques for holding brooders of this species in captivity.

It can be concluded that the naked carp hatchery work has made a good start on schedule.

8. RAINBOW TROUT FEEDS

Diets formulated during 1990 by feeds consultant Tacon (Field Document 8) are being manufactured in Xining by the Qinghai Mixed Feeds Factory, and are being used successfully both at the project's Nanmenxia hatchery and at the Longyangxia cage farm. This production of good quality diets in Qinghai is a very important prerequisite for the future development of commercial trout farming in the province. The availability of factory-made feeds now makes it much easier for new entrants to the business, private or public, to begin trout farming in Qinghai Province.

9. MONEY AND EQUIPMENT

As in previous years, Government financial contributions to the project were always forthcoming when needed. Government funding of this project is very substantial, covering as it does most of the building costs for the fish farms, as well as staff, vehicle and boat running, etc. Project management expresses gratitude for this continuing, timely support from Government.

Delays in equipment delivery reported previously did not significantly affect the progress of project activities, which are continuing approximately according to plan.

10. CONCLUSIONS

Project management was generally satisfied with the progress of the work during the first half of 1991. All planned fish culture activities started on or ahead of schedule, and the Qinghai Lake investigation finally became fully operational, albeit a year later than planned. The CTA was especially pleased with the motivation shown by the fish culture team leader and by key members of the fish farm staff at all the units operated by the project. The work seems to have stimulated a genuine interest amongst the counterparts, which promises well for the future.

There are currently no apparent obstacles to the production of all the planned outputs of this project within the original time schedule.